Introduction

The following are the events for OpenJDK 27 (jdk-27+5, permalink, 18-January-2026). The events are collected from the event configuration and the source code. Visit the jfreventcollector repository for more information. This is also the place you can contribute additional event descriptions, if you don't want to contribute them directly to the OpenJDK. The site generator lives on GitHub, too.

This page is maintained by Johannes Bechberger of the SapMachine team at SAP and contributors.

Some events have fake end times/durations; these are hidden in the event description here.

Flight Recorder

DumpReason

profiling default startTime 11 17 21 25 26 27

Category: Flight Recorder

Who requested the recording and why

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/recorder/repository/jfrEmergencyDump.cpp:

    if (_jt != nullptr) {
      assert(_jt->thread_state() == _thread_in_vm, "invariant");
      _jt->set_thread_state(_thread_in_native);
    }
  }
};

static void post_events(bool exception_handler, bool oom, Thread * thread) {
  if (exception_handler) {
    EventShutdown e;
    e.set_reason(oom ? "CrashOnOutOfMemoryError" : "VM Error");
    e.commit();
  }
  EventDumpReason event;
  event.set_reason(exception_handler && oom ? "CrashOnOutOfMemoryError" : exception_handler ? "Crash" : "Out of Memory");
  event.set_recordingId(-1);
  event.commit();
}

static volatile traceid _jfr_shutdown_tid = 0;

static bool guard_reentrancy() {
  const traceid shutdown_tid = AtomicAccess::load(&_jfr_shutdown_tid);
  if (shutdown_tid == max_julong) {
    // Someone tried but did not have a proper thread for the purpose.

Configuration enabled
profiling true
default true

Field Type Description
reason string Reason Reason for writing recording data to disk
recordingId int Recording Id Id of the recording that triggered the dump, or -1 if it was not related to a recording

DataLoss

profiling default startTime 11 17 21 25 26 27

Category: Flight Recorder

Data could not be copied out from a buffer, typically because of contention

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/jni/jfrJniMethod.cpp:

  // We want the host swap memory, not the container value.
  physical_memory_size_type host_swap = 0;
  (void)os::Linux::host_swap(host_swap); // Discard return value and treat as no swap
  return static_cast<jlong>(host_swap);
#else
  physical_memory_size_type total_swap_space = 0;
  // Return value ignored - defaulting to 0 on failure.
  (void)os::total_swap_space(total_swap_space);
  return static_cast<jlong>(total_swap_space);
#endif
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_emit_data_loss(JNIEnv* env, jclass jvm, jlong bytes))
  EventDataLoss::commit(bytes, min_jlong);
JVM_END

JVM_ENTRY_NO_ENV(jlong, jfr_register_stack_filter(JNIEnv* env,  jclass jvm, jobjectArray classes, jobjectArray methods))
  return JfrStackFilterRegistry::add(classes, methods, thread);
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_unregister_stack_filter(JNIEnv* env,  jclass jvm, jlong id))
  JfrStackFilterRegistry::remove(id);
JVM_END

NO_TRANSITION(jlong, jfr_nanos_now(JNIEnv* env, jclass jvm))

src/hotspot/share/jfr/recorder/storage/jfrStorage.cpp:

      assert(!buffer->transient(), "invariant");
      assert(buffer->lease(), "invariant");
      storage_instance.control().increment_leased();
      return buffer;
    }
  }
  return acquire_transient(size, thread);
}

static void write_data_loss_event(JfrBuffer* buffer, u8 unflushed_size, Thread* thread) {
  assert(buffer != nullptr, "invariant");
  assert(buffer->empty(), "invariant");
  const u8 total_data_loss = thread->jfr_thread_local()->add_data_lost(unflushed_size);
  if (EventDataLoss::is_enabled()) {
    JfrNativeEventWriter writer(buffer, thread);
    writer.begin_event_write(false);
    writer.write<u8>(EventDataLoss::eventId);
    writer.write(JfrTicks::now());
    writer.write(unflushed_size);
    writer.write(total_data_loss);
    writer.end_event_write(false);
  }
}

static void write_data_loss(BufferPtr buffer, Thread* thread) {
  assert(buffer != nullptr, "invariant");
  const size_t unflushed_size = buffer->unflushed_size();
  buffer->reinitialize();

Configuration enabled
profiling true
default true

Field Type Description
amount ulong: bytes Amount Amount lost data
total ulong: bytes Total Total lost amount for thread

Flush

experimental startTime duration 14 17 21 25 26 27

Category: Flight Recorder

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/recorder/service/jfrRecorderService.cpp:

template <typename Functor>
static u4 invoke(Functor& f) {
  f.process();
  return f.elements();
}

template <typename Functor>
static u4 invoke_with_flush_event(Functor& f) {
  const u4 elements = invoke(f);
  EventFlush e(UNTIMED);
  e.set_starttime(f.start_time());
  e.set_endtime(f.end_time());
  e.set_flushId(flushpoint_id);
  e.set_elements(f.elements());
  e.set_size(f.size());
  e.commit();
  return elements;
}

class StackTraceRepository : public StackObj {
 private:

Configuration enabled threshold
profiling false 0 ns
default false 0 ns

Field Type Description
flushId ulong Flush Identifier
elements ulong Elements Written
size ulong: bytes Size Written

Examples 3
elements ulong
10935
flushId ulong
194
size ulong: bytes
1800741
startTime long: millis
449678136751
elements ulong
270
flushId ulong
213
size ulong: bytes
102097
startTime long: millis
442698354549
elements ulong
9317
flushId ulong
260
size ulong: bytes
1411717
startTime long: millis
353505292730

ActiveRecording

profiling default startTime duration stackTrace 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/ActiveRecordingEvent.java

Category: Flight Recorder

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/ActiveRecordingEvent.java:

@Name(Type.EVENT_NAME_PREFIX + "ActiveRecording")
@Label("Flight Recording")
@Category("Flight Recorder")
@RemoveFields({"duration", "eventThread", "stackTrace"})
public final class ActiveRecordingEvent extends AbstractJDKEvent {

    // The order of these fields must be the same as the parameters in
    // commit(... , long, String, String, long, long, long, long, long)

    @Label("Id")
    public long id;

    @Label("Name")
    public String name;

    @Label("Destination")

src/jdk.jfr/share/classes/jdk/jfr/internal/PlatformRecorder.java:

                // and check for missing files. This will emit more error logs that can be seen in subsequent recordings.
                for (PlatformRecording r : getRecordings()) {
                    r.removeNonExistantPaths();
                }
            }
        }
        // Decrease initial reference count
        chunk.release();
        FilePurger.purge();
    }

    private void writeMetaEvents() {
        long timestamp = JVM.counterTime();
        if (ActiveRecordingEvent.enabled()) {
            for (PlatformRecording r : getRecordings()) {
                if (r.getState() == RecordingState.RUNNING && r.shouldWriteMetadataEvent()) {
                    WriteablePath path = r.getDestination();
                    Duration age = r.getMaxAge();
                    Duration flush = r.getFlushInterval();
                    Long size = r.getMaxSize();
                    Instant rStart = r.getStartTime();
                    Duration rDuration = r.getDuration();
                    ActiveRecordingEvent.commit(
                        timestamp,
                        r.getId(),
                        r.getName(),
                        path == null ? null : path.getRealPathText(),
                        r.isToDisk(),
                        age == null ? Long.MAX_VALUE : age.toMillis(),
                        flush == null ? Long.MAX_VALUE : flush.toMillis(),
                        size == null ? Long.MAX_VALUE : size,
                        rStart == null ? Long.MAX_VALUE : rStart.toEpochMilli(),
                        rDuration == null ? Long.MAX_VALUE : rDuration.toMillis()
                    );

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

public final class JDKEvents {

    private static final Class<?>[] eventClasses = {
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        // jdk.internal.event.* classes need their mirror
        // event class to be listed in the MirrorEvents class.
        jdk.internal.event.DeserializationEvent.class,
        jdk.internal.event.ErrorThrownEvent.class,
        jdk.internal.event.ExceptionStatisticsEvent.class,
        jdk.internal.event.ExceptionThrownEvent.class,
        jdk.internal.event.FileForceEvent.class,
        jdk.internal.event.FileReadEvent.class,
        jdk.internal.event.FileWriteEvent.class,
        jdk.internal.event.ProcessStartEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,

Configuration enabled
profiling true
default true

Field Type Description
id long Id
name string Name
destination string Destination
disk boolean 21+ To Disk
maxAge long: millis Max Age
flushInterval long: millis 14+ Flush Interval
maxSize long: bytes Max Size
recordingStart long: epochmillis Start Time
recordingDuration long: millis Recording Duration

Examples 3
destination string
/home/runner/work/jfrevents/jfrevents/jfr/sample_UseG1GC.jfr
disk boolean
true
flushInterval long: millis
1000
id long
1
maxAge long: millis
9223372036854775807
maxSize long: bytes
262144000
name string
1
recordingDuration long: millis
9223372036854775807
recordingStart long: epochmillis
1767487167450
stackTrace StackTrace
null
startTime long: millis
280640729663
destination string
/home/runner/work/jfrevents/jfrevents/jfr/sample_UseParallelGC.jfr
disk boolean
true
flushInterval long: millis
1000
id long
1
maxAge long: millis
9223372036854775807
maxSize long: bytes
262144000
name string
1
recordingDuration long: millis
9223372036854775807
recordingStart long: epochmillis
1767487168217
stackTrace StackTrace
null
startTime long: millis
471653640856
destination string
/home/runner/work/jfrevents/jfrevents/jfr/sample_UseSerialGC.jfr
disk boolean
true
flushInterval long: millis
1000
id long
1
maxAge long: millis
9223372036854775807
maxSize long: bytes
262144000
name string
1
recordingDuration long: millis
9223372036854775807
recordingStart long: epochmillis
1767487156514
stackTrace StackTrace
null
startTime long: millis
422005363381

ActiveSetting

profiling default startTime duration stackTrace 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/ActiveSettingEvent.java

Category: Flight Recorder

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/ActiveSettingEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.internal.RemoveFields;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "ActiveSetting")
@Label("Recording Setting")
@Category("Flight Recorder")
@RemoveFields({"duration", "eventThread", "stackTrace"})
public final class ActiveSettingEvent extends AbstractJDKEvent {

    // The order of these fields must be the same as the parameters in
    // commit(... , long, String, String)

    @Label("Event Id")
    public long id;

    @Label("Setting Name")
    public String name;

    @Label("Setting Value")

src/jdk.jfr/share/classes/jdk/jfr/internal/EventControl.java:

    void writeActiveSettingEvent(long timestamp) {
        if (!type.isRegistered()) {
            return;
        }
        for (NamedControl nc : namedControls) {
            if (nc.control.isVisible(type.hasEventHook()) && type.isVisible()) {
                String value = nc.control.getLastValue();
                if (value == null) {
                    value = nc.control.getDefaultValue();
                }
                if (ActiveSettingEvent.enabled()) {
                    ActiveSettingEvent.commit(timestamp, type.getId(), nc.name(), value);
                }
            }
        }
    }

    public ArrayList<NamedControl> getNamedControls() {
        return namedControls;
    }

    public PlatformEventType getEventType() {
        return type;

src/jdk.jfr/share/classes/jdk/jfr/internal/PlatformRecorder.java:

                        r.getId(),
                        r.getName(),
                        path == null ? null : path.getRealPathText(),
                        r.isToDisk(),
                        age == null ? Long.MAX_VALUE : age.toMillis(),
                        flush == null ? Long.MAX_VALUE : flush.toMillis(),
                        size == null ? Long.MAX_VALUE : size,
                        rStart == null ? Long.MAX_VALUE : rStart.toEpochMilli(),
                        rDuration == null ? Long.MAX_VALUE : rDuration.toMillis()
                    );
                }
            }
        }
        if (ActiveSettingEvent.enabled()) {
            for (EventControl ec : MetadataRepository.getInstance().getEventControls()) {
                ec.writeActiveSettingEvent(timestamp);
            }
        }
    }

    private void periodicTask() {
        if (!JVMSupport.hasJFR()) {
            return;
        }
        while (true) {

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

public final class JDKEvents {

    private static final Class<?>[] eventClasses = {
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        // jdk.internal.event.* classes need their mirror
        // event class to be listed in the MirrorEvents class.
        jdk.internal.event.DeserializationEvent.class,
        jdk.internal.event.ErrorThrownEvent.class,
        jdk.internal.event.ExceptionStatisticsEvent.class,
        jdk.internal.event.ExceptionThrownEvent.class,
        jdk.internal.event.FileForceEvent.class,
        jdk.internal.event.FileReadEvent.class,
        jdk.internal.event.FileWriteEvent.class,
        jdk.internal.event.ProcessStartEvent.class,

Configuration enabled
profiling true
default true

Field Type Description
id long Event Id
name string Setting Name
value string Setting Value

Examples 3
id long
1542
name string
enabled
stackTrace StackTrace
null
startTime long: millis
371338931988
value string
true
id long
61
name string
enabled
stackTrace StackTrace
null
startTime long: millis
278162944220
value string
true
id long
22
name string
threshold
stackTrace StackTrace
null
startTime long: millis
378896523380
value string
0 ms

JVM

JVMInformation

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine

Description of JVM and the Java application

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

PeriodicType JfrPeriodicEventSet::type(void) {
  return _type;
}

TRACE_REQUEST_FUNC(ResidentSetSize) {
  os::jfr_report_memory_info();
}

TRACE_REQUEST_FUNC(JVMInformation) {
  ResourceMark rm;
  EventJVMInformation event;
  event.set_jvmName(VM_Version::vm_name());
  event.set_jvmVersion(VM_Version::internal_vm_info_string());
  event.set_javaArguments(Arguments::java_command());
  event.set_jvmArguments(Arguments::jvm_args());
  event.set_jvmFlags(Arguments::jvm_flags());
  event.set_jvmStartTime(Management::vm_init_done_time());
  event.set_pid(os::current_process_id());
  event.commit();
 }

TRACE_REQUEST_FUNC(OSInformation) {

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
jvmName string JVM Name
jvmVersion string JVM Version
jvmArguments string JVM Command Line Arguments
jvmFlags string JVM Settings File Arguments
javaArguments string Java Application Arguments
jvmStartTime long: epochmillis JVM Start Time
pid long Process Identifier

Examples 3
javaArguments string
/home/runner/work/jfrevents/jfrevents/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=/home/runner/work/jfrevents/jfrevents/jfr/sample_UseParallelGC.jfr,settings=/home/runner/work/jfrevents/jfrevents/.cache/jfc.jfc -XX:+UseParallelGC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1767487167754
jvmVersion string
OpenJDK 64-Bit Server VM (21.0.9+10-LTS) for linux-amd64 JRE (21.0.9+10-LTS), built on 2025-10-17T14:44:04Z by "jenkinsi" with gcc 11.3.0
pid long
2925
startTime long: millis
478558882461
javaArguments string
/home/runner/work/jfrevents/jfrevents/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=/home/runner/work/jfrevents/jfrevents/jfr/sample_UseSerialGC.jfr,settings=/home/runner/work/jfrevents/jfrevents/.cache/jfc.jfc -XX:+UseSerialGC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1767487156005
jvmVersion string
OpenJDK 64-Bit Server VM (21.0.9+10-LTS) for linux-amd64 JRE (21.0.9+10-LTS), built on 2025-10-17T14:44:04Z by "jenkinsi" with gcc 11.3.0
pid long
2254
startTime long: millis
413436337949
javaArguments string
/home/runner/work/jfrevents/jfrevents/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=/home/runner/work/jfrevents/jfrevents/jfr/sample_UseG1GC.jfr,settings=/home/runner/work/jfrevents/jfrevents/.cache/jfc.jfc -XX:+UseG1GC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1767487166908
jvmVersion string
OpenJDK 64-Bit Server VM (21.0.9+10-LTS) for linux-amd64 JRE (21.0.9+10-LTS), built on 2025-10-17T14:44:04Z by "jenkinsi" with gcc 11.3.0
pid long
2289
startTime long: millis
331112808443

InitialSystemProperty

profiling default startTime end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine

System Property at JVM start

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  jlong max_size = conf.has_max_size_default_value() ? jmc_undefined_long : conf.max_size();
  EventYoungGenerationConfiguration event;
  event.set_maxSize((u8)max_size);
  event.set_minSize(conf.min_size());
  event.set_newRatio(static_cast<unsigned int>(conf.new_ratio()));
  event.commit();
}

TRACE_REQUEST_FUNC(InitialSystemProperty) {
  SystemProperty* p = Arguments::system_properties();
  JfrTicks time_stamp = JfrTicks::now();
  while (p !=  nullptr) {
    if (!p->internal()) {
      EventInitialSystemProperty event(UNTIMED);
      event.set_key(p->key());
      event.set_value(p->value());
      event.set_starttime(time_stamp);
      event.set_endtime(time_stamp);
      event.commit();
    }
    p = p->next();
  }
}

TRACE_REQUEST_FUNC(ThreadAllocationStatistics) {

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
key string Key
value string Value

Examples 3
key string
jdk.debug
startTime long: millis
289286352022
value string
release
key string
java.home
startTime long: millis
392328866994
value string
/opt/hostedtoolcache/Java_SapMachine_jdk/21.0.9/x64
key string
java.home
startTime long: millis
383169991067
value string
/opt/hostedtoolcache/Java_SapMachine_jdk/21.0.9/x64

JVM: Class Loading

ClassLoad

startTime duration eventThread stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / Class Loading

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/cds/lambdaProxyClassDictionary.cpp:

  assert(shared_nest_host->is_same_class_package(lambda_ik),
         "lambda proxy class and its nest host must be in the same package");
  // The lambda proxy class and its nest host have the same class loader and class loader data,
  // as verified in add_lambda_proxy_class()
  assert(shared_nest_host->class_loader() == class_loader(), "mismatched class loader");
  assert(shared_nest_host->class_loader_data() == ClassLoaderData::class_loader_data(class_loader()), "mismatched class loader data");
  lambda_ik->set_nest_host(shared_nest_host);

  // Ensures the nest host is the same as the lambda proxy's
  // nest host recorded at dump time.
  InstanceKlass* nest_host = caller_ik->nest_host(THREAD);
  assert(nest_host == shared_nest_host, "mismatched nest host");

  EventClassLoad class_load_event;

  // Add to class hierarchy, and do possible deoptimizations.
  lambda_ik->add_to_hierarchy(THREAD);
  // But, do not add to dictionary.

  lambda_ik->link_class(CHECK_NULL);
  // notify jvmti
  if (JvmtiExport::should_post_class_load()) {
    JvmtiExport::post_class_load(THREAD, lambda_ik);
  }
  if (class_load_event.should_commit()) {

src/hotspot/share/classfile/systemDictionary.hpp:

//         readers (we must ensure write ordering)
//
// Note that placeholders are deleted at any time, as they are removed
// when a class is completely loaded. Therefore, readers as well as writers
// of placeholders must hold the SystemDictionary_lock.
//

class BootstrapInfo;
class ClassFileStream;
class ClassLoadInfo;
class Dictionary;
class PackageEntry;
class GCTimer;
class EventClassLoad;
class Symbol;

template <class E> class GrowableArray;

class SystemDictionary : AllStatic {
  friend class AOTLinkedClassBulkLoader;
  friend class BootstrapInfo;
  friend class LambdaProxyClassDictionary;
  friend class vmClasses;

 public:

src/hotspot/share/classfile/systemDictionary.hpp:

  static bool add_loader_constraint(Symbol* name, Klass* klass_being_linked,  Handle loader1,
                                    Handle loader2);
  static InstanceKlass* load_shared_class(InstanceKlass* ik,
                                          Handle class_loader,
                                          Handle protection_domain,
                                          const ClassFileStream *cfs,
                                          PackageEntry* pkg_entry,
                                          TRAPS);
  static void preload_class(Handle class_loader, InstanceKlass* ik, TRAPS);
  static Handle get_loader_lock_or_null(Handle class_loader);
  static InstanceKlass* find_or_define_instance_class(Symbol* class_name,
                                                      Handle class_loader,
                                                      InstanceKlass* k, TRAPS);
  JFR_ONLY(static void post_class_load_event(EventClassLoad* event,
                                             const InstanceKlass* k,
                                             const ClassLoaderData* init_cld);)

public:
  static bool is_system_class_loader(oop class_loader);
  static bool is_platform_class_loader(oop class_loader);
  static bool is_boot_class_loader(oop class_loader) { return class_loader == nullptr; }
  static bool is_builtin_class_loader(oop class_loader) {
    return is_boot_class_loader(class_loader)      ||
           is_platform_class_loader(class_loader)  ||
           is_system_class_loader(class_loader);

src/hotspot/share/classfile/systemDictionary.cpp:

// SystemDictionary::resolve_instance_class_or_null is the main function for class name resolution.
// After checking if the InstanceKlass already exists, it checks for ClassCircularityError and
// whether the thread must wait for loading in parallel.  It eventually calls load_instance_class,
// which will load the class via the bootstrap loader or call ClassLoader.loadClass().
// This can return null, an exception or an InstanceKlass.
InstanceKlass* SystemDictionary::resolve_instance_class_or_null(Symbol* name,
                                                                Handle class_loader,
                                                                TRAPS) {
  // name must be in the form of "java/lang/Object" -- cannot be "Ljava/lang/Object;"
  DEBUG_ONLY(ResourceMark rm(THREAD));
  assert(name != nullptr && !Signature::is_array(name) &&
         !Signature::has_envelope(name), "invalid class name: %s", name == nullptr ? "nullptr" : name->as_C_string());

  EventClassLoad class_load_event;

  HandleMark hm(THREAD);

  ClassLoaderData* loader_data = register_loader(class_loader);
  Dictionary* dictionary = loader_data->dictionary();

  // Do lookup to see if class already exists.
  InstanceKlass* probe = dictionary->find_class(THREAD, name);
  if (probe != nullptr) return probe;

  // Non-bootstrap class loaders will call out to class loader and

src/hotspot/share/classfile/systemDictionary.cpp:

// Note: this method is much like resolve_class_from_stream, but
// does not publish the classes in the SystemDictionary.
// Handles Lookup.defineClass hidden.
InstanceKlass* SystemDictionary::resolve_hidden_class_from_stream(
                                                     ClassFileStream* st,
                                                     Symbol* class_name,
                                                     Handle class_loader,
                                                     const ClassLoadInfo& cl_info,
                                                     TRAPS) {

  EventClassLoad class_load_event;
  ClassLoaderData* loader_data;

  // - for hidden classes that are not strong: create a new CLD that has a class holder and
  //                                           whose loader is the Lookup class's loader.
  // - for hidden class: add the class to the Lookup class's loader's CLD.
  assert (cl_info.is_hidden(), "only used for hidden classes");
  bool create_mirror_cld = !cl_info.is_strong_hidden();
  loader_data = register_loader(class_loader, create_mirror_cld);

  assert(st != nullptr, "invariant");

src/hotspot/share/classfile/systemDictionary.cpp:

  // preload_class() must be called in the correct order -- all super types must have
  // already been loaded.
  if (ik->java_super() != nullptr) {
    assert(ik->java_super()->is_loaded(), "must be");
  }

  Array<InstanceKlass*>* interfaces = ik->local_interfaces();
  int num_interfaces = interfaces->length();
  for (int index = 0; index < num_interfaces; index++) {
    assert(interfaces->at(index)->is_loaded(), "must be");
  }
#endif

  EventClassLoad class_load_event;

  ClassLoaderData* loader_data = ClassLoaderData::class_loader_data(class_loader());
  oop java_mirror = ik->archived_java_mirror();
  precond(java_mirror != nullptr);
  assert(java_lang_Class::module(java_mirror) != nullptr, "must have been archived");

  Handle pd(THREAD, java_lang_Class::protection_domain(java_mirror));
  PackageEntry* pkg_entry = ik->package();
  assert(pkg_entry != nullptr || ClassLoader::package_from_class_name(ik->name()) == nullptr,
         "non-empty packages must have been archived");

src/hotspot/share/classfile/systemDictionary.cpp:

    update_dictionary(THREAD, ik, loader_data);
  }

  if (class_load_event.should_commit()) {
    JFR_ONLY(post_class_load_event(&class_load_event, ik, loader_data);)
  }

  assert(ik->is_loaded(), "Must be in at least loaded state");
}

#endif // INCLUDE_CDS

#if INCLUDE_JFR
void SystemDictionary::post_class_load_event(EventClassLoad* event, const InstanceKlass* k, const ClassLoaderData* init_cld) {
  assert(event != nullptr, "invariant");
  assert(k != nullptr, "invariant");
  event->set_loadedClass(k);
  event->set_definingClassLoader(k->class_loader_data());
  event->set_initiatingClassLoader(init_cld);
  event->commit();
}
#endif // INCLUDE_JFR

InstanceKlass* SystemDictionary::load_instance_class_impl(Symbol* class_name, Handle class_loader, TRAPS) {

src/hotspot/share/classfile/vmClasses.cpp:

  InstanceStackChunkKlass::init_offset_of_stack();
}

#if INCLUDE_CDS

void vmClasses::resolve_shared_class(InstanceKlass* klass, ClassLoaderData* loader_data, Handle domain, TRAPS) {
  assert(!Universe::is_fully_initialized(), "We can make short cuts only during VM initialization");
  assert(klass->in_aot_cache(), "Must be shared class");
  if (klass->class_loader_data() != nullptr) {
    return;
  }

  EventClassLoad class_load_event;

  // add super and interfaces first
  InstanceKlass* super = klass->super();
  if (super != nullptr && super->class_loader_data() == nullptr) {
    assert(super->is_instance_klass(), "Super should be instance klass");
    resolve_shared_class(super, loader_data, domain, CHECK);
  }

  Array<InstanceKlass*>* ifs = klass->local_interfaces();
  for (int i = 0; i < ifs->length(); i++) {
    InstanceKlass* ik = ifs->at(i);

Configuration enabled stackTrace threshold
profiling false true 0 ms
default false true 0 ms

Field Type Description
loadedClass Class Loaded Class
definingClassLoader ClassLoader Defining Class Loader
initiatingClassLoader ClassLoader Initiating Class Loader

Examples 3
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
initiatingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
loadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
true
modifiers int
4112
name string
org.apache.spark.storage.BlockManager$$Lambda/0x00007f307527f4f0
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
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null
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org/apache/spark/storage
stackTrace StackTrace
frames StackFrame
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0
lineNumber int
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method Method
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264
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defineClass0
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classLoader ClassLoader
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null
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java/lang/ClassLoader
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true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
420312465109
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
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true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
initiatingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
loadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
17
name string
scala/collection/MapOps$$anon$2
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
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name string
java/net
location string
null
name string
null
version string
null
name string
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stackTrace StackTrace
frames StackFrame
bytecodeIndex int
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descriptor string
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1
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classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
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name string
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modifiers int
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name string
scala/collection/MapOps
package Package
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true
module Module
classLoader ClassLoader
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null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
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21.0.9
name string
java/net
location string
null
name string
null
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null
name string
scala/collection
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
424075245272
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
initiatingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
loadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
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21.0.9
name string
java/net
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modifiers int
17
name string
org/apache/spark/sql/SQLImplicits$$typecreator1$9
package Package
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module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
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21.0.9
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java/net
location string
null
name string
null
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null
name string
org/apache/spark/sql
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12
lineNumber int
825
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descriptor string
()V
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18
name string
implicits$lzycompute$1
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classLoader ClassLoader
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type Class
classLoader ClassLoader
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bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
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module Module
classLoader ClassLoader
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bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
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21.0.9
name string
java/net
hidden boolean
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modifiers int
1
name string
org/apache/spark/sql/SparkSession
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/sql
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
310090546640

ClassDefine

startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / Class Loading

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/support/jfrClassDefineEvent.cpp:

static traceid get_source(const InstanceKlass* ik, JavaThread* jt) {
  traceid source_id = 0;
  if (is_jdk_module(ik, jt)) {
    source_id = module_path(ik, jt);
  } else if (ik->class_loader_data()->is_the_null_class_loader_data()) {
    source_id = caller_path(ik, jt);
  } else {
    source_id = class_loader_path(ik, jt);
  }
  return source_id;
}

static inline void send_event(const InstanceKlass* ik, traceid source_id) {
  EventClassDefine event;
  event.set_definedClass(ik);
  event.set_definingClassLoader(ik->class_loader_data());
  event.set_source(source_id);
  event.commit();
}

void JfrClassDefineEvent::on_creation(const InstanceKlass* ik, const ClassFileParser& parser, JavaThread* jt) {
  assert(ik != nullptr, "invariant");
  assert(ik->trace_id() != 0, "invariant");
  assert(!parser.is_internal(), "invariant");
  assert(jt != nullptr, "invariant");

  if (EventClassDefine::is_enabled() && is_not_retransforming(ik, jt)) {
    ResourceMark rm(jt);
    traceid source_id = 0;
    const ClassFileStream& stream = parser.stream();
    if (stream.source() != nullptr) {
      if (stream.from_boot_loader_modules_image()) {
        assert(is_jdk_module(ik, jt), "invariant");
        source_id = module_path(ik, jt);
      } else {
        source_id = JfrSymbolTable::add(stream.source());
      }
    } else {

src/hotspot/share/jfr/support/jfrClassDefineEvent.cpp:

  const char* file_type = cl->file_type_string();
  assert(file_type != nullptr, "invariant");
  len += strlen(file_type) + 3; // ":/" + null
  char* const url = NEW_RESOURCE_ARRAY_IN_THREAD(jt, char, len);
  jio_snprintf(url, len, "%s%s%s", file_type, ":/", path);
  return JfrSymbolTable::add(url);
}

void JfrClassDefineEvent::on_restoration(const InstanceKlass* ik, JavaThread* jt) {
  assert(ik != nullptr, "invariant");
  assert(ik->trace_id() != 0, "invariant");
  assert(jt != nullptr, "invariant");

  if (EventClassDefine::is_enabled()) {
    ResourceMark rm(jt);
    assert(is_not_retransforming(ik, jt), "invariant");
    const int index = ik->shared_classpath_index();
    assert(index >= 0, "invariant");
    const AOTClassLocation* const cl = AOTClassLocationConfig::runtime()->class_location_at(index);
    assert(cl != nullptr, "invariant");
    send_event(ik, cl->is_modules_image() ? module_path(ik, jt) : get_source(cl, jt));
  }
}
#endif

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
definedClass Class Defined Class
definingClassLoader ClassLoader Defining Class Loader
source Symbol 26+ Source

Examples 3
definedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1537
name string
scala/reflect/internal/tpe/GlbLubs
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/reflect/internal/tpe
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
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-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
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false
modifiers int
264
name string
defineClass1
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1025
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Native
truncated boolean
true
startTime long: millis
431329965534
definedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1537
name string
scala/reflect/internal/Names
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/reflect/internal
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
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21.0.9
name string
java/net
stackTrace StackTrace
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bytecodeIndex int
0
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-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass1
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1025
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
310162472946
definedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1537
name string
scala/reflect/internal/tpe/TypeToStrings
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/reflect/internal/tpe
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass1
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1025
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Native
truncated boolean
true
startTime long: millis
428500007464

ClassRedefinition

profiling default startTime 15 17 21 25 26 27

Category: Java Virtual Machine / Class Loading

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/prims/jvmtiRedefineClasses.cpp:

  _timer_rsc_phase1.stop();
  if (log_is_enabled(Info, redefine, class, timer)) {
    _timer_rsc_phase2.start();
  }

  if (the_class->oop_map_cache() != nullptr) {
    // Flush references to any obsolete methods from the oop map cache
    // so that obsolete methods are not pinned.
    the_class->oop_map_cache()->flush_obsolete_entries();
  }

  increment_class_counter(the_class);

  if (EventClassRedefinition::is_enabled()) {
    EventClassRedefinition event;
    event.set_classModificationCount(java_lang_Class::classRedefinedCount(the_class->java_mirror()));
    event.set_redefinedClass(the_class);
    event.set_redefinitionId(_id);
    event.commit();
  }

  {
    ResourceMark rm(current);
    // increment the classRedefinedCount field in the_class and in any
    // direct and indirect subclasses of the_class
    physical_memory_size_type avail_mem = 0;

Configuration enabled
profiling true
default true

Field Type Description
redefinedClass Class Redefined Class
classModificationCount int Class Modification Count The number of times the class has changed
redefinitionId ulong Class Redefinition Id

RedefineClasses

profiling default startTime duration eventThread stackTrace 15 17 21 25 26 27

Category: Java Virtual Machine / Class Loading

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/prims/jvmtiEnv.cpp:

    event.set_classCount(class_count);
    event.set_redefinitionId(op.id());
    event.commit();
  }
  return error;
} /* end RetransformClasses */


// class_count - pre-checked to be greater than or equal to 0
// class_definitions - pre-checked for null
jvmtiError
JvmtiEnv::RedefineClasses(jint class_count, const jvmtiClassDefinition* class_definitions) {
//TODO: add locking
  EventRedefineClasses event;
  VM_RedefineClasses op(class_count, class_definitions, jvmti_class_load_kind_redefine);
  VMThread::execute(&op);
  jvmtiError error = op.check_error();
  if (error == JVMTI_ERROR_NONE) {
    event.set_classCount(class_count);
    event.set_redefinitionId(op.id());
    event.commit();
  }
  return error;
} /* end RedefineClasses */

Configuration enabled stackTrace threshold
profiling true true 0 ms
default true true 0 ms

Field Type Description
classCount int Class Count
redefinitionId ulong Class Redefinition Id

RetransformClasses

profiling default startTime duration eventThread stackTrace 15 17 21 25 26 27

Category: Java Virtual Machine / Class Loading

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/prims/jvmtiEnv.cpp:

      class_definitions[index].class_byte_count = (jint)reconstituter.class_file_size();
      class_definitions[index].class_bytes      = (unsigned char*)
                                                       reconstituter.class_file_bytes();
    } else {
      // it is cached, get it from the cache
      class_definitions[index].class_byte_count = ik->get_cached_class_file_len();
      class_definitions[index].class_bytes      = ik->get_cached_class_file_bytes();
    }
    class_definitions[index].klass              = jcls;
  }
  EventRetransformClasses event;
  VM_RedefineClasses op(class_count, class_definitions, jvmti_class_load_kind_retransform);
  VMThread::execute(&op);
  jvmtiError error = op.check_error();
  if (error == JVMTI_ERROR_NONE) {
    event.set_classCount(class_count);
    event.set_redefinitionId(op.id());
    event.commit();
  }
  return error;
} /* end RetransformClasses */

Configuration enabled stackTrace threshold
profiling true true 0 ms
default true true 0 ms

Field Type Description
classCount int Class Count
redefinitionId ulong Class Redefinition Id

ClassUnload

startTime eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Class Loading

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/oops/instanceKlass.cpp:

  ClassLoadingService::notify_class_unloaded(ik);

  SystemDictionaryShared::handle_class_unloading(ik);

  if (log_is_enabled(Info, class, unload)) {
    ResourceMark rm;
    log_info(class, unload)("unloading class %s " PTR_FORMAT, ik->external_name(), p2i(ik));
  }

  Events::log_class_unloading(Thread::current(), ik);

#if INCLUDE_JFR
  assert(ik != nullptr, "invariant");
  EventClassUnload event;
  event.set_unloadedClass(ik);
  event.set_definingClassLoader(ik->class_loader_data());
  event.commit();
#endif
}

static void method_release_C_heap_structures(Method* m) {
  m->release_C_heap_structures();
}

// Called also by InstanceKlass::deallocate_contents, with false for release_sub_metadata.

Configuration enabled
profiling false
default false

Field Type Description
unloadedClass Class Unloaded Class
definingClassLoader ClassLoader Defining Class Loader

Examples 3
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
startTime long: millis
448431680836
unloadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1537
name string
scala/runtime/java8/JFunction0$mcJ$sp
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/runtime/java8
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
startTime long: millis
437555893356
unloadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1537
name string
scala/collection/StrictOptimizedMapOps
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
startTime long: millis
316588396622
unloadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
9
name string
scala/collection/MapFactory$Delegate
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection

JVM: Code Cache

CodeCacheFull

profiling default startTime eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Code Cache

A code heap is full, this leads to disabling the compiler

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/code/codeCache.cpp:

    {
      ttyLocker ttyl;
      tty->print("%s", s.freeze());
    }

    if (full_count == 1) {
      if (PrintCodeHeapAnalytics) {
        CompileBroker::print_heapinfo(tty, "all", 4096); // details, may be a lot!
      }
    }
  }

  EventCodeCacheFull event;
  if (event.should_commit()) {
    event.set_codeBlobType((u1)code_blob_type);
    event.set_startAddress((u8)heap->low_boundary());
    event.set_commitedTopAddress((u8)heap->high());
    event.set_reservedTopAddress((u8)heap->high_boundary());
    event.set_entryCount(heap->blob_count());
    event.set_methodCount(heap->nmethod_count());
    event.set_adaptorCount(heap->adapter_count());
    event.set_unallocatedCapacity(heap->unallocated_capacity());
    event.set_fullCount(heap->full_count());
    event.set_codeCacheMaxCapacity(CodeCache::max_capacity());

Configuration enabled
profiling true
default true

Field Type Description
codeBlobType CodeBlobType Code Heap
startAddress ulong: address Start Address
commitedTopAddress ulong: address Commited Top
reservedTopAddress ulong: address Reserved Top
entryCount int Entries
methodCount int Methods
adaptorCount int Adaptors
unallocatedCapacity ulong: bytes Unallocated
fullCount int Full Count
codeCacheMaxCapacity ulong: bytes 17+ Code Cache Maximum Capacity

CodeCacheStatistics

profiling default startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Code Cache

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

TRACE_REQUEST_FUNC(CompilerConfiguration) {
  EventCompilerConfiguration event;
  event.set_threadCount(static_cast<s4>(CICompilerCount));
  event.set_tieredCompilation(TieredCompilation);
  event.set_dynamicCompilerThreadCount(UseDynamicNumberOfCompilerThreads);
  event.commit();
}

TRACE_REQUEST_FUNC(CodeCacheStatistics) {
  // Emit stats for all available code heaps
  for (int bt_index = 0; bt_index < static_cast<int>(CodeBlobType::NumTypes); ++bt_index) {
    const CodeBlobType bt = static_cast<CodeBlobType>(bt_index);
    if (CodeCache::heap_available(bt)) {
      EventCodeCacheStatistics event;
      event.set_codeBlobType((u1)bt);
      event.set_startAddress((u8)CodeCache::low_bound(bt));
      event.set_reservedTopAddress((u8)CodeCache::high_bound(bt));
      event.set_entryCount(CodeCache::blob_count(bt));
      event.set_methodCount(CodeCache::nmethod_count(bt));
      event.set_adaptorCount(CodeCache::adapter_count(bt));
      event.set_unallocatedCapacity(CodeCache::unallocated_capacity(bt));
      event.set_fullCount(CodeCache::get_codemem_full_count(bt));
      event.commit();
    }
  }

Configuration enabled period
profiling true everyChunk
default true everyChunk

Field Type Description
codeBlobType CodeBlobType Code Heap
startAddress ulong: address Start Address
reservedTopAddress ulong: address Reserved Top
entryCount int Entries
methodCount int Methods
adaptorCount int Adaptors
unallocatedCapacity ulong: bytes Unallocated
fullCount int Full Count

Examples 3
adaptorCount int
0
codeBlobType CodeBlobType
CodeHeap 'non-profiled nmethods'
entryCount int
7021
fullCount int
0
methodCount int
7021
reservedTopAddress ulong: address
140021361278976
startAddress ulong: address
140021238366208
startTime long: millis
278185477410
unallocatedCapacity ulong: bytes
110050304
adaptorCount int
2310
codeBlobType CodeBlobType
CodeHeap 'non-nmethods'
entryCount int
2407
fullCount int
0
methodCount int
0
reservedTopAddress ulong: address
139847426408448
startAddress ulong: address
139847420571648
startTime long: millis
371363161349
unallocatedCapacity ulong: bytes
2865792
adaptorCount int
0
codeBlobType CodeBlobType
CodeHeap 'non-profiled nmethods'
entryCount int
9843
fullCount int
0
methodCount int
9843
reservedTopAddress ulong: address
140435422969856
startAddress ulong: address
140435300057088
startTime long: millis
470155460465
unallocatedCapacity ulong: bytes
107323008

CodeCacheConfiguration

profiling default startTime end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Code Cache

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

      event.set_startAddress((u8)CodeCache::low_bound(bt));
      event.set_reservedTopAddress((u8)CodeCache::high_bound(bt));
      event.set_entryCount(CodeCache::blob_count(bt));
      event.set_methodCount(CodeCache::nmethod_count(bt));
      event.set_adaptorCount(CodeCache::adapter_count(bt));
      event.set_unallocatedCapacity(CodeCache::unallocated_capacity(bt));
      event.set_fullCount(CodeCache::get_codemem_full_count(bt));
      event.commit();
    }
  }
}

TRACE_REQUEST_FUNC(CodeCacheConfiguration) {
  EventCodeCacheConfiguration event;
  event.set_initialSize(InitialCodeCacheSize);
  event.set_reservedSize(ReservedCodeCacheSize);
  event.set_nonNMethodSize(NonNMethodCodeHeapSize);
  event.set_profiledSize(ProfiledCodeHeapSize);
  event.set_nonProfiledSize(NonProfiledCodeHeapSize);
  event.set_expansionSize(CodeCacheExpansionSize);
  event.set_minBlockLength(CodeCacheMinBlockLength);
  event.set_startAddress((u8)CodeCache::low_bound());
  event.set_reservedTopAddress((u8)CodeCache::high_bound());
  event.commit();
}

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
initialSize ulong: bytes Initial Size
reservedSize ulong: bytes Reserved Size
nonNMethodSize ulong: bytes Non-Nmethod Size
profiledSize ulong: bytes Profiled Size
nonProfiledSize ulong: bytes Non-Profiled Size
expansionSize ulong: bytes Expansion Size
minBlockLength ulong: bytes Minimum Block Length
startAddress ulong: address Start Address
reservedTopAddress ulong: address Reserved Top

Examples 3
expansionSize ulong: bytes
65536
initialSize ulong: bytes
2555904
minBlockLength ulong: bytes
6
nonNMethodSize ulong: bytes
5832780
nonProfiledSize ulong: bytes
122912730
profiledSize ulong: bytes
122912730
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
140021361278976
startAddress ulong: address
140021109620736
startTime long: millis
285196581812
expansionSize ulong: bytes
65536
initialSize ulong: bytes
2555904
minBlockLength ulong: bytes
6
nonNMethodSize ulong: bytes
5832780
nonProfiledSize ulong: bytes
122912730
profiledSize ulong: bytes
122912730
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
139847549321216
startAddress ulong: address
139847297662976
startTime long: millis
371363162030
expansionSize ulong: bytes
65536
initialSize ulong: bytes
2555904
minBlockLength ulong: bytes
6
nonNMethodSize ulong: bytes
5832780
nonProfiledSize ulong: bytes
122912730
profiledSize ulong: bytes
122912730
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
140435422969856
startAddress ulong: address
140435171311616
startTime long: millis
428293899989

JVM: Compiler

JITRestart

profiling default startTime eventThread 17 21 25 26 27

Category: Java Virtual Machine / Compiler

Restart of the JIT compilers after they were stopped

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/code/codeCache.cpp:

    delete curr;
    curr = next;
  }
  _exception_cache_purge_list = nullptr;
}

// Restart compiler if possible and required..
void CodeCache::maybe_restart_compiler(size_t freed_memory) {

  // Try to start the compiler again if we freed any memory
  if (!CompileBroker::should_compile_new_jobs() && freed_memory != 0) {
    CompileBroker::set_should_compile_new_jobs(CompileBroker::run_compilation);
    log_info(codecache)("Restarting compiler");
    EventJITRestart event;
    event.set_freedMemory(freed_memory);
    event.set_codeCacheMaxCapacity(CodeCache::max_capacity());
    event.commit();
  }
}

uint8_t CodeCache::_unloading_cycle = 1;

void CodeCache::increment_unloading_cycle() {
  // 2-bit value (see IsUnloadingState in nmethod.cpp for details)
  // 0 is reserved for new methods.

Configuration enabled
profiling true
default true

Field Type Description
freedMemory ulong: bytes Freed Memory
codeCacheMaxCapacity ulong: bytes Code Cache Maximum Capacity

Compilation

profiling default startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Compiler

Results of method compilation attempts

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/compiler/compileBroker.cpp:

void CompileBroker::handle_compile_error(CompilerThread* thread, CompileTask* task, ciEnv* ci_env,
                                         int compilable, const char* failure_reason) {
  if (!AbortVMOnCompilationFailure) {
    return;
  }
  if (compilable == ciEnv::MethodCompilable_not_at_tier) {
    fatal("Not compilable at tier %d: %s", task->comp_level(), failure_reason);
  }
  if (compilable == ciEnv::MethodCompilable_never) {
    fatal("Never compilable: %s", failure_reason);
  }
}

static void post_compilation_event(EventCompilation& event, CompileTask* task) {
  assert(task != nullptr, "invariant");
  CompilerEvent::CompilationEvent::post(event,
                                        task->compile_id(),
                                        task->compiler()->type(),
                                        task->method(),
                                        task->comp_level(),
                                        task->is_success(),
                                        task->osr_bci() != CompileBroker::standard_entry_bci,
                                        task->nm_total_size(),
                                        task->num_inlined_bytecodes(),
                                        task->arena_bytes());
}

src/hotspot/share/compiler/compileBroker.cpp:

  // Allocate a new set of JNI handles.
  JNIHandleMark jhm(thread);
  Method* target_handle = task->method();
  int compilable = ciEnv::MethodCompilable;
  const char* failure_reason = nullptr;
  bool failure_reason_on_C_heap = false;
  const char* retry_message = nullptr;

#if INCLUDE_JVMCI
  if (UseJVMCICompiler && comp != nullptr && comp->is_jvmci()) {
    JVMCICompiler* jvmci = (JVMCICompiler*) comp;

    TraceTime t1("compilation", &time);
    EventCompilation event;
    JVMCICompileState compile_state(task, jvmci);
    JVMCIRuntime *runtime = nullptr;

    if (JVMCI::in_shutdown()) {
      failure_reason = "in JVMCI shutdown";
      retry_message = "not retryable";
      compilable = ciEnv::MethodCompilable_never;
    } else if (compile_state.target_method_is_old()) {
      // Skip redefined methods
      failure_reason = "redefined method";
      retry_message = "not retryable";

src/hotspot/share/compiler/compileBroker.cpp:

    bool method_is_old = ci_env.cache_jvmti_state();

    // Skip redefined methods
    if (method_is_old) {
      ci_env.record_method_not_compilable("redefined method", true);
    }

    // Cache DTrace flags
    ci_env.cache_dtrace_flags();

    ciMethod* target = ci_env.get_method_from_handle(target_handle);

    TraceTime t1("compilation", &time);
    EventCompilation event;

    if (comp == nullptr) {
      ci_env.record_method_not_compilable("no compiler");
    } else if (!ci_env.failing()) {
      if (WhiteBoxAPI && WhiteBox::compilation_locked) {
        whitebox_lock_compilation();
      }
      comp->compile_method(&ci_env, target, osr_bci, true, directive);

      /* Repeat compilation without installing code for profiling purposes */
      int repeat_compilation_count = directive->RepeatCompilationOption;

src/hotspot/share/compiler/compilerEvent.hpp:

#if INCLUDE_JFR
#include "jfr/utilities/jfrTime.hpp"
#endif

class ciMethod;
template <typename>
class GrowableArray;
class Method;
class EventCompilation;
class EventCompilationFailure;
class EventCompilerInlining;
class EventCompilerPhase;
struct JfrStructCalleeMethod;

class CompilerEvent : AllStatic {
 public:
  static jlong ticksNow() {
    // Using Ticks for consistent usage outside JFR folder.
    JFR_ONLY(return JfrTime::is_ft_enabled() ? Ticks::now().ft_value() : Ticks::now().value();) NOT_JFR_RETURN_(0L);
  }

  class CompilationEvent : AllStatic {
   public:
    static void post(EventCompilation& event, int compile_id, CompilerType type, Method* method,
                     int compile_level, bool success, bool is_osr, int code_size,
                     int inlined_bytecodes, size_t arenaBytes) NOT_JFR_RETURN();
  };

  class CompilationFailureEvent : AllStatic {
   public:
    static void post(EventCompilationFailure& event, int compile_id, const char* reason) NOT_JFR_RETURN();
  };

  class PhaseEvent : AllStatic {
    friend class CompilerPhaseTypeConstant;

src/hotspot/share/compiler/compilerEvent.cpp:

template <typename EventType>
static inline void commit(EventType& event) {
  JavaThread* thread = JavaThread::current();
  JavaThreadState state = thread->thread_state();
  if (state == _thread_in_native) {
    ThreadInVMfromNative transition(thread);
    event.commit();
  } else {
    assert(state == _thread_in_vm, "coming from wrong thread state %d", state);
    event.commit();
  }
 }

void CompilerEvent::CompilationEvent::post(EventCompilation& event, int compile_id, CompilerType compiler_type, Method* method,
    int compile_level, bool success, bool is_osr, int code_size,
    int inlined_bytecodes, size_t arenaBytes) {
  event.set_compileId(compile_id);
  event.set_compiler(compiler_type);
  event.set_method(method);
  event.set_compileLevel((short)compile_level);
  event.set_succeded(success);
  event.set_isOsr(is_osr);
  event.set_codeSize(code_size);
  event.set_inlinedBytes(inlined_bytecodes);
  event.set_arenaBytes(arenaBytes);

src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/EmptyEventProvider.java:

package jdk.vm.ci.hotspot;

/**
 * An empty implementation for {@link EventProvider}. This implementation is used when no logging is
 * requested.
 */
final class EmptyEventProvider implements EventProvider {

    static InternalError shouldNotReachHere() {
        throw new InternalError("should not reach here");
    }

    @Override
    public CompilationEvent newCompilationEvent() {
        return new EmptyCompilationEvent();
    }

    static class EmptyCompilationEvent implements CompilationEvent {
        @Override
        public void commit() {
            throw shouldNotReachHere();
        }

        @Override
        public boolean shouldWrite() {
            // Events of this class should never been written.
            return false;
        }

src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/EventProvider.java:

     * Creates and returns an empty implementation for {@link EventProvider}. This implementation
     * can be used when no logging is requested.
     */
    static EventProvider createEmptyEventProvider() {
        return new EmptyEventProvider();
    }

    /**
     * Creates and returns an empty implementation for {@link CompilationEvent}.
     */
    static CompilationEvent createEmptyCompilationEvent() {
        return new EmptyCompilationEvent();
    }

    /**
     * Creates and returns an empty implementation for {@link CompilationEvent}.
     */
    static CompilerFailureEvent createEmptyCompilerFailureEvent() {
        return new EmptyCompilerFailureEvent();
    }

    /**
     * An instant event is an event that is not considered to have taken any time.

src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/EventProvider.java:

        /**
         * Ends the timing period for this event.
         */
        void end();
    }

    /**
     * Creates a new {@link CompilationEvent}.
     *
     * @return a compilation event
     */
    CompilationEvent newCompilationEvent();

    /**
     * A compilation event.
     */
    public interface CompilationEvent extends TimedEvent {
        void setMethod(String method);

        void setCompileId(int compileId);

        void setCompileLevel(int compileLevel);

        void setSucceeded(boolean succeeded);

Configuration enabled threshold
profiling true 100 ms
default true 1000 ms

Field Type Description
compileId int Compilation Identifier
compiler CompilerType 14+ Compiler
method Method Method
compileLevel ushort Compilation Level
succeded boolean Succeeded
isOsr boolean On Stack Replacement
codeSize ulong: bytes Compiled Code Size
inlinedBytes ulong: bytes Inlined Code Size
arenaBytes ulong: bytes 23+ Arena Usage

Examples 3
codeSize ulong: bytes
30896
compileId int
86729
compileLevel ushort
4
compiler CompilerType
c2
inlinedBytes ulong: bytes
6332
isOsr boolean
false
method Method
descriptor string
(Ljava/lang/Class;Ljava/lang/invoke/MethodHandle;Ljava/lang/String;Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Class;)Ljava/lang/Object;
hidden boolean
false
modifiers int
8
name string
invoke
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
16
name string
java/lang/invoke/BootstrapMethodInvoker
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang/invoke
startTime long: millis
455035385660
succeded boolean
true
codeSize ulong: bytes
37096
compileId int
91811
compileLevel ushort
4
compiler CompilerType
c2
inlinedBytes ulong: bytes
6489
isOsr boolean
false
method Method
descriptor string
(Ldotty/tools/dotc/ast/Trees$Tree;Ldotty/tools/dotc/core/Types$Type;Ldotty/tools/dotc/core/Contexts$Context;)Ldotty/tools/dotc/ast/Trees$Tree;
hidden boolean
false
modifiers int
1
name string
typed
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
dotty/tools/dotc/typer/Typer
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
dotty/tools/dotc/typer
startTime long: millis
472867478697
succeded boolean
true
codeSize ulong: bytes
58160
compileId int
98803
compileLevel ushort
4
compiler CompilerType
c2
inlinedBytes ulong: bytes
6521
isOsr boolean
false
method Method
descriptor string
(Ldotty/tools/dotc/core/Types$Type;Ldotty/tools/dotc/core/Contexts$Context;)Ldotty/tools/dotc/core/Types$Type;
hidden boolean
false
modifiers int
1
name string
dotty$tools$dotc$core$TypeErasure$$apply
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
dotty/tools/dotc/core/TypeErasure
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
dotty/tools/dotc/core
startTime long: millis
353137172711
succeded boolean
true

CompilerPhase

profiling default startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Compiler

Describes various phases of the compilation process like inlining or string optimization related phases

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/compiler/compilerEvent.hpp:

#if INCLUDE_JFR
#include "jfr/utilities/jfrTime.hpp"
#endif

class ciMethod;
template <typename>
class GrowableArray;
class Method;
class EventCompilation;
class EventCompilationFailure;
class EventCompilerInlining;
class EventCompilerPhase;
struct JfrStructCalleeMethod;

class CompilerEvent : AllStatic {
 public:
  static jlong ticksNow() {
    // Using Ticks for consistent usage outside JFR folder.
    JFR_ONLY(return JfrTime::is_ft_enabled() ? Ticks::now().ft_value() : Ticks::now().value();) NOT_JFR_RETURN_(0L);
  }

  class CompilationEvent : AllStatic {
   public:

src/hotspot/share/compiler/compilerEvent.hpp:

  class PhaseEvent : AllStatic {
    friend class CompilerPhaseTypeConstant;
   public:

    // Gets a unique identifier for `phase_name`, computing and registering it first if necessary.
    // If `may_exist` is true, then current registrations are searched first. If false, then
    // there must not be an existing registration for `phase_name`.
    // If `use_strdup` is true, then `phase_name` is strdup'ed before registration.
    // If `sync` is true, then access to the registration table is synchronized.
    static int get_phase_id(const char* phase_name, bool may_exist, bool use_strdup, bool sync) NOT_JFR_RETURN_(-1);

    static void post(EventCompilerPhase& event, const Ticks& start_time, int phase, int compile_id, int level) NOT_JFR_RETURN();
    static void post(EventCompilerPhase& event, jlong start_time, int phase, int compile_id, int level) {
      JFR_ONLY(post(event, Ticks(start_time), phase, compile_id, level);)
    }
  };

  class InlineEvent : AllStatic {
    static void post(EventCompilerInlining& event, int compile_id, Method* caller, const JfrStructCalleeMethod& callee, bool success, const char* msg, int bci) NOT_JFR_RETURN();
   public:
    static void post(EventCompilerInlining& event, int compile_id, Method* caller, Method* callee, bool success, const char* msg, int bci) NOT_JFR_RETURN();
    static void post(EventCompilerInlining& event, int compile_id, Method* caller, ciMethod* callee, bool success, const char* msg, int bci) NOT_JFR_RETURN();
  };
};

src/hotspot/share/compiler/compilerEvent.cpp:

  event.set_isOsr(is_osr);
  event.set_codeSize(code_size);
  event.set_inlinedBytes(inlined_bytecodes);
  event.set_arenaBytes(arenaBytes);
  commit(event);
}

void CompilerEvent::CompilationFailureEvent::post(EventCompilationFailure& event, int compile_id, const char* reason) {
  event.set_compileId(compile_id);
  event.set_failureMessage(reason);
  event.commit();
}

void CompilerEvent::PhaseEvent::post(EventCompilerPhase& event, const Ticks& start_time, int phase, int compile_id, int level) {
  event.set_starttime(start_time);
  event.set_phase((u1) phase);
  event.set_compileId(compile_id);
  event.set_phaseLevel((short)level);
  event.commit();
}

void CompilerEvent::InlineEvent::post(EventCompilerInlining& event, int compile_id, Method* caller, const JfrStructCalleeMethod& callee, bool success, const char* msg, int bci) {
  event.set_compileId(compile_id);
  event.set_caller(caller);
  event.set_callee(callee);

src/hotspot/share/jvmci/jvmciCompilerToVM.cpp:

C2V_END

C2V_VMENTRY_0(jint, registerCompilerPhase, (JNIEnv* env, jobject, jstring jphase_name))
#if INCLUDE_JFR
  JVMCIObject phase_name = JVMCIENV->wrap(jphase_name);
  const char *name = JVMCIENV->as_utf8_string(phase_name);
  return CompilerEvent::PhaseEvent::get_phase_id(name, true, true, true);
#else
  return -1;
#endif // !INCLUDE_JFR
C2V_END

C2V_VMENTRY(void, notifyCompilerPhaseEvent, (JNIEnv* env, jobject, jlong startTime, jint phase, jint compileId, jint level))
  EventCompilerPhase event(UNTIMED);
  if (event.should_commit()) {
    CompilerEvent::PhaseEvent::post(event, startTime, phase, compileId, level);
  }
C2V_END

C2V_VMENTRY(void, notifyCompilerInliningEvent, (JNIEnv* env, jobject, jint compileId, ARGUMENT_PAIR(caller), ARGUMENT_PAIR(callee), jboolean succeeded, jstring jmessage, jint bci))
  EventCompilerInlining event;
  if (event.should_commit()) {
    Method* caller = UNPACK_PAIR(Method, caller);
    Method* callee = UNPACK_PAIR(Method, callee);
    JVMCIObject message = JVMCIENV->wrap(jmessage);

src/hotspot/share/opto/compile.cpp:

    if (n->is_Allocate()) {
      if (i != allocates) {
        Node* tmp = macro_node(allocates);
        _macro_nodes.at_put(allocates, n);
        _macro_nodes.at_put(i, tmp);
      }
      allocates++;
    }
  }
}

void Compile::print_method(CompilerPhaseType cpt, int level, Node* n) {
  if (failing_internal()) { return; } // failing_internal to not stress bailouts from printing code.
  EventCompilerPhase event(UNTIMED);
  if (event.should_commit()) {
    CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, cpt, C->_compile_id, level);
  }
#ifndef PRODUCT
  ResourceMark rm;
  stringStream ss;
  ss.print_raw(CompilerPhaseTypeHelper::to_description(cpt));
  int iter = ++_igv_phase_iter[cpt];
  if (iter > 1) {
    ss.print(" %d", iter);
  }

src/hotspot/share/opto/compile.cpp:

// Only used from CompileWrapper
void Compile::begin_method() {
#ifndef PRODUCT
  if (_method != nullptr && should_print_igv(1)) {
    _igv_printer->begin_method();
  }
#endif
  C->_latest_stage_start_counter.stamp();
}

// Only used from CompileWrapper
void Compile::end_method() {
  EventCompilerPhase event(UNTIMED);
  if (event.should_commit()) {
    CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, PHASE_END, C->_compile_id, 1);
  }

#ifndef PRODUCT
  if (_method != nullptr && should_print_igv(1)) {
    _igv_printer->end_method();
  }
#endif
}

src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/JFR.java:

        /**
         * @return current JFR time stamp
         */
        public static long now() {
            return compilerToVM().ticksNow();
        }
    }

    /**
     * Helper methods for managing JFR CompilerPhase events. The events are defined in {@code
     * src/share/jfr/metadata/metadata.xml}.
     */
    public static final class CompilerPhaseEvent {

        private static final ConcurrentHashMap<String, Integer> phaseToId = new ConcurrentHashMap<>();

        private static int getPhaseToId(String phaseName) {
            return phaseToId.computeIfAbsent(phaseName, k -> compilerToVM().registerCompilerPhase(phaseName));
        }

        /**
         * Commits a CompilerPhase event.
         *
         * @param startTime time captured at the start of compiler phase

Configuration enabled threshold
profiling true 10 s
default true 60 s

Field Type Description
phase CompilerPhaseType Compile Phase
compileId int Compilation Identifier
phaseLevel ushort Phase Level

CompilationFailure

profiling startTime eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Compiler

In case a JIT compilation failed, a compilation failure is triggered, reporting the reason

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/compiler/compilerEvent.hpp:

#if INCLUDE_JFR
#include "jfr/utilities/jfrTime.hpp"
#endif

class ciMethod;
template <typename>
class GrowableArray;
class Method;
class EventCompilation;
class EventCompilationFailure;
class EventCompilerInlining;
class EventCompilerPhase;
struct JfrStructCalleeMethod;

class CompilerEvent : AllStatic {
 public:
  static jlong ticksNow() {
    // Using Ticks for consistent usage outside JFR folder.
    JFR_ONLY(return JfrTime::is_ft_enabled() ? Ticks::now().ft_value() : Ticks::now().value();) NOT_JFR_RETURN_(0L);
  }

  class CompilationEvent : AllStatic {
   public:
    static void post(EventCompilation& event, int compile_id, CompilerType type, Method* method,
                     int compile_level, bool success, bool is_osr, int code_size,
                     int inlined_bytecodes, size_t arenaBytes) NOT_JFR_RETURN();
  };

  class CompilationFailureEvent : AllStatic {
   public:
    static void post(EventCompilationFailure& event, int compile_id, const char* reason) NOT_JFR_RETURN();
  };

  class PhaseEvent : AllStatic {
    friend class CompilerPhaseTypeConstant;
   public:

    // Gets a unique identifier for `phase_name`, computing and registering it first if necessary.
    // If `may_exist` is true, then current registrations are searched first. If false, then
    // there must not be an existing registration for `phase_name`.
    // If `use_strdup` is true, then `phase_name` is strdup'ed before registration.
    // If `sync` is true, then access to the registration table is synchronized.

src/hotspot/share/compiler/compilerEvent.cpp:

    int inlined_bytecodes, size_t arenaBytes) {
  event.set_compileId(compile_id);
  event.set_compiler(compiler_type);
  event.set_method(method);
  event.set_compileLevel((short)compile_level);
  event.set_succeded(success);
  event.set_isOsr(is_osr);
  event.set_codeSize(code_size);
  event.set_inlinedBytes(inlined_bytecodes);
  event.set_arenaBytes(arenaBytes);
  commit(event);
}

void CompilerEvent::CompilationFailureEvent::post(EventCompilationFailure& event, int compile_id, const char* reason) {
  event.set_compileId(compile_id);
  event.set_failureMessage(reason);
  event.commit();
}

void CompilerEvent::PhaseEvent::post(EventCompilerPhase& event, const Ticks& start_time, int phase, int compile_id, int level) {
  event.set_starttime(start_time);
  event.set_phase((u1) phase);
  event.set_compileId(compile_id);
  event.set_phaseLevel((short)level);
  event.commit();

src/hotspot/share/ci/ciEnv.cpp:

      CompilerThread* thread = CompilerThread::current();
      CompileTask* task = thread->task();
      CompilationLog::log()->log_failure(thread, task, reason, nullptr);
    }
  }

  if (_failure_reason.get() == nullptr) {
    // Record the first failure reason.
    _failure_reason.set(reason);
  }
}

void ciEnv::report_failure(const char* reason) {
  EventCompilationFailure event;
  if (event.should_commit()) {
    CompilerEvent::CompilationFailureEvent::post(event, compile_id(), reason);
  }
}

// ------------------------------------------------------------------
// ciEnv::record_method_not_compilable()
void ciEnv::record_method_not_compilable(const char* reason, bool all_tiers) {
  int new_compilable =
    all_tiers ? MethodCompilable_never : MethodCompilable_not_at_tier ;

  // Only note transitions to a worse state
  if (new_compilable > _compilable) {

Configuration enabled
profiling true
default false

Field Type Description
failureMessage string Failure Message
compileId int Compilation Identifier

Examples 3
compileId int
83104
failureMessage string
concurrent class loading
startTime long: millis
458656901423
compileId int
80256
failureMessage string
retry without subsuming loads
startTime long: millis
327239150889
compileId int
94075
failureMessage string
retry without subsuming loads
startTime long: millis
465124950110

CompilerInlining

startTime eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Compiler / Optimization

Describes the result of a method inlining attempt

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/c1/c1_GraphBuilder.cpp:

  append(new MemBar(lir_membar_storestore));
}

void GraphBuilder::print_inlining(ciMethod* callee, const char* msg, bool success) {
  CompileLog* log = compilation()->log();
  if (log != nullptr) {
    assert(msg != nullptr, "inlining msg should not be null!");
    if (success) {
      log->inline_success(msg);
    } else {
      log->inline_fail(msg);
    }
  }
  EventCompilerInlining event;
  if (event.should_commit()) {
    CompilerEvent::InlineEvent::post(event, compilation()->env()->task()->compile_id(), method()->get_Method(), callee, success, msg, bci());
  }

  CompileTask::print_inlining_ul(callee, scope()->level(), bci(), inlining_result_of(success), msg);

  if (!compilation()->directive()->PrintInliningOption) {
    return;
  }
  CompileTask::print_inlining_tty(callee, scope()->level(), bci(), inlining_result_of(success), msg);
  if (success && CIPrintMethodCodes) {

src/hotspot/share/compiler/compilerEvent.hpp:

#if INCLUDE_JFR
#include "jfr/utilities/jfrTime.hpp"
#endif

class ciMethod;
template <typename>
class GrowableArray;
class Method;
class EventCompilation;
class EventCompilationFailure;
class EventCompilerInlining;
class EventCompilerPhase;
struct JfrStructCalleeMethod;

class CompilerEvent : AllStatic {
 public:
  static jlong ticksNow() {
    // Using Ticks for consistent usage outside JFR folder.
    JFR_ONLY(return JfrTime::is_ft_enabled() ? Ticks::now().ft_value() : Ticks::now().value();) NOT_JFR_RETURN_(0L);
  }

src/hotspot/share/compiler/compilerEvent.hpp:

    // there must not be an existing registration for `phase_name`.
    // If `use_strdup` is true, then `phase_name` is strdup'ed before registration.
    // If `sync` is true, then access to the registration table is synchronized.
    static int get_phase_id(const char* phase_name, bool may_exist, bool use_strdup, bool sync) NOT_JFR_RETURN_(-1);

    static void post(EventCompilerPhase& event, const Ticks& start_time, int phase, int compile_id, int level) NOT_JFR_RETURN();
    static void post(EventCompilerPhase& event, jlong start_time, int phase, int compile_id, int level) {
      JFR_ONLY(post(event, Ticks(start_time), phase, compile_id, level);)
    }
  };

  class InlineEvent : AllStatic {
    static void post(EventCompilerInlining& event, int compile_id, Method* caller, const JfrStructCalleeMethod& callee, bool success, const char* msg, int bci) NOT_JFR_RETURN();
   public:
    static void post(EventCompilerInlining& event, int compile_id, Method* caller, Method* callee, bool success, const char* msg, int bci) NOT_JFR_RETURN();
    static void post(EventCompilerInlining& event, int compile_id, Method* caller, ciMethod* callee, bool success, const char* msg, int bci) NOT_JFR_RETURN();
  };
};
#endif // SHARE_COMPILER_COMPILEREVENT_HPP

src/hotspot/share/compiler/compilerEvent.cpp:

  event.set_compileId(compile_id);
  event.set_failureMessage(reason);
  event.commit();
}

void CompilerEvent::PhaseEvent::post(EventCompilerPhase& event, const Ticks& start_time, int phase, int compile_id, int level) {
  event.set_starttime(start_time);
  event.set_phase((u1) phase);
  event.set_compileId(compile_id);
  event.set_phaseLevel((short)level);
  event.commit();
}

void CompilerEvent::InlineEvent::post(EventCompilerInlining& event, int compile_id, Method* caller, const JfrStructCalleeMethod& callee, bool success, const char* msg, int bci) {
  event.set_compileId(compile_id);
  event.set_caller(caller);
  event.set_callee(callee);
  event.set_succeeded(success);
  event.set_message(msg);
  event.set_bci(bci);
  commit(event);
}

void CompilerEvent::InlineEvent::post(EventCompilerInlining& event, int compile_id, Method* caller, Method* callee, bool success, const char* msg, int bci) {
  JfrStructCalleeMethod callee_struct;
  callee_struct.set_type(callee->klass_name()->as_utf8());
  callee_struct.set_name(callee->name()->as_utf8());
  callee_struct.set_descriptor(callee->signature()->as_utf8());
  post(event, compile_id, caller, callee_struct, success, msg, bci);
}

void CompilerEvent::InlineEvent::post(EventCompilerInlining& event, int compile_id, Method* caller, ciMethod* callee, bool success, const char* msg, int bci) {
  JfrStructCalleeMethod callee_struct;
  callee_struct.set_type(callee->holder()->name()->as_utf8());
  callee_struct.set_name(callee->name()->as_utf8());
  callee_struct.set_descriptor(callee->signature()->as_symbol()->as_utf8());
  post(event, compile_id, caller, callee_struct, success, msg, bci);
}

src/hotspot/share/jvmci/jvmciCompilerToVM.cpp:

#else
  return -1;
#endif // !INCLUDE_JFR
C2V_END

C2V_VMENTRY(void, notifyCompilerPhaseEvent, (JNIEnv* env, jobject, jlong startTime, jint phase, jint compileId, jint level))
  EventCompilerPhase event(UNTIMED);
  if (event.should_commit()) {
    CompilerEvent::PhaseEvent::post(event, startTime, phase, compileId, level);
  }
C2V_END

C2V_VMENTRY(void, notifyCompilerInliningEvent, (JNIEnv* env, jobject, jint compileId, ARGUMENT_PAIR(caller), ARGUMENT_PAIR(callee), jboolean succeeded, jstring jmessage, jint bci))
  EventCompilerInlining event;
  if (event.should_commit()) {
    Method* caller = UNPACK_PAIR(Method, caller);
    Method* callee = UNPACK_PAIR(Method, callee);
    JVMCIObject message = JVMCIENV->wrap(jmessage);
    CompilerEvent::InlineEvent::post(event, compileId, caller, callee, succeeded, JVMCIENV->as_utf8_string(message), bci);
  }
C2V_END

C2V_VMENTRY(void, setThreadLocalObject, (JNIEnv* env, jobject, jint id, jobject value))
  requireInHotSpot("setThreadLocalObject", JVMCI_CHECK);
  if (id == 0) {

src/hotspot/share/opto/bytecodeInfo.cpp:

  int caller_bci = jvm->bci();
  ciMethod* caller_method = jvm->method();
  const char* inline_msg = msg();
  assert(inline_msg != nullptr, "just checking");
  if (C->log() != nullptr) {
    if (success) {
      C->log()->inline_success(inline_msg);
    } else {
      C->log()->inline_fail(inline_msg);
    }
  }
  CompileTask::print_inlining_ul(callee_method, inline_level(), caller_bci, inlining_result_of(success), inline_msg);
  C->inline_printer()->record(callee_method, jvm, inlining_result_of(success), inline_msg);
  EventCompilerInlining event;
  if (event.should_commit()) {
    guarantee(callee_method != nullptr, "would crash in CompilerEvent::InlineEvent::post");
    CompilerEvent::InlineEvent::post(event, C->compile_id(), caller_method->get_Method(), callee_method, success, inline_msg, caller_bci);
  }
}

//------------------------------ok_to_inline-----------------------------------
bool InlineTree::ok_to_inline(ciMethod* callee_method, JVMState* jvms, ciCallProfile& profile,
                              bool& should_delay) {
#ifdef ASSERT
  assert(callee_method != nullptr, "caller checks for optimized virtual!");

src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/JFR.java:

         * @param phaseName compiler phase name
         * @param compileId current compilation unit id
         * @param phaseLevel compiler phase nesting level
         */
        public static void write(long startTime, String phaseName, int compileId, int phaseLevel) {
            compilerToVM().notifyCompilerPhaseEvent(startTime, getPhaseToId(phaseName), compileId, phaseLevel);
        }
    }

    /**
     * Helper methods for managing JFR CompilerInlining events. The events are defined in {@code
     * src/share/jfr/metadata/metadata.xml}.
     */
    public static final class CompilerInliningEvent {

        /**
         * Commits a CompilerInlining event.
         *
         * @param compileId current compilation unit id
         * @param caller caller method
         * @param callee callee method
         * @param succeeded inlining succeeded or not
         * @param message extra information on inlining
         * @param bci invocation byte code index
         */

Configuration enabled
profiling false
default false

Field Type Description
compileId int Compilation Identifier
caller Method Caller Method
callee CalleeMethod struct Callee Method
succeeded boolean Succeeded
message string Message
bci int Bytecode Index

Examples 3
bci int
1
callee CalleeMethod
descriptor string
(Ljava/lang/Object;)Ljava/lang/Object;
name string
allocateInstance
type string
java/lang/invoke/DirectMethodHandle
caller Method
descriptor string
(Ljava/lang/Object;II)Ljava/lang/Object;
hidden boolean
true
modifiers int
8
name string
newInvokeSpecial
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
16
name string
java/lang/invoke/DirectMethodHandle$Holder
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang/invoke
compileId int
73536
message string
inline (hot)
startTime long: millis
366724487841
succeeded boolean
true
bci int
93
callee CalleeMethod
descriptor string
(ILjava/lang/Object;)Ljava/util/concurrent/ConcurrentHashMap$Node;
name string
find
type string
java/util/concurrent/ConcurrentHashMap$TreeBin
caller Method
descriptor string
(Ljava/lang/Object;)Ljava/lang/Object;
hidden boolean
false
modifiers int
1
name string
get
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/concurrent/ConcurrentHashMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent
compileId int
73388
message string
too big
startTime long: millis
278685999953
succeeded boolean
false
bci int
154
callee CalleeMethod
descriptor string
(Lscala/collection/mutable/LinkedHashMap$LinkedEntry;)V
name string
next_$eq
type string
scala/collection/mutable/LinkedHashMap$LinkedEntry
caller Method
descriptor string
(I)V
hidden boolean
false
modifiers int
2
name string
growTable
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
scala/collection/mutable/LinkedHashMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection/mutable
compileId int
72214
message string
inline
startTime long: millis
378898627383
succeeded boolean
true

Deoptimization

profiling default startTime eventThread stackTrace 14 17 21 25 26 27

Category: Java Virtual Machine / Compiler

Describes the detection of an uncommon situation in a compiled method which may lead to deoptimization of the method

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/deoptimization.cpp:

  JfrSerializer::register_serializer(TYPE_DEOPTIMIZATIONREASON, true, new DeoptReasonSerializer());
  JfrSerializer::register_serializer(TYPE_DEOPTIMIZATIONACTION, true, new DeoptActionSerializer());
}

static void post_deoptimization_event(nmethod* nm,
                                      const Method* method,
                                      int trap_bci,
                                      int instruction,
                                      Deoptimization::DeoptReason reason,
                                      Deoptimization::DeoptAction action) {
  assert(nm != nullptr, "invariant");
  assert(method != nullptr, "invariant");
  if (EventDeoptimization::is_enabled()) {
    static bool serializers_registered = false;
    if (!serializers_registered) {
      register_serializers();
      serializers_registered = true;
    }
    EventDeoptimization event;
    event.set_compileId(nm->compile_id());
    event.set_compiler(nm->compiler_type());
    event.set_method(method);
    event.set_lineNumber(method->line_number_from_bci(trap_bci));
    event.set_bci(trap_bci);
    event.set_instruction(instruction);
    event.set_reason(reason);
    event.set_action(action);
    event.commit();
  }
}

Configuration enabled stackTrace
profiling true true
default true false

Field Type Description
compileId int Compilation Identifier
compiler CompilerType Compiler
method Method Method
lineNumber int Line Number
bci int Bytecode Index
instruction Bytecode Instruction
reason DeoptimizationReason Reason
action DeoptimizationAction Action

Examples 3
action DeoptimizationAction
maybe_recompile
bci int
4
compileId int
74439
compiler CompilerType
c2
instruction Bytecode
invokeinterface
lineNumber int
799
method Method
descriptor string
()Z
hidden boolean
false
modifiers int
1
name string
hasNext
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
17
name string
scala/collection/Iterator$$anon$14
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection
reason DeoptimizationReason
class_check
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
4
lineNumber int
799
method Method
descriptor string
()Z
hidden boolean
false
modifiers int
1
name string
hasNext
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
17
name string
scala/collection/Iterator$$anon$14
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
310824233352
action DeoptimizationAction
reinterpret
bci int
23
compileId int
76681
compiler CompilerType
c2
instruction Bytecode
if_icmpne
lineNumber int
538
method Method
descriptor string
(I)V
hidden boolean
false
modifiers int
2
name string
checkBarging
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
scala/concurrent/stm/ccstm/InTxnImpl
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/concurrent/stm/ccstm
reason DeoptimizationReason
unstable_if
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
23
lineNumber int
538
method Method
descriptor string
(I)V
hidden boolean
false
modifiers int
2
name string
checkBarging
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
scala/concurrent/stm/ccstm/InTxnImpl
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/concurrent/stm/ccstm
type FrameType
Inlined
truncated boolean
false
startTime long: millis
438391712473
action DeoptimizationAction
maybe_recompile
bci int
1
compileId int
74742
compiler CompilerType
c2
instruction Bytecode
invokevirtual
lineNumber int
300
method Method
descriptor string
(Lscala/Function1;)V
hidden boolean
false
modifiers int
17
name string
foreach
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1025
name string
scala/collection/immutable/Vector
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection/immutable
reason DeoptimizationReason
class_check
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
1
lineNumber int
300
method Method
descriptor string
(Lscala/Function1;)V
hidden boolean
false
modifiers int
17
name string
foreach
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1025
name string
scala/collection/immutable/Vector
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection/immutable
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
443396728319

CompilerQueueUtilization

profiling default startTime duration every chunk 22 25 26 27

Category: Java Virtual Machine / Compiler

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrCompilerQueueUtilization.cpp:

    {CompileBroker::c2_compile_queue(), c2_compiler_queue_id, &CompileBroker::get_c2_thread_count, 0, 0}};

  const JfrTicks cur_time = JfrTicks::now();
  static JfrTicks last_sample_instant;
  const JfrTickspan interval = cur_time - last_sample_instant;
  for (int i = 0; i < num_compiler_queues; i ++) {
    CompilerQueueEntry* entry = &compilerQueueEntries[i];
    if (entry->compilerQueue != nullptr) {
      const uint64_t current_added = entry->compilerQueue->get_total_added();
      const uint64_t current_removed = entry->compilerQueue->get_total_removed();
      const uint64_t addedRate = rate_per_second(current_added, entry->added, interval);
      const uint64_t removedRate = rate_per_second(current_removed, entry->removed, interval);

      EventCompilerQueueUtilization event;
      event.set_compiler(entry->compiler_queue_id);
      event.set_addedRate(addedRate);
      event.set_removedRate(removedRate);
      event.set_queueSize(entry->compilerQueue->size());
      event.set_peakQueueSize(entry->compilerQueue->get_peak_size());
      event.set_addedCount(current_added - entry->added);
      event.set_removedCount(current_removed - entry->removed);
      event.set_totalAddedCount(current_added);
      event.set_totalRemovedCount(current_removed);
      event.set_compilerThreadCount(entry->get_compiler_thread_count());
      event.commit();

Configuration enabled period
profiling true 5 s
default true 10 s

Field Type Description
compiler CompilerType Compiler
addedRate long: hertz Requets Added Rate Requests added per second
removedRate long: hertz Requests Removed Rate Requests removed per second
queueSize long Queue Size
peakQueueSize long Peak Queue Size
addedCount long Requests Added
removedCount long Requests Removed
totalAddedCount long Total Requests Added
totalRemovedCount long Total Requests Removed
compilerThreadCount int Compiler Thread Count

CompilerStatistics

profiling default startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Compiler

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

TRACE_REQUEST_FUNC(SymbolTableStatistics) {
  TableStatistics statistics = SymbolTable::get_table_statistics();
  emit_table_statistics<EventSymbolTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(StringTableStatistics) {
  TableStatistics statistics = StringTable::get_table_statistics();
  emit_table_statistics<EventStringTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(CompilerStatistics) {
  EventCompilerStatistics event;
  event.set_compileCount(CompileBroker::get_total_compile_count());
  event.set_bailoutCount(CompileBroker::get_total_bailout_count());
  event.set_invalidatedCount(CompileBroker::get_total_invalidated_count());
  event.set_osrCompileCount(CompileBroker::get_total_osr_compile_count());
  event.set_standardCompileCount(CompileBroker::get_total_standard_compile_count());
  event.set_osrBytesCompiled(CompileBroker::get_sum_osr_bytes_compiled());
  event.set_standardBytesCompiled(CompileBroker::get_sum_standard_bytes_compiled());
  event.set_nmethodsSize(CompileBroker::get_sum_nmethod_size());
  event.set_nmethodCodeSize(CompileBroker::get_sum_nmethod_code_size());
  event.set_peakTimeSpent(CompileBroker::get_peak_compilation_time());
  event.set_totalTimeSpent(CompileBroker::get_total_compilation_time());

Configuration enabled period
profiling true 1000 ms
default true 1000 ms

Field Type Description
compileCount int Compiled Methods
bailoutCount int Bailouts
invalidatedCount int Invalidated Compilations
osrCompileCount int OSR Compilations
standardCompileCount int Standard Compilations
osrBytesCompiled ulong: bytes OSR Bytes Compiled
standardBytesCompiled ulong: bytes Standard Bytes Compiled
nmethodsSize ulong: bytes Compilation Resulting Size
nmethodCodeSize ulong: bytes Compilation Resulting Code Size
peakTimeSpent long: millis Peak Time
totalTimeSpent long: millis Total Time

Examples 3
bailoutCount int
13
compileCount int
78551
invalidatedCount int
0
nmethodCodeSize ulong: bytes
105129840
nmethodsSize ulong: bytes
155396936
osrBytesCompiled ulong: bytes
0
osrCompileCount int
863
peakTimeSpent long: millis
10482
standardBytesCompiled ulong: bytes
0
standardCompileCount int
77688
startTime long: millis
453312256670
totalTimeSpent long: millis
639553
bailoutCount int
13
compileCount int
73071
invalidatedCount int
0
nmethodCodeSize ulong: bytes
96594592
nmethodsSize ulong: bytes
143385424
osrBytesCompiled ulong: bytes
0
osrCompileCount int
862
peakTimeSpent long: millis
12707
standardBytesCompiled ulong: bytes
0
standardCompileCount int
72209
startTime long: millis
426757193036
totalTimeSpent long: millis
730774
bailoutCount int
12
compileCount int
75342
invalidatedCount int
0
nmethodCodeSize ulong: bytes
106547536
nmethodsSize ulong: bytes
154532320
osrBytesCompiled ulong: bytes
0
osrCompileCount int
885
peakTimeSpent long: millis
5268
standardBytesCompiled ulong: bytes
0
standardCompileCount int
74457
startTime long: millis
319600820072
totalTimeSpent long: millis
323986

CompilerConfiguration

profiling default startTime end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Compiler

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.set_invalidatedCount(CompileBroker::get_total_invalidated_count());
  event.set_osrCompileCount(CompileBroker::get_total_osr_compile_count());
  event.set_standardCompileCount(CompileBroker::get_total_standard_compile_count());
  event.set_osrBytesCompiled(CompileBroker::get_sum_osr_bytes_compiled());
  event.set_standardBytesCompiled(CompileBroker::get_sum_standard_bytes_compiled());
  event.set_nmethodsSize(CompileBroker::get_sum_nmethod_size());
  event.set_nmethodCodeSize(CompileBroker::get_sum_nmethod_code_size());
  event.set_peakTimeSpent(CompileBroker::get_peak_compilation_time());
  event.set_totalTimeSpent(CompileBroker::get_total_compilation_time());
  event.commit();
}

TRACE_REQUEST_FUNC(CompilerConfiguration) {
  EventCompilerConfiguration event;
  event.set_threadCount(static_cast<s4>(CICompilerCount));
  event.set_tieredCompilation(TieredCompilation);
  event.set_dynamicCompilerThreadCount(UseDynamicNumberOfCompilerThreads);
  event.commit();
}

TRACE_REQUEST_FUNC(CodeCacheStatistics) {
  // Emit stats for all available code heaps
  for (int bt_index = 0; bt_index < static_cast<int>(CodeBlobType::NumTypes); ++bt_index) {
    const CodeBlobType bt = static_cast<CodeBlobType>(bt_index);
    if (CodeCache::heap_available(bt)) {

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
threadCount int Thread Count
tieredCompilation boolean Tiered Compilation
dynamicCompilerThreadCount boolean 20+ Uses Dynamic Number of Compiler Threads

Examples 3
dynamicCompilerThreadCount boolean
true
startTime long: millis
345549980203
threadCount int
3
tieredCompilation boolean
true
dynamicCompilerThreadCount boolean
true
startTime long: millis
455890098571
threadCount int
3
tieredCompilation boolean
true
dynamicCompilerThreadCount boolean
true
startTime long: millis
433017158154
threadCount int
3
tieredCompilation boolean
true

JVM: Diagnostics

SyncOnValueBasedClass

experimental profiling default startTime eventThread stackTrace 16 17 21 25 26 27

Category: Java Virtual Machine / Diagnostics

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/synchronizer.cpp:

  } else {
    assert(DiagnoseSyncOnValueBasedClasses == LOG_WARNING, "invalid value for DiagnoseSyncOnValueBasedClasses");
    ResourceMark rm;
    Log(valuebasedclasses) vblog;

    vblog.info("Synchronizing on object " INTPTR_FORMAT " of klass %s", p2i(obj()), obj->klass()->external_name());
    if (locking_thread->has_last_Java_frame()) {
      LogStream info_stream(vblog.info());
      locking_thread->print_active_stack_on(&info_stream);
    } else {
      vblog.info("Cannot find the last Java frame");
    }

    EventSyncOnValueBasedClass event;
    if (event.should_commit()) {
      event.set_valueBasedClass(obj->klass());
      event.commit();
    }
  }

  if (bcp_was_adjusted) {
    last_frame.interpreter_frame_set_bcp(last_frame.interpreter_frame_bcp() + 1);
  }
}

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
valueBasedClass Class Value Based Class

HeapDump

profiling default startTime duration eventThread stackTrace 15 17 21 25 26 27

Category: Java Virtual Machine / Diagnostics

Information about a successfully written Java heap dump

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/services/heapDumper.cpp:

    // (DumpWriter buffer, DumperClassCacheTable, GZipCompressor buffers).
    // For the OOM handling we may already be limited in memory.
    // Lets ensure we have at least 20MB per thread.
    physical_memory_size_type free_memory = 0;
    // Return value ignored - defaulting to 0 on failure.
    (void)os::free_memory(free_memory);
    julong max_threads = free_memory / (20 * M);
    if (num_dump_threads > max_threads) {
      num_dump_threads = MAX2<uint>(1, (uint)max_threads);
    }
  }

  // create JFR event
  EventHeapDump event;

  AbstractCompressor* compressor = nullptr;

  if (compression > 0) {
    compressor = new (std::nothrow) GZipCompressor(compression);

    if (compressor == nullptr) {
      set_error("Could not allocate gzip compressor");
      return -1;
    }
  }

Configuration enabled stackTrace threshold
profiling true true 0 ns
default true true 0 ns

Field Type Description
destination string Destination Path of the Dump
size long Size
gcBeforeDump boolean GC Before Dump
onOutOfMemoryError boolean Heap Dump on Out of Memory Error
overwrite boolean 21+ Overwrite Heap dump overwrites previous file location if it exists
compression int 21+ Compression Level Compression level of the dump, if larger than 0 we use gzip compression with this level

JavaAgent

profiling default startTime end of every chunk 21 25 26 27

Category: Java Virtual Machine / Diagnostics

A Java programming language agent making use of the java.lang.instrument package for instrumenting programs running on the JVM

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.set_name(agent->name());
  event.set_options(agent->options());
  event.set_dynamic(agent->is_dynamic());
  event.set_initializationTime(agent->initialization_time());
  event.set_initializationDuration(agent->initialization_duration());
  event.commit();
}

TRACE_REQUEST_FUNC(JavaAgent) {
  JvmtiAgentList::Iterator it = JvmtiAgentList::java_agents();
  while (it.has_next()) {
    const JvmtiAgent* agent = it.next();
    assert(agent->is_jplis(), "invariant");
    EventJavaAgent event;
    send_agent_event(event, agent);
  }
}

static void send_native_agent_events(JvmtiAgentList::Iterator& it) {
  while (it.has_next()) {
    const JvmtiAgent* agent = it.next();
    assert(!agent->is_jplis(), "invariant");
    EventNativeAgent event;
    event.set_path(agent->os_lib_path());
    send_agent_event(event, agent);

Configuration enabled period
profiling true endChunk
default true endChunk

Field Type Description
name string Name
options string Options
dynamic boolean Dynamic If the agent attached to the JVM dynamically during runtime, i.e. not at startup
initializationTime Ticks Initialization Time The time the JVM initialized the agent
initializationDuration Tickspan Initialization Duration The duration of executing the initialization method, either premain or agentmain

NativeAgent

profiling default startTime end of every chunk 21 25 26 27

Category: Java Virtual Machine / Diagnostics

A native programming language agent making use of the JVMTI interface used by development, profiling and monitoring tools

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  JvmtiAgentList::Iterator it = JvmtiAgentList::java_agents();
  while (it.has_next()) {
    const JvmtiAgent* agent = it.next();
    assert(agent->is_jplis(), "invariant");
    EventJavaAgent event;
    send_agent_event(event, agent);
  }
}

static void send_native_agent_events(JvmtiAgentList::Iterator& it) {
  while (it.has_next()) {
    const JvmtiAgent* agent = it.next();
    assert(!agent->is_jplis(), "invariant");
    EventNativeAgent event;
    event.set_path(agent->os_lib_path());
    send_agent_event(event, agent);
  }
}

TRACE_REQUEST_FUNC(NativeAgent) {
  JvmtiAgentList::Iterator native_agents_it = JvmtiAgentList::native_agents();
  send_native_agent_events(native_agents_it);
  JvmtiAgentList::Iterator xrun_agents_it = JvmtiAgentList::xrun_agents();
  send_native_agent_events(xrun_agents_it);
}

Configuration enabled period
profiling true endChunk
default true endChunk

Field Type Description
name string Name
options string Options
dynamic boolean Dynamic If the library attached to the JVM dynamically during runtime, i.e. not at startup
initializationTime Ticks Initialization Time The time the JVM initialized the agent
initializationDuration Tickspan Initialization Duration The duration of executing the JVMTI VMInit event callback. If no VMInit callback is specified, the duration is 0. For a dynamically loaded agent, it is the duration of executing the call to Agent_OnAttach.
path string Path The path of the library

JVM: Flag

IntFlagChanged

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/flags/jvmFlagAccess.cpp:

  virtual void print_range(outputStream* st, const JVMFlagLimit* range) const {
    const JVMTypedFlagLimit<T>* r = (const JVMTypedFlagLimit<T>*)range;
    print_range_impl(st, r->min(), r->max());
  }

  virtual void range_error(const char* name, T value, T min, T max, bool verbose) const = 0;
  virtual void print_range_impl(outputStream* st, T min, T max) const = 0;
};

class FlagAccessImpl_int : public RangedFlagAccessImpl<int, EventIntFlagChanged> {
public:
  void range_error(const char* name, int value, int min, int max, bool verbose) const {
    JVMFlag::printError(verbose,
                        "int %s=%d is outside the allowed range "
                        "[ %d ... %d ]\n",
                        name, value, min, max);
  }
  JVMFlag::Error typed_check_constraint(void* func, int value, bool verbose) const {
    return ((JVMFlagConstraintFunc_int)func)(value, verbose);
  }
  void print_range_impl(outputStream* st, int min, int max) const {

Configuration enabled
profiling true
default true

Field Type Description
name string Name
oldValue int Old Value
newValue int New Value
origin FlagValueOrigin Origin

UnsignedIntFlagChanged

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/flags/jvmFlagAccess.cpp:

                        name, value, min, max);
  }
  JVMFlag::Error typed_check_constraint(void* func, int value, bool verbose) const {
    return ((JVMFlagConstraintFunc_int)func)(value, verbose);
  }
  void print_range_impl(outputStream* st, int min, int max) const {
    st->print("[ %-25d ... %25d ]", min, max);
  }
  void print_default_range(outputStream* st) const {
    st->print("[ " INT32_FORMAT_W(-25) " ... " INT32_FORMAT_W(25) " ]", INT_MIN, INT_MAX);
  }
};

class FlagAccessImpl_uint : public RangedFlagAccessImpl<uint, EventUnsignedIntFlagChanged> {
public:
  void range_error(const char* name, uint value, uint min, uint max, bool verbose) const {
    JVMFlag::printError(verbose,
                        "uint %s=%u is outside the allowed range "
                        "[ %u ... %u ]\n",
                        name, value, min, max);
  }
  JVMFlag::Error typed_check_constraint(void* func, uint value, bool verbose) const {
    return ((JVMFlagConstraintFunc_uint)func)(value, verbose);
  }
  void print_range_impl(outputStream* st, uint min, uint max) const {

Configuration enabled
profiling true
default true

Field Type Description
name string Name
oldValue uint Old Value
newValue uint New Value
origin FlagValueOrigin Origin

LongFlagChanged

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/flags/jvmFlagAccess.cpp:

                        name, value, min, max);
  }
  JVMFlag::Error typed_check_constraint(void* func, uint value, bool verbose) const {
    return ((JVMFlagConstraintFunc_uint)func)(value, verbose);
  }
  void print_range_impl(outputStream* st, uint min, uint max) const {
    st->print("[ %-25u ... %25u ]", min, max);
  }
  void print_default_range(outputStream* st) const {
    st->print("[ " UINT32_FORMAT_W(-25) " ... " UINT32_FORMAT_W(25) " ]", 0, UINT_MAX);
  }
};

class FlagAccessImpl_intx : public RangedFlagAccessImpl<intx, EventLongFlagChanged> {
public:
  void range_error(const char* name, intx value, intx min, intx max, bool verbose) const {
    JVMFlag::printError(verbose,
                        "intx %s=%zd is outside the allowed range "
                        "[ %zd ... %zd ]\n",
                        name, value, min, max);
  }
  JVMFlag::Error typed_check_constraint(void* func, intx value, bool verbose) const {
    return ((JVMFlagConstraintFunc_intx)func)(value, verbose);
  }
  void print_range_impl(outputStream* st, intx min, intx max) const {

Configuration enabled
profiling true
default true

Field Type Description
name string Name
oldValue long Old Value
newValue long New Value
origin FlagValueOrigin Origin

UnsignedLongFlagChanged

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/flags/jvmFlagAccess.cpp:

                        name, value, min, max);
  }
  JVMFlag::Error typed_check_constraint(void* func, intx value, bool verbose) const {
    return ((JVMFlagConstraintFunc_intx)func)(value, verbose);
  }
  void print_range_impl(outputStream* st, intx min, intx max) const {
    st->print("[ %-25zd ... %25zd ]", min, max);
  }
  void print_default_range(outputStream* st) const {
    st->print("[ %-25zd ... %25zd ]", min_intx, max_intx);
  }
};

class FlagAccessImpl_uintx : public RangedFlagAccessImpl<uintx, EventUnsignedLongFlagChanged> {
public:
  void range_error(const char* name, uintx value, uintx min, uintx max, bool verbose) const {
    JVMFlag::printError(verbose,
                        "uintx %s=%zu is outside the allowed range "
                        "[ %zu ... %zu ]\n",
                        name, value, min, max);
  }
  JVMFlag::Error typed_check_constraint(void* func, uintx value, bool verbose) const {
    return ((JVMFlagConstraintFunc_uintx)func)(value, verbose);
  }
  void print_range_impl(outputStream* st, uintx min, uintx max) const {
    st->print("[ %-25zu ... %25zu ]", min, max);
  }
  void print_default_range(outputStream* st) const {
    st->print("[ %-25zu ... %25zu ]", uintx(0), max_uintx);
  }
};

class FlagAccessImpl_uint64_t : public RangedFlagAccessImpl<uint64_t, EventUnsignedLongFlagChanged> {
public:
  void range_error(const char* name, uint64_t value, uint64_t min, uint64_t max, bool verbose) const {
    JVMFlag::printError(verbose,
                        "uint64_t %s=" UINT64_FORMAT " is outside the allowed range "
                        "[ " UINT64_FORMAT " ... " UINT64_FORMAT " ]\n",
                        name, value, min, max);
  }
  JVMFlag::Error typed_check_constraint(void* func, uint64_t value, bool verbose) const {
    return ((JVMFlagConstraintFunc_uint64_t)func)(value, verbose);
  }
  void print_range_impl(outputStream* st, uint64_t min, uint64_t max) const {
    st->print("[ " UINT64_FORMAT_W(-25) " ... " UINT64_FORMAT_W(25) " ]", min, max);
  }
  void print_default_range(outputStream* st) const {
    st->print("[ " UINT64_FORMAT_W(-25) " ... " UINT64_FORMAT_W(25) " ]", uint64_t(0), uint64_t(max_juint));
  }
};

class FlagAccessImpl_size_t : public RangedFlagAccessImpl<size_t, EventUnsignedLongFlagChanged> {
public:
  void range_error(const char* name, size_t value, size_t min, size_t max, bool verbose) const {
    JVMFlag::printError(verbose,
                        "size_t %s=%zu is outside the allowed range "
                        "[ %zu ... %zu ]\n",
                        name, value, min, max);
  }
  JVMFlag::Error typed_check_constraint(void* func, size_t value, bool verbose) const {
    return ((JVMFlagConstraintFunc_size_t)func)(value, verbose);
  }
  void print_range_impl(outputStream* st, size_t min, size_t max) const {

Configuration enabled
profiling true
default true

Field Type Description
name string Name
oldValue ulong Old Value
newValue ulong New Value
origin FlagValueOrigin Origin

DoubleFlagChanged

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/flags/jvmFlagAccess.cpp:

                        name, value, min, max);
  }
  JVMFlag::Error typed_check_constraint(void* func, size_t value, bool verbose) const {
    return ((JVMFlagConstraintFunc_size_t)func)(value, verbose);
  }
  void print_range_impl(outputStream* st, size_t min, size_t max) const {
    st->print("[ %-25zu ... %25zu ]", min, max);
  }
  void print_default_range(outputStream* st) const {
    st->print("[ %-25zu ... %25zu ]", size_t(0), size_t(SIZE_MAX));
  }
};

class FlagAccessImpl_double : public RangedFlagAccessImpl<double, EventDoubleFlagChanged> {
public:
  void range_error(const char* name, double value, double min, double max, bool verbose) const {
    JVMFlag::printError(verbose,
                          "double %s=%f is outside the allowed range "
                          "[ %f ... %f ]\n",
                        name, value, min, max);
  }
  JVMFlag::Error typed_check_constraint(void* func, double value, bool verbose) const {
    return ((JVMFlagConstraintFunc_double)func)(value, verbose);
  }
  void print_range_impl(outputStream* st, double min, double max) const {

Configuration enabled
profiling true
default true

Field Type Description
name string Name
oldValue double Old Value
newValue double New Value
origin FlagValueOrigin Origin

BooleanFlagChanged

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/flags/jvmFlagAccess.cpp:

    *((T*)value_addr) = old_value;
    flag->set_origin(origin);

    return JVMFlag::SUCCESS;
  }

  JVMFlag::Error check_constraint(const JVMFlag* flag, void * func, bool verbose) const  {
    return typed_check_constraint(func, flag->read<T>(), verbose);
  }

  virtual JVMFlag::Error typed_check_constraint(void * func, T value, bool verbose) const = 0;
};

class FlagAccessImpl_bool : public TypedFlagAccessImpl<bool, EventBooleanFlagChanged> {
public:
  JVMFlag::Error set_impl(JVMFlag* flag, void* value_addr, JVMFlagOrigin origin) const {
    bool verbose = JVMFlagLimit::verbose_checks_needed();
    return TypedFlagAccessImpl<bool, EventBooleanFlagChanged>
               ::check_constraint_and_set(flag, value_addr, origin, verbose);
  }

  JVMFlag::Error typed_check_constraint(void* func, bool value, bool verbose) const {
    return ((JVMFlagConstraintFunc_bool)func)(value, verbose);
  }
};

template <typename T, typename EVENT>
class RangedFlagAccessImpl : public TypedFlagAccessImpl<T, EVENT> {
public:

Configuration enabled
profiling true
default true

Field Type Description
name string Name
oldValue boolean Old Value
newValue boolean New Value
origin FlagValueOrigin Origin

StringFlagChanged

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/flags/jvmFlagAccess.cpp:

  if (!flag->is_ccstr()) return JVMFlag::WRONG_FORMAT;
  const JVMTypedFlagLimit<ccstr>* constraint = (const JVMTypedFlagLimit<ccstr>*)JVMFlagLimit::get_constraint(flag);
  if (constraint != nullptr && constraint->phase() <= JVMFlagLimit::validating_phase()) {
    bool verbose = JVMFlagLimit::verbose_checks_needed() | (origin == JVMFlagOrigin::ERGONOMIC);
    JVMFlag::Error err = ((JVMFlagConstraintFunc_ccstr)constraint->constraint_func())(*value, verbose);
    if (err != JVMFlag::SUCCESS) {
      if (origin == JVMFlagOrigin::ERGONOMIC) {
        fatal("FLAG_SET_ERGO cannot be used to set an invalid value for %s", flag->name());
      }
      return err;
    }
  }
  ccstr old_value = flag->get_ccstr();
  trace_flag_changed<ccstr, EventStringFlagChanged>(flag, old_value, *value, origin);
  char* new_value = nullptr;
  if (*value != nullptr) {
    new_value = os::strdup_check_oom(*value);
  }
  flag->set_ccstr(new_value);
  if (!flag->is_default() && old_value != nullptr) {
    // Old value is heap allocated so free it.
    FREE_C_HEAP_ARRAY(char, old_value);
  }
  // Unlike the other APIs, the old value is NOT returned, so the caller won't need to free it.
  // The callers typically don't care what the old value is.

Configuration enabled
profiling true
default true

Field Type Description
name string Name
oldValue string Old Value
newValue string New Value
origin FlagValueOrigin Origin

IntFlag

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
name string Name
value int Value
origin FlagValueOrigin Origin

Examples 3
name string
JavaPriority9_To_OSPriority
origin FlagValueOrigin
Default
startTime long: millis
404635139844
value int
-1
name string
JavaPriority1_To_OSPriority
origin FlagValueOrigin
Default
startTime long: millis
286474457287
value int
-1
name string
UseSSE
origin FlagValueOrigin
Default
startTime long: millis
383182308803
value int
4

UnsignedIntFlag

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
name string Name
value uint Value
origin FlagValueOrigin Origin

Examples 3
name string
TestCrashInErrorHandler
origin FlagValueOrigin
Default
startTime long: millis
388177898752
value uint
0
name string
ParallelGCThreads
origin FlagValueOrigin
Default
startTime long: millis
280663485708
value uint
4
name string
VerifyIterativeGVN
origin FlagValueOrigin
Default
startTime long: millis
416740995324
value uint
0

LongFlag

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
name string Name
value long Value
origin FlagValueOrigin Origin

Examples 3
name string
Tier3DelayOn
origin FlagValueOrigin
Default
startTime long: millis
378913125497
value long
5
name string
NestedInliningSizeRatio
origin FlagValueOrigin
Default
startTime long: millis
278185496115
value long
90
name string
ImplicitNullCheckThreshold
origin FlagValueOrigin
Default
startTime long: millis
371363183770
value long
3

UnsignedLongFlag

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
name string Name
value ulong Value
origin FlagValueOrigin Origin

Examples 3
name string
MaxGCPauseMillis
origin FlagValueOrigin
Default
startTime long: millis
371363219957
value ulong
-2
name string
ReservedCodeCacheSize
origin FlagValueOrigin
Ergonomic
startTime long: millis
278185527834
value ulong
251658240
name string
GCDrainStackTargetSize
origin FlagValueOrigin
Default
startTime long: millis
378913156705
value ulong
64

DoubleFlag

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
name string Name
value double Value
origin FlagValueOrigin Origin

Examples 3
name string
G1ConcMarkStepDurationMillis
origin FlagValueOrigin
Default
startTime long: millis
380799256707
value double
10.0
name string
InitialRAMPercentage
origin FlagValueOrigin
Default
startTime long: millis
392343958909
value double
1.5625
name string
InitialRAMPercentage
origin FlagValueOrigin
Default
startTime long: millis
285196656311
value double
1.5625

BooleanFlag

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
name string Name
value boolean Value
origin FlagValueOrigin Origin

Examples 3
name string
DTraceAllocProbes
origin FlagValueOrigin
Default
startTime long: millis
278185621238
value boolean
false
name string
SelectivePhiFunctions
origin FlagValueOrigin
Default
startTime long: millis
378913179929
value boolean
true
name string
G1PeriodicGCInvokesConcurrent
origin FlagValueOrigin
Default
startTime long: millis
371363306759
value boolean
true

StringFlag

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
name string Name
value string Value
origin FlagValueOrigin Origin

Examples 3
name string
ShenandoahGCHeuristics
origin FlagValueOrigin
Default
startTime long: millis
378913254838
value string
adaptive
name string
PerfDataSaveFile
origin FlagValueOrigin
Default
startTime long: millis
380799337908
value string
null
name string
CompilationMode
origin FlagValueOrigin
Default
startTime long: millis
285196733545
value string
default

JVM: GC: Collector

GarbageCollection

profiling default startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Collector

Garbage collection performed by the JVM

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

// All GC dependencies against the trace framework is contained within this file.

typedef uintptr_t TraceAddress;

bool GCTracer::should_send_cpu_time_event() const {
  return EventGCCPUTime::is_enabled();
}

void GCTracer::send_garbage_collection_event() const {
  EventGarbageCollection event(UNTIMED);
  if (event.should_commit()) {
    event.set_gcId(GCId::current());
    event.set_name(_shared_gc_info.name());
    event.set_cause((u2) _shared_gc_info.cause());
    event.set_sumOfPauses(_shared_gc_info.sum_of_pauses());
    event.set_longestPause(_shared_gc_info.longest_pause());
    event.set_starttime(_shared_gc_info.start_timestamp());
    event.set_endtime(_shared_gc_info.end_timestamp());
    event.commit();
  }
}

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
name GCName Name The name of the Garbage Collector
cause GCCause Cause The reason for triggering this Garbage Collection
sumOfPauses Tickspan Sum of Pauses Sum of all the times in which Java execution was paused during the garbage collection
longestPause Tickspan Longest Pause Longest individual pause during the garbage collection

Examples 3
cause GCCause
Allocation Failure
gcId uint
465
longestPause Tickspan
3186709
name GCName
ParallelScavenge
startTime long: millis
456003891797
sumOfPauses Tickspan
3186709
cause GCCause
Heap Inspection Initiated GC
gcId uint
982
longestPause Tickspan
159030622
name GCName
G1Full
startTime long: millis
296173087661
sumOfPauses Tickspan
159030622
cause GCCause
Heap Inspection Initiated GC
gcId uint
879
longestPause Tickspan
323520819
name GCName
SerialOld
startTime long: millis
389981907751
sumOfPauses Tickspan
323520819

SystemGC

profiling default startTime duration eventThread stackTrace 17 21 25 26 27

Category: Java Virtual Machine / GC / Collector

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/prims/jvm.cpp:

    event.commit();
  }
JVM_END


JVM_ENTRY_NO_ENV(void, JVM_Halt(jint code))
  before_exit(thread, true);
  vm_exit(code);
JVM_END


JVM_ENTRY_NO_ENV(void, JVM_GC(void))
  if (!DisableExplicitGC) {
    EventSystemGC event;
    event.set_invokedConcurrent(ExplicitGCInvokesConcurrent);
    Universe::heap()->collect(GCCause::_java_lang_system_gc);
    event.commit();
  }
JVM_END


JVM_LEAF(jlong, JVM_MaxObjectInspectionAge(void))
  return Universe::heap()->millis_since_last_whole_heap_examined();
JVM_END

Configuration enabled stackTrace threshold
profiling true true 0 ms
default true true 0 ms

Field Type Description
invokedConcurrent boolean Invoked Concurrent

Examples 3
invokedConcurrent boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
()V
hidden boolean
false
modifiers int
257
name string
gc
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Runtime
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
433417538322
invokedConcurrent boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
()V
hidden boolean
false
modifiers int
257
name string
gc
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Runtime
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
467751551859
invokedConcurrent boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
()V
hidden boolean
false
modifiers int
257
name string
gc
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Runtime
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
333867338992

ParallelOldGarbageCollection

profiling default startTime duration 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Collector

Appearing in: ParallelGC

Missing in: G1GC, SerialGC, ShenandoahGC, ZGC

Extra information specific to Parallel Old Garbage Collections

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    e.set_smallChunksTotalSize(summary.small_chunks_size_in_bytes());

    e.set_mediumChunks(summary.num_medium_chunks());
    e.set_mediumChunksTotalSize(summary.medium_chunks_size_in_bytes());

    e.set_humongousChunks(summary.num_humongous_chunks());
    e.set_humongousChunksTotalSize(summary.humongous_chunks_size_in_bytes());

    e.commit();
  }
}

void ParallelOldTracer::send_parallel_old_event() const {
  EventParallelOldGarbageCollection e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_densePrefix((TraceAddress)_parallel_old_gc_info.dense_prefix());
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

void YoungGCTracer::send_young_gc_event() const {
  EventYoungGarbageCollection e(UNTIMED);

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
densePrefix ulong: address Dense Prefix The address of the dense prefix, used when compacting

Examples 1
densePrefix ulong: address
30363090944
gcId uint
447
startTime long: millis
442987989720

YoungGarbageCollection

profiling default startTime duration 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Collector

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Extra information specific to Young Garbage Collections

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

void ParallelOldTracer::send_parallel_old_event() const {
  EventParallelOldGarbageCollection e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_densePrefix((TraceAddress)_parallel_old_gc_info.dense_prefix());
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

void YoungGCTracer::send_young_gc_event() const {
  EventYoungGarbageCollection e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_tenuringThreshold(_tenuring_threshold);
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

bool YoungGCTracer::should_send_promotion_in_new_plab_event() const {
  return EventPromoteObjectInNewPLAB::is_enabled();

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
tenuringThreshold uint Tenuring Threshold

Examples 3
gcId uint
946
startTime long: millis
454552032606
tenuringThreshold uint
4
gcId uint
964
startTime long: millis
286993070382
tenuringThreshold uint
15
gcId uint
450
startTime long: millis
446259444519
tenuringThreshold uint
15

OldGarbageCollection

profiling default startTime duration 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Collector

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Extra information specific to Old Garbage Collections

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

  EventPromoteObjectOutsidePLAB event;
  if (event.should_commit()) {
    event.set_gcId(GCId::current());
    event.set_objectClass(klass);
    event.set_objectSize(obj_size);
    event.set_tenured(tenured);
    event.set_tenuringAge(age);
    event.commit();
  }
}

void OldGCTracer::send_old_gc_event() const {
  EventOldGarbageCollection e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

static JfrStructCopyFailed to_struct(const CopyFailedInfo& cf_info) {
  JfrStructCopyFailed failed_info;
  failed_info.set_objectCount(cf_info.failed_count());

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier

Examples 3
gcId uint
950
startTime long: millis
455395536529
gcId uint
405
startTime long: millis
384391350143
gcId uint
955
startTime long: millis
282314579961

G1GarbageCollection

profiling default startTime duration 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Collector

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Extra information specific to G1 Young Garbage Collections

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/g1/g1Trace.cpp:

  send_adaptive_ihop_statistics(threshold,
                                internal_target_occupancy,
                                current_occupancy,
                                additional_buffer_size,
                                predicted_allocation_rate,
                                predicted_marking_length,
                                prediction_active);
}

void G1NewTracer::send_g1_young_gc_event() {
  // Check that the pause type has been updated to something valid for this event.
  G1GCPauseTypeHelper::assert_is_young_pause(_pause);

  EventG1GarbageCollection e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_type(static_cast<uint>(_pause));
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

void G1NewTracer::send_evacuation_info_event(G1EvacInfo* info) {
  EventEvacuationInformation e;

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
type G1YCType Type

Examples 1
gcId uint
952
startTime long: millis
282051456955
type G1YCType
Concurrent Start

ZYoungGarbageCollection

profiling default startTime duration eventThread 21 25 26 27

Category: Java Virtual Machine / GC / Collector

Extra information specific to ZGC Young Garbage Collections

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/z/zTracer.cpp:

ZMinorTracer::ZMinorTracer()
  : GCTracer(ZMinor) {}

ZMajorTracer::ZMajorTracer()
  : GCTracer(ZMajor) {}

void ZGenerationTracer::report_start(const Ticks& timestamp) {
  _start = timestamp;
}

void ZYoungTracer::report_end(const Ticks& timestamp) {
  NoSafepointVerifier nsv;

  EventZYoungGarbageCollection e(UNTIMED);
  e.set_gcId(GCId::current());
  e.set_tenuringThreshold(ZGeneration::young()->tenuring_threshold());
  e.set_starttime(_start);
  e.set_endtime(timestamp);
  e.commit();
}

void ZOldTracer::report_end(const Ticks& timestamp) {
  NoSafepointVerifier nsv;

  EventZOldGarbageCollection e(UNTIMED);

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
tenuringThreshold uint Tenuring Threshold

ZOldGarbageCollection

profiling default startTime duration eventThread 21 25 26 27

Category: Java Virtual Machine / GC / Collector

Extra information specific to ZGC Old Garbage Collections

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/z/zTracer.cpp:

  NoSafepointVerifier nsv;

  EventZYoungGarbageCollection e(UNTIMED);
  e.set_gcId(GCId::current());
  e.set_tenuringThreshold(ZGeneration::young()->tenuring_threshold());
  e.set_starttime(_start);
  e.set_endtime(timestamp);
  e.commit();
}

void ZOldTracer::report_end(const Ticks& timestamp) {
  NoSafepointVerifier nsv;

  EventZOldGarbageCollection e(UNTIMED);
  e.set_gcId(GCId::current());
  e.set_starttime(_start);
  e.set_endtime(timestamp);
  e.commit();
}

void ZTracer::initialize() {
  JFR_ONLY(register_jfr_type_serializers();)
}

void ZTracer::send_stat_counter(const ZStatCounter& counter, uint64_t increment, uint64_t value) {

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier

JVM: GC: Configuration

GCConfiguration

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Configuration

The configuration of the garbage collector

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

TRACE_REQUEST_FUNC(G1HeapRegionInformation) {
  G1GC_ONLY(G1HeapRegionEventSender::send_events());
}

// Java Mission Control (JMC) uses (Java) Long.MIN_VALUE to describe that a
// long value is undefined.
static jlong jmc_undefined_long = min_jlong;

TRACE_REQUEST_FUNC(GCConfiguration) {
  GCConfiguration conf;
  jlong pause_target = conf.has_pause_target_default_value() ? jmc_undefined_long : conf.pause_target();
  EventGCConfiguration event;
  event.set_youngCollector(conf.young_collector());
  event.set_oldCollector(conf.old_collector());
  event.set_parallelGCThreads(conf.num_parallel_gc_threads());
  event.set_concurrentGCThreads(conf.num_concurrent_gc_threads());
  event.set_usesDynamicGCThreads(conf.uses_dynamic_gc_threads());
  event.set_isExplicitGCConcurrent(conf.is_explicit_gc_concurrent());
  event.set_isExplicitGCDisabled(conf.is_explicit_gc_disabled());
  event.set_gcTimeRatio(static_cast<unsigned int>(conf.gc_time_ratio()));
  event.set_pauseTarget((s8)pause_target);
  event.commit();
}

Configuration enabled period
profiling true everyChunk
default true everyChunk

Field Type Description
youngCollector GCName Young Garbage Collector The garbage collector used for the young generation
oldCollector GCName Old Garbage Collector The garbage collector used for the old generation
parallelGCThreads uint Parallel GC Threads Number of parallel threads to use for garbage collection
concurrentGCThreads uint Concurrent GC Threads Number of concurrent threads to use for garbage collection
usesDynamicGCThreads boolean Uses Dynamic GC Threads Whether a dynamic number of GC threads are used or not
isExplicitGCConcurrent boolean Concurrent Explicit GC Whether System.gc() is concurrent or not
isExplicitGCDisabled boolean Disabled Explicit GC Whether System.gc() will cause a garbage collection or not
pauseTarget long: millis Pause Target Target for GC pauses
gcTimeRatio uint GC Time Ratio Target for runtime vs garbage collection time

Examples 3
concurrentGCThreads uint
0
gcTimeRatio uint
99
isExplicitGCConcurrent boolean
false
isExplicitGCDisabled boolean
false
oldCollector GCName
SerialOld
parallelGCThreads uint
0
pauseTarget long: millis
-9223372036854775808
startTime long: millis
450717994064
usesDynamicGCThreads boolean
true
youngCollector GCName
DefNew
concurrentGCThreads uint
0
gcTimeRatio uint
99
isExplicitGCConcurrent boolean
false
isExplicitGCDisabled boolean
false
oldCollector GCName
ParallelOld
parallelGCThreads uint
4
pauseTarget long: millis
-9223372036854775808
startTime long: millis
448592107618
usesDynamicGCThreads boolean
true
youngCollector GCName
ParallelScavenge
concurrentGCThreads uint
1
gcTimeRatio uint
12
isExplicitGCConcurrent boolean
false
isExplicitGCDisabled boolean
false
oldCollector GCName
G1Old
parallelGCThreads uint
4
pauseTarget long: millis
-9223372036854775808
startTime long: millis
305057346187
usesDynamicGCThreads boolean
true
youngCollector GCName
G1New

GCSurvivorConfiguration

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Configuration

The configuration of the survivors of garbage collection

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

TRACE_REQUEST_FUNC(GCTLABConfiguration) {
  GCTLABConfiguration conf;
  EventGCTLABConfiguration event;
  event.set_usesTLABs(conf.uses_tlabs());
  event.set_minTLABSize(conf.min_tlab_size());
  event.set_tlabRefillWasteLimit(conf.tlab_refill_waste_limit());
  event.commit();
}

TRACE_REQUEST_FUNC(GCSurvivorConfiguration) {
  GCSurvivorConfiguration conf;
  EventGCSurvivorConfiguration event;
  event.set_maxTenuringThreshold(static_cast<u1>(conf.max_tenuring_threshold()));
  event.set_initialTenuringThreshold(static_cast<u1>(conf.initial_tenuring_threshold()));
  event.commit();
}

TRACE_REQUEST_FUNC(GCHeapConfiguration) {
  GCHeapConfiguration conf;
  EventGCHeapConfiguration event;
  event.set_minSize(conf.min_size());
  event.set_maxSize(conf.max_size());
  event.set_initialSize(conf.initial_size());

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
maxTenuringThreshold ubyte Maximum Tenuring Threshold Upper limit for the age of how old objects to keep in the survivor area
initialTenuringThreshold ubyte Initial Tenuring Threshold Initial age limit for how old objects to keep in survivor area

Examples 3
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
299932217028
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
388495624442
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
467801453428

GCTLABConfiguration

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Configuration

The configuration of the Thread Local Allocation Buffers (TLABs)

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.set_oldCollector(conf.old_collector());
  event.set_parallelGCThreads(conf.num_parallel_gc_threads());
  event.set_concurrentGCThreads(conf.num_concurrent_gc_threads());
  event.set_usesDynamicGCThreads(conf.uses_dynamic_gc_threads());
  event.set_isExplicitGCConcurrent(conf.is_explicit_gc_concurrent());
  event.set_isExplicitGCDisabled(conf.is_explicit_gc_disabled());
  event.set_gcTimeRatio(static_cast<unsigned int>(conf.gc_time_ratio()));
  event.set_pauseTarget((s8)pause_target);
  event.commit();
}

TRACE_REQUEST_FUNC(GCTLABConfiguration) {
  GCTLABConfiguration conf;
  EventGCTLABConfiguration event;
  event.set_usesTLABs(conf.uses_tlabs());
  event.set_minTLABSize(conf.min_tlab_size());
  event.set_tlabRefillWasteLimit(conf.tlab_refill_waste_limit());
  event.commit();
}

TRACE_REQUEST_FUNC(GCSurvivorConfiguration) {
  GCSurvivorConfiguration conf;
  EventGCSurvivorConfiguration event;
  event.set_maxTenuringThreshold(static_cast<u1>(conf.max_tenuring_threshold()));
  event.set_initialTenuringThreshold(static_cast<u1>(conf.initial_tenuring_threshold()));

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
usesTLABs boolean TLABs Used If Thread Local Allocation Buffers (TLABs) are in use
minTLABSize ulong: bytes Minimum TLAB Size
tlabRefillWasteLimit ulong: bytes TLAB Refill Waste Limit

Examples 3
minTLABSize ulong: bytes
2048
startTime long: millis
443487066770
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true
minTLABSize ulong: bytes
2048
startTime long: millis
451294344139
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true
minTLABSize ulong: bytes
2048
startTime long: millis
285352591732
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true

GCHeapConfiguration

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Configuration

The configuration of the garbage collected heap

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.commit();
}

TRACE_REQUEST_FUNC(GCSurvivorConfiguration) {
  GCSurvivorConfiguration conf;
  EventGCSurvivorConfiguration event;
  event.set_maxTenuringThreshold(static_cast<u1>(conf.max_tenuring_threshold()));
  event.set_initialTenuringThreshold(static_cast<u1>(conf.initial_tenuring_threshold()));
  event.commit();
}

TRACE_REQUEST_FUNC(GCHeapConfiguration) {
  GCHeapConfiguration conf;
  EventGCHeapConfiguration event;
  event.set_minSize(conf.min_size());
  event.set_maxSize(conf.max_size());
  event.set_initialSize(conf.initial_size());
  event.set_usesCompressedOops(conf.uses_compressed_oops());
  event.set_compressedOopsMode(conf.narrow_oop_mode());
  event.set_objectAlignment(conf.object_alignment_in_bytes());
  event.set_heapAddressBits(static_cast<u1>(conf.heap_address_size_in_bits()));
  event.commit();
}

TRACE_REQUEST_FUNC(YoungGenerationConfiguration) {

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
minSize ulong: bytes Minimum Heap Size
maxSize ulong: bytes Maximum Heap Size
initialSize ulong: bytes Initial Heap Size
usesCompressedOops boolean If Compressed Oops Are Used If compressed Oops (Ordinary Object Pointers) are enabled
compressedOopsMode NarrowOopMode Compressed Oops Mode The kind of compressed oops being used
objectAlignment ulong: bytes Object Alignment Object alignment (in bytes) on the heap
heapAddressBits ubyte Heap Address Size Heap Address Size (in bits)

Examples 3
compressedOopsMode NarrowOopMode
Zero based
heapAddressBits ubyte
32
initialSize ulong: bytes
262144000
maxSize ulong: bytes
4194304000
minSize ulong: bytes
8388608
objectAlignment ulong: bytes
8
startTime long: millis
380959125706
usesCompressedOops boolean
true
compressedOopsMode NarrowOopMode
Zero based
heapAddressBits ubyte
32
initialSize ulong: bytes
262144000
maxSize ulong: bytes
4194304000
minSize ulong: bytes
8388608
objectAlignment ulong: bytes
8
startTime long: millis
304082783755
usesCompressedOops boolean
true
compressedOopsMode NarrowOopMode
Zero based
heapAddressBits ubyte
32
initialSize ulong: bytes
262144000
maxSize ulong: bytes
4194304000
minSize ulong: bytes
8388608
objectAlignment ulong: bytes
8
startTime long: millis
422343700127
usesCompressedOops boolean
true

YoungGenerationConfiguration

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Configuration

The configuration of the young generation of the garbage collected heap

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.set_minSize(conf.min_size());
  event.set_maxSize(conf.max_size());
  event.set_initialSize(conf.initial_size());
  event.set_usesCompressedOops(conf.uses_compressed_oops());
  event.set_compressedOopsMode(conf.narrow_oop_mode());
  event.set_objectAlignment(conf.object_alignment_in_bytes());
  event.set_heapAddressBits(static_cast<u1>(conf.heap_address_size_in_bits()));
  event.commit();
}

TRACE_REQUEST_FUNC(YoungGenerationConfiguration) {
  GCYoungGenerationConfiguration conf;
  jlong max_size = conf.has_max_size_default_value() ? jmc_undefined_long : conf.max_size();
  EventYoungGenerationConfiguration event;
  event.set_maxSize((u8)max_size);
  event.set_minSize(conf.min_size());
  event.set_newRatio(static_cast<unsigned int>(conf.new_ratio()));
  event.commit();
}

TRACE_REQUEST_FUNC(InitialSystemProperty) {
  SystemProperty* p = Arguments::system_properties();
  JfrTicks time_stamp = JfrTicks::now();
  while (p !=  nullptr) {
    if (!p->internal()) {

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
minSize ulong: bytes Minimum Young Generation Size
maxSize ulong: bytes Maximum Young Generation Size
newRatio uint New Ratio The size of the young generation relative to the tenured generation

Examples 3
maxSize ulong: bytes
2516582400
minSize ulong: bytes
1363144
newRatio uint
2
startTime long: millis
286626497451
maxSize ulong: bytes
1398079488
minSize ulong: bytes
87359488
newRatio uint
2
startTime long: millis
451294346944
maxSize ulong: bytes
1397751808
minSize ulong: bytes
87031808
newRatio uint
2
startTime long: millis
386180308234

JVM: GC: Detailed

ZThreadDebug

internal startTime duration eventThread 18 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Temporary latency measurements used during development and debugging of ZGC

Only valid for the ZGC.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/z/zTracer.inline.hpp:

inline void ZTracer::report_stat_sampler(const ZStatSampler& sampler, uint64_t value) {
  if (EventZStatisticsSampler::is_enabled()) {
    send_stat_sampler(sampler, value);
  }
}

inline void ZTracer::report_thread_phase(const char* name, const Ticks& start, const Ticks& end) {
  if (EventZThreadPhase::is_enabled()) {
    send_thread_phase(name, start, end);
  }
}

inline void ZTracer::report_thread_debug(const char* name, const Ticks& start, const Ticks& end) {
  if (EventZThreadDebug::is_enabled()) {
    send_thread_debug(name, start, end);
  }
}

inline ZTraceThreadDebug::ZTraceThreadDebug(const char* name)
  : _start(Ticks::now()),
    _name(name) {}

inline ZTraceThreadDebug::~ZTraceThreadDebug() {
  ZTracer::report_thread_debug(_name, _start, Ticks::now());
}

src/hotspot/share/gc/z/zTracer.cpp:

  NoSafepointVerifier nsv;

  EventZThreadPhase e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current_or_undefined());
    e.set_name(name);
    e.set_starttime(start);
    e.set_endtime(end);
    e.commit();
  }
}

void ZTracer::send_thread_debug(const char* name, const Ticks& start, const Ticks& end) {
  NoSafepointVerifier nsv;

  EventZThreadDebug e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current_or_undefined());
    e.set_name(name);
    e.set_starttime(start);
    e.set_endtime(end);
    e.commit();
  }
}

Field Type Description
gcId uint GC Identifier
name string Name The name of the GC runner

G1MMU

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/g1/g1Trace.cpp:

void G1OldTracer::report_gc_start_impl(GCCause::Cause cause, const Ticks& timestamp) {
  _shared_gc_info.set_start_timestamp(timestamp);
}

void G1OldTracer::set_gc_cause(GCCause::Cause cause) {
  _shared_gc_info.set_cause(cause);
}

void G1MMUTracer::report_mmu(double time_slice_sec, double gc_time_sec, double max_time_sec) {
  send_g1_mmu_event(time_slice_sec * MILLIUNITS,
                    gc_time_sec * MILLIUNITS,
                    max_time_sec * MILLIUNITS);
}

void G1MMUTracer::send_g1_mmu_event(double time_slice_ms, double gc_time_ms, double max_time_ms) {
  EventG1MMU e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_timeSlice(time_slice_ms);
    e.set_gcTime(gc_time_ms);
    e.set_pauseTarget(max_time_ms);
    e.commit();
  }
}

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier
timeSlice long: millis Time Slice Time slice used to calculate MMU
gcTime long: millis GC Time Time stopped because of GC during last time slice
pauseTarget long: millis Pause Target Max time allowed to be spent on GC during last time slice

Examples 1
gcId uint
1001
gcTime long: millis
5
pauseTarget long: millis
200
startTime long: millis
308186886622
timeSlice long: millis
201

EvacuationInformation

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/g1/g1Trace.cpp:

  G1GCPauseTypeHelper::assert_is_young_pause(_pause);

  EventG1GarbageCollection e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_type(static_cast<uint>(_pause));
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

void G1NewTracer::send_evacuation_info_event(G1EvacInfo* info) {
  EventEvacuationInformation e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_cSetRegions(info->collection_set_regions());
    e.set_cSetUsedBefore(info->collection_set_used_before());
    e.set_cSetUsedAfter(info->collection_set_used_after());
    e.set_allocationRegions(info->allocation_regions());
    e.set_allocationRegionsUsedBefore(info->alloc_regions_used_before());
    e.set_allocationRegionsUsedAfter(info->alloc_regions_used_before() + info->bytes_used());
    e.set_bytesCopied(info->bytes_used());
    e.set_regionsFreed(info->regions_freed());
    e.commit();

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier
cSetRegions uint Collection Set Regions
cSetUsedBefore ulong: bytes Collection Set Before Memory usage before GC in the collection set regions
cSetUsedAfter ulong: bytes Collection Set After Memory usage after GC in the collection set regions
allocationRegions uint Allocation Regions Regions chosen as allocation regions during evacuation (includes survivors and old space regions)
allocationRegionsUsedBefore ulong: bytes Allocation Regions Before Memory usage before GC in allocation regions
allocationRegionsUsedAfter ulong: bytes Allocation Regions After Memory usage after GC in allocation regions
bytesCopied ulong: bytes Bytes Copied
regionsFreed uint Regions Freed

Examples 1
allocationRegions uint
4
allocationRegionsUsedAfter ulong: bytes
4675744
allocationRegionsUsedBefore ulong: bytes
285080
bytesCopied ulong: bytes
4390664
cSetRegions uint
33
cSetUsedAfter ulong: bytes
0
cSetUsedBefore ulong: bytes
66367680
gcId uint
1065
regionsFreed uint
33
startTime long: millis
337767036058

ObjectCountAfterGC

startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/objectCountEventSender.cpp:

#if INCLUDE_SERVICES

bool ObjectCountEventSender::should_send_event() {
#if INCLUDE_JFR
  return _should_send_requestable_event || EventObjectCountAfterGC::is_enabled();
#else
  return false;
#endif // INCLUDE_JFR
}

bool ObjectCountEventSender::_should_send_requestable_event = false;

void ObjectCountEventSender::enable_requestable_event() {
  _should_send_requestable_event = true;
}

void ObjectCountEventSender::disable_requestable_event() {

src/hotspot/share/gc/shared/objectCountEventSender.cpp:

template <typename T>
void ObjectCountEventSender::send_event_if_enabled(Klass* klass, jlong count, julong size, const Ticks& timestamp) {
  T event(UNTIMED);
  if (event.should_commit()) {
    event.set_starttime(timestamp);
    event.set_endtime(timestamp);
    event.set_gcId(GCId::current());
    event.set_objectClass(klass);
    event.set_count(count);
    event.set_totalSize(size);
    event.commit();
  }
}

void ObjectCountEventSender::send(const KlassInfoEntry* entry, const Ticks& timestamp) {
  Klass* klass = entry->klass();
  jlong count = entry->count();
  julong total_size = entry->words() * BytesPerWord;

  send_event_if_enabled<EventObjectCount>(klass, count, total_size, timestamp);
  send_event_if_enabled<EventObjectCountAfterGC>(klass, count, total_size, timestamp);
}

#endif // INCLUDE_SERVICES

Configuration enabled
profiling false
default false

Field Type Description
gcId uint GC Identifier
objectClass Class Object Class
count long Count
totalSize ulong: bytes Total Size

Examples 3
count long
23221
gcId uint
403
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1040
name string
[Ljava/util/HashMap$Node;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util
startTime long: millis
383295230229
totalSize ulong: bytes
1851088
count long
3619
gcId uint
878
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1040
name string
[Ljava/util/concurrent/ConcurrentHashMap$Node;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent
startTime long: millis
388387486248
totalSize ulong: bytes
28061640
count long
45447
gcId uint
946
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
8
name string
java/util/LinkedHashMap$Entry
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util
startTime long: millis
279741338458
totalSize ulong: bytes
1817880

G1EvacuationYoungStatistics

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Memory related evacuation statistics during GC for the young generation

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/g1/g1Trace.cpp:

  s.set_allocated(summary.allocated() * HeapWordSize);
  s.set_wasted(summary.wasted() * HeapWordSize);
  s.set_used(summary.used() * HeapWordSize);
  s.set_undoWaste(summary.undo_wasted() * HeapWordSize);
  s.set_regionEndWaste(summary.region_end_waste() * HeapWordSize);
  s.set_regionsRefilled(summary.regions_filled());
  s.set_directAllocated(summary.direct_allocated() * HeapWordSize);
  s.set_failureUsed(summary.failure_used() * HeapWordSize);
  s.set_failureWaste(summary.failure_waste() * HeapWordSize);
  return s;
}

void G1NewTracer::send_young_evacuation_statistics(const G1EvacSummary& summary) const {
  EventG1EvacuationYoungStatistics surv_evt;
  if (surv_evt.should_commit()) {
    surv_evt.set_statistics(create_g1_evacstats(GCId::current(), summary));
    surv_evt.commit();
  }
}

void G1NewTracer::send_old_evacuation_statistics(const G1EvacSummary& summary) const {
  EventG1EvacuationOldStatistics old_evt;
  if (old_evt.should_commit()) {
    old_evt.set_statistics(create_g1_evacstats(GCId::current(), summary));
    old_evt.commit();

Configuration enabled
profiling true
default true

Field Type Description
statistics G1EvacuationStatistics struct Evacuation Statistics

Examples 1
startTime long: millis
282048995661
statistics G1EvacuationStatistics
allocated ulong: bytes
460576
directAllocated ulong: bytes
0
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
950
numDirectAllocated ulong
0
numPlabsFilled ulong
0
regionEndWaste ulong: bytes
0
regionsRefilled uint
1
undoWaste ulong: bytes
0
used ulong: bytes
127272
wasted ulong: bytes
0

G1EvacuationOldStatistics

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Memory related evacuation statistics during GC for the old generation

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/g1/g1Trace.cpp:

  s.set_failureWaste(summary.failure_waste() * HeapWordSize);
  return s;
}

void G1NewTracer::send_young_evacuation_statistics(const G1EvacSummary& summary) const {
  EventG1EvacuationYoungStatistics surv_evt;
  if (surv_evt.should_commit()) {
    surv_evt.set_statistics(create_g1_evacstats(GCId::current(), summary));
    surv_evt.commit();
  }
}

void G1NewTracer::send_old_evacuation_statistics(const G1EvacSummary& summary) const {
  EventG1EvacuationOldStatistics old_evt;
  if (old_evt.should_commit()) {
    old_evt.set_statistics(create_g1_evacstats(GCId::current(), summary));
    old_evt.commit();
  }
}

void G1NewTracer::send_basic_ihop_statistics(size_t threshold,
                                             size_t target_occupancy,
                                             size_t non_young_occupancy,
                                             size_t last_allocation_size,
                                             double last_allocation_duration,

Configuration enabled
profiling true
default true

Field Type Description
statistics G1EvacuationStatistics struct Evacuation Statistics

Examples 1
startTime long: millis
341444886044
statistics G1EvacuationStatistics
allocated ulong: bytes
924672
directAllocated ulong: bytes
188272
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
1078
numDirectAllocated ulong
0
numPlabsFilled ulong
0
regionEndWaste ulong: bytes
0
regionsRefilled uint
1
undoWaste ulong: bytes
0
used ulong: bytes
884536
wasted ulong: bytes
4552

G1BasicIHOP

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Basic statistics related to current IHOP calculation

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/g1/g1Trace.cpp:

  EventG1EvacuationOldStatistics old_evt;
  if (old_evt.should_commit()) {
    old_evt.set_statistics(create_g1_evacstats(GCId::current(), summary));
    old_evt.commit();
  }
}

void G1NewTracer::send_basic_ihop_statistics(size_t threshold,
                                             size_t target_occupancy,
                                             size_t non_young_occupancy,
                                             size_t last_allocation_size,
                                             double last_allocation_duration,
                                             double last_marking_length) {
  EventG1BasicIHOP evt;
  if (evt.should_commit()) {
    evt.set_gcId(GCId::current());
    evt.set_threshold(threshold);
    evt.set_targetOccupancy(target_occupancy);
    evt.set_thresholdPercentage(target_occupancy > 0 ? ((double)threshold / target_occupancy) : 0.0);
    evt.set_currentOccupancy(non_young_occupancy);
    evt.set_recentMutatorAllocationSize(last_allocation_size);
    evt.set_recentMutatorDuration(last_allocation_duration * MILLIUNITS);
    evt.set_recentAllocationRate(last_allocation_duration != 0.0 ? last_allocation_size / last_allocation_duration : 0.0);
    evt.set_lastMarkingDuration(last_marking_length * MILLIUNITS);
    evt.commit();

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier
threshold ulong: bytes Current IHOP Threshold Current IHOP threshold
thresholdPercentage float: percentage Current IHOP Threshold Current IHOP threshold in percent of old generation
targetOccupancy ulong: bytes Target Occupancy Target old generation occupancy to reach at the start of mixed GC
currentOccupancy ulong: bytes Current Occupancy Current old generation occupancy
recentMutatorAllocationSize ulong: bytes Recent Mutator Allocation Size Mutator allocation during mutator operation in the most recent interval
recentMutatorDuration long: millis Recent Mutator Duration Time the mutator ran in the most recent interval
recentAllocationRate double: bytes-per-second Recent Allocation Rate Allocation rate of the mutator in the most recent interval in bytes/second
lastMarkingDuration long: millis Last Marking Duration Last time from the end of the last concurrent start to the first mixed GC

Examples 1
currentOccupancy ulong: bytes
243444456
gcId uint
1025
lastMarkingDuration long: millis
613
recentAllocationRate double: bytes-per-second
0.0
recentMutatorAllocationSize ulong: bytes
0
recentMutatorDuration long: millis
194
startTime long: millis
314910600653
targetOccupancy ulong: bytes
811597824
threshold ulong: bytes
40234605
thresholdPercentage float: percentage
0.04957456

G1AdaptiveIHOP

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Statistics related to current adaptive IHOP calculation

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/g1/g1Trace.cpp:

    evt.set_recentAllocationRate(last_allocation_duration != 0.0 ? last_allocation_size / last_allocation_duration : 0.0);
    evt.set_lastMarkingDuration(last_marking_length * MILLIUNITS);
    evt.commit();
  }
}

void G1NewTracer::send_adaptive_ihop_statistics(size_t threshold,
                                                size_t internal_target_occupancy,
                                                size_t current_occupancy,
                                                size_t additional_buffer_size,
                                                double predicted_allocation_rate,
                                                double predicted_marking_length,
                                                bool prediction_active) {
  EventG1AdaptiveIHOP evt;
  if (evt.should_commit()) {
    evt.set_gcId(GCId::current());
    evt.set_threshold(threshold);
    evt.set_thresholdPercentage(internal_target_occupancy > 0 ? ((double)threshold / internal_target_occupancy) : 0.0);
    evt.set_ihopTargetOccupancy(internal_target_occupancy);
    evt.set_currentOccupancy(current_occupancy);
    evt.set_additionalBufferSize(additional_buffer_size);
    evt.set_predictedAllocationRate(predicted_allocation_rate);
    evt.set_predictedMarkingDuration(predicted_marking_length * MILLIUNITS);
    evt.set_predictionActive(prediction_active);
    evt.commit();

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier
threshold ulong: bytes Threshold Current IHOP Threshold
thresholdPercentage float: percentage Threshold Current IHOP threshold in percent of the internal target occupancy
ihopTargetOccupancy ulong: bytes IHOP Target Occupancy Internal target old generation occupancy to reach at the start of mixed GC
currentOccupancy ulong: bytes Current Occupancy Current old generation occupancy
additionalBufferSize ulong: bytes Additional Buffer Additional buffer size
predictedAllocationRate double: bytes-per-second Predicted Allocation Rate Current predicted allocation rate for the mutator in bytes/second
predictedMarkingDuration long: millis Predicted Marking Duration Current predicted time from the end of the last concurrent start to the first mixed GC
predictionActive boolean Prediction Active Indicates whether the adaptive IHOP prediction is active

Examples 1
additionalBufferSize ulong: bytes
528482304
currentOccupancy ulong: bytes
272750256
gcId uint
1098
ihopTargetOccupancy ulong: bytes
836763648
predictedAllocationRate double: bytes-per-second
2.4814065956924498E8
predictedMarkingDuration long: millis
1434
predictionActive boolean
true
startTime long: millis
364412101315
threshold ulong: bytes
0
thresholdPercentage float: percentage
0.0

PromoteObjectInNewPLAB

profiling startTime eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

Object survived scavenge and was copied to a new Promotion Local Allocation Buffer (PLAB). Supported GCs are Parallel Scavenge, G1 and CMS with Parallel New. Due to promotion being done in parallel an object might be reported multiple times as the GC threads race to copy all objects.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

void YoungGCTracer::send_young_gc_event() const {
  EventYoungGarbageCollection e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_tenuringThreshold(_tenuring_threshold);
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

bool YoungGCTracer::should_send_promotion_in_new_plab_event() const {
  return EventPromoteObjectInNewPLAB::is_enabled();
}

bool YoungGCTracer::should_send_promotion_outside_plab_event() const {
  return EventPromoteObjectOutsidePLAB::is_enabled();
}

void YoungGCTracer::send_promotion_in_new_plab_event(Klass* klass, size_t obj_size,
                                                     uint age, bool tenured,
                                                     size_t plab_size) const {

  EventPromoteObjectInNewPLAB event;
  if (event.should_commit()) {
    event.set_gcId(GCId::current());
    event.set_objectClass(klass);
    event.set_objectSize(obj_size);
    event.set_tenured(tenured);
    event.set_tenuringAge(age);
    event.set_plabSize(plab_size);
    event.commit();
  }
}

Configuration enabled
profiling true
default false

Field Type Description
gcId uint GC Identifier Identifier signifying GC during which the object was promoted
objectClass Class Object Class Class of promoted object
objectSize ulong: bytes Object Size Size of promoted object
tenuringAge uint Object Tenuring Age Tenuring age of a surviving object before being copied. The tenuring age of an object is a value between 0-15 and is incremented each scavenge the object survives. Newly allocated objects have tenuring age 0.
tenured boolean Tenured True if object was promoted to Old space, otherwise the object was aged and copied to a Survivor space
plabSize ulong: bytes PLAB Size Size of the allocated PLAB to which the object was copied

Examples 2
gcId uint
394
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[F
package Package
null
objectSize ulong: bytes
56
plabSize ulong: bytes
32752
startTime long: millis
371365204733
tenured boolean
false
tenuringAge uint
0
gcId uint
941
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[F
package Package
null
objectSize ulong: bytes
56
plabSize ulong: bytes
19048
startTime long: millis
278158221654
tenured boolean
false
tenuringAge uint
0

PromoteObjectOutsidePLAB

profiling startTime eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

Object survived scavenge and was copied directly to the heap. Supported GCs are Parallel Scavenge, G1 and CMS with Parallel New. Due to promotion being done in parallel an object might be reported multiple times as the GC threads race to copy all objects.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    e.set_gcId(GCId::current());
    e.set_tenuringThreshold(_tenuring_threshold);
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

bool YoungGCTracer::should_send_promotion_in_new_plab_event() const {
  return EventPromoteObjectInNewPLAB::is_enabled();
}

bool YoungGCTracer::should_send_promotion_outside_plab_event() const {
  return EventPromoteObjectOutsidePLAB::is_enabled();
}

void YoungGCTracer::send_promotion_in_new_plab_event(Klass* klass, size_t obj_size,
                                                     uint age, bool tenured,
                                                     size_t plab_size) const {

  EventPromoteObjectInNewPLAB event;
  if (event.should_commit()) {
    event.set_gcId(GCId::current());
    event.set_objectClass(klass);
    event.set_objectSize(obj_size);
    event.set_tenured(tenured);
    event.set_tenuringAge(age);
    event.set_plabSize(plab_size);
    event.commit();
  }
}

void YoungGCTracer::send_promotion_outside_plab_event(Klass* klass, size_t obj_size,
                                                      uint age, bool tenured) const {

  EventPromoteObjectOutsidePLAB event;
  if (event.should_commit()) {
    event.set_gcId(GCId::current());
    event.set_objectClass(klass);
    event.set_objectSize(obj_size);
    event.set_tenured(tenured);
    event.set_tenuringAge(age);
    event.commit();
  }
}

void OldGCTracer::send_old_gc_event() const {

Configuration enabled
profiling true
default false

Field Type Description
gcId uint GC Identifier Identifier signifying GC during which the object was promoted
objectClass Class Object Class Class of promoted object
objectSize ulong: bytes Object Size Size of promoted object
tenuringAge uint Object Tenuring Age Tenuring age of a surviving object before being copied. The tenuring age of an object is a value between 0-15 and is incremented each scavenge the object survives. Newly allocated objects have tenuring age 0.
tenured boolean Tenured True if object was promoted to Old space, otherwise the object was aged and copied to a Survivor space

Examples 2
gcId uint
989
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[B
package Package
null
objectSize ulong: bytes
32784
startTime long: millis
303894524313
tenured boolean
false
tenuringAge uint
0
gcId uint
414
objectClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1041
name string
[Lorg/apache/spark/unsafe/memory/MemoryBlock;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/unsafe/memory
objectSize ulong: bytes
32784
startTime long: millis
398118964111
tenured boolean
false
tenuringAge uint
0

PromotionFailed

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Promotion of an object failed

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

static JfrStructCopyFailed to_struct(const CopyFailedInfo& cf_info) {
  JfrStructCopyFailed failed_info;
  failed_info.set_objectCount(cf_info.failed_count());
  failed_info.set_firstSize(cf_info.first_size() * HeapWordSize);
  failed_info.set_smallestSize(cf_info.smallest_size() * HeapWordSize);
  failed_info.set_totalSize(cf_info.total_size() * HeapWordSize);
  return failed_info;
}

void YoungGCTracer::send_promotion_failed_event(const PromotionFailedInfo& pf_info) const {
  EventPromotionFailed e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_promotionFailed(to_struct(pf_info));
    e.set_thread(pf_info.thread_trace_id());
    e.commit();
  }
}

// G1
void OldGCTracer::send_concurrent_mode_failure_event() {
  EventConcurrentModeFailure e;

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier
promotionFailed CopyFailed struct Promotion Failed Data
thread Thread Running Thread

EvacuationFailed

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Evacuation of an object failed

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/g1/g1Trace.cpp:

    e.set_cSetRegions(info->collection_set_regions());
    e.set_cSetUsedBefore(info->collection_set_used_before());
    e.set_cSetUsedAfter(info->collection_set_used_after());
    e.set_allocationRegions(info->allocation_regions());
    e.set_allocationRegionsUsedBefore(info->alloc_regions_used_before());
    e.set_allocationRegionsUsedAfter(info->alloc_regions_used_before() + info->bytes_used());
    e.set_bytesCopied(info->bytes_used());
    e.set_regionsFreed(info->regions_freed());
    e.commit();
  }
}

void G1NewTracer::send_evacuation_failed_event(const EvacuationFailedInfo& ef_info) const {
  EventEvacuationFailed e;
  if (e.should_commit()) {
    // Create JFR structured failure data
    JfrStructCopyFailed evac_failed;
    evac_failed.set_objectCount(ef_info.failed_count());
    evac_failed.set_firstSize(ef_info.first_size() * HeapWordSize);
    evac_failed.set_smallestSize(ef_info.smallest_size() * HeapWordSize);
    evac_failed.set_totalSize(ef_info.total_size() * HeapWordSize);
    // Add to the event
    e.set_gcId(GCId::current());
    e.set_evacuationFailed(evac_failed);
    e.commit();

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier
evacuationFailed CopyFailed struct Evacuation Failed Data

ConcurrentModeFailure

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Concurrent Mode failed

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

void YoungGCTracer::send_promotion_failed_event(const PromotionFailedInfo& pf_info) const {
  EventPromotionFailed e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_promotionFailed(to_struct(pf_info));
    e.set_thread(pf_info.thread_trace_id());
    e.commit();
  }
}

// G1
void OldGCTracer::send_concurrent_mode_failure_event() {
  EventConcurrentModeFailure e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.commit();
  }
}

static JfrStructVirtualSpace to_struct(const VirtualSpaceSummary& summary) {
  JfrStructVirtualSpace space;
  space.set_start((TraceAddress)summary.start());
  space.set_committedEnd((TraceAddress)summary.committed_end());
  space.set_committedSize(summary.committed_size());

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier

Examples 1
gcId uint
1052
startTime long: millis
331300549971

GCCPUTime

profiling default startTime 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

GC CPU Time information. Supported: G1GC, ParallelGC and SerialGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

// All GC dependencies against the trace framework is contained within this file.

typedef uintptr_t TraceAddress;

bool GCTracer::should_send_cpu_time_event() const {
  return EventGCCPUTime::is_enabled();
}

void GCTracer::send_garbage_collection_event() const {
  EventGarbageCollection event(UNTIMED);
  if (event.should_commit()) {
    event.set_gcId(GCId::current());
    event.set_name(_shared_gc_info.name());
    event.set_cause((u2) _shared_gc_info.cause());
    event.set_sumOfPauses(_shared_gc_info.sum_of_pauses());
    event.set_longestPause(_shared_gc_info.longest_pause());
    event.set_starttime(_shared_gc_info.start_timestamp());
    event.set_endtime(_shared_gc_info.end_timestamp());
    event.commit();
  }
}

void GCTracer::send_cpu_time_event(double user_time, double system_time, double real_time) const {
  EventGCCPUTime e;
  if (e.should_commit()) {
      e.set_gcId(GCId::current());
      e.set_userTime((size_t)(user_time * NANOUNITS));
      e.set_systemTime((size_t)(system_time * NANOUNITS));
      e.set_realTime((size_t)(real_time * NANOUNITS));
      e.commit();
  }
}

void GCTracer::send_reference_stats_event(ReferenceType type, size_t count) const {
  EventGCReferenceStatistics e;

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier
userTime ulong: nanos User Time
systemTime ulong: nanos System Time
realTime ulong: nanos Real Time

Examples 3
gcId uint
1035
realTime ulong: nanos
59999999
startTime long: millis
324737051543
systemTime ulong: nanos
0
userTime ulong: nanos
199999999
gcId uint
481
realTime ulong: nanos
310000000
startTime long: millis
467523508399
systemTime ulong: nanos
10000000
userTime ulong: nanos
1029999999
gcId uint
932
realTime ulong: nanos
0
startTime long: millis
451447161068
systemTime ulong: nanos
0
userTime ulong: nanos
9999999

AllocationRequiringGC

startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/allocTracer.cpp:

    event.set_allocationSize(alloc_size);
    event.commit();
  }
}

void AllocTracer::send_allocation_in_new_tlab(Klass* klass, HeapWord* obj, size_t tlab_size, size_t alloc_size, JavaThread* thread) {
  JFR_ONLY(JfrAllocationTracer tracer(klass, obj, alloc_size, false, thread);)
  EventObjectAllocationInNewTLAB event;
  if (event.should_commit()) {
    event.set_objectClass(klass);
    event.set_allocationSize(alloc_size);
    event.set_tlabSize(tlab_size);
    event.commit();
  }
}

void AllocTracer::send_allocation_requiring_gc_event(size_t size, uint gcId) {
  EventAllocationRequiringGC event;
  if (event.should_commit()) {
    event.set_gcId(gcId);
    event.set_size(size);
    event.commit();
  }
}

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
gcId uint Pending GC Identifier
size ulong: bytes Allocation Size

Examples 3
gcId uint
438
size ulong: bytes
32
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
180
method Method
descriptor string
()Ljava/util/stream/ReduceOps$3ReducingSink;
hidden boolean
false
modifiers int
1
name string
makeSink
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/util/stream/ReduceOps$3
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/stream
type FrameType
Inlined
truncated boolean
true
startTime long: millis
436011343220
gcId uint
1010
size ulong: bytes
1048576
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
27
lineNumber int
177
method Method
descriptor string
(Ljava/util/stream/Collector;)Ljava/util/stream/TerminalOp;
hidden boolean
false
modifiers int
9
name string
makeRef
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
16
name string
java/util/stream/ReduceOps
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/stream
type FrameType
Inlined
truncated boolean
true
startTime long: millis
311855882722
gcId uint
1006
size ulong: bytes
24
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
90
method Method
descriptor string
(Lcom/twitter/finagle/Service;)Lcom/twitter/finagle/Service;
hidden boolean
false
modifiers int
1
name string
com$twitter$finagle$Filter$$andThenService
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1025
name string
com/twitter/finagle/Filter
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
com/twitter/finagle
type FrameType
Inlined
truncated boolean
true
startTime long: millis
493212455943

TenuringDistribution

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, SerialGC

Missing in: ParallelGC, ShenandoahGC, ZGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/ageTableTracer.cpp:

void AgeTableTracer::send_tenuring_distribution_event(uint age, size_t size) {
  EventTenuringDistribution e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_age(age);
    e.set_size(size);
    e.commit();
  }
}

bool AgeTableTracer::is_tenuring_distribution_event_enabled() {
  return EventTenuringDistribution::is_enabled();
}

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier
age uint Age
size ulong: bytes Size

Examples 2
age uint
2
gcId uint
899
size ulong: bytes
4206528
startTime long: millis
439838578802
age uint
7
gcId uint
946
size ulong: bytes
0
startTime long: millis
279786614948

G1HeapRegionTypeChange

startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Information about a G1 heap region type change

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/g1/g1HeapRegionTracer.cpp:

void G1HeapRegionTracer::send_region_type_change(uint index,
                                               G1HeapRegionTraceType::Type from,
                                               G1HeapRegionTraceType::Type to,
                                               uintptr_t start,
                                               size_t used) {
  EventG1HeapRegionTypeChange e;
  if (e.should_commit()) {
    e.set_index(index);
    e.set_from(from);
    e.set_to(to);
    e.set_start(start);
    e.set_used(used);
    e.commit();
  }
}

Configuration enabled
profiling false
default false

Field Type Description
index uint Index
from G1HeapRegionType From
to G1HeapRegionType To
start ulong: address Start
used ulong: bytes Used

Examples 1
from G1HeapRegionType
Free
index uint
138
start ulong: address
30454841344
startTime long: millis
278331333005
to G1HeapRegionType
Free
used ulong: bytes
0

ObjectCount

startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/objectCountEventSender.cpp:

template <typename T>
void ObjectCountEventSender::send_event_if_enabled(Klass* klass, jlong count, julong size, const Ticks& timestamp) {
  T event(UNTIMED);
  if (event.should_commit()) {
    event.set_starttime(timestamp);
    event.set_endtime(timestamp);
    event.set_gcId(GCId::current());
    event.set_objectClass(klass);
    event.set_count(count);
    event.set_totalSize(size);
    event.commit();
  }
}

void ObjectCountEventSender::send(const KlassInfoEntry* entry, const Ticks& timestamp) {
  Klass* klass = entry->klass();
  jlong count = entry->count();
  julong total_size = entry->words() * BytesPerWord;

  send_event_if_enabled<EventObjectCount>(klass, count, total_size, timestamp);
  send_event_if_enabled<EventObjectCountAfterGC>(klass, count, total_size, timestamp);
}

#endif // INCLUDE_SERVICES

Configuration enabled period
profiling false everyChunk
default false everyChunk

Field Type Description
gcId uint GC Identifier
objectClass Class Object Class
count long Count
totalSize ulong: bytes Total Size

Examples 3
count long
82469
gcId uint
945
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
8
name string
java/util/HashMap$Node
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util
startTime long: millis
278996931583
totalSize ulong: bytes
2639008
count long
62120
gcId uint
877
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/reflect/Method
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang/reflect
startTime long: millis
382574691462
totalSize ulong: bytes
5466560
count long
78167
gcId uint
401
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
8
name string
java/util/HashMap$Node
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util
startTime long: millis
381914241558
totalSize ulong: bytes
2501344

G1HeapRegionInformation

startTime duration every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Information about a specific heap region in the G1 GC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/g1/g1HeapRegionEventSender.cpp:

class DumpEventInfoClosure : public G1HeapRegionClosure {
public:
  bool do_heap_region(G1HeapRegion* r) {
    EventG1HeapRegionInformation evt;
    evt.set_index(r->hrm_index());
    evt.set_type(r->get_trace_type());
    evt.set_start((uintptr_t)r->bottom());
    evt.set_used(r->used());
    evt.commit();
    return false;
  }
};

class VM_G1SendHeapRegionInfoEvents : public VM_Operation {
  virtual void doit() {
    DumpEventInfoClosure c;
    G1CollectedHeap::heap()->heap_region_iterate(&c);

Configuration enabled period
profiling false everyChunk
default false everyChunk

Field Type Description
index uint Index
type G1HeapRegionType Type
start ulong: address Start
used ulong: bytes Used

Examples 1
index uint
389
start ulong: address
30981226496
startTime long: millis
278345513678
type G1HeapRegionType
Free
used ulong: bytes
0

ZAllocationStall

profiling default startTime duration eventThread stackTrace 15 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Time spent waiting for memory to become available

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/z/zPageAllocator.cpp:

  if (harvested > 0) {
    ZStatInc(ZCounterMappedCacheHarvest, harvested);
    log_debug(gc, heap)("Mapped Cache Harvested: %zuM (%d)", harvested / M, num_harvested_vmems);
  }

  // Send event for successful allocation
  allocation.send_event(true /* successful */);

  return page;
}

bool ZPageAllocator::alloc_page_stall(ZPageAllocation* allocation) {
  ZStatTimer timer(ZCriticalPhaseAllocationStall);
  EventZAllocationStall event;

  // We can only block if the VM is fully initialized
  check_out_of_memory_during_initialization();

  // Start asynchronous minor GC
  const ZDriverRequest request(GCCause::_z_allocation_stall, ZYoungGCThreads, 0);
  ZDriver::minor()->collect(request);

  // Wait for allocation to complete or fail
  const bool result = allocation->wait();

Configuration enabled stackTrace threshold
profiling true true 17+ 0 ms
default true true 17+ 0 ms

Field Type Description
type ZPageTypeType Type
size ulong: bytes Size

ZPageAllocation

profiling default startTime duration eventThread stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Allocation of a ZPage

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/z/zPageAllocator.cpp:

          _multi_partition_allocation.sum_num_harvested_vmems(),
          _multi_partition_allocation.sum_harvested(),
          _multi_partition_allocation.sum_committed_increased_capacity());
    } else {
      return ZPageAllocationStats(
          _single_partition_allocation.allocation()->num_harvested(),
          _single_partition_allocation.allocation()->harvested(),
          _single_partition_allocation.allocation()->committed_capacity());
    }
  }

  void send_event(bool successful) {
    if (!EventZPageAllocation::is_enabled()) {
      // Event not enabled, exit early
      return;
    }

    Ticks end_timestamp = Ticks::now();
    const ZPageAllocationStats st = stats();

    EventZPageAllocation::commit(_start_timestamp,
                                 end_timestamp,
                                 (u8)_type,
                                 size(),
                                 st._total_harvested,
                                 st._total_committed_capacity,
                                 (unsigned)st._num_harvested_vmems,
                                 _is_multi_partition,
                                 successful,
                                 _flags.non_blocking());
  }
};

src/hotspot/share/gc/z/zPageAllocator.cpp:

  assert(to->age() == ZPageAge::old,   "must be promotion");

  decrease_used_generation(ZGenerationId::young, to->size());
  increase_used_generation(ZGenerationId::old, to->size());
}

static void check_out_of_memory_during_initialization() {
  if (!is_init_completed()) {
    vm_exit_during_initialization("java.lang.OutOfMemoryError", "Java heap too small");
  }
}

ZPage* ZPageAllocator::alloc_page(ZPageType type, size_t size, ZAllocationFlags flags, ZPageAge age, uint32_t preferred_partition) {
  EventZPageAllocation event;

  ZPageAllocation allocation(type, size, flags, age, preferred_partition);

  // Allocate the page
  ZPage* const page = alloc_page_inner(&allocation);
  if (page == nullptr) {
    return nullptr;
  }

  // Update allocation statistics. Exclude gc relocations to avoid
  // artificial inflation of the allocation rate during relocation.

Configuration enabled stackTrace threshold
profiling true true 15+ 1 ms
default true true 15+ 1 ms

Field Type Description
type ZPageTypeType 15+ Type
size ulong: bytes 15+ Size
harvested ulong: bytes 25+ Harvested
committed ulong: bytes 15+ Committed
harvestedRanges uint 25+ Harvested Ranges Number of harvested memory ranges
multiPartition boolean 25+ Multi-Partition
successful boolean 25+ Successful
nonBlocking boolean Non-Blocking

Examples 1
committed ulong: bytes
0
nonBlocking boolean
false
size ulong: bytes
2097152
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
6
lineNumber int
71
method Method
descriptor string
(IILjava/lang/foreign/MemorySegment;)V
hidden boolean
false
modifiers int
0
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/nio/HeapCharBuffer
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/nio
type FrameType
Inlined
truncated boolean
false
startTime long: millis
464673230630
type ZPageTypeType
Small

ZRelocationSet

profiling default startTime duration eventThread 15 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/z/zRelocationSetSelector.cpp:

ZRelocationSetSelector::ZRelocationSetSelector(double fragmentation_limit)
  : _small("Small", ZPageType::small, ZPageSizeSmall, ZObjectSizeLimitSmall, fragmentation_limit),
    _medium("Medium", ZPageType::medium, ZPageSizeMediumMax, ZObjectSizeLimitMedium, fragmentation_limit),
    _large("Large", ZPageType::large, 0 /* max_page_size */, 0 /* object_size_limit */, fragmentation_limit),
    _empty_pages() {}

void ZRelocationSetSelector::select() {
  // Select pages to relocate. The resulting relocation set will be
  // sorted such that medium pages comes first, followed by small
  // pages. Pages within each page group will be semi-sorted by live
  // bytes in ascending order. Relocating pages in this order allows
  // us to start reclaiming memory more quickly.

  EventZRelocationSet event;

  // Select pages from each group
  _large.select();
  _medium.select();
  _small.select();

  // Send event
  event.commit(total(), empty(), relocate());
}

ZRelocationSetSelectorStats ZRelocationSetSelector::stats() const {

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
total ulong: bytes Total
empty ulong: bytes Empty
relocate ulong: bytes 16+ Relocate

Examples 1
empty ulong: bytes
1260388352
relocate ulong: bytes
18887720
startTime long: millis
453675496601
total ulong: bytes
1667235840

ZRelocationSetGroup

profiling default startTime duration eventThread 15 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/z/zRelocationSetSelector.cpp:

    _stats[i]._relocate = selected_live_bytes[i];
    _stats[i]._npages_selected = npages_selected[i];
  }

  log_debug(gc, reloc)("Relocation Set (%s Pages): %d->%d, %d skipped, %zu forwarding entries",
                       _name, selected_from, selected_to, npages - selected_from, selected_forwarding_entries);
}

void ZRelocationSetSelectorGroup::select() {
  if (is_disabled()) {
    return;
  }

  EventZRelocationSetGroup event;

  if (is_selectable()) {
    select_inner();
  } else {
    // Mark pages as not selected
    const int npages = _live_pages.length();
    for (int from = 1; from <= npages; from++) {
      ZPage* const page = _live_pages.at(from - 1);
      _not_selected_pages.append(page);
    }
  }

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
type ZPageTypeType Type
candidatePages ulong 21+ Candidate Pages
total ulong: bytes Total
empty ulong: bytes Empty
selectedPages ulong 21+ Selected Pages
relocate ulong: bytes 16+ Relocate

Examples 1
candidatePages ulong
172
empty ulong: bytes
29360128
relocate ulong: bytes
6535104
selectedPages ulong
39
startTime long: millis
421771080197
total ulong: bytes
360710144
type ZPageTypeType
Small

ZStatisticsCounter

experimental startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/z/zTracer.inline.hpp:

#ifndef SHARE_GC_Z_ZTRACER_INLINE_HPP
#define SHARE_GC_Z_ZTRACER_INLINE_HPP

#include "gc/z/zTracer.hpp"

#include "jfr/jfrEvents.hpp"

inline void ZTracer::report_stat_counter(const ZStatCounter& counter, uint64_t increment, uint64_t value) {
  if (EventZStatisticsCounter::is_enabled()) {
    send_stat_counter(counter, increment, value);
  }
}

inline void ZTracer::report_stat_sampler(const ZStatSampler& sampler, uint64_t value) {
  if (EventZStatisticsSampler::is_enabled()) {
    send_stat_sampler(sampler, value);
  }
}

inline void ZTracer::report_thread_phase(const char* name, const Ticks& start, const Ticks& end) {
  if (EventZThreadPhase::is_enabled()) {
    send_thread_phase(name, start, end);
  }
}

src/hotspot/share/gc/z/zTracer.cpp:

  e.set_gcId(GCId::current());
  e.set_starttime(_start);
  e.set_endtime(timestamp);
  e.commit();
}

void ZTracer::initialize() {
  JFR_ONLY(register_jfr_type_serializers();)
}

void ZTracer::send_stat_counter(const ZStatCounter& counter, uint64_t increment, uint64_t value) {
  NoSafepointVerifier nsv;

  JfrNonReentrant<EventZStatisticsCounter> e;
  if (e.should_commit()) {
    e.set_id(counter.id());
    e.set_increment(increment);
    e.set_value(value);
    e.commit();
  }
}

void ZTracer::send_stat_sampler(const ZStatSampler& sampler, uint64_t value) {
  NoSafepointVerifier nsv;

Configuration enabled threshold
profiling false 0 ms
default false 0 ms

Field Type Description
id ZStatisticsCounterType Id
increment ulong Increment
value ulong Value

Examples 1
id ZStatisticsCounterType
Allocation Rate
increment ulong
2097152
startTime long: millis
373310464172
value ulong
6291456

ZStatisticsSampler

experimental startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/z/zTracer.inline.hpp:

#define SHARE_GC_Z_ZTRACER_INLINE_HPP

#include "gc/z/zTracer.hpp"

#include "jfr/jfrEvents.hpp"

inline void ZTracer::report_stat_counter(const ZStatCounter& counter, uint64_t increment, uint64_t value) {
  if (EventZStatisticsCounter::is_enabled()) {
    send_stat_counter(counter, increment, value);
  }
}

inline void ZTracer::report_stat_sampler(const ZStatSampler& sampler, uint64_t value) {
  if (EventZStatisticsSampler::is_enabled()) {
    send_stat_sampler(sampler, value);
  }
}

inline void ZTracer::report_thread_phase(const char* name, const Ticks& start, const Ticks& end) {
  if (EventZThreadPhase::is_enabled()) {
    send_thread_phase(name, start, end);
  }
}

inline void ZTracer::report_thread_debug(const char* name, const Ticks& start, const Ticks& end) {

src/hotspot/share/gc/z/zTracer.cpp:

  JfrNonReentrant<EventZStatisticsCounter> e;
  if (e.should_commit()) {
    e.set_id(counter.id());
    e.set_increment(increment);
    e.set_value(value);
    e.commit();
  }
}

void ZTracer::send_stat_sampler(const ZStatSampler& sampler, uint64_t value) {
  NoSafepointVerifier nsv;

  JfrNonReentrant<EventZStatisticsSampler> e;
  if (e.should_commit()) {
    e.set_id(sampler.id());
    e.set_value(value);
    e.commit();
  }
}

void ZTracer::send_thread_phase(const char* name, const Ticks& start, const Ticks& end) {
  NoSafepointVerifier nsv;

  EventZThreadPhase e(UNTIMED);

Configuration enabled threshold
profiling false 0 ms
default false 0 ms

Field Type Description
id ZStatisticsSamplerType Id
value ulong Value

Examples 1
id ZStatisticsSamplerType
Page Cache Hit L2
startTime long: millis
377093389999
value ulong
0

ZThreadPhase

experimental startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/z/zTracer.inline.hpp:

inline void ZTracer::report_stat_counter(const ZStatCounter& counter, uint64_t increment, uint64_t value) {
  if (EventZStatisticsCounter::is_enabled()) {
    send_stat_counter(counter, increment, value);
  }
}

inline void ZTracer::report_stat_sampler(const ZStatSampler& sampler, uint64_t value) {
  if (EventZStatisticsSampler::is_enabled()) {
    send_stat_sampler(sampler, value);
  }
}

inline void ZTracer::report_thread_phase(const char* name, const Ticks& start, const Ticks& end) {
  if (EventZThreadPhase::is_enabled()) {
    send_thread_phase(name, start, end);
  }
}

inline void ZTracer::report_thread_debug(const char* name, const Ticks& start, const Ticks& end) {
  if (EventZThreadDebug::is_enabled()) {
    send_thread_debug(name, start, end);
  }
}

inline ZTraceThreadDebug::ZTraceThreadDebug(const char* name)

src/hotspot/share/gc/z/zTracer.cpp:

  NoSafepointVerifier nsv;

  JfrNonReentrant<EventZStatisticsSampler> e;
  if (e.should_commit()) {
    e.set_id(sampler.id());
    e.set_value(value);
    e.commit();
  }
}

void ZTracer::send_thread_phase(const char* name, const Ticks& start, const Ticks& end) {
  NoSafepointVerifier nsv;

  EventZThreadPhase e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current_or_undefined());
    e.set_name(name);
    e.set_starttime(start);
    e.set_endtime(end);
    e.commit();
  }
}

void ZTracer::send_thread_debug(const char* name, const Ticks& start, const Ticks& end) {
  NoSafepointVerifier nsv;

Configuration enabled threshold
profiling false 0 ms
default false 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 1
gcId uint
230
name string
Concurrent References Process
startTime long: millis
403382627834

ZUncommit

profiling default startTime duration eventThread 15 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Uncommitting of memory

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/z/zUncommitter.cpp:

bool ZUncommitter::should_continue() const {
  ZLocker<ZConditionLock> locker(&_lock);
  return !_stop;
}

void ZUncommitter::update_statistics(size_t uncommitted, Ticks start, Tickspan* accumulated_time) const {
  // Update counter
  ZStatInc(ZCounterUncommit, uncommitted);

  Ticks end = Ticks::now();

  // Send event
  EventZUncommit::commit(start, end, uncommitted);

  // Track accumulated time
  *accumulated_time += end - start;
}

void ZUncommitter::run_thread() {
  // Initialize first cycle timeout
  _next_cycle_timeout = to_millis(ZUncommitDelay);

  while (wait(_next_cycle_timeout)) {
    // Counters for event and statistics

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
uncommitted ulong: bytes Uncommitted

ShenandoahHeapRegionStateChange

startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

Information about a Shenandoah heap region state change

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shenandoah/shenandoahHeapRegion.cpp:

    bool success = os::uncommit_memory((char *) bottom(), RegionSizeBytes);
    if (!success) {
      log_warning(gc)("Region uncommit failed: " PTR_FORMAT " (%zu bytes)", p2i(bottom()), RegionSizeBytes);
      assert(false, "Region uncommit should always succeed");
    }
  }
  if (!heap->is_bitmap_region_special()) {
    heap->uncommit_bitmap_slice(this);
  }
  heap->decrease_committed(ShenandoahHeapRegion::region_size_bytes());
}

void ShenandoahHeapRegion::set_state(RegionState to) {
  EventShenandoahHeapRegionStateChange evt;
  if (evt.should_commit()){
    evt.set_index((unsigned) index());
    evt.set_start((uintptr_t)bottom());
    evt.set_used(used());
    evt.set_from(state());
    evt.set_to(to);
    evt.commit();
  }
  AtomicAccess::store(&_state, to);
}

Configuration enabled
profiling false
default false

Field Type Description
index uint Index
from ShenandoahHeapRegionState From
to ShenandoahHeapRegionState To
start ulong: address Start
used ulong: bytes Used

Examples 1
from ShenandoahHeapRegionState
Empty Committed
index uint
115
start ulong: address
30287069184
startTime long: millis
293084456377
to ShenandoahHeapRegionState
Empty Uncommitted
used ulong: bytes
0

ShenandoahHeapRegionInformation

startTime duration every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

Information about a specific heap region in the Shenandoah GC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shenandoah/shenandoahJfrSupport.cpp:

void ShenandoahJFRSupport::register_jfr_type_serializers() {
  JfrSerializer::register_serializer(TYPE_SHENANDOAHHEAPREGIONSTATE,
                                     true,
                                     new ShenandoahHeapRegionStateConstant());
}
#endif

class ShenandoahDumpHeapRegionInfoClosure : public ShenandoahHeapRegionClosure {
public:
  virtual void heap_region_do(ShenandoahHeapRegion* r) {
    EventShenandoahHeapRegionInformation evt;
    evt.set_index((unsigned) r->index());
    evt.set_state((u8)r->state());
    evt.set_start((uintptr_t)r->bottom());
    evt.set_used(r->used());
    evt.commit();
  }
};

void VM_ShenandoahSendHeapRegionInfoEvents::doit() {
  ShenandoahDumpHeapRegionInfoClosure c;
  ShenandoahHeap::heap()->heap_region_iterate(&c);

Configuration enabled period
profiling false everyChunk
default false everyChunk

Field Type Description
index uint Index
state ShenandoahHeapRegionState State
start ulong: address Start
used ulong: bytes Used

Examples 1
index uint
3903
start ulong: address
34259075072
startTime long: millis
294908968688
state ShenandoahHeapRegionState
Regular
used ulong: bytes
1048576

ShenandoahEvacuationInformation

startTime 24 25 26 27

Category: Java Virtual Machine / GC / Detailed

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shenandoah/shenandoahTrace.cpp:

void ShenandoahTracer::report_evacuation_info(const ShenandoahCollectionSet* cset,
    size_t free_regions, size_t regions_promoted_humongous, size_t regions_promoted_regular,
    size_t regular_promoted_garbage, size_t regular_promoted_free, size_t regions_immediate,
    size_t immediate_size) {

  EventShenandoahEvacuationInformation e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_cSetRegions(cset->count());
    e.set_cSetUsedBefore(cset->used());
    e.set_cSetUsedAfter(cset->live());
    e.set_collectedOld(cset->get_live_bytes_in_old_regions());
    e.set_collectedPromoted(cset->get_live_bytes_in_tenurable_regions());
    e.set_collectedYoung(cset->get_live_bytes_in_untenurable_regions());
    e.set_regionsPromotedHumongous(regions_promoted_humongous);
    e.set_regionsPromotedRegular(regions_promoted_regular);
    e.set_regularPromotedGarbage(regular_promoted_garbage);
    e.set_regularPromotedFree(regular_promoted_free);
    e.set_freeRegions(free_regions);
    e.set_regionsImmediate(regions_immediate);

Configuration enabled
profiling false
default false

Field Type Description
gcId uint GC Identifier
cSetRegions ulong Collection Set Regions
cSetUsedBefore ulong: bytes Collection Set Before Memory usage before GC in the collection set regions
cSetUsedAfter ulong: bytes Collection Set After Memory usage after GC in the collection set regions
collectedOld ulong: bytes Collected Old Memory collected from old generation
collectedPromoted ulong: bytes Collected Promoted Memory collected from generation promotion
collectedYoung ulong: bytes Collection Young Memory collected from young generation
regionsPromotedHumongous ulong Regions Promoted Humongous
regionsPromotedRegular ulong Regions Promoted Regular
regularPromotedGarbage ulong: bytes Regular Promoted Garbage Garbage memory of in place promoted regular regions
regularPromotedFree ulong: bytes Regular Promoted Free Free memory of in place promoted regular regions
freeRegions ulong 25+ Free Regions Free regions prior to collection
regionsImmediate ulong Regions Immediate
immediateBytes ulong: bytes Immediate Bytes

StringDeduplication

profiling default startTime duration 26 27

Category: Java Virtual Machine / GC / Detailed

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/stringdedup/stringDedupStat.cpp:

void StringDedup::Stat::emit_statistics(bool total) const {
  if (log_is_enabled(Debug, stringdedup)) {
    log_times(total ? "Total" : "Last");
    log_statistics();
  }

  if (total) {
    // Send only JFR events about the last stats
    return;
  }

  EventStringDeduplication e;
  if (e.should_commit()) {
    e.set_starttime(_active_start);
    Ticks active_end = _active_start;
    active_end += _active_elapsed;
    e.set_endtime(active_end);

    e.set_inspected(_inspected);
    e.set_known(_known);
    e.set_shared(_known_shared);
    e.set_newStrings(_new);
    e.set_newSize(_new_bytes);

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
inspected ulong Inspected
known ulong Known
shared ulong Shared
newStrings ulong New Strings New unknown strings
newSize ulong: bytes New Size Size of new unknown strings
replaced ulong Replaced
deleted ulong Deleted
deduplicated ulong Deduplicated
deduplicatedSize ulong: bytes Deduplicated Size
skippedDead ulong Skipped Dead
skippedIncomplete ulong Skipped Incomplete
skippedShared ulong Skipped Shared
processing Tickspan Processing
tableResize Tickspan Table Resize
tableCleanup Tickspan Table Cleanup

JVM: GC: Heap

GCHeapSummary

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Heap

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

  space.set_used(summary.used());
  space.set_size(summary.size());
  return space;
}

class GCHeapSummaryEventSender : public GCHeapSummaryVisitor {
  GCWhen::Type _when;
 public:
  GCHeapSummaryEventSender(GCWhen::Type when) : _when(when) {}

  void visit(const GCHeapSummary* heap_summary) const {
    const VirtualSpaceSummary& heap_space = heap_summary->heap();

    EventGCHeapSummary e;
    if (e.should_commit()) {
      e.set_gcId(GCId::current());
      e.set_when((u1)_when);
      e.set_heapSpace(to_struct(heap_space));
      e.set_heapUsed(heap_summary->used());
      e.commit();
    }
  }

  void visit(const G1HeapSummary* g1_heap_summary) const {
    visit((GCHeapSummary*)g1_heap_summary);

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier
when GCWhen When
heapSpace VirtualSpace struct Heap Space
heapUsed ulong: bytes Heap Used Bytes allocated by objects in the heap

Examples 3
gcId uint
920
heapSpace VirtualSpace
committedEnd ulong: address
31159918592
committedSize ulong: bytes
994484224
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4194304000
start ulong: address
30165434368
heapUsed ulong: bytes
243568128
startTime long: millis
442229321155
when GCWhen
After GC
gcId uint
396
heapSpace VirtualSpace
committedEnd ulong: address
33047445504
committedSize ulong: bytes
2882011136
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4194304000
start ulong: address
30165434368
heapUsed ulong: bytes
356911144
startTime long: millis
374647901925
when GCWhen
Before GC
gcId uint
962
heapSpace VirtualSpace
committedEnd ulong: address
31144804352
committedSize ulong: bytes
979369984
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4194304000
start ulong: address
30165434368
heapUsed ulong: bytes
285136536
startTime long: millis
286340192988
when GCWhen
After GC

MetaspaceSummary

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Heap

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

  GCHeapSummaryEventSender visitor(when);
  heap_summary.accept(&visitor);
}

static JfrStructMetaspaceSizes to_struct(const MetaspaceStats& sizes) {
  JfrStructMetaspaceSizes meta_sizes;
  meta_sizes.set_committed(sizes.committed());
  meta_sizes.set_used(sizes.used());
  meta_sizes.set_reserved(sizes.reserved());
  return meta_sizes;
}

void GCTracer::send_meta_space_summary_event(GCWhen::Type when, const MetaspaceSummary& meta_space_summary) const {
  EventMetaspaceSummary e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_when((u1) when);
    e.set_gcThreshold(meta_space_summary.capacity_until_GC());
    e.set_metaspace(to_struct(meta_space_summary.stats())); // total stats (class + nonclass)
    e.set_dataSpace(to_struct(meta_space_summary.stats().non_class_space_stats())); // "dataspace" aka non-class space
    e.set_classSpace(to_struct(meta_space_summary.stats().class_space_stats()));
    e.commit();
  }
}

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier
when GCWhen When
gcThreshold ulong: bytes GC Threshold
metaspace MetaspaceSizes struct Total
dataSpace MetaspaceSizes struct Data
classSpace MetaspaceSizes struct Class

Examples 3
classSpace MetaspaceSizes
committed ulong: bytes
88080384
reserved ulong: bytes
1073741824
used ulong: bytes
86220768
dataSpace MetaspaceSizes
committed ulong: bytes
571080704
reserved ulong: bytes
603979776
used ulong: bytes
569170248
gcId uint
977
gcThreshold ulong: bytes
1098383360
metaspace MetaspaceSizes
committed ulong: bytes
659161088
reserved ulong: bytes
1677721600
used ulong: bytes
655391016
startTime long: millis
293417503377
when GCWhen
Before GC
classSpace MetaspaceSizes
committed ulong: bytes
88408064
reserved ulong: bytes
1073741824
used ulong: bytes
86459400
dataSpace MetaspaceSizes
committed ulong: bytes
571211776
reserved ulong: bytes
603979776
used ulong: bytes
569350824
gcId uint
883
gcThreshold ulong: bytes
1099300864
metaspace MetaspaceSizes
committed ulong: bytes
659619840
reserved ulong: bytes
1677721600
used ulong: bytes
655810224
startTime long: millis
405727011444
when GCWhen
Before GC
classSpace MetaspaceSizes
committed ulong: bytes
86441984
reserved ulong: bytes
1073741824
used ulong: bytes
84644096
dataSpace MetaspaceSizes
committed ulong: bytes
559808512
reserved ulong: bytes
603979776
used ulong: bytes
557976056
gcId uint
397
gcThreshold ulong: bytes
1077084160
metaspace MetaspaceSizes
committed ulong: bytes
646250496
reserved ulong: bytes
1677721600
used ulong: bytes
642620152
startTime long: millis
374807350312
when GCWhen
After GC

PSHeapSummary

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Heap

Appearing in: ParallelGC

Missing in: G1GC, SerialGC, ShenandoahGC, ZGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

  void visit(const PSHeapSummary* ps_heap_summary) const {
    visit((GCHeapSummary*)ps_heap_summary);

    const VirtualSpaceSummary& old_summary = ps_heap_summary->old();
    const SpaceSummary& old_space = ps_heap_summary->old_space();
    const VirtualSpaceSummary& young_summary = ps_heap_summary->young();
    const SpaceSummary& eden_space = ps_heap_summary->eden();
    const SpaceSummary& from_space = ps_heap_summary->from();
    const SpaceSummary& to_space = ps_heap_summary->to();

    EventPSHeapSummary e;
    if (e.should_commit()) {
      e.set_gcId(GCId::current());
      e.set_when((u1)_when);

      e.set_oldSpace(to_struct(ps_heap_summary->old()));
      e.set_oldObjectSpace(to_struct(ps_heap_summary->old_space()));
      e.set_youngSpace(to_struct(ps_heap_summary->young()));
      e.set_edenSpace(to_struct(ps_heap_summary->eden()));
      e.set_fromSpace(to_struct(ps_heap_summary->from()));
      e.set_toSpace(to_struct(ps_heap_summary->to()));
      e.commit();

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier
when GCWhen When
oldSpace VirtualSpace struct Old Space
oldObjectSpace ObjectSpace struct Old Object Space
youngSpace VirtualSpace struct Young Space
edenSpace ObjectSpace struct Eden Space
fromSpace ObjectSpace struct From Space
toSpace ObjectSpace struct To Space

Examples 1
edenSpace ObjectSpace
end ulong: address
34230239232
size ulong: bytes
1268252672
start ulong: address
32961986560
used ulong: bytes
12540504
fromSpace ObjectSpace
end ulong: address
34234433536
size ulong: bytes
4194304
start ulong: address
34230239232
used ulong: bytes
0
gcId uint
430
oldObjectSpace ObjectSpace
end ulong: address
31729909760
size ulong: bytes
1564475392
start ulong: address
30165434368
used ulong: bytes
210748448
oldSpace VirtualSpace
committedEnd ulong: address
31729909760
committedSize ulong: bytes
1564475392
reservedEnd ulong: address
32961986560
reservedSize ulong: bytes
2796552192
start ulong: address
30165434368
startTime long: millis
433017326675
toSpace ObjectSpace
end ulong: address
34267987968
size ulong: bytes
18874368
start ulong: address
34249113600
used ulong: bytes
0
when GCWhen
Before GC
youngSpace VirtualSpace
committedEnd ulong: address
34267987968
committedSize ulong: bytes
1306001408
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
1397751808
start ulong: address
32961986560

G1HeapSummary

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Heap

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    EventGCHeapSummary e;
    if (e.should_commit()) {
      e.set_gcId(GCId::current());
      e.set_when((u1)_when);
      e.set_heapSpace(to_struct(heap_space));
      e.set_heapUsed(heap_summary->used());
      e.commit();
    }
  }

  void visit(const G1HeapSummary* g1_heap_summary) const {
    visit((GCHeapSummary*)g1_heap_summary);

    EventG1HeapSummary e;
    if (e.should_commit()) {
      e.set_gcId(GCId::current());
      e.set_when((u1)_when);
      e.set_edenUsedSize(g1_heap_summary->edenUsed());
      e.set_edenTotalSize(g1_heap_summary->edenCapacity());
      e.set_survivorUsedSize(g1_heap_summary->survivorUsed());
      e.set_oldGenUsedSize(g1_heap_summary->oldGenUsed());
      e.set_numberOfRegions(g1_heap_summary->numberOfRegions());
      e.commit();
    }
  }

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier
when GCWhen When
edenUsedSize ulong: bytes Eden Used Size
edenTotalSize ulong: bytes Eden Total Size
survivorUsedSize ulong: bytes Survivor Used Size
oldGenUsedSize ulong: bytes 21+ Old Generation Used Size
numberOfRegions uint Number of Regions

Examples 1
edenTotalSize ulong: bytes
534456672
edenUsedSize ulong: bytes
0
gcId uint
973
numberOfRegions uint
474
oldGenUsedSize ulong: bytes
287386496
startTime long: millis
289466617031
survivorUsedSize ulong: bytes
317088
when GCWhen
Before GC

JVM: GC: Metaspace

MetaspaceGCThreshold

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Metaspace

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/memory/metaspaceTracer.cpp:

void MetaspaceTracer::report_gc_threshold(size_t old_val,
                                          size_t new_val,
                                          MetaspaceGCThresholdUpdater::Type updater) const {
  EventMetaspaceGCThreshold event;
  if (event.should_commit()) {
    event.set_oldValue(old_val);
    event.set_newValue(new_val);
    event.set_updater((u1)updater);
    event.commit();
  }
}

void MetaspaceTracer::report_metaspace_allocation_failure(ClassLoaderData *cld,
                                                          size_t word_size,
                                                          MetaspaceObj::Type objtype,
                                                          Metaspace::MetadataType mdtype) const {
  send_allocation_failure_event<EventMetaspaceAllocationFailure>(cld, word_size, objtype, mdtype);
}

Configuration enabled
profiling true
default true

Field Type Description
oldValue ulong: bytes Old Value
newValue ulong: bytes New Value
updater GCThresholdUpdater Updater

Examples 3
newValue ulong: bytes
1377894400
oldValue ulong: bytes
1317928960
startTime long: millis
451220172696
updater GCThresholdUpdater
compute_new_size
newValue ulong: bytes
1098055680
oldValue ulong: bytes
1097728000
startTime long: millis
282558474552
updater GCThresholdUpdater
compute_new_size
newValue ulong: bytes
1471217664
oldValue ulong: bytes
1432616960
startTime long: millis
463656292362
updater GCThresholdUpdater
compute_new_size

MetaspaceAllocationFailure

profiling default startTime stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Metaspace

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/memory/metaspaceTracer.cpp:

  EventMetaspaceGCThreshold event;
  if (event.should_commit()) {
    event.set_oldValue(old_val);
    event.set_newValue(new_val);
    event.set_updater((u1)updater);
    event.commit();
  }
}

void MetaspaceTracer::report_metaspace_allocation_failure(ClassLoaderData *cld,
                                                          size_t word_size,
                                                          MetaspaceObj::Type objtype,
                                                          Metaspace::MetadataType mdtype) const {
  send_allocation_failure_event<EventMetaspaceAllocationFailure>(cld, word_size, objtype, mdtype);
}

void MetaspaceTracer::report_metadata_oom(ClassLoaderData *cld,
                                         size_t word_size,
                                         MetaspaceObj::Type objtype,
                                         Metaspace::MetadataType mdtype) const {
  send_allocation_failure_event<EventMetaspaceOOM>(cld, word_size, objtype, mdtype);
}

template <typename E>
void MetaspaceTracer::send_allocation_failure_event(ClassLoaderData *cld,

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
classLoader ClassLoader Class Loader
hiddenClassLoader boolean 15+ Hidden Class Loader
size ulong: bytes Size
metadataType MetadataType Metadata Type
metaspaceObjectType MetaspaceObjectType Metaspace Object Type

MetaspaceOOM

profiling default startTime stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Metaspace

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/memory/metaspaceTracer.cpp:

void MetaspaceTracer::report_metaspace_allocation_failure(ClassLoaderData *cld,
                                                          size_t word_size,
                                                          MetaspaceObj::Type objtype,
                                                          Metaspace::MetadataType mdtype) const {
  send_allocation_failure_event<EventMetaspaceAllocationFailure>(cld, word_size, objtype, mdtype);
}

void MetaspaceTracer::report_metadata_oom(ClassLoaderData *cld,
                                         size_t word_size,
                                         MetaspaceObj::Type objtype,
                                         Metaspace::MetadataType mdtype) const {
  send_allocation_failure_event<EventMetaspaceOOM>(cld, word_size, objtype, mdtype);
}

template <typename E>
void MetaspaceTracer::send_allocation_failure_event(ClassLoaderData *cld,
                                                    size_t word_size,
                                                    MetaspaceObj::Type objtype,
                                                    Metaspace::MetadataType mdtype) const {
  E event;
  if (event.should_commit()) {
    event.set_classLoader(cld);
    event.set_hiddenClassLoader(cld->has_class_mirror_holder());

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
classLoader ClassLoader Class Loader
hiddenClassLoader boolean 15+ Hidden Class Loader
size ulong: bytes Size
metadataType MetadataType Metadata Type
metaspaceObjectType MetaspaceObjectType Metaspace Object Type

MetaspaceChunkFreeListSummary

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Metaspace

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

void GCTracer::send_reference_stats_event(ReferenceType type, size_t count) const {
  EventGCReferenceStatistics e;
  if (e.should_commit()) {
      e.set_gcId(GCId::current());
      e.set_type((u1)type);
      e.set_count(count);
      e.commit();
  }
}

void GCTracer::send_metaspace_chunk_free_list_summary(GCWhen::Type when, Metaspace::MetadataType mdtype,
                                                      const MetaspaceChunkFreeListSummary& summary) const {
  EventMetaspaceChunkFreeListSummary e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_when(when);
    e.set_metadataType(mdtype);

    e.set_specializedChunks(summary.num_specialized_chunks());
    e.set_specializedChunksTotalSize(summary.specialized_chunks_size_in_bytes());

    e.set_smallChunks(summary.num_small_chunks());
    e.set_smallChunksTotalSize(summary.small_chunks_size_in_bytes());

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier
when GCWhen When
metadataType MetadataType Metadata Type
specializedChunks ulong Specialized Chunks
specializedChunksTotalSize ulong: bytes Specialized Chunks Total Size
smallChunks ulong Small Chunks
smallChunksTotalSize ulong: bytes Small Chunks Total Size
mediumChunks ulong Medium Chunks
mediumChunksTotalSize ulong: bytes Medium Chunks Total Size
humongousChunks ulong Humongous Chunks
humongousChunksTotalSize ulong: bytes Humongous Chunks Total Size

Examples 3
gcId uint
964
humongousChunks ulong
0
humongousChunksTotalSize ulong: bytes
0
mediumChunks ulong
0
mediumChunksTotalSize ulong: bytes
0
metadataType MetadataType
Class
smallChunks ulong
0
smallChunksTotalSize ulong: bytes
0
specializedChunks ulong
0
specializedChunksTotalSize ulong: bytes
0
startTime long: millis
286993075762
when GCWhen
Before GC
gcId uint
888
humongousChunks ulong
0
humongousChunksTotalSize ulong: bytes
0
mediumChunks ulong
0
mediumChunksTotalSize ulong: bytes
0
metadataType MetadataType
Class
smallChunks ulong
0
smallChunksTotalSize ulong: bytes
0
specializedChunks ulong
0
specializedChunksTotalSize ulong: bytes
0
startTime long: millis
415717985989
when GCWhen
Before GC
gcId uint
399
humongousChunks ulong
0
humongousChunksTotalSize ulong: bytes
0
mediumChunks ulong
0
mediumChunksTotalSize ulong: bytes
0
metadataType MetadataType
Class
smallChunks ulong
0
smallChunksTotalSize ulong: bytes
0
specializedChunks ulong
0
specializedChunksTotalSize ulong: bytes
0
startTime long: millis
380956003527
when GCWhen
After GC

JVM: GC: Phases

GCPhasePause

profiling default startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    e.set_gcThreshold(meta_space_summary.capacity_until_GC());
    e.set_metaspace(to_struct(meta_space_summary.stats())); // total stats (class + nonclass)
    e.set_dataSpace(to_struct(meta_space_summary.stats().non_class_space_stats())); // "dataspace" aka non-class space
    e.set_classSpace(to_struct(meta_space_summary.stats().class_space_stats()));
    e.commit();
  }
}

class PhaseSender : public PhaseVisitor {
  void visit_pause(GCPhase* phase) {
    assert(phase->level() < PhasesStack::PHASE_LEVELS, "Need more event types for PausePhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 3, "There are only three levels for ConcurrentPhase");

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 3
gcId uint
981
name string
Pause Cleanup
startTime long: millis
295877558866
gcId uint
936
name string
GC Pause
startTime long: millis
451731560706
gcId uint
428
name string
GC Pause
startTime long: millis
429094350004

GCPhasePauseLevel1

profiling default startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Missing in: ZGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    e.set_metaspace(to_struct(meta_space_summary.stats())); // total stats (class + nonclass)
    e.set_dataSpace(to_struct(meta_space_summary.stats().non_class_space_stats())); // "dataspace" aka non-class space
    e.set_classSpace(to_struct(meta_space_summary.stats().class_space_stats()));
    e.commit();
  }
}

class PhaseSender : public PhaseVisitor {
  void visit_pause(GCPhase* phase) {
    assert(phase->level() < PhasesStack::PHASE_LEVELS, "Need more event types for PausePhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 3, "There are only three levels for ConcurrentPhase");

    switch (phase->level()) {

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 3
gcId uint
409
name string
Compaction Phase
startTime long: millis
387828471971
gcId uint
966
name string
Notify Soft/WeakReferences
startTime long: millis
287021249105
gcId uint
885
name string
Notify and keep alive finalizable
startTime long: millis
409668651025

GCPhasePauseLevel2

profiling default startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    e.set_dataSpace(to_struct(meta_space_summary.stats().non_class_space_stats())); // "dataspace" aka non-class space
    e.set_classSpace(to_struct(meta_space_summary.stats().class_space_stats()));
    e.commit();
  }
}

class PhaseSender : public PhaseVisitor {
  void visit_pause(GCPhase* phase) {
    assert(phase->level() < PhasesStack::PHASE_LEVELS, "Need more event types for PausePhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 3, "There are only three levels for ConcurrentPhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhaseConcurrent>(phase); break;

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 3
gcId uint
890
name string
Reference Processing
startTime long: millis
424563745575
gcId uint
959
name string
Phase 2: Determine work lists
startTime long: millis
285307894578
gcId uint
404
name string
Notify PhantomReferences
startTime long: millis
384390742294

GCPhasePauseLevel3

startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    e.set_classSpace(to_struct(meta_space_summary.stats().class_space_stats()));
    e.commit();
  }
}

class PhaseSender : public PhaseVisitor {
  void visit_pause(GCPhase* phase) {
    assert(phase->level() < PhasesStack::PHASE_LEVELS, "Need more event types for PausePhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 3, "There are only three levels for ConcurrentPhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhaseConcurrent>(phase); break;
      case 1: send_phase<EventGCPhaseConcurrentLevel1>(phase); break;

Configuration enabled threshold
profiling false 0 ms
default false 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 3
gcId uint
943
name string
Free Code Blobs
startTime long: millis
278260232203
gcId uint
883
name string
Notify PhantomReferences
startTime long: millis
405850511981
gcId uint
403
name string
Purge Unlinked NMethods
startTime long: millis
383264666455

GCPhasePauseLevel4

startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

    e.commit();
  }
}

class PhaseSender : public PhaseVisitor {
  void visit_pause(GCPhase* phase) {
    assert(phase->level() < PhasesStack::PHASE_LEVELS, "Need more event types for PausePhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 3, "There are only three levels for ConcurrentPhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhaseConcurrent>(phase); break;
      case 1: send_phase<EventGCPhaseConcurrentLevel1>(phase); break;
      case 2: send_phase<EventGCPhaseConcurrentLevel2>(phase); break;

Configuration enabled threshold
profiling false 0 ms
default false 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 2
gcId uint
1000
name string
Balance queues
startTime long: millis
306735325042
gcId uint
473
name string
Balance queues
startTime long: millis
460972977569

GCPhaseConcurrent

profiling default startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ShenandoahGC, ZGC

Missing in: ParallelGC, SerialGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shenandoah/shenandoahUtils.hpp:

class ShenandoahWorkerSession : public StackObj {
protected:
  ShenandoahWorkerSession(uint worker_id);
public:
  static inline uint worker_id() {
    return WorkerThread::worker_id();
  }
};

class ShenandoahConcurrentWorkerSession : public ShenandoahWorkerSession {
private:
  EventGCPhaseConcurrent _event;

public:
  ShenandoahConcurrentWorkerSession(uint worker_id) : ShenandoahWorkerSession(worker_id) { }
  ~ShenandoahConcurrentWorkerSession();
};

class ShenandoahParallelWorkerSession : public ShenandoahWorkerSession {
private:
  EventGCPhaseParallel _event;

public:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 3, "There are only three levels for ConcurrentPhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhaseConcurrent>(phase); break;
      case 1: send_phase<EventGCPhaseConcurrentLevel1>(phase); break;
      case 2: send_phase<EventGCPhaseConcurrentLevel2>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

 public:
  template<typename T>
  void send_phase(GCPhase* phase) {
    T event(UNTIMED);
    if (event.should_commit()) {

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 3
gcId uint
229
name string
Concurrent Process Non-Strong References
startTime long: millis
394422230560
gcId uint
226
name string
Concurrent strong roots
startTime long: millis
297526740310
gcId uint
1005
name string
Concurrent Mark From Roots
startTime long: millis
309870544359

GCPhaseConcurrentLevel1

profiling default startTime duration eventThread 15 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ShenandoahGC, ZGC

Missing in: ParallelGC, SerialGC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 3, "There are only three levels for ConcurrentPhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhaseConcurrent>(phase); break;
      case 1: send_phase<EventGCPhaseConcurrentLevel1>(phase); break;
      case 2: send_phase<EventGCPhaseConcurrentLevel2>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

 public:
  template<typename T>
  void send_phase(GCPhase* phase) {
    T event(UNTIMED);
    if (event.should_commit()) {
      event.set_gcId(GCId::current());

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 3
gcId uint
973
name string
Preclean FinalReferences
startTime long: millis
289734102584
gcId uint
243
name string
Trigger cleanups
startTime long: millis
343524481606
gcId uint
237
name string
ClassLoaderData
startTime long: millis
447035415820

GCPhaseConcurrentLevel2

profiling default startTime duration eventThread 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 3, "There are only three levels for ConcurrentPhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhaseConcurrent>(phase); break;
      case 1: send_phase<EventGCPhaseConcurrentLevel1>(phase); break;
      case 2: send_phase<EventGCPhaseConcurrentLevel2>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

 public:
  template<typename T>
  void send_phase(GCPhase* phase) {
    T event(UNTIMED);
    if (event.should_commit()) {
      event.set_gcId(GCId::current());
      event.set_name(phase->name());

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

GCPhaseParallel

profiling default startTime duration eventThread 12 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ShenandoahGC

Missing in: ParallelGC, SerialGC, ZGC

GC phases for parallel workers

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/g1/g1HeapRegionManager.cpp:

      _worker_freelists[worker].~G1FreeRegionList();
    }
    FREE_C_HEAP_ARRAY(G1FreeRegionList, _worker_freelists);
  }

  G1FreeRegionList* worker_freelist(uint worker) {
    return &_worker_freelists[worker];
  }

  // Each worker creates a free list for a chunk of the heap. The chunks won't
  // be overlapping so we don't need to do any claiming.
  void work(uint worker_id) {
    Ticks start_time = Ticks::now();
    EventGCPhaseParallel event;

    uint start = worker_id * _worker_chunk_size;
    uint end = MIN2(start + _worker_chunk_size, _hrm->max_num_regions());

    // If start is outside the heap, this worker has nothing to do.
    if (start > end) {
      return;
    }

    G1FreeRegionList* free_list = worker_freelist(worker_id);
    for (uint i = start; i < end; i++) {

src/hotspot/share/gc/g1/g1YoungCollector.cpp:

  G1CollectedHeap*              _g1h;
  G1ParScanThreadState*         _par_scan_state;
  G1ScannerTasksQueueSet*       _queues;
  TaskTerminator*               _terminator;
  G1GCPhaseTimes::GCParPhases   _phase;

  G1ParScanThreadState*   par_scan_state() { return _par_scan_state; }
  G1ScannerTasksQueueSet* queues()         { return _queues; }
  TaskTerminator*         terminator()     { return _terminator; }

  inline bool offer_termination() {
    EventGCPhaseParallel event;
    G1ParScanThreadState* const pss = par_scan_state();
    start_term_time();
    const bool res = (terminator() == nullptr) ? true : terminator()->offer_termination();
    end_term_time();
    event.commit(GCId::current(), pss->worker_id(), G1GCPhaseTimes::phase_name(G1GCPhaseTimes::Termination));
    return res;
  }

public:
  G1ParEvacuateFollowersClosure(G1CollectedHeap* g1h,
                                G1ParScanThreadState* par_scan_state,
                                G1ScannerTasksQueueSet* queues,
                                TaskTerminator* terminator,
                                G1GCPhaseTimes::GCParPhases phase)
    : _start_term(0.0), _term_time(0.0), _term_attempts(0),
      _g1h(g1h), _par_scan_state(par_scan_state),
      _queues(queues), _terminator(terminator), _phase(phase) {}

  void do_void() {
    EventGCPhaseParallel event;
    G1ParScanThreadState* const pss = par_scan_state();
    pss->trim_queue();
    event.commit(GCId::current(), pss->worker_id(), G1GCPhaseTimes::phase_name(_phase));
    do {
      EventGCPhaseParallel event;
      pss->steal_and_trim_queue(queues());
      event.commit(GCId::current(), pss->worker_id(), G1GCPhaseTimes::phase_name(_phase));
    } while (!offer_termination());
  }

  double term_time() const { return _term_time; }
  size_t term_attempts() const { return _term_attempts; }
};

class G1EvacuateRegionsBaseTask : public WorkerTask {

src/hotspot/share/gc/g1/g1RemSet.cpp:

  size_t cards_scanned_empty() const { return _cards_empty; }
  size_t cards_scanned() const { return _cards_scanned; }
  size_t blocks_scanned() const { return _blocks_scanned; }
  size_t chunks_claimed() const { return _chunks_claimed; }
  size_t heap_roots_found() const { return _heap_roots_found; }
};

void G1RemSet::scan_heap_roots(G1ParScanThreadState* pss,
                               uint worker_id,
                               G1GCPhaseTimes::GCParPhases scan_phase,
                               G1GCPhaseTimes::GCParPhases objcopy_phase,
                               bool remember_already_scanned_cards) {
  EventGCPhaseParallel event;
  G1ScanHRForRegionClosure cl(_scan_state, pss, worker_id, scan_phase, remember_already_scanned_cards);
  _scan_state->iterate_dirty_regions_from(&cl, worker_id);

  event.commit(GCId::current(), worker_id, G1GCPhaseTimes::phase_name(scan_phase));

  G1GCPhaseTimes* p = _g1p->phase_times();

  p->record_or_add_time_secs(objcopy_phase, worker_id, cl.rem_set_trim_partially_time().seconds());

  p->record_or_add_time_secs(scan_phase, worker_id, cl.rem_set_root_scan_time().seconds());

src/hotspot/share/gc/g1/g1RemSet.cpp:

    r->code_roots_do(&cl);
    _code_roots_scanned += cl.count();
    return false;
  }

  size_t code_roots_scanned() const { return _code_roots_scanned; }
};

void G1RemSet::scan_collection_set_code_roots(G1ParScanThreadState* pss,
                                              uint worker_id,
                                              G1GCPhaseTimes::GCParPhases coderoots_phase,
                                              G1GCPhaseTimes::GCParPhases objcopy_phase) {
  EventGCPhaseParallel event;
  Tickspan code_root_scan_time;
  Tickspan code_root_trim_partially_time;

  G1GCPhaseTimes* p = _g1h->phase_times();
  {
    G1EvacPhaseWithTrimTimeTracker timer(pss, code_root_scan_time, code_root_trim_partially_time);

    G1ScanCodeRootsClosure cl(_scan_state, pss, worker_id);
    // Code roots work distribution occurs inside the iteration method. So scan all collection
    // set regions for all threads.

src/hotspot/share/gc/g1/g1RemSet.cpp:

  size_t opt_roots_scanned() const { return _opt_roots_scanned; }
  size_t opt_refs_scanned() const { return _opt_refs_scanned; }
  size_t opt_refs_memory_used() const { return _opt_refs_memory_used; }
};

void G1RemSet::scan_collection_set_optional_roots(G1ParScanThreadState* pss,
                                                  uint worker_id,
                                                  G1GCPhaseTimes::GCParPhases scan_phase,
                                                  G1GCPhaseTimes::GCParPhases objcopy_phase) {
  assert(scan_phase == G1GCPhaseTimes::OptScanHR, "must be");

  EventGCPhaseParallel event;

  Tickspan rem_set_opt_root_scan_time;
  Tickspan rem_set_opt_trim_partially_time;
  G1EvacPhaseWithTrimTimeTracker timer(pss, rem_set_opt_root_scan_time, rem_set_opt_trim_partially_time);

  G1GCPhaseTimes* p = _g1h->phase_times();

  G1ScanOptionalRemSetRootsClosure cl(pss, worker_id, scan_phase);
  // The individual references for the optional remembered set are per-worker, so every worker
  // always need to scan all regions (no claimer).

src/hotspot/share/gc/g1/g1YoungGCPostEvacuateTasks.cpp:

  void account_evacuated_region(G1HeapRegion* r) {
    size_t used = r->used();
    assert(used > 0, "region %u %s zero used", r->hrm_index(), r->get_short_type_str());
    _before_used_bytes += used;
    _regions_freed += 1;
  }
};

// Closure applied to all regions in the collection set.
class FreeCSetClosure : public G1HeapRegionClosure {
  // Helper to send JFR events for regions.
  class JFREventForRegion {
    EventGCPhaseParallel _event;

  public:
    JFREventForRegion(G1HeapRegion* region, uint worker_id) : _event() {
      _event.set_gcId(GCId::current());
      _event.set_gcWorkerId(worker_id);
      if (region->is_young()) {
        _event.set_name(G1GCPhaseTimes::phase_name(G1GCPhaseTimes::YoungFreeCSet));
      } else {
        _event.set_name(G1GCPhaseTimes::phase_name(G1GCPhaseTimes::NonYoungFreeCSet));
      }
    }

src/hotspot/share/gc/g1/g1GCParPhaseTimesTracker.hpp:

#ifndef SHARE_GC_G1_G1GCPARPHASETIMESTRACKER_HPP
#define SHARE_GC_G1_G1GCPARPHASETIMESTRACKER_HPP

#include "gc/g1/g1GCPhaseTimes.hpp"
#include "jfr/jfrEvents.hpp"
#include "utilities/ticks.hpp"

class G1GCParPhaseTimesTracker : public CHeapObj<mtGC> {
protected:
  Ticks _start_time;
  G1GCPhaseTimes::GCParPhases _phase;
  G1GCPhaseTimes* _phase_times;
  uint _worker_id;
  EventGCPhaseParallel _event;
  bool _allow_multiple_record;

public:
  G1GCParPhaseTimesTracker(G1GCPhaseTimes* phase_times, G1GCPhaseTimes::GCParPhases phase, uint worker_id, bool allow_multiple_record = false);
  virtual ~G1GCParPhaseTimesTracker();
};

class G1EvacPhaseTimesTracker : public G1GCParPhaseTimesTracker {
  Tickspan _total_time;
  Tickspan _trim_time;

src/hotspot/share/gc/shenandoah/shenandoahPhaseTimings.hpp:

  void print_cycle_on(outputStream* out) const;
  void print_global_on(outputStream* out) const;
};

class ShenandoahWorkerTimingsTracker : public StackObj {
private:
  ShenandoahPhaseTimings*          const _timings;
  ShenandoahPhaseTimings::Phase    const _phase;
  ShenandoahPhaseTimings::ParPhase const _par_phase;
  uint const _worker_id;

  double _start_time;
  EventGCPhaseParallel _event;
public:
  ShenandoahWorkerTimingsTracker(ShenandoahPhaseTimings::Phase phase,
                                 ShenandoahPhaseTimings::ParPhase par_phase,
                                 uint worker_id,
                                 bool cumulative = false);
  ~ShenandoahWorkerTimingsTracker();
};

#endif // SHARE_GC_SHENANDOAH_SHENANDOAHPHASETIMINGS_HPP

src/hotspot/share/gc/shenandoah/shenandoahUtils.hpp:

class ShenandoahConcurrentWorkerSession : public ShenandoahWorkerSession {
private:
  EventGCPhaseConcurrent _event;

public:
  ShenandoahConcurrentWorkerSession(uint worker_id) : ShenandoahWorkerSession(worker_id) { }
  ~ShenandoahConcurrentWorkerSession();
};

class ShenandoahParallelWorkerSession : public ShenandoahWorkerSession {
private:
  EventGCPhaseParallel _event;

public:
  ShenandoahParallelWorkerSession(uint worker_id) : ShenandoahWorkerSession(worker_id) { }
  ~ShenandoahParallelWorkerSession();
};

class ShenandoahSuspendibleThreadSetJoiner {
private:
  SuspendibleThreadSetJoiner _joiner;
public:
  ShenandoahSuspendibleThreadSetJoiner(bool active = true) : _joiner(active) {

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
gcWorkerId uint GC Worker Identifier
name string Name

Examples 2
gcId uint
256
gcWorkerId uint
0
name string
Finish Mark
startTime long: millis
364318840658
gcId uint
941
gcWorkerId uint
1
name string
ResizeTLABs
startTime long: millis
278161991283

JVM: GC: Reference

GCReferenceStatistics

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Reference

Total count of processed references during GC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/gcTraceSend.cpp:

void GCTracer::send_cpu_time_event(double user_time, double system_time, double real_time) const {
  EventGCCPUTime e;
  if (e.should_commit()) {
      e.set_gcId(GCId::current());
      e.set_userTime((size_t)(user_time * NANOUNITS));
      e.set_systemTime((size_t)(system_time * NANOUNITS));
      e.set_realTime((size_t)(real_time * NANOUNITS));
      e.commit();
  }
}

void GCTracer::send_reference_stats_event(ReferenceType type, size_t count) const {
  EventGCReferenceStatistics e;
  if (e.should_commit()) {
      e.set_gcId(GCId::current());
      e.set_type((u1)type);
      e.set_count(count);
      e.commit();
  }
}

void GCTracer::send_metaspace_chunk_free_list_summary(GCWhen::Type when, Metaspace::MetadataType mdtype,
                                                      const MetaspaceChunkFreeListSummary& summary) const {
  EventMetaspaceChunkFreeListSummary e;

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier
type ReferenceType Type
count ulong Total Count

Examples 3
count ulong
0
gcId uint
398
startTime long: millis
380801025221
type ReferenceType
Soft reference
count ulong
0
gcId uint
877
startTime long: millis
382487555562
type ReferenceType
Soft reference
count ulong
0
gcId uint
963
startTime long: millis
286538179074
type ReferenceType
Soft reference

JVM: Heap

GCHeapMemoryUsage

profiling default startTime every chunk 21 25 26 27

Category: Java Virtual Machine / Heap

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

TRACE_REQUEST_FUNC(JavaThreadStatistics) {
  EventJavaThreadStatistics event;
  event.set_activeCount(ThreadService::get_live_thread_count());
  event.set_daemonCount(ThreadService::get_daemon_thread_count());
  event.set_accumulatedCount(ThreadService::get_total_thread_count());
  event.set_peakCount(ThreadService::get_peak_thread_count());
  event.commit();
}

TRACE_REQUEST_FUNC(GCHeapMemoryUsage) {
  MemoryUsage usage = Universe::heap()->memory_usage();
  EventGCHeapMemoryUsage event(UNTIMED);
  event.set_used(usage.used());
  event.set_committed(usage.committed());
  event.set_max(usage.max_size());
  event.set_starttime(timestamp());
  event.set_endtime(timestamp());
  event.commit();
}

TRACE_REQUEST_FUNC(GCHeapMemoryPoolUsage) {
  ResourceMark mark;
  GrowableArray<MemoryPool*> pools = Universe::heap()->memory_pools();

Configuration enabled period
profiling true everyChunk
default true everyChunk

Field Type Description
used ulong: bytes Heap Used Bytes allocated for storing objects on the heap
committed ulong: bytes Heap Committed Bytes committed for storing objects on the heap
max ulong: bytes Heap Max Max size for the heap

Examples 3
committed ulong: bytes
2834825216
max ulong: bytes
3728736256
startTime long: millis
416727301069
used ulong: bytes
356888216
committed ulong: bytes
973078528
max ulong: bytes
4194304000
startTime long: millis
306643277948
used ulong: bytes
474353832
committed ulong: bytes
994484224
max ulong: bytes
4054515712
startTime long: millis
404623024611
used ulong: bytes
310055128

GCHeapMemoryPoolUsage

profiling default startTime every chunk 21 25 26 27

Category: Java Virtual Machine / Heap

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.set_max(usage.max_size());
  event.set_starttime(timestamp());
  event.set_endtime(timestamp());
  event.commit();
}

TRACE_REQUEST_FUNC(GCHeapMemoryPoolUsage) {
  ResourceMark mark;
  GrowableArray<MemoryPool*> pools = Universe::heap()->memory_pools();
  for (int i = 0; i < pools.length(); i++) {
    MemoryPool* pool = pools.at(i);
    if (pool->is_heap()) {
      MemoryUsage usage = pool->get_memory_usage();
      EventGCHeapMemoryPoolUsage event(UNTIMED);
      event.set_name(pool->name());
      event.set_used(usage.used());
      event.set_committed(usage.committed());
      event.set_max(usage.max_size());
      event.set_starttime(timestamp());
      event.set_endtime(timestamp());
      event.commit();
    }
  }
}

Configuration enabled period
profiling true everyChunk
default true everyChunk

Field Type Description
name string Name GC Heap Memory Pool Name
used ulong: bytes GC Heap Memory Pool Used Bytes used for storing objects in this memory pool
committed ulong: bytes GC Heap Memory Pool Committed Bytes committed for storing objects in this memory pool
max ulong: bytes GC Heap Memory Pool Max Max size for storing objects in this memory pool

Examples 3
committed ulong: bytes
478150656
max ulong: bytes
4194304000
name string
G1 Old Gen
startTime long: millis
280646713449
used ulong: bytes
290484432
committed ulong: bytes
685809664
max ulong: bytes
2796224512
name string
Tenured Gen
startTime long: millis
378900828452
used ulong: bytes
265857872
committed ulong: bytes
1292894208
max ulong: bytes
1292894208
name string
PS Eden Space
startTime long: millis
447980798173
used ulong: bytes
72562608

JVM: Internal

Duration

internal startTime duration eventThread 18 21 25 26 27

Category: Java Virtual Machine / Internal

Instant

internal startTime eventThread 18 21 25 26 27

Category: Java Virtual Machine / Internal

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/EventProvider.java:

    /**
     * Creates and returns an empty implementation for {@link CompilationEvent}.
     */
    static CompilerFailureEvent createEmptyCompilerFailureEvent() {
        return new EmptyCompilerFailureEvent();
    }

    /**
     * An instant event is an event that is not considered to have taken any time.
     */
    public interface InstantEvent {
        /**
         * Commits the event.
         */
        void commit();

        /**
         * Determines if this particular event instance would be committed to the data stream right
         * now if application called {@link #commit()}. This in turn depends on whether the event is
         * enabled and possible other factors.
         *
         * @return if this event would be committed on a call to {@link #commit()}.
         */
        boolean shouldWrite();
    }

    /**
     * Timed events describe an operation that somehow consumes time.
     */
    public interface TimedEvent extends InstantEvent {
        /**
         * Starts the timing for this event.
         */
        void begin();

        /**
         * Ends the timing period for this event.
         */
        void end();
    }

src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/EventProvider.java:

        void setIsOsr(boolean isOsr);

        void setCodeSize(int codeSize);

        void setInlinedBytes(int inlinedBytes);
    }

    /**
     * Creates a new {@link CompilerFailureEvent}.
     *
     * @return a compiler failure event
     */
    CompilerFailureEvent newCompilerFailureEvent();

    /**
     * A compiler failure event.
     */
    public interface CompilerFailureEvent extends InstantEvent {
        void setCompileId(int compileId);

        void setMessage(String message);
    }
}

Value

internal startTime eventThread 18 21 25 26 27

Category: Java Virtual Machine / Internal

Field Type Description
value ulong Value

Text

internal startTime eventThread 18 21 25 26 27

Category: Java Virtual Machine / Internal

Field Type Description
text string Text

JVM: Memory

ResidentSetSize

profiling default startTime duration every chunk 21 25 26 27

Category: Java Virtual Machine / Memory

Resident set size of the process

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/os/windows/os_windows.cpp:

#if INCLUDE_JFR

void os::jfr_report_memory_info() {
  PROCESS_MEMORY_COUNTERS_EX pmex;
  ZeroMemory(&pmex, sizeof(PROCESS_MEMORY_COUNTERS_EX));
  pmex.cb = sizeof(pmex);

  BOOL ret = GetProcessMemoryInfo(GetCurrentProcess(), (PROCESS_MEMORY_COUNTERS*) &pmex, sizeof(pmex));
  if (ret != 0) {
    // Send the RSS JFR event
    EventResidentSetSize event;
    event.set_size(pmex.WorkingSetSize);
    event.set_peak(pmex.PeakWorkingSetSize);
    event.commit();
  } else {
    // Log a warning
    static bool first_warning = true;
    if (first_warning) {
      log_warning(jfr)("Error fetching RSS values: GetProcessMemoryInfo failed");
      first_warning = false;
    }
  }

src/hotspot/os/linux/os_linux.cpp:

  if (!print_model_name_and_flags(st, buf, buflen)) {
    _print_ascii_file_h("/proc/cpuinfo", "/proc/cpuinfo", st, false);
  }
  st->cr();
  print_sys_devices_cpu_info(st);
}

#if INCLUDE_JFR

void os::jfr_report_memory_info() {
  os::Linux::meminfo_t info;
  if (os::Linux::query_process_memory_info(&info)) {
    // Send the RSS JFR event
    EventResidentSetSize event;
    event.set_size(info.vmrss * K);
    event.set_peak(info.vmhwm * K);
    event.commit();
  } else {
    // Log a warning
    static bool first_warning = true;
    if (first_warning) {
      log_warning(jfr)("Error fetching RSS values: query_process_memory_info failed");
      first_warning = false;
    }
  }

src/hotspot/os/bsd/os_bsd.cpp:

void os::print_memory_mappings(char* addr, size_t bytes, outputStream* st) {}

#if INCLUDE_JFR

void os::jfr_report_memory_info() {
#ifdef __APPLE__
  mach_task_basic_info info;
  mach_msg_type_number_t count = MACH_TASK_BASIC_INFO_COUNT;

  kern_return_t ret = task_info(mach_task_self(), MACH_TASK_BASIC_INFO, (task_info_t)&info, &count);
  if (ret == KERN_SUCCESS) {
    // Send the RSS JFR event
    EventResidentSetSize event;
    event.set_size(info.resident_size);
    // We've seen that resident_size_max sometimes trails resident_size with one page.
    // Make sure we always report size <= peak
    event.set_peak(MAX2(info.resident_size_max, info.resident_size));
    event.commit();
  } else {
    // Log a warning
    static bool first_warning = true;
    if (first_warning) {
      log_warning(jfr)("Error fetching RSS values: task_info failed");
      first_warning = false;

Configuration enabled period
profiling true 1000 ms
default true 1000 ms

Field Type Description
size ulong: bytes Resident Set Size Resident set size of the process
peak ulong: bytes Resident Set Size Peak Value Resident set size peak value of the process

Examples 3
peak ulong: bytes
4790820864
size ulong: bytes
3328102400
startTime long: millis
482526895366
peak ulong: bytes
6049906688
size ulong: bytes
5364862976
startTime long: millis
463833821184
peak ulong: bytes
5153132544
size ulong: bytes
3874660352
startTime long: millis
341445088358

NativeMemoryUsage

profiling default startTime duration every chunk 20 21 25 26 27

Category: Java Virtual Machine / Memory

Native memory usage for a given memory tag in the JVM

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrNativeMemoryEvent.cpp:

    return;
  }

  NMTUsage* usage = get_usage(timestamp);

  EventNativeMemoryUsageTotal event(UNTIMED);
  event.set_starttime(timestamp);
  event.set_reserved(usage->total_reserved());
  event.set_committed(usage->total_committed());
  event.commit();
}

void JfrNativeMemoryEvent::send_type_event(const Ticks& starttime, MemTag mem_tag, size_t reserved, size_t committed) {
  EventNativeMemoryUsage event(UNTIMED);
  event.set_starttime(starttime);
  event.set_type(NMTUtil::tag_to_index(mem_tag));
  event.set_reserved(reserved);
  event.set_committed(committed);
  event.commit();
}

void JfrNativeMemoryEvent::send_type_events(const Ticks& timestamp) {
  if (!MemTracker::enabled()) {
    return;
  }

Configuration enabled period
profiling true 1000 ms
default true 1000 ms

Field Type Description
type NMTType Memory Type Type used for the native memory allocation
reserved ulong: bytes Reserved Memory Reserved bytes for this type
committed ulong: bytes Committed Memory Committed bytes for this type

NativeMemoryUsageTotal

profiling default startTime duration every chunk 20 21 25 26 27

Category: Java Virtual Machine / Memory

Total native memory usage for the JVM. Might not be the exact sum of the NativeMemoryUsage events due to timeing.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrNativeMemoryEvent.cpp:

    usage->refresh();
    last_timestamp = timestamp;
  }
  return usage;
}

void JfrNativeMemoryEvent::send_total_event(const Ticks& timestamp) {
  if (!MemTracker::enabled()) {
    return;
  }

  NMTUsage* usage = get_usage(timestamp);

  EventNativeMemoryUsageTotal event(UNTIMED);
  event.set_starttime(timestamp);
  event.set_reserved(usage->total_reserved());
  event.set_committed(usage->total_committed());
  event.commit();
}

void JfrNativeMemoryEvent::send_type_event(const Ticks& starttime, MemTag mem_tag, size_t reserved, size_t committed) {
  EventNativeMemoryUsage event(UNTIMED);
  event.set_starttime(starttime);
  event.set_type(NMTUtil::tag_to_index(mem_tag));
  event.set_reserved(reserved);

Configuration enabled period
profiling true 1000 ms
default true 1000 ms

Field Type Description
reserved ulong: bytes Reserved Memory Total amount of reserved bytes for the JVM
committed ulong: bytes Committed Memory Total amount of committed bytes for the JVM

JVM: Method Tracing

MethodTrace

profiling default startTime duration stackTrace 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/MethodTraceEvent.java

Category: Java Virtual Machine / Method Tracing

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/MethodTraceEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Contextual;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.StackTrace;

@Name("jdk.MethodTrace")
@Label("Method Trace")
@Category({ "Java Virtual Machine", "Method Tracing" })
@StackTrace(true)
public final class MethodTraceEvent extends AbstractJDKEvent {

    @Contextual
    @Label("Method")
    private long method;

    public static void commit(long start, long duration, long method) {
        // Generated by JFR
    }

    public static long timestamp() {
        // Generated by JFR
        return 0;

src/jdk.jfr/share/classes/jdk/jfr/events/MethodTraceEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Contextual;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.StackTrace;

@Name("jdk.MethodTrace")
@Label("Method Trace")
@Category({ "Java Virtual Machine", "Method Tracing" })
@StackTrace(true)
public final class MethodTraceEvent extends AbstractJDKEvent {

    @Contextual
    @Label("Method")
    private long method;

    public static void commit(long start, long duration, long method) {
        // Generated by JFR
    }

    public static long timestamp() {
        // Generated by JFR
        return 0;

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void traceObjectInit(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTraceEvent.shouldCommit(duration) && JVM.getEventWriter() != null) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
    }

    public static void timingObjectInit(long startTime, long methodId) {

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void traceTimingObjectInit(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTraceEvent.shouldCommit(duration) && JVM.getEventWriter() != null) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addObjectTiming(duration);
        }

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void trace(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTraceEvent.shouldCommit(duration)) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
    }

    public static void timing(long startTime, long methodId) {

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addTiming(methodId, duration);
        }
        if (MethodTraceEvent.shouldCommit(duration)) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
    }
}

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void traceObjectInit(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTraceEvent.shouldCommit(duration) && JVM.getEventWriter() != null) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
    }

    public static void timingObjectInit(long startTime, long methodId) {

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void traceTimingObjectInit(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTraceEvent.shouldCommit(duration) && JVM.getEventWriter() != null) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addObjectTiming(duration);
        }

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void trace(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTraceEvent.shouldCommit(duration)) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
    }

    public static void timing(long startTime, long methodId) {

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addTiming(methodId, duration);
        }
        if (MethodTraceEvent.shouldCommit(duration)) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
    }
}

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

        jdk.internal.event.SerializationMisdeclarationEvent.class,
        jdk.internal.event.SocketReadEvent.class,
        jdk.internal.event.SocketWriteEvent.class,
        jdk.internal.event.ThreadSleepEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.VirtualThreadStartEvent.class,
        jdk.internal.event.VirtualThreadEndEvent.class,
        jdk.internal.event.VirtualThreadSubmitFailedEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class,
        jdk.internal.event.FinalFieldMutationEvent.class,
        DirectBufferStatisticsEvent.class,
        InitialSecurityPropertyEvent.class,
        MethodTraceEvent.class,
        MethodTimingEvent.class,
    };

    private static final Runnable emitExceptionStatistics = JDKEvents::emitExceptionStatistics;
    private static final Runnable emitDirectBufferStatistics = JDKEvents::emitDirectBufferStatistics;
    private static final Runnable emitContainerConfiguration = JDKEvents::emitContainerConfiguration;
    private static final Runnable emitContainerCPUUsage = JDKEvents::emitContainerCPUUsage;
    private static final Runnable emitContainerCPUThrottling = JDKEvents::emitContainerCPUThrottling;
    private static final Runnable emitContainerMemoryUsage = JDKEvents::emitContainerMemoryUsage;
    private static final Runnable emitContainerIOUsage = JDKEvents::emitContainerIOUsage;
    private static final Runnable emitInitialSecurityProperties = JDKEvents::emitInitialSecurityProperties;

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

        jdk.internal.event.SerializationMisdeclarationEvent.class,
        jdk.internal.event.SocketReadEvent.class,
        jdk.internal.event.SocketWriteEvent.class,
        jdk.internal.event.ThreadSleepEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.VirtualThreadStartEvent.class,
        jdk.internal.event.VirtualThreadEndEvent.class,
        jdk.internal.event.VirtualThreadSubmitFailedEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class,
        jdk.internal.event.FinalFieldMutationEvent.class,
        DirectBufferStatisticsEvent.class,
        InitialSecurityPropertyEvent.class,
        MethodTraceEvent.class,
        MethodTimingEvent.class,
    };

    private static final Runnable emitExceptionStatistics = JDKEvents::emitExceptionStatistics;
    private static final Runnable emitDirectBufferStatistics = JDKEvents::emitDirectBufferStatistics;
    private static final Runnable emitContainerConfiguration = JDKEvents::emitContainerConfiguration;
    private static final Runnable emitContainerCPUUsage = JDKEvents::emitContainerCPUUsage;
    private static final Runnable emitContainerCPUThrottling = JDKEvents::emitContainerCPUThrottling;
    private static final Runnable emitContainerMemoryUsage = JDKEvents::emitContainerMemoryUsage;
    private static final Runnable emitContainerIOUsage = JDKEvents::emitContainerIOUsage;
    private static final Runnable emitInitialSecurityProperties = JDKEvents::emitInitialSecurityProperties;

Configuration enabled filter stackTrace threshold
profiling true null true 0 ms
default true null true 0 ms

MethodTiming

profiling default startTime duration stackTrace 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/MethodTimingEvent.java

Category: Java Virtual Machine / Method Tracing

Measures the approximate time it takes for a method to execute, including all delays, not just CPU processing time

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/MethodTimingEvent.java:

@Name("jdk.MethodTiming")
@Label("Method Timing")
@Category({ "Java Virtual Machine", "Method Tracing" })
@RemoveFields({ "duration", "eventThread", "stackTrace" })
@Description("Measures the approximate time it takes for a method to execute, including all delays, not just CPU processing time")
public final class MethodTimingEvent extends AbstractJDKEvent {

    @Label("Method")
    public long method;

    @Label("Invocations")
    public long invocations;

    @Label("Minimum Time")
    @Description("The value may be missing (Long.MIN_VALUE) if the clock-resolution is too low to establish a minimum time")
    @Timespan(Timespan.TICKS)
    public long minimum;

src/jdk.jfr/share/classes/jdk/jfr/events/MethodTimingEvent.java:

@Name("jdk.MethodTiming")
@Label("Method Timing")
@Category({ "Java Virtual Machine", "Method Tracing" })
@RemoveFields({ "duration", "eventThread", "stackTrace" })
@Description("Measures the approximate time it takes for a method to execute, including all delays, not just CPU processing time")
public final class MethodTimingEvent extends AbstractJDKEvent {

    @Label("Method")
    public long method;

    @Label("Invocations")
    public long invocations;

    @Label("Minimum Time")
    @Description("The value may be missing (Long.MIN_VALUE) if the clock-resolution is too low to establish a minimum time")
    @Timespan(Timespan.TICKS)
    public long minimum;

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void timingObjectInit(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addObjectTiming(duration);
        }
    }

    public static void traceTimingObjectInit(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTraceEvent.shouldCommit(duration) && JVM.getEventWriter() != null) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addObjectTiming(duration);
        }
    }

    public static void trace(long startTime, long methodId) {

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void timing(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addTiming(methodId, duration);
        }
    }

    public static void traceTiming(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addTiming(methodId, duration);
        }
        if (MethodTraceEvent.shouldCommit(duration)) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void timingObjectInit(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addObjectTiming(duration);
        }
    }

    public static void traceTimingObjectInit(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTraceEvent.shouldCommit(duration) && JVM.getEventWriter() != null) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addObjectTiming(duration);
        }
    }

    public static void trace(long startTime, long methodId) {

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void timing(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addTiming(methodId, duration);
        }
    }

    public static void traceTiming(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addTiming(methodId, duration);
        }
        if (MethodTraceEvent.shouldCommit(duration)) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }

src/jdk.jfr/share/classes/jdk/jfr/internal/tracing/TimedClass.java:

    public void emit(long timestamp) {
        for (var tm : methods.values()) {
            if (tm.published().get()) {
                long methodId = tm.method().methodId();
                long invocations = tm.invocations().get();
                long time = tm.time().get();
                long min = tm.minimum().get();
                long max = tm.maximum().get();
                if (time == 0 || invocations == 0) {
                    // If time is zero, it's a low resolution clock and more invocations are needed.
                    MethodTimingEvent.commit(timestamp, methodId, invocations, MISSING, MISSING, MISSING);
                } else {
                    long average = (time + invocations / 2) / invocations;
                    if (min == Long.MAX_VALUE) {
                        min = average;
                    }
                    if (max == Long.MIN_VALUE) {
                        max = average;
                    }
                    min = Math.min(min, average);
                    max = Math.max(max, average);
                    MethodTimingEvent.commit(timestamp, methodId, invocations, min, average, max);
                }
                tm.method().log("Emitted event");
            }
        }
    }
}

src/jdk.jfr/share/classes/jdk/jfr/internal/tracing/TimedClass.java:

    public void emit(long timestamp) {
        for (var tm : methods.values()) {
            if (tm.published().get()) {
                long methodId = tm.method().methodId();
                long invocations = tm.invocations().get();
                long time = tm.time().get();
                long min = tm.minimum().get();
                long max = tm.maximum().get();
                if (time == 0 || invocations == 0) {
                    // If time is zero, it's a low resolution clock and more invocations are needed.
                    MethodTimingEvent.commit(timestamp, methodId, invocations, MISSING, MISSING, MISSING);
                } else {
                    long average = (time + invocations / 2) / invocations;
                    if (min == Long.MAX_VALUE) {
                        min = average;
                    }
                    if (max == Long.MIN_VALUE) {
                        max = average;
                    }
                    min = Math.min(min, average);
                    max = Math.max(max, average);
                    MethodTimingEvent.commit(timestamp, methodId, invocations, min, average, max);
                }
                tm.method().log("Emitted event");
            }
        }
    }
}

src/jdk.jfr/share/classes/jdk/jfr/internal/tracing/PlatformTracer.java:

        s.append(message);
        s.append(" for ");
        s.append(className.replace("/", "."));
        s.append(" in module ");
        s.append(module.getName());
        s.append(" and class loader " + module.getClassLoader());
        Logger.log(LogTag.JFR_METHODTRACE, level, s.toString());
    }

    public static void emitTiming() {
        // Metadata lock prevents rotation/flush while emitting events.
        synchronized (MetadataRepository.getInstance()) {
            removeClasses(JVM.drainStaleMethodTracerIds());
            long timestamp = MethodTimingEvent.timestamp();
            for (var tc : timedClasses.values()) {
                tc.emit(timestamp);
            }
        }
    }

    public static void addObjectTiming(long duration) {
        OBJECT.invocations().getAndIncrement();
        OBJECT.time().addAndGet(duration);
        OBJECT.updateMinMax(duration);
    }

src/jdk.jfr/share/classes/jdk/jfr/internal/tracing/PlatformTracer.java:

        s.append(message);
        s.append(" for ");
        s.append(className.replace("/", "."));
        s.append(" in module ");
        s.append(module.getName());
        s.append(" and class loader " + module.getClassLoader());
        Logger.log(LogTag.JFR_METHODTRACE, level, s.toString());
    }

    public static void emitTiming() {
        // Metadata lock prevents rotation/flush while emitting events.
        synchronized (MetadataRepository.getInstance()) {
            removeClasses(JVM.drainStaleMethodTracerIds());
            long timestamp = MethodTimingEvent.timestamp();
            for (var tc : timedClasses.values()) {
                tc.emit(timestamp);
            }
        }
    }

    public static void addObjectTiming(long duration) {
        OBJECT.invocations().getAndIncrement();
        OBJECT.time().addAndGet(duration);
        OBJECT.updateMinMax(duration);
    }

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

        jdk.internal.event.VirtualThreadEndEvent.class,
        jdk.internal.event.VirtualThreadSubmitFailedEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class,
        jdk.internal.event.FinalFieldMutationEvent.class,
        DirectBufferStatisticsEvent.class,
        InitialSecurityPropertyEvent.class,
        MethodTraceEvent.class,
        MethodTimingEvent.class,
    };

    private static final Runnable emitExceptionStatistics = JDKEvents::emitExceptionStatistics;
    private static final Runnable emitDirectBufferStatistics = JDKEvents::emitDirectBufferStatistics;
    private static final Runnable emitContainerConfiguration = JDKEvents::emitContainerConfiguration;
    private static final Runnable emitContainerCPUUsage = JDKEvents::emitContainerCPUUsage;
    private static final Runnable emitContainerCPUThrottling = JDKEvents::emitContainerCPUThrottling;

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

        try {
            if (initializationTriggered == false) {
                for (Class<?> eventClass : eventClasses) {
                    MetadataRepository.getInstance().register((Class<? extends Event>) eventClass);
                }
                PeriodicEvents.addJavaEvent(jdk.internal.event.ExceptionStatisticsEvent.class, emitExceptionStatistics);
                PeriodicEvents.addJavaEvent(DirectBufferStatisticsEvent.class, emitDirectBufferStatistics);
                PeriodicEvents.addJavaEvent(InitialSecurityPropertyEvent.class, emitInitialSecurityProperties);
                PeriodicEvents.addJavaEvent(MethodTimingEvent.class, emitMethodTiming);

                initializeContainerEvents();
                JFRTracing.enable();
                initializationTriggered = true;
            }
        } catch (Exception e) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.WARN, "Could not initialize JDK events. " + e.getMessage());

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

            for (String key : p.stringPropertyNames()) {
                InitialSecurityPropertyEvent e = new InitialSecurityPropertyEvent();
                e.key = key;
                e.value = p.getProperty(key);
                e.commit();
            }
        }
    }

    private static void emitMethodTiming() {
        if (MethodSetting.isInitialized() && MethodTimingEvent.enabled()) {
            PlatformTracer.emitTiming();
        }
    }
}

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

        jdk.internal.event.VirtualThreadEndEvent.class,
        jdk.internal.event.VirtualThreadSubmitFailedEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class,
        jdk.internal.event.FinalFieldMutationEvent.class,
        DirectBufferStatisticsEvent.class,
        InitialSecurityPropertyEvent.class,
        MethodTraceEvent.class,
        MethodTimingEvent.class,
    };

    private static final Runnable emitExceptionStatistics = JDKEvents::emitExceptionStatistics;
    private static final Runnable emitDirectBufferStatistics = JDKEvents::emitDirectBufferStatistics;
    private static final Runnable emitContainerConfiguration = JDKEvents::emitContainerConfiguration;
    private static final Runnable emitContainerCPUUsage = JDKEvents::emitContainerCPUUsage;
    private static final Runnable emitContainerCPUThrottling = JDKEvents::emitContainerCPUThrottling;

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

        try {
            if (initializationTriggered == false) {
                for (Class<?> eventClass : eventClasses) {
                    MetadataRepository.getInstance().register((Class<? extends Event>) eventClass);
                }
                PeriodicEvents.addJavaEvent(jdk.internal.event.ExceptionStatisticsEvent.class, emitExceptionStatistics);
                PeriodicEvents.addJavaEvent(DirectBufferStatisticsEvent.class, emitDirectBufferStatistics);
                PeriodicEvents.addJavaEvent(InitialSecurityPropertyEvent.class, emitInitialSecurityProperties);
                PeriodicEvents.addJavaEvent(MethodTimingEvent.class, emitMethodTiming);

                initializeContainerEvents();
                JFRTracing.enable();
                initializationTriggered = true;
            }
        } catch (Exception e) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.WARN, "Could not initialize JDK events. " + e.getMessage());

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

            for (String key : p.stringPropertyNames()) {
                InitialSecurityPropertyEvent e = new InitialSecurityPropertyEvent();
                e.key = key;
                e.value = p.getProperty(key);
                e.commit();
            }
        }
    }

    private static void emitMethodTiming() {
        if (MethodSetting.isInitialized() && MethodTimingEvent.enabled()) {
            PlatformTracer.emitTiming();
        }
    }
}

Configuration enabled filter period
profiling true null endChunk
default true null endChunk

Field Type Description
method long Method
invocations long Invocations
minimum long: tickspan Minimum Time The value may be missing (Long.MIN_VALUE) if the clock-resolution is too low to establish a minimum time
average long: tickspan Average Time The value may be missing (Long.MIN_VALUE) if the clock-resolution is too low to establish an average time
maximum long: tickspan Maximum Time The value may be missing (Long.MIN_VALUE) if the clock-resolution is too low to establish a maximum time

JVM: Profiling

OldObjectSample

cutoff profiling default startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / Profiling

Appearing in: G1GC, ParallelGC, SerialGC, ZGC

Missing in: ShenandoahGC

A potential memory leak

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/jni/jfrJniMethod.cpp:

NO_TRANSITION(jlong, jfr_elapsed_counter(JNIEnv* env, jclass jvm))
  return JfrTicks::now();
NO_TRANSITION_END

NO_TRANSITION(void, jfr_retransform_classes(JNIEnv* env, jclass jvm, jobjectArray classes))
  JfrJvmtiAgent::retransform_classes(env, classes, JavaThread::thread_from_jni_environment(env));
NO_TRANSITION_END

NO_TRANSITION(void, jfr_set_enabled(JNIEnv* env, jclass jvm, jlong event_type_id, jboolean enabled))
  JfrEventSetting::set_enabled(event_type_id, JNI_TRUE == enabled);
  if (EventOldObjectSample::eventId == event_type_id) {
    JavaThread* thread = JavaThread::thread_from_jni_environment(env);
    MACOS_AARCH64_ONLY(ThreadWXEnable __wx(WXWrite, thread));
    ThreadInVMfromNative transition(thread);
    if (JNI_TRUE == enabled) {
      LeakProfiler::start(JfrOptionSet::old_object_queue_size());
    } else {
      LeakProfiler::stop();
    }
  }
NO_TRANSITION_END

src/hotspot/share/jfr/leakprofiler/sampling/objectSampler.cpp:

    // for regular threads, the blob is cached in the thread local data structure
    tl->set_thread_blob(JfrCheckpointManager::create_thread_blob(thread, tid));
    assert(tl->has_thread_blob(), "invariant");
  }
  return tl->thread_blob();
}

class RecordStackTrace {
 private:
  JavaThread* _jt;
  bool _enabled;
 public:
  RecordStackTrace(JavaThread* jt) : _jt(jt),
    _enabled(JfrEventSetting::has_stacktrace(EventOldObjectSample::eventId)) {
    if (_enabled) {
      JfrStackTraceRepository::record_for_leak_profiler(jt);
    }
  }
  ~RecordStackTrace() {
    if (_enabled) {
      _jt->jfr_thread_local()->clear_cached_stack_trace();
    }
  }
};

src/hotspot/share/jfr/leakprofiler/checkpoint/eventEmitter.cpp:

  assert(!sample->is_dead(), "invariant");
  assert(edge_store != nullptr, "invariant");
  assert(_jfr_thread_local != nullptr, "invariant");

  const StoredEdge* const edge = edge_store->get(sample);
  assert(edge != nullptr, "invariant");
  assert(edge->pointee() == sample->object(), "invariant");
  const traceid object_id = edge_store->get_id(edge);
  assert(object_id != 0, "invariant");
  const traceid gc_root_id = edge->gc_root_id();

  Tickspan object_age = Ticks(_start_time.value()) - sample->allocation_time();

  EventOldObjectSample e(UNTIMED);
  e.set_starttime(_start_time);
  e.set_endtime(_end_time);
  e.set_allocationTime(sample->allocation_time());
  e.set_objectSize(sample->allocated());
  e.set_objectAge(object_age);
  e.set_lastKnownHeapUsage(sample->heap_used_at_last_gc());
  e.set_object(object_id);
  e.set_arrayElements(array_size(edge->pointee()));
  e.set_root(gc_root_id);

  // Temporarily assigning both the stack trace id and thread id

src/hotspot/share/jfr/recorder/service/jfrRecorderService.cpp:

                                                  bool skip_bfs) {
  JavaThread* const jt = JavaThread::current();
  DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_native(jt);)
  if (exclude_paths_to_gc_roots(cutoff_ticks)) {
    ::emit_leakprofiler_events(emit_all, skip_bfs, jt);
    return;
  }
  emit_leakprofiler_events_paths_to_gc_roots(cutoff_ticks, emit_all, skip_bfs, /* oom */ false, jt);
}

// Leakprofiler serialization request, the report_on_java_out_of_memory VM entry point.
void JfrRecorderService::emit_leakprofiler_events_on_oom() {
  assert(CrashOnOutOfMemoryError, "invariant");
  if (EventOldObjectSample::is_enabled()) {
    JavaThread* const jt = JavaThread::current();
    DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(jt);)
    ThreadToNativeFromVM transition(jt);
    emit_leakprofiler_events_paths_to_gc_roots(max_jlong, false, false, /* oom */ true, jt);
  }
}

// The worker routine for the JFR Recorder Thread when processing MSG_EMIT_LEAKP_REFCHAINS messages.
void JfrRecorderService::emit_leakprofiler_events() {
  JavaThread* const jt = JavaThread::current();
  DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_native(jt));

Configuration cutoff enabled stackTrace
profiling 0 ns true true
default 0 ns true false

Field Type Description
allocationTime Ticks Allocation Time
objectSize ulong: bytes 18+ Object Size
objectAge Tickspan 14+ Object Age
lastKnownHeapUsage ulong: bytes Last Known Heap Usage
object OldObject Object
arrayElements int Array Elements If the object is an array, the number of elements, or minimum value for the type int if it is not an array
root OldObjectGcRoot GC Root

Examples 3
allocationTime Ticks
484304776660
arrayElements int
64
lastKnownHeapUsage ulong: bytes
248764064
object OldObject
address ulong: address
31812930656
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[Ljava/util/concurrent/ForkJoinTask;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent
objectAge Tickspan
9096928898
objectSize ulong: bytes
272
root OldObjectGcRoot
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
32
lineNumber int
1607
method Method
descriptor string
(Ljava/util/concurrent/ForkJoinPool$WorkQueue;)V
hidden boolean
false
modifiers int
16
name string
registerWorker
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/concurrent/ForkJoinPool
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
493401705558
allocationTime Ticks
330226165751
arrayElements int
-2147483648
lastKnownHeapUsage ulong: bytes
186983696
object OldObject
address ulong: address
30351632312
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/reflect/Method
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang/reflect
objectAge Tickspan
152218702808
objectSize ulong: bytes
88
root OldObjectGcRoot
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Z)[Ljava/lang/reflect/Method;
hidden boolean
false
modifiers int
258
name string
getDeclaredMethods0
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/Class
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
482444868559
allocationTime Ticks
356487792667
arrayElements int
-2147483648
lastKnownHeapUsage ulong: bytes
268020616
object OldObject
address ulong: address
30384410024
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/String
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
objectAge Tickspan
10848898807
objectSize ulong: bytes
24
root OldObjectGcRoot
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
10
lineNumber int
333
method Method
descriptor string
()V
hidden boolean
false
modifiers int
1
name string
run
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/renaissance/twitter/finagle/FinagleChirper$Client
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/renaissance/twitter/finagle
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
367336691474

ExecutionSample

profiling default startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Profiling

Snapshot of a thread executing Java code. Threads that are not executing Java code, including those waiting or executing native code, are not included.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/jni/jfrJniMethod.cpp:

JVM_ENTRY_NO_ENV(void, jfr_subscribe_log_level(JNIEnv* env, jclass jvm, jobject log_tag, jint id))
  JfrJavaLog::subscribe_log_level(log_tag, id, thread);
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_set_output(JNIEnv* env, jclass jvm, jstring path))
  JfrRepository::set_chunk_path(path, thread);
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_set_method_sampling_period(JNIEnv* env, jclass jvm, jlong type, jlong periodMillis))
  if (periodMillis < 0) {
    periodMillis = 0;
  }
  JfrEventId typed_event_id = (JfrEventId)type;
  assert(EventExecutionSample::eventId == typed_event_id || EventNativeMethodSample::eventId == typed_event_id, "invariant");
  JfrEventSetting::set_enabled(typed_event_id, periodMillis > 0);
  if (EventExecutionSample::eventId == type) {
    JfrThreadSampler::set_java_sample_period(periodMillis);
  } else {
    JfrThreadSampler::set_native_sample_period(periodMillis);
  }
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_store_metadata_descriptor(JNIEnv* env, jclass jvm, jbyteArray descriptor))
  JfrMetadataEvent::update(descriptor);
JVM_END

// trace thread id for a thread object

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampling.cpp:

  traceid sid;
  {
    ResourceMark rm(current);
    JfrStackTrace stacktrace;
    if (!stacktrace.record(jt, top_frame, in_continuation, request)) {
      // Unable to record stacktrace. Fail.
      return;
    }
    sid = JfrStackTraceRepository::add(stacktrace);
  }
  assert(sid != 0, "invariant");
  const traceid tid = in_continuation ? tl->vthread_id_with_epoch_update(jt) : JfrThreadLocal::jvm_thread_id(jt);
  send_sample_event<EventExecutionSample>(request._sample_ticks, now, sid, tid);
  if (current == jt) {
    send_safepoint_latency_event(request, now, sid, jt);
  }
}

#ifdef LINUX
static void record_cpu_time_thread(const JfrCPUTimeSampleRequest& request, const JfrTicks& now, const JfrThreadLocal* tl, JavaThread* jt, Thread* current) {
  assert(jt != nullptr, "invariant");
  assert(tl != nullptr, "invariant");
  assert(current != nullptr, "invariant");
  frame top_frame;

Configuration enabled period
profiling true 10 ms
default true 20 ms

Field Type Description
sampledThread Thread Thread
stackTrace StackTrace Stack Trace
state ThreadState Thread State

Examples 3
sampledThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
Executor task launch worker for task 6.0 in stage 18.0 (TID 113)
javaThreadId long
1164
osName string
Executor task launch worker for task 6.0 in stage 18.0 (TID 113)
osThreadId long
3755
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
13
lineNumber int
3440
method Method
descriptor string
(Ljava/lang/String;ID[DII[DI)V
hidden boolean
false
modifiers int
4
name string
dsprK
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
0
name string
dev/ludovic/netlib/blas/Java8BLAS
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
dev/ludovic/netlib/blas
type FrameType
Inlined
truncated boolean
false
startTime long: millis
389496972817
state ThreadState
STATE_RUNNABLE
sampledThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
Executor task launch worker for task 1.0 in stage 18.0 (TID 108)
javaThreadId long
1181
osName string
Executor task launch worker for task 1.0 in stage 18.0 (TID 108)
osThreadId long
3740
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
258
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/String;ID[DII[DI)V
hidden boolean
false
modifiers int
9
name string
dspr
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
17
name string
org/netlib/blas/Dspr
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/netlib/blas
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
278340408759
state ThreadState
STATE_RUNNABLE
sampledThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
Executor task launch worker for task 5.0 in stage 18.0 (TID 112)
javaThreadId long
1178
osName string
Executor task launch worker for task 5.0 in stage 18.0 (TID 112)
osThreadId long
4412
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
258
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/String;ID[DII[DI)V
hidden boolean
false
modifiers int
9
name string
dspr
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
17
name string
org/netlib/blas/Dspr
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/netlib/blas
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
374885271891
state ThreadState
STATE_RUNNABLE

NativeMethodSample

profiling default startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Profiling

Snapshot of a thread in native code, executing or waiting. Threads that are executing Java code are not included.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/jni/jfrJniMethod.cpp:

JVM_ENTRY_NO_ENV(void, jfr_subscribe_log_level(JNIEnv* env, jclass jvm, jobject log_tag, jint id))
  JfrJavaLog::subscribe_log_level(log_tag, id, thread);
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_set_output(JNIEnv* env, jclass jvm, jstring path))
  JfrRepository::set_chunk_path(path, thread);
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_set_method_sampling_period(JNIEnv* env, jclass jvm, jlong type, jlong periodMillis))
  if (periodMillis < 0) {
    periodMillis = 0;
  }
  JfrEventId typed_event_id = (JfrEventId)type;
  assert(EventExecutionSample::eventId == typed_event_id || EventNativeMethodSample::eventId == typed_event_id, "invariant");
  JfrEventSetting::set_enabled(typed_event_id, periodMillis > 0);
  if (EventExecutionSample::eventId == type) {
    JfrThreadSampler::set_java_sample_period(periodMillis);
  } else {
    JfrThreadSampler::set_native_sample_period(periodMillis);
  }
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_store_metadata_descriptor(JNIEnv* env, jclass jvm, jbyteArray descriptor))
  JfrMetadataEvent::update(descriptor);
JVM_END

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampling.cpp:

      const frame top_frame = jt->last_frame();
      if (!stacktrace.record_inner(jt, top_frame, is_in_continuation(top_frame, jt), 0 /* skip level */)) {
        // Unable to record stacktrace. Fail.
        return false;
      }
      sid = JfrStackTraceRepository::add(stacktrace);
    }
    // Read the tid under the monitor to ensure that if its a virtual thread,
    // it is not unmounted until we are done with it.
    tid = JfrThreadLocal::thread_id(jt);
  }

  assert(tl->sample_state() == NO_SAMPLE, "invariant");
  send_sample_event<EventNativeMethodSample>(start_time, start_time, sid, tid);
  return true;
}

// Entry point for a sampled thread that discovered pending Jfr Sample Requests as part of a safepoint poll.
void JfrThreadSampling::process_sample_request(JavaThread* jt) {
  assert(JavaThread::current() == jt, "should be current thread");
  assert(jt->thread_state() == _thread_in_vm || jt->thread_state() == _thread_in_Java, "invariant");

  const JfrTicks now = JfrTicks::now();

  JfrThreadLocal* const tl = jt->jfr_thread_local();

Configuration enabled period
profiling true 20 ms
default true 20 ms

Field Type Description
sampledThread Thread Thread
stackTrace StackTrace Stack Trace
state ThreadState Thread State

Examples 3
sampledThread Thread
group ThreadGroup
name string
finagle/netty4
parent ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
finagle/netty4-2-7
javaThreadId long
871
osName string
finagle/netty4-2-7
osThreadId long
3411
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(IJII)I
hidden boolean
false
modifiers int
266
name string
epollWait
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
17
name string
io/netty/channel/epoll/Native
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
io/netty/channel/epoll
type FrameType
Native
truncated boolean
false
startTime long: millis
379428577983
state ThreadState
STATE_RUNNABLE
sampledThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
shuffle-boss-6-1
javaThreadId long
1168
osName string
shuffle-boss-6-1
osThreadId long
4397
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(IJII)I
hidden boolean
false
modifiers int
264
name string
wait
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
sun/nio/ch/EPoll
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
sun/nio/ch
type FrameType
Native
truncated boolean
false
startTime long: millis
371703516152
state ThreadState
STATE_RUNNABLE
sampledThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
shuffle-boss-6-1
javaThreadId long
1170
osName string
shuffle-boss-6-1
osThreadId long
3723
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(IJII)I
hidden boolean
false
modifiers int
264
name string
wait
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
sun/nio/ch/EPoll
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
sun/nio/ch
type FrameType
Native
truncated boolean
false
startTime long: millis
278821803958
state ThreadState
STATE_RUNNABLE

CPUTimeSample

experimental throttle startTime 25 26 27

Category: Java Virtual Machine / Profiling

Snapshot of a threads state from the CPU time sampler, both threads executing native and Java code are included. The throttle setting can be either an upper bound for the event emission rate, e.g. 100/s, or the cpu-time period, e.g. 10ms, with s, ms, us and ns supported as time units.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/sampling/jfrCPUTimeThreadSampler.cpp:

      if (jt->has_last_Java_frame()) {
        JfrThreadSampling::process_cpu_time_request(jt, tl, current, false);
      } else {
        tl->set_do_async_processing_of_cpu_time_jfr_requests(false);
      }
      tl->release_cpu_time_jfr_queue_lock();
    }
  }
}

static volatile size_t count = 0;

void JfrCPUTimeThreadSampling::send_empty_event(const JfrTicks &start_time, traceid tid, Tickspan cpu_time_period) {
  EventCPUTimeSample event(UNTIMED);
  event.set_failed(true);
  event.set_starttime(start_time);
  event.set_eventThread(tid);
  event.set_stackTrace(0);
  event.set_samplingPeriod(cpu_time_period);
  event.set_biased(false);
  event.commit();
}


static volatile size_t biased_count = 0;

void JfrCPUTimeThreadSampling::send_event(const JfrTicks &start_time, traceid sid, traceid tid, Tickspan cpu_time_period, bool biased) {
  EventCPUTimeSample event(UNTIMED);
  event.set_failed(false);
  event.set_starttime(start_time);
  event.set_eventThread(tid);
  event.set_stackTrace(sid);
  event.set_samplingPeriod(cpu_time_period);
  event.set_biased(biased);
  event.commit();
  AtomicAccess::inc(&count);
  if (biased) {
    AtomicAccess::inc(&biased_count);
  }

Configuration enabled stackTrace throttle
profiling false true 10ms
default false true 500/s

Field Type Description
stackTrace StackTrace Stack Trace
eventThread Thread Thread
failed boolean Failed Failed to obtain the stack trace
samplingPeriod Tickspan CPU Time Sampling Period
biased boolean Biased The sample is safepoint-biased

CPUTimeSamplesLost

experimental profiling default startTime 25 26 27

Category: Java Virtual Machine / Profiling

Records that the CPU time sampler lost samples

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/sampling/jfrCPUTimeThreadSampler.cpp:

  event.set_samplingPeriod(cpu_time_period);
  event.set_biased(biased);
  event.commit();
  AtomicAccess::inc(&count);
  if (biased) {
    AtomicAccess::inc(&biased_count);
  }
  if (AtomicAccess::load(&count) % 1000 == 0) {
    log_debug(jfr)("CPU thread sampler sent %zu events, lost %d, biased %zu\n", AtomicAccess::load(&count), AtomicAccess::load(&_lost_samples_sum), AtomicAccess::load(&biased_count));
  }
}

void JfrCPUTimeThreadSampling::send_lost_event(const JfrTicks &time, traceid tid, s4 lost_samples) {
  if (!EventCPUTimeSamplesLost::is_enabled()) {
    return;
  }
  EventCPUTimeSamplesLost event(UNTIMED);
  event.set_starttime(time);
  event.set_lostSamples(lost_samples);
  event.set_eventThread(tid);
  event.commit();
}

void JfrCPUSamplerThread::post_run() {
  this->NonJavaThread::post_run();
  delete this;
}

Configuration enabled
profiling true
default true

Field Type Description
lostSamples int Lost Samples
eventThread Thread Thread

JVM: Runtime

ContinuationFreeze

experimental startTime duration eventThread stackTrace 19 21 25 26 27

Category: Java Virtual Machine / Runtime

Invocation of Continuation.yield()

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/continuationFreezeThaw.cpp:

  DEBUG_ONLY(log_preempt_after_freeze(cont);)
  return freeze_epilog(cont);
}

template<typename ConfigT, bool preempt>
static inline freeze_result freeze_internal(JavaThread* current, intptr_t* const sp) {
  assert(!current->has_pending_exception(), "");

#ifdef ASSERT
  log_trace(continuations)("~~~~ freeze sp: " INTPTR_FORMAT "JavaThread: " INTPTR_FORMAT, p2i(current->last_continuation()->entry_sp()), p2i(current));
  log_frames(current);
#endif

  CONT_JFR_ONLY(EventContinuationFreeze event;)

  ContinuationEntry* entry = current->last_continuation();

  oop oopCont = entry->cont_oop(current);
  assert(oopCont == current->last_continuation()->cont_oop(current), "");
  assert(ContinuationEntry::assert_entry_frame_laid_out(current), "");

  verify_continuation(oopCont);
  ContinuationWrapper cont(current, oopCont);
  log_develop_debug(continuations)("FREEZE #" INTPTR_FORMAT " " INTPTR_FORMAT, cont.hash(), p2i((oopDesc*)oopCont));

Configuration enabled stackTrace threshold
profiling false false 0 ms
default false false 0 ms

Field Type Description
carrierThread Thread Carrier Thread Thread enlisted as a carrier
continuationClass Class Continuation Class
interpretedFrames ushort Interpreted Frames
size ushort: bytes Stack Size

ContinuationThaw

experimental startTime duration eventThread stackTrace 19 21 25 26 27

Category: Java Virtual Machine / Runtime

Invocation of Continuation.run() on a started continuation

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/continuationFreezeThaw.cpp:

    " to: " INTPTR_FORMAT " top_address: " INTPTR_FORMAT, p2i(f.sp() - frame::metadata_words), p2i(_top_stack_address));
  ContinuationHelper::Frame::patch_pc(f, f.raw_pc()); // in case we want to deopt the frame in a full transition, this is checked.
  ContinuationHelper::push_pd(f);

  assert(ContinuationHelper::Frame::assert_frame_laid_out(f), "");
}

// returns new top sp
// called after preparations (stack overflow check and making room)
template<typename ConfigT>
static inline intptr_t* thaw_internal(JavaThread* thread, const Continuation::thaw_kind kind) {
  assert(thread == JavaThread::current(), "Must be current thread");

  CONT_JFR_ONLY(EventContinuationThaw event;)

  log_develop_trace(continuations)("~~~~ thaw kind: %d sp: " INTPTR_FORMAT, kind, p2i(thread->last_continuation()->entry_sp()));

  ContinuationEntry* entry = thread->last_continuation();
  assert(entry != nullptr, "");
  oop oopCont = entry->cont_oop(thread);

  assert(!jdk_internal_vm_Continuation::done(oopCont), "");
  assert(oopCont == get_continuation(thread), "");
  verify_continuation(oopCont);

Configuration enabled stackTrace threshold
profiling false false 0 ms
default false false 0 ms

Field Type Description
carrierThread Thread Carrier Thread Thread enlisted as a carrier
continuationClass Class Continuation Class
interpretedFrames ushort Interpreted Frames
size ushort: bytes Stack Size

ContinuationFreezeFast

experimental startTime eventThread 20 21 25 26 27

Category: Java Virtual Machine / Runtime

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/continuationFreezeThaw.cpp:

  log_develop_trace(continuations)("FREEZE CHUNK #" INTPTR_FORMAT " (young)", _cont.hash());
  LogTarget(Trace, continuations) lt;
  if (lt.develop_is_enabled()) {
    LogStream ls(lt);
    chunk->print_on(true, &ls);
  }

  // Verification
  assert(_cont.chunk_invariant(), "");
  chunk->verify();

#if CONT_JFR
  EventContinuationFreezeFast e;
  if (e.should_commit()) {
    e.set_id(cast_from_oop<u8>(chunk));
    DEBUG_ONLY(e.set_allocate(chunk_is_allocated);)
    e.set_size(cont_size() << LogBytesPerWord);
    e.commit();
  }
#endif
}

NOINLINE freeze_result FreezeBase::freeze_slow() {
#ifdef ASSERT

Configuration enabled
profiling false
default false

Field Type Description
id ulong Continuation ID
size uint Size
allocate boolean Allocated New

ContinuationFreezeSlow

experimental startTime eventThread 20 21 25 26 27

Category: Java Virtual Machine / Runtime

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/continuationFreezeThaw.cpp:

NOINLINE freeze_result FreezeBase::freeze_slow() {
#ifdef ASSERT
  ResourceMark rm;
#endif

  log_develop_trace(continuations)("freeze_slow  #" INTPTR_FORMAT, _cont.hash());
  assert(_thread->thread_state() == _thread_in_vm || _thread->thread_state() == _thread_blocked, "");

#if CONT_JFR
  EventContinuationFreezeSlow e;
  if (e.should_commit()) {
    e.set_id(cast_from_oop<u8>(_cont.continuation()));
    e.commit();
  }
#endif

  init_rest();

  HandleMark hm(Thread::current());

  frame f = freeze_start_frame();

Configuration enabled
profiling false
default false

Field Type Description
id ulong Continuation ID

ContinuationThawFast

experimental startTime eventThread 20 21 25 26 27

Category: Java Virtual Machine / Runtime

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/continuationFreezeThaw.cpp:

  log_develop_trace(continuations)("setting entry argsize: %d", _cont.argsize());
  assert(rs.bottom_sp() == _cont.entry()->bottom_sender_sp(), "");

  // install the return barrier if not last frame, or the entry's pc if last
  patch_return(rs.bottom_sp(), is_last);

  // insert the back links from callee to caller frames
  patch_caller_links(rs.top(), rs.top() + rs.total_size());

  assert(is_last == _cont.is_empty(), "");
  assert(_cont.chunk_invariant(), "");

#if CONT_JFR
  EventContinuationThawFast e;
  if (e.should_commit()) {
    e.set_id(cast_from_oop<u8>(chunk));
    e.set_size(thaw_size << LogBytesPerWord);
    e.set_full(!partial);
    e.commit();
  }
#endif

#ifdef ASSERT
  if (LoomDeoptAfterThaw) {
    frame top(rs.sp());

Configuration enabled
profiling false
default false

Field Type Description
id ulong Continuation ID
full boolean Full
size uint Size

ContinuationThawSlow

experimental startTime eventThread 20 21 25 26 27

Category: Java Virtual Machine / Runtime

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/continuationFreezeThaw.cpp:

  LogTarget(Trace, continuations) lt;
  if (lt.develop_is_enabled()) {
    LogStream ls(lt);
    ls.print_cr("thaw slow return_barrier: %d " INTPTR_FORMAT, kind, p2i(chunk));
    chunk->print_on(true, &ls);
  }

#if CONT_JFR
  EventContinuationThawSlow e;
  if (e.should_commit()) {
    e.set_id(cast_from_oop<u8>(_cont.continuation()));
    e.commit();
  }
#endif

  DEBUG_ONLY(_frames = 0;)
  _align_size = 0;
  int num_frames = kind == Continuation::thaw_top ? 2 : 1;

  _stream = StackChunkFrameStream<ChunkFrames::Mixed>(chunk);

Configuration enabled
profiling false
default false

Field Type Description
id ulong Continuation ID

ReservedStackActivation

profiling default startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime

Activation of Reserved Stack Area caused by stack overflow with ReservedStackAccess annotated method in call stack

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/sharedRuntime.cpp:

        for (ScopeDesc *sd = nm->scope_desc_near(fr.pc()); sd != nullptr; sd = sd->sender()) {
          method = sd->method();
          if (method != nullptr && method->has_reserved_stack_access()) {
            found = true;
          }
        }
      }
    }
    if (found) {
      activation = fr;
      warning("Potentially dangerous stack overflow in "
              "ReservedStackAccess annotated method %s [%d]",
              method->name_and_sig_as_C_string(), count++);
      EventReservedStackActivation event;
      if (event.should_commit()) {
        event.set_method(method);
        event.commit();
      }
    }
  }
  return activation;
}

void SharedRuntime::on_slowpath_allocation_exit(JavaThread* current) {
  // After any safepoint, just before going back to compiled code,

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
method Method Java Method

SafepointBegin

profiling default startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime / Safepoint

Safepointing begin

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/safepoint.cpp:

static void post_safepoint_begin_event(EventSafepointBegin& event,
                                       uint64_t safepoint_id,
                                       int thread_count,
                                       int critical_thread_count) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.set_totalThreadCount(thread_count);
    event.set_jniCriticalThreadCount(critical_thread_count);
    event.commit();
  }
}

src/hotspot/share/runtime/safepoint.cpp:

    SafepointMechanism::arm_local_poll(cur);
  }
  if (UseSystemMemoryBarrier) {
    SystemMemoryBarrier::emit(); // storestore|storeload, global state -> local state
  } else {
    OrderAccess::fence(); // storestore|storeload, global state -> local state
  }
}

// Roll all threads forward to a safepoint and suspend them all
void SafepointSynchronize::begin() {
  assert(Thread::current()->is_VM_thread(), "Only VM thread may execute a safepoint");

  EventSafepointBegin begin_event;
  SafepointTracing::begin(VMThread::vm_op_type());

  log_trace(safepoint)("Suspending GC threads");
  Universe::heap()->safepoint_synchronize_begin();

  // By getting the Threads_lock, we assure that no threads are about to start or
  // exit. It is released again in SafepointSynchronize::end().
  log_trace(safepoint)("Blocking threads from starting/exiting");
  Threads_lock->lock();

  assert( _state == _not_synchronized, "trying to safepoint synchronize with wrong state");

Configuration enabled threshold
profiling true 0 ms
default true 10 ms

Field Type Description
safepointId ulong Safepoint Identifier
totalThreadCount int Total Threads The total number of threads at the start of safe point
jniCriticalThreadCount int JNI Critical Threads The number of threads in JNI critical sections

Examples 3
jniCriticalThreadCount int
0
safepointId ulong
718
startTime long: millis
411794810255
totalThreadCount int
207
jniCriticalThreadCount int
0
safepointId ulong
1223
startTime long: millis
424344760409
totalThreadCount int
191
jniCriticalThreadCount int
0
safepointId ulong
1486
startTime long: millis
278360391248
totalThreadCount int
170

SafepointStateSynchronization

startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime / Safepoint

Synchronize run state of threads

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/safepoint.cpp:

static void post_safepoint_begin_event(EventSafepointBegin& event,
                                       uint64_t safepoint_id,
                                       int thread_count,
                                       int critical_thread_count) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.set_totalThreadCount(thread_count);
    event.set_jniCriticalThreadCount(critical_thread_count);
    event.commit();
  }
}


static void post_safepoint_synchronize_event(EventSafepointStateSynchronization& event,
                                             uint64_t safepoint_id,
                                             int initial_number_of_threads,
                                             int threads_waiting_to_block,
                                             int iterations) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.set_initialThreadCount(initial_number_of_threads);
    event.set_runningThreadCount(threads_waiting_to_block);
    event.set_iterations(checked_cast<u4>(iterations));
    event.commit();
  }

src/hotspot/share/runtime/safepoint.cpp:

  _current_jni_active_count = 0;

  // Set number of threads to wait for
  _waiting_to_block = nof_threads;

  jlong safepoint_limit_time = 0;
  if (SafepointTimeout) {
    // Set the limit time, so that it can be compared to see if this has taken
    // too long to complete.
    safepoint_limit_time = SafepointTracing::start_of_safepoint() + (jlong)(SafepointTimeoutDelay * NANOSECS_PER_MILLISEC);
    timeout_error_printed = false;
  }

  EventSafepointStateSynchronization sync_event;
  int initial_running = 0;

  // Arms the safepoint, _current_jni_active_count and _waiting_to_block must be set before.
  log_trace(safepoint)("Arming safepoint using %s wait barrier", _wait_barrier->description());
  arm_safepoint();

  // Will spin until all threads are safe.
  int iterations = synchronize_threads(safepoint_limit_time, nof_threads, &initial_running);
  assert(_waiting_to_block == 0, "No thread should be running");

#ifndef PRODUCT

Configuration enabled threshold
profiling false 0 ms
default false 10 ms

Field Type Description
safepointId ulong Safepoint Identifier
initialThreadCount int Initial Threads The number of threads running at the beginning of state check
runningThreadCount int Running Threads The number of threads still running
iterations int Iterations Number of state check iterations

Examples 3
initialThreadCount int
0
iterations int
1
runningThreadCount int
0
safepointId ulong
722
startTime long: millis
420434167685
initialThreadCount int
4
iterations int
3
runningThreadCount int
0
safepointId ulong
1494
startTime long: millis
280646873577
initialThreadCount int
1
iterations int
3
runningThreadCount int
0
safepointId ulong
1248
startTime long: millis
440030026199

SafepointEnd

startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime / Safepoint

Safepointing end

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/safepoint.cpp:

                                             uint64_t safepoint_id,
                                             int initial_number_of_threads,
                                             int threads_waiting_to_block,
                                             int iterations) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.set_initialThreadCount(initial_number_of_threads);
    event.set_runningThreadCount(threads_waiting_to_block);
    event.set_iterations(checked_cast<u4>(iterations));
    event.commit();
  }
}

static void post_safepoint_end_event(EventSafepointEnd& event, uint64_t safepoint_id) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.commit();
  }
}

// SafepointCheck
SafepointStateTracker::SafepointStateTracker(uint64_t safepoint_id, bool at_safepoint)
  : _safepoint_id(safepoint_id), _at_safepoint(at_safepoint) {}

bool SafepointStateTracker::safepoint_state_changed() {

src/hotspot/share/runtime/safepoint.cpp:

  // Release threads lock, so threads can be created/destroyed again.
  Threads_lock->unlock();

  // Wake threads after local state is correctly set.
  _wait_barrier->disarm();
}

// Wake up all threads, so they are ready to resume execution after the safepoint
// operation has been carried out
void SafepointSynchronize::end() {
  assert(Threads_lock->owned_by_self(), "must hold Threads_lock");
  SafepointTracing::leave();

  EventSafepointEnd event;
  assert(Thread::current()->is_VM_thread(), "Only VM thread can execute a safepoint");

  log_trace(safepoint)("Disarming safepoint");
  disarm_safepoint();

  log_trace(safepoint)("Resuming GC threads");
  Universe::heap()->safepoint_synchronize_end();

  SafepointTracing::end();

  post_safepoint_end_event(event, safepoint_id());

Configuration enabled threshold
profiling false 0 ms
default false 10 ms

Field Type Description
safepointId ulong Safepoint Identifier

Examples 3
safepointId ulong
724
startTime long: millis
420629364028
safepointId ulong
1490
startTime long: millis
279786673728
safepointId ulong
1217
startTime long: millis
415694863789

SafepointLatency

throttle startTime duration eventThread stackTrace 25 26 27

Category: Java Virtual Machine / Runtime / Safepoint

The delay for a thread to reach its next safepoint poll instruction after receiving an asynchronous sampling interrupt

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampling.cpp:

static inline void send_sample_event(const JfrTicks& start_time, const JfrTicks& end_time, traceid sid, traceid tid) {
  EventType event(UNTIMED);
  event.set_starttime(start_time);
  event.set_endtime(end_time);
  event.set_sampledThread(tid);
  event.set_state(static_cast<u8>(JavaThreadStatus::RUNNABLE));
  event.set_stackTrace(sid);
  event.commit();
}

static inline void send_safepoint_latency_event(const JfrSampleRequest& request, const JfrTicks& end_time, traceid sid, const JavaThread* jt) {
  assert(jt != nullptr, "invariant");
  assert(!jt->jfr_thread_local()->has_cached_stack_trace(), "invariant");
  EventSafepointLatency event(UNTIMED);
  event.set_starttime(request._sample_ticks);
  event.set_endtime(end_time);
  if (event.should_commit()) {
    event.set_threadState(_thread_in_Java);
    jt->jfr_thread_local()->set_cached_stack_trace_id(sid);
    event.commit();
    jt->jfr_thread_local()->clear_cached_stack_trace();
  }
}

static inline bool is_interpreter(address pc) {

Configuration enabled stackTrace threshold throttle
profiling false false 0 ms off
default false true 0 ms off

Field Type Description
threadState VMThreadState VM Thread State

ExecuteVMOperation

profiling default startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime

Execution of a VM Operation

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/vmThread.cpp:

  // Wait until VM thread is terminated
  // Note: it should be OK to use Terminator_lock here. But this is called
  // at a very delicate time (VM shutdown) and we are operating in non- VM
  // thread at Safepoint. It's safer to not share lock with other threads.
  {
    MonitorLocker ml(_terminate_lock, Mutex::_no_safepoint_check_flag);
    while (!VMThread::is_terminated()) {
      ml.wait();
    }
  }
}

static void post_vm_operation_event(EventExecuteVMOperation* event, VM_Operation* op) {
  assert(event != nullptr, "invariant");
  assert(op != nullptr, "invariant");
  const bool evaluate_at_safepoint = op->evaluate_at_safepoint();
  event->set_operation(op->type());
  event->set_safepoint(evaluate_at_safepoint);
  event->set_blocking(true);
  event->set_caller(JFR_THREAD_ID(op->calling_thread()));
  event->set_safepointId(evaluate_at_safepoint ? SafepointSynchronize::safepoint_id() : 0);
  event->commit();
}

void VMThread::evaluate_operation(VM_Operation* op) {
  ResourceMark rm;

  {
    PerfTraceTime vm_op_timer(perf_accumulated_vm_operation_time());
    HOTSPOT_VMOPS_BEGIN(
                     (char*) op->name(), strlen(op->name()),
                     op->evaluate_at_safepoint() ? 0 : 1);

    EventExecuteVMOperation event;
    VMThreadCPUTimeScope CPUTimeScope(this, op->is_gc_operation());
    op->evaluate();
    if (event.should_commit()) {
      post_vm_operation_event(&event, op);
    }

    HOTSPOT_VMOPS_END(
                     (char*) op->name(), strlen(op->name()),
                     op->evaluate_at_safepoint() ? 0 : 1);
  }
}

Configuration enabled threshold
profiling true 0 ms
default true 10 ms

Field Type Description
operation VMOperationType Operation
safepoint boolean At Safepoint If the operation occurred at a safepoint
blocking boolean Caller Blocked If the calling thread was blocked until the operation was complete
caller Thread Caller Thread requesting operation. If non-blocking, will be set to 0 indicating thread is unknown
safepointId ulong Safepoint Identifier The safepoint (if any) under which this operation was completed

Examples 3
blocking boolean
true
caller Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
JFR Periodic Tasks
javaThreadId long
22
osName string
JFR Periodic Tasks
osThreadId long
2311
virtual boolean
false
operation VMOperationType
ClassLoaderStatsOperation
safepoint boolean
true
safepointId ulong
1524
startTime long: millis
287889429185
blocking boolean
true
caller Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
main
javaThreadId long
1
osName string
main
osThreadId long
2926
virtual boolean
false
operation VMOperationType
HandshakeAllThreads
safepoint boolean
false
safepointId ulong
0
startTime long: millis
441346571759
blocking boolean
true
caller Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
JFR Periodic Tasks
javaThreadId long
14
osName string
JFR Periodic Tasks
osThreadId long
2269
virtual boolean
false
operation VMOperationType
GC_HeapInspection
safepoint boolean
true
safepointId ulong
1216
startTime long: millis
413449354988

Shutdown

profiling default startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime

JVM shutting down

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/threads.cpp:

  // Wait until we are the last non-daemon thread to execute, or
  // if we are a daemon then wait until the last non-daemon thread has
  // executed.
  bool daemon = java_lang_Thread::is_daemon(thread->threadObj());
  int expected = daemon ? 0 : 1;
  {
    MonitorLocker nu(Threads_lock);
    while (Threads::number_of_non_daemon_threads() > expected)
      // This wait should make safepoint checks, wait without a timeout.
      nu.wait(0);
  }

  EventShutdown e;
  if (e.should_commit()) {
    e.set_reason("No remaining non-daemon Java threads");
    e.commit();
  }

  // Hang forever on exit if we are reporting an error.
  if (ShowMessageBoxOnError && VMError::is_error_reported()) {
    os::infinite_sleep();
  }
  os::wait_for_keypress_at_exit();

src/hotspot/share/jfr/recorder/repository/jfrEmergencyDump.cpp:

  void transition_to_native() {
    if (_jt != nullptr) {
      assert(_jt->thread_state() == _thread_in_vm, "invariant");
      _jt->set_thread_state(_thread_in_native);
    }
  }
};

static void post_events(bool exception_handler, bool oom, Thread * thread) {
  if (exception_handler) {
    EventShutdown e;
    e.set_reason(oom ? "CrashOnOutOfMemoryError" : "VM Error");
    e.commit();
  }
  EventDumpReason event;
  event.set_reason(exception_handler && oom ? "CrashOnOutOfMemoryError" : exception_handler ? "Crash" : "Out of Memory");
  event.set_recordingId(-1);
  event.commit();
}

static volatile traceid _jfr_shutdown_tid = 0;

src/hotspot/share/prims/jvm.cpp:

JVM_ENTRY(jstring, JVM_GetTemporaryDirectory(JNIEnv *env))
  HandleMark hm(THREAD);
  const char* temp_dir = os::get_temp_directory();
  Handle h = java_lang_String::create_from_platform_dependent_str(temp_dir, CHECK_NULL);
  return (jstring) JNIHandles::make_local(THREAD, h());
JVM_END


// java.lang.Runtime /////////////////////////////////////////////////////////////////////////

extern volatile jint vm_created;

JVM_ENTRY_NO_ENV(void, JVM_BeforeHalt())
  EventShutdown event;
  if (event.should_commit()) {
    event.set_reason("Shutdown requested from Java");
    event.commit();
  }
JVM_END


JVM_ENTRY_NO_ENV(void, JVM_Halt(jint code))
  before_exit(thread, true);
  vm_exit(code);
JVM_END

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
reason string Reason Reason for JVM shutdown

Examples 3
reason string
No remaining non-daemon Java threads
stackTrace StackTrace
null
startTime long: millis
367335947087
reason string
No remaining non-daemon Java threads
stackTrace StackTrace
null
startTime long: millis
482443717902
reason string
No remaining non-daemon Java threads
stackTrace StackTrace
null
startTime long: millis
493401214751

SymbolTableStatistics

profiling startTime duration every chunk 13 17 21 25 26 27

Category: Java Virtual Machine / Runtime / Tables

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.set_entryCount(statistics._number_of_entries);
  event.set_totalFootprint(statistics._total_footprint);
  event.set_bucketCountMaximum(statistics._maximum_bucket_size);
  event.set_bucketCountAverage(statistics._average_bucket_size);
  event.set_bucketCountVariance(statistics._variance_of_bucket_size);
  event.set_bucketCountStandardDeviation(statistics._stddev_of_bucket_size);
  event.set_insertionRate(statistics._add_rate);
  event.set_removalRate(statistics._remove_rate);
  event.commit();
}

TRACE_REQUEST_FUNC(SymbolTableStatistics) {
  TableStatistics statistics = SymbolTable::get_table_statistics();
  emit_table_statistics<EventSymbolTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(StringTableStatistics) {
  TableStatistics statistics = StringTable::get_table_statistics();
  emit_table_statistics<EventStringTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(CompilerStatistics) {
  EventCompilerStatistics event;
  event.set_compileCount(CompileBroker::get_total_compile_count());
  event.set_bailoutCount(CompileBroker::get_total_bailout_count());

Configuration enabled period
profiling true 10 s
default false 10 s

Field Type Description
bucketCount ulong Bucket Count Number of buckets
entryCount ulong Entry Count Number of all entries
totalFootprint ulong: bytes Total Footprint Total memory footprint (the table itself plus all of the entries)
bucketCountMaximum ulong Maximum Bucket Count The maximum bucket length (entries in a single bucket)
bucketCountAverage float Average Bucket Count The average bucket length
bucketCountVariance float Bucket Count Variance How far bucket lengths are spread out from their average value
bucketCountStandardDeviation float Bucket Count Standard Deviation How far bucket lengths are spread out from their mean (expected) value
insertionRate float Insertion Rate How many items were added since last event (per second)
removalRate float Removal Rate How many items were removed since last event (per second)

Examples 3
bucketCount ulong
131072
bucketCountAverage float
4.3553925
bucketCountMaximum ulong
17
bucketCountStandardDeviation float
2.088268
bucketCountVariance float
4.3608637
entryCount ulong
570870
insertionRate float
454.71884
removalRate float
4614.919
startTime long: millis
363644732907
totalFootprint ulong: bytes
64516584
bucketCount ulong
65536
bucketCountAverage float
7.723053
bucketCountMaximum ulong
21
bucketCountStandardDeviation float
2.783897
bucketCountVariance float
7.7500825
entryCount ulong
506138
insertionRate float
776.41315
removalRate float
210.8083
startTime long: millis
445591318730
totalFootprint ulong: bytes
54797720
bucketCount ulong
65536
bucketCountAverage float
7.8194885
bucketCountMaximum ulong
21
bucketCountStandardDeviation float
2.806837
bucketCountVariance float
7.878335
entryCount ulong
512458
insertionRate float
697.4281
removalRate float
194.95113
startTime long: millis
449986484396
totalFootprint ulong: bytes
55223752

StringTableStatistics

profiling startTime duration every chunk 13 17 21 25 26 27

Category: Java Virtual Machine / Runtime / Tables

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.set_bucketCountStandardDeviation(statistics._stddev_of_bucket_size);
  event.set_insertionRate(statistics._add_rate);
  event.set_removalRate(statistics._remove_rate);
  event.commit();
}

TRACE_REQUEST_FUNC(SymbolTableStatistics) {
  TableStatistics statistics = SymbolTable::get_table_statistics();
  emit_table_statistics<EventSymbolTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(StringTableStatistics) {
  TableStatistics statistics = StringTable::get_table_statistics();
  emit_table_statistics<EventStringTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(CompilerStatistics) {
  EventCompilerStatistics event;
  event.set_compileCount(CompileBroker::get_total_compile_count());
  event.set_bailoutCount(CompileBroker::get_total_bailout_count());
  event.set_invalidatedCount(CompileBroker::get_total_invalidated_count());
  event.set_osrCompileCount(CompileBroker::get_total_osr_compile_count());
  event.set_standardCompileCount(CompileBroker::get_total_standard_compile_count());
  event.set_osrBytesCompiled(CompileBroker::get_sum_osr_bytes_compiled());
  event.set_standardBytesCompiled(CompileBroker::get_sum_standard_bytes_compiled());

Configuration enabled period
profiling true 10 s
default false 10 s

Field Type Description
bucketCount ulong Bucket Count Number of buckets
entryCount ulong Entry Count Number of all entries
totalFootprint ulong: bytes Total Footprint Total memory footprint (the table itself plus all of the entries)
bucketCountMaximum ulong Maximum Bucket Count The maximum bucket length (entries in a single bucket)
bucketCountAverage float Average Bucket Count The average bucket length
bucketCountVariance float Bucket Count Variance How far bucket lengths are spread out from their average value
bucketCountStandardDeviation float Bucket Count Standard Deviation How far bucket lengths are spread out from their mean (expected) value
insertionRate float Insertion Rate How many items were added since last event (per second)
removalRate float Removal Rate How many items were removed since last event (per second)

Examples 3
bucketCount ulong
65536
bucketCountAverage float
1.8015137
bucketCountMaximum ulong
10
bucketCountStandardDeviation float
1.3373764
bucketCountVariance float
1.7885756
entryCount ulong
118064
insertionRate float
186.0301
removalRate float
13.969474
startTime long: millis
363670276960
totalFootprint ulong: bytes
12102712
bucketCount ulong
65536
bucketCountAverage float
1.7816162
bucketCountMaximum ulong
10
bucketCountStandardDeviation float
1.3207544
bucketCountVariance float
1.7443923
entryCount ulong
116760
insertionRate float
434.7887
removalRate float
36.967827
startTime long: millis
476128955040
totalFootprint ulong: bytes
11956552
bucketCount ulong
65536
bucketCountAverage float
1.581253
bucketCountMaximum ulong
9
bucketCountStandardDeviation float
1.2578933
bucketCountVariance float
1.5822957
entryCount ulong
103629
insertionRate float
549.9137
removalRate float
49.690456
startTime long: millis
461149014010
totalFootprint ulong: bytes
11683080

ThreadDump

profiling default startTime duration every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

/*
 * This is left empty on purpose, having ExecutionSample as a requestable
 * is a way of getting the period. The period is passed to ThreadSampling::update_period.
 * Implementation in periodic/sampling/jfrThreadSampler.cpp.
 */
TRACE_REQUEST_FUNC(ExecutionSample) {
}
TRACE_REQUEST_FUNC(NativeMethodSample) {
}

TRACE_REQUEST_FUNC(ThreadDump) {
  ResourceMark rm;
  EventThreadDump event;
  event.set_result(JfrDcmdEvent::thread_dump());
  event.commit();
}

static int _native_library_callback(const char* name, address base, address top, void *param) {
  EventNativeLibrary event(UNTIMED);
  event.set_name(name);
  event.set_baseAddress((u8)base);
  event.set_topAddress((u8)top);
  event.set_starttime(*(JfrTicks*)param);
  event.set_endtime(*(JfrTicks*) param);

Configuration enabled period
profiling true 60 s
default true everyChunk

Field Type Description
result string Thread Dump

Examples 3
result string
2026-01-04 00:46:43 Full thread dump OpenJDK 64-Bit Server VM (21.0.9+10-LTS mixed mode, sharing): Threads class SMR info: _java_thread_list=0x00007f303c3b0e00, length=45, elements={ 0x00007f30d4057c80, 0x00007f30d41320c0, 0x00007f30d41335f0, 0x00007f30d4134d40, 0x00007f30d4136340, 0x00007f30d41378
startTime long: millis
435465753170
result string
2026-01-04 00:44:59 Full thread dump OpenJDK 64-Bit Server VM (21.0.9+10-LTS mixed mode, sharing): Threads class SMR info: _java_thread_list=0x00007f58c0689570, length=68, elements={ 0x00007f594c057cc0, 0x00007f594c196b80, 0x00007f594c1980e0, 0x00007f594c199860, 0x00007f594c19ae90, 0x00007f594c19c4
startTime long: millis
332347553041
result string
2026-01-04 00:47:08 Full thread dump OpenJDK 64-Bit Server VM (21.0.9+10-LTS mixed mode, sharing): Threads class SMR info: _java_thread_list=0x00007fb93401c0d0, length=51, elements={ 0x00007fb9b4057c60, 0x00007fb9b40ac860, 0x00007fb9b40add90, 0x00007fb9b40af4e0, 0x00007fb9b40b0ae0, 0x00007fb9b40b20
startTime long: millis
472193057213

NativeLibrary

profiling default startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime

Information about a dynamic library or other native image loaded by the JVM process

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

TRACE_REQUEST_FUNC(ExecutionSample) {
}
TRACE_REQUEST_FUNC(NativeMethodSample) {
}

TRACE_REQUEST_FUNC(ThreadDump) {
  ResourceMark rm;
  EventThreadDump event;
  event.set_result(JfrDcmdEvent::thread_dump());
  event.commit();
}

static int _native_library_callback(const char* name, address base, address top, void *param) {
  EventNativeLibrary event(UNTIMED);
  event.set_name(name);
  event.set_baseAddress((u8)base);
  event.set_topAddress((u8)top);
  event.set_starttime(*(JfrTicks*)param);
  event.set_endtime(*(JfrTicks*) param);
  event.commit();
  return 0;
}

TRACE_REQUEST_FUNC(NativeLibrary) {
  JfrTicks ts= JfrTicks::now();

Configuration enabled period
profiling true everyChunk
default true everyChunk

Field Type Description
name string Name
baseAddress ulong: address Base Address Starting address of the module
topAddress ulong: address Top Address Ending address of the module, if available

Examples 3
baseAddress ulong: address
140435722596352
name string
/lib/x86_64-linux-gnu/libpthread.so.0
startTime long: millis
382361844279
topAddress ulong: address
140435722616832
baseAddress ulong: address
140021578309632
name string
/opt/hostedtoolcache/Java_SapMachine_jdk/21.0.9/x64/lib/libextnet.so
startTime long: millis
282840145773
topAddress ulong: address
140021578326016
baseAddress ulong: address
139847843352576
name string
/lib64/ld-linux-x86-64.so.2
startTime long: millis
371363139548
topAddress ulong: address
139847843590144

NativeLibraryLoad

profiling default startTime duration eventThread stackTrace 22 25 26 27

Category: Java Virtual Machine / Runtime

Information about a dynamic library or other native image load operation

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/support/jfrNativeLibraryLoadEvent.cpp:

/*
 * The JfrTicks value is heap allocated inside an object of type JfrTicksWrapper.
 * The reason is that a raw value object of type Ticks is not possible at this
 * location because this code runs as part of early VM bootstrap, at a moment
 * where Ticks support is not yet initialized.
 */
template <typename EventType>
static inline JfrTicksWrapper* allocate_start_time() {
  return EventType::is_enabled() ? new JfrTicksWrapper() : nullptr;
}

NativeLibraryLoadEvent::NativeLibraryLoadEvent(const char* name, void** result) : JfrNativeLibraryEventBase(name), _result(result), _fp_env_correction_attempt(false), _fp_env_correction_success(false) {
  assert(_result != nullptr, "invariant");
  _start_time = allocate_start_time<EventNativeLibraryLoad>();
}

bool NativeLibraryLoadEvent::success() const {
  return *_result != nullptr;
}

NativeLibraryUnloadEvent::NativeLibraryUnloadEvent(const char* name) : JfrNativeLibraryEventBase(name), _result(false) {
  _start_time = allocate_start_time<EventNativeLibraryUnload>();
}

bool NativeLibraryUnloadEvent::success() const {
  return _result;
}

void NativeLibraryUnloadEvent::set_result(bool result) {
  _result = result;
}

static void set_additional_data(EventNativeLibraryLoad& event, const NativeLibraryLoadEvent& helper) {
  event.set_fpuCorrectionAttempt(helper.get_fp_env_correction_attempt());
  event.set_fpuCorrectionSuccess(helper.get_fp_env_correction_success());
}

static void set_additional_data(EventNativeLibraryUnload& event, const NativeLibraryUnloadEvent& helper) {
  // no additional entries atm. for the unload event
}

template <typename EventType, typename HelperType>
static void commit(const HelperType& helper) {
  if (!helper.has_start_time()) {

src/hotspot/share/jfr/support/jfrNativeLibraryLoadEvent.cpp:

  assert(thread != nullptr, "invariant");
  if (thread->is_Java_thread()) {
    JavaThread* jt = JavaThread::cast(thread);
    if (jt->thread_state() == _thread_in_native) {
      // For a JavaThread to take a JFR stacktrace, it must be in _thread_in_vm. Can safepoint here.
      MACOS_AARCH64_ONLY(ThreadWXEnable __wx(WXWrite, jt));
      ThreadInVMfromNative transition(jt);
      event.commit();
      return;
    }
    // If a thread comes here still _thread_in_Java, which can happen for example
    // when loading the disassembler library in response to traps in JIT code - all is ok.
    // Since there is no ljf, an event will be committed without a stacktrace.
  }
  event.commit();
}

NativeLibraryLoadEvent::~NativeLibraryLoadEvent() {
  commit<EventNativeLibraryLoad>(*this);
}

NativeLibraryUnloadEvent::~NativeLibraryUnloadEvent() {
  commit<EventNativeLibraryUnload>(*this);
}

Configuration enabled stackTrace threshold
profiling true true 0 ms
default true true 0 ms

Field Type Description
name string Name
success boolean Success Success or failure of the load operation
errorMessage string Error Message In case of a load error, error description
fpuCorrectionAttempt boolean 23+ FPU Environment Correction In case of IEEE conformance issues we might reset the FP environment
fpuCorrectionSuccess boolean 23+ FPU Environment Correction Result Stores the result in the case of an FP environment correction

NativeLibraryUnload

profiling default startTime duration eventThread stackTrace 22 25 26 27

Category: Java Virtual Machine / Runtime

Information about a dynamic library or other native image unload operation

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/support/jfrNativeLibraryLoadEvent.cpp:

static inline JfrTicksWrapper* allocate_start_time() {
  return EventType::is_enabled() ? new JfrTicksWrapper() : nullptr;
}

NativeLibraryLoadEvent::NativeLibraryLoadEvent(const char* name, void** result) : JfrNativeLibraryEventBase(name), _result(result), _fp_env_correction_attempt(false), _fp_env_correction_success(false) {
  assert(_result != nullptr, "invariant");
  _start_time = allocate_start_time<EventNativeLibraryLoad>();
}

bool NativeLibraryLoadEvent::success() const {
  return *_result != nullptr;
}

NativeLibraryUnloadEvent::NativeLibraryUnloadEvent(const char* name) : JfrNativeLibraryEventBase(name), _result(false) {
  _start_time = allocate_start_time<EventNativeLibraryUnload>();
}

bool NativeLibraryUnloadEvent::success() const {
  return _result;
}

void NativeLibraryUnloadEvent::set_result(bool result) {
  _result = result;
}

static void set_additional_data(EventNativeLibraryLoad& event, const NativeLibraryLoadEvent& helper) {
  event.set_fpuCorrectionAttempt(helper.get_fp_env_correction_attempt());
  event.set_fpuCorrectionSuccess(helper.get_fp_env_correction_success());
}

static void set_additional_data(EventNativeLibraryUnload& event, const NativeLibraryUnloadEvent& helper) {
  // no additional entries atm. for the unload event
}

template <typename EventType, typename HelperType>
static void commit(const HelperType& helper) {
  if (!helper.has_start_time()) {
    return;
  }
  EventType event(UNTIMED);
  event.set_endtime(JfrTicks::now());
  event.set_starttime(*helper.start_time());

src/hotspot/share/jfr/support/jfrNativeLibraryLoadEvent.cpp:

  assert(thread != nullptr, "invariant");
  if (thread->is_Java_thread()) {
    JavaThread* jt = JavaThread::cast(thread);
    if (jt->thread_state() == _thread_in_native) {
      // For a JavaThread to take a JFR stacktrace, it must be in _thread_in_vm. Can safepoint here.
      MACOS_AARCH64_ONLY(ThreadWXEnable __wx(WXWrite, jt));
      ThreadInVMfromNative transition(jt);
      event.commit();
      return;
    }
    // If a thread comes here still _thread_in_Java, which can happen for example
    // when loading the disassembler library in response to traps in JIT code - all is ok.
    // Since there is no ljf, an event will be committed without a stacktrace.
  }
  event.commit();
}

NativeLibraryLoadEvent::~NativeLibraryLoadEvent() {
  commit<EventNativeLibraryLoad>(*this);
}

NativeLibraryUnloadEvent::~NativeLibraryUnloadEvent() {
  commit<EventNativeLibraryUnload>(*this);
}

Configuration enabled stackTrace threshold
profiling true true 0 ms
default true true 0 ms

Field Type Description
name string Name
success boolean Success Success or failure of the unload operation
errorMessage string Error Message In case of an unload error, error description

ModuleRequire

profiling default startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime / Modules

A directed edge representing a dependency

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrModuleEvent.cpp:

   ModuleDependencyClosure(const ModuleEntry* module, EventFunc ef) : ModuleEventCallbackClosure(ef), _module(module) {}
   void do_module(ModuleEntry* entry);
};

class ModuleExportClosure : public ModuleEventCallbackClosure {
 private:
  const PackageEntry* const _package;
 public:
  ModuleExportClosure(const PackageEntry* pkg, EventFunc ef) : ModuleEventCallbackClosure(ef), _package(pkg) {}
  void do_module(ModuleEntry* entry);
};

static void write_module_dependency_event(const void* from_module, const ModuleEntry* to_module) {
  EventModuleRequire event(UNTIMED);
  event.set_starttime(invocation_time);
  event.set_endtime(invocation_time);
  event.set_source((const ModuleEntry*)from_module);
  event.set_requiredModule(to_module);
  event.commit();
}

static void write_module_export_event(const void* package, const ModuleEntry* qualified_export) {
  EventModuleExport event(UNTIMED);
  event.set_starttime(invocation_time);
  event.set_endtime(invocation_time);

Configuration enabled period
profiling true endChunk
default true endChunk

Field Type Description
source Module Source Module
requiredModule Module Required Module

Examples 3
requiredModule Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.xml
name string
java.xml
version string
21.0.9
source Module
classLoader ClassLoader
name string
app
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
10
name string
jdk/internal/loader/ClassLoaders$AppClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
jdk/internal/loader
location string
jrt:/jdk.javadoc
name string
jdk.javadoc
version string
21.0.9
startTime long: millis
382361859327
requiredModule Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
source Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
jdk.proxy7
version string
null
startTime long: millis
374646122291
requiredModule Module
classLoader ClassLoader
name string
platform
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
10
name string
jdk/internal/loader/ClassLoaders$PlatformClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
jdk/internal/loader
location string
jrt:/java.compiler
name string
java.compiler
version string
21.0.9
source Module
classLoader ClassLoader
name string
app
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
10
name string
jdk/internal/loader/ClassLoaders$AppClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
jdk/internal/loader
location string
jrt:/jdk.jshell
name string
jdk.jshell
version string
21.0.9
startTime long: millis
279631473390

ModuleExport

profiling startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime / Modules

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrModuleEvent.cpp:

  void do_module(ModuleEntry* entry);
};

static void write_module_dependency_event(const void* from_module, const ModuleEntry* to_module) {
  EventModuleRequire event(UNTIMED);
  event.set_starttime(invocation_time);
  event.set_endtime(invocation_time);
  event.set_source((const ModuleEntry*)from_module);
  event.set_requiredModule(to_module);
  event.commit();
}

static void write_module_export_event(const void* package, const ModuleEntry* qualified_export) {
  EventModuleExport event(UNTIMED);
  event.set_starttime(invocation_time);
  event.set_endtime(invocation_time);
  event.set_exportedPackage((const PackageEntry*)package);
  event.set_targetModule(qualified_export);
  event.commit();
}

void ModuleDependencyClosure::do_module(ModuleEntry* to_module) {
  assert_locked_or_safepoint(Module_lock);
  assert(to_module != nullptr, "invariant");
  assert(_module != nullptr, "invariant");

Configuration enabled period
profiling true endChunk
default false endChunk

Field Type Description
exportedPackage Package Exported Package
targetModule Module Target Module Module to which the package is qualifiedly exported. If null or N/A, the package is unqualifiedly exported

Examples 3
exportedPackage Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
io/netty/handler/timeout
startTime long: millis
279631749684
targetModule Module
null
exportedPackage Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/sql/execution/datasources/csv
startTime long: millis
374646561997
targetModule Module
null
exportedPackage Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.management
name string
java.management
version string
21.0.9
name string
sun/management
startTime long: millis
382362306931
targetModule Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/jdk.management
name string
jdk.management
version string
21.0.9

Java Application

ThreadStart

profiling default startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Application

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/support/jfrThreadLocal.cpp:

  assert(Thread::is_starting_thread(jt), "invariant");
  assert(jt->threadObj() == nullptr, "invariant");
  assert(jt->jfr_thread_local()->_jvm_thread_id == 0, "invariant");
  jt->jfr_thread_local()->_jvm_thread_id = ThreadIdentifier::initial();
}

static void send_java_thread_start_event(JavaThread* jt) {
  assert(jt != nullptr, "invariant");
  assert(Thread::current() == jt, "invariant");
  if (!JfrJavaSupport::on_thread_start(jt)) {
    // thread is excluded
    return;
  }
  EventThreadStart event;
  traceid thread_id = JfrThreadLocal::jvm_thread_id(jt);
  assert(thread_id != 0, "invariant");
  event.set_thread(thread_id);
  event.set_parentThread(jt->jfr_thread_local()->parent_thread_id());
  event.commit();
}

void JfrThreadLocal::on_start(Thread* t) {
  JfrThreadLocal* const tl = t->jfr_thread_local();
  assert(tl != nullptr, "invariant");
  assign_thread_id(t, tl);

src/hotspot/share/jfr/support/jfrThreadLocal.cpp:

// The starter thread ensures that the startee has a valid _vm_thread_id and _contextual_id.
// This is to avoid recursion in thread assignment since accessing the java threadObj can lead
// to events being fired, a situation the starter thread can handle but not the startee.
void JfrThreadLocal::on_java_thread_start(JavaThread* starter, JavaThread* startee) {
  assert(starter != nullptr, "invariant");
  assert(startee != nullptr, "invariant");
  JfrThreadLocal* const tl = startee->jfr_thread_local();
  assign_thread_id(startee, tl);
  assert(vthread_id(startee) != 0, "invariant");
  assert(jvm_thread_id(startee) == vthread_id(startee), "invariant");
  if (JfrRecorder::is_recording() && EventThreadStart::is_enabled() && EventThreadStart::is_stacktrace_enabled()) {
    // skip level 2 to skip frames Thread.start() and Thread.start0()
    startee->jfr_thread_local()->set_cached_stack_trace_id(JfrStackTraceRepository::record(starter, 2));
  }
}

void JfrThreadLocal::release(Thread* t) {
  if (has_java_event_writer()) {
    assert(t->is_Java_thread(), "invariant");
    JfrJavaSupport::destroy_global_jni_handle(java_event_writer());
    _java_event_writer = nullptr;
  }

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
thread Thread New Java Thread
parentThread Thread Parent Java Thread

Examples 3
parentThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-75
javaThreadId long
1319
osName string
block-manager-storage-async-thread-pool-75
osThreadId long
3921
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
2
lineNumber int
2577
method Method
descriptor string
(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden boolean
false
modifiers int
1
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/lang/System$2
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Inlined
truncated boolean
false
startTime long: millis
305062413344
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-77
javaThreadId long
1321
osName string
block-manager-storage-async-thread-pool-77
osThreadId long
3923
virtual boolean
false
parentThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-69
javaThreadId long
1306
osName string
block-manager-storage-async-thread-pool-69
osThreadId long
4563
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
2
lineNumber int
2577
method Method
descriptor string
(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden boolean
false
modifiers int
1
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/lang/System$2
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Inlined
truncated boolean
false
startTime long: millis
400784241923
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-71
javaThreadId long
1308
osName string
block-manager-storage-async-thread-pool-71
osThreadId long
4565
virtual boolean
false
parentThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-84
javaThreadId long
1316
osName string
block-manager-storage-async-thread-pool-84
osThreadId long
3936
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
2
lineNumber int
2577
method Method
descriptor string
(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden boolean
false
modifiers int
1
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/lang/System$2
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Inlined
truncated boolean
false
startTime long: millis
424084554655
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-91
javaThreadId long
1324
osName string
block-manager-storage-async-thread-pool-91
osThreadId long
3944
virtual boolean
false

ThreadEnd

profiling default startTime eventThread 11 17 21 25 26 27

Category: Java Application

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/java.cpp:

#if INCLUDE_CDS
  ClassListWriter::write_resolved_constants();

  if (CDSConfig::is_dumping_preimage_static_archive()) {
    AOTMetaspace::dump_static_archive(thread);
  }
#endif

  // Hang forever on exit if we're reporting an error.
  if (ShowMessageBoxOnError && VMError::is_error_reported()) {
    os::infinite_sleep();
  }

  EventThreadEnd event;
  if (event.should_commit()) {
    event.set_thread(JFR_JVM_THREAD_ID(thread));
    event.commit();
  }

  JFR_ONLY(Jfr::on_vm_shutdown(false, halt);)

  // Stop the WatcherThread. We do this before disenrolling various
  // PeriodicTasks to reduce the likelihood of races.
  WatcherThread::stop();

src/hotspot/share/jfr/support/jfrThreadLocal.cpp:

  assert(t != nullptr, "invariant");
  assert(Thread::current() == t, "invariant");
  assert(!tl->is_dead(), "invariant");
  assert(tl->shelved_buffer() == nullptr, "invariant");
  tl->_dead = true;
  tl->release(t);
}

static void send_java_thread_end_event(JavaThread* jt, traceid tid) {
  assert(jt != nullptr, "invariant");
  assert(Thread::current() == jt, "invariant");
  assert(tid != 0, "invariant");
  if (JfrRecorder::is_recording()) {
    EventThreadEnd event;
    event.set_thread(tid);
    event.commit();
    ObjectSampleCheckpoint::on_thread_exit(tid);
  }
}

void JfrThreadLocal::on_exit(Thread* t) {
  assert(t != nullptr, "invariant");
  JfrThreadLocal * const tl = t->jfr_thread_local();
  assert(!tl->is_dead(), "invariant");
  if (JfrRecorder::is_recording()) {

Configuration enabled
profiling true
default true

Field Type Description
thread Thread Java Thread

Examples 3
startTime long: millis
417462258569
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-23
javaThreadId long
1213
osName string
block-manager-storage-async-thread-pool-23
osThreadId long
3818
virtual boolean
false
startTime long: millis
406970678125
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-ask-thread-pool-0
javaThreadId long
1190
osName string
block-manager-ask-thread-pool-0
osThreadId long
4431
virtual boolean
false
startTime long: millis
310949691039
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
SparkUI-1154-acceptor-0@b5b215d-Spark@59cde46{HTTP/1.1, (http/1.1)}{0.0.0.0:4040}
javaThreadId long
1154
osName string
SparkUI-1154-acceptor-0@b5b215d-Spark@59cde46{HTTP/1.1, (http/1.1)}{0.0.0.0:4040}
osThreadId long
3708
virtual boolean
false

ThreadPark

profiling default startTime duration eventThread stackTrace 11 17 21 25 26 27

Category: Java Application

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/prims/unsafe.cpp:

UNSAFE_ENTRY_SCOPED(jboolean, Unsafe_CompareAndSetInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
  oop p = JNIHandles::resolve(obj);
  volatile jint* addr = (volatile jint*)index_oop_from_field_offset_long(p, offset);
  return AtomicAccess::cmpxchg(addr, e, x) == e;
} UNSAFE_END

UNSAFE_ENTRY_SCOPED(jboolean, Unsafe_CompareAndSetLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
  oop p = JNIHandles::resolve(obj);
  volatile jlong* addr = (volatile jlong*)index_oop_from_field_offset_long(p, offset);
  return AtomicAccess::cmpxchg(addr, e, x) == e;
} UNSAFE_END

static void post_thread_park_event(EventThreadPark* event, const oop obj, jlong timeout_nanos, jlong until_epoch_millis) {
  assert(event != nullptr, "invariant");
  event->set_parkedClass((obj != nullptr) ? obj->klass() : nullptr);
  event->set_timeout(timeout_nanos);
  event->set_until(until_epoch_millis);
  event->set_address((obj != nullptr) ? (u8)cast_from_oop<uintptr_t>(obj) : 0);
  event->commit();
}

UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time)) {
  HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time);
  EventThreadPark event;

  JavaThreadParkedState jtps(thread, time != 0);
  thread->parker()->park(isAbsolute != 0, time);
  if (event.should_commit()) {
    const oop obj = thread->current_park_blocker();
    if (time == 0) {
      post_thread_park_event(&event, obj, min_jlong, min_jlong);
    } else {
      if (isAbsolute != 0) {
        post_thread_park_event(&event, obj, min_jlong, time);
      } else {

Configuration enabled stackTrace threshold
profiling true true 10 ms
default true true 20 ms

Field Type Description
parkedClass Class Class Parked On
timeout long: nanos Park Timeout
until long: epochmillis Park Until
address ulong: address Address of Object Parked

Examples 3
address ulong: address
30347316376
parkedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionObject
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent/locks
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(ZJ)V
hidden boolean
false
modifiers int
257
name string
park
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
jdk/internal/misc/Unsafe
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
jdk/internal/misc
type FrameType
Native
truncated boolean
false
startTime long: millis
366275063726
timeout long: nanos
119998263947
until long: epochmillis
-9223372036854775808
address ulong: address
30318888256
parkedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionObject
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent/locks
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(ZJ)V
hidden boolean
false
modifiers int
257
name string
park
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
jdk/internal/misc/Unsafe
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
jdk/internal/misc
type FrameType
Native
truncated boolean
false
startTime long: millis
278781409091
timeout long: nanos
99999910
until long: epochmillis
-9223372036854775808
address ulong: address
31746013088
parkedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionObject
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent/locks
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(ZJ)V
hidden boolean
false
modifiers int
257
name string
park
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
jdk/internal/misc/Unsafe
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
jdk/internal/misc
type FrameType
Native
truncated boolean
false
startTime long: millis
373341463242
timeout long: nanos
999999920
until long: epochmillis
-9223372036854775808

JavaMonitorEnter

profiling default startTime duration eventThread stackTrace 11 17 21 25 26 27

Category: Java Application

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/objectMonitor.cpp:

    // yet appear on any queues that would get it made the successor.
    // This means that the JVMTI_EVENT_MONITOR_CONTENDED_ENTER event
    // handler cannot accidentally consume an unpark() meant for the
    // ParkEvent associated with this ObjectMonitor.
  }
}

void ObjectMonitor::enter_with_contention_mark(JavaThread* current, ObjectMonitorContentionMark &cm) {
  assert(current == JavaThread::current(), "must be");
  assert(!has_owner(current), "must be");
  assert(cm._monitor == this, "must be");
  assert(!is_being_async_deflated(), "must be");

  JFR_ONLY(JfrConditionalFlush<EventJavaMonitorEnter> flush(current);)
  EventJavaMonitorEnter enter_event;
  if (enter_event.is_started()) {
    enter_event.set_monitorClass(object()->klass());
    // Set an address that is 'unique enough', such that events close in
    // time and with the same address are likely (but not guaranteed) to
    // belong to the same object.
    enter_event.set_address((uintptr_t)this);
  }
  EventVirtualThreadPinned vthread_pinned_event;

  freeze_result result;

src/hotspot/share/runtime/objectMonitor.cpp:

    assert(false, "Non-balanced monitor enter/exit!");
#endif
    return;
  }

  if (_recursions != 0) {
    _recursions--;        // this is simple recursive enter
    return;
  }

#if INCLUDE_JFR
  // get the owner's thread id for the MonitorEnter event
  // if it is enabled and the thread isn't suspended
  if (not_suspended && EventJavaMonitorEnter::is_enabled()) {
    _previous_owner_tid = JFR_THREAD_ID(current);
  }
#endif

  for (;;) {
    // If there is a successor we should release the lock as soon as
    // possible, so that the successor can acquire the lock. If there is
    // no successor, we might need to wake up a waiting thread.
    if (!has_successor()) {
      ObjectWaiter* w = AtomicAccess::load(&_entry_list);
      if (w != nullptr) {

Configuration enabled stackTrace threshold
profiling true true 10 ms
default true true 20 ms

Field Type Description
monitorClass Class Monitor Class
previousOwner Thread Previous Monitor Owner
address ulong: address Monitor Address

Examples 3
address ulong: address
94727161778672
monitorClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Object
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
previousOwner Thread
group ThreadGroup
name string
finagle/netty4
parent ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
finagle/netty4-2-5
javaThreadId long
1929
osName string
finagle/netty4-2-5
osThreadId long
4581
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
8
lineNumber int
162
method Method
descriptor string
(Lcom/twitter/finagle/http/Request;)Lcom/twitter/util/Future;
hidden boolean
false
modifiers int
1
name string
apply
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/renaissance/twitter/finagle/FinagleChirper$Master
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/renaissance/twitter/finagle
type FrameType
Interpreted
truncated boolean
true
startTime long: millis
483539648687
address ulong: address
140018725020448
monitorClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
scala/concurrent/stm/ccstm/TxnLevelImpl
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/concurrent/stm/ccstm
previousOwner Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
Thread-257
javaThreadId long
1385
osName string
Thread-257
osThreadId long
3995
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
93
lineNumber int
186
method Method
descriptor string
(Lscala/concurrent/stm/ccstm/TxnLevelImpl;Ljava/lang/Object;)V
hidden boolean
false
modifiers int
1
name string
awaitCompleted
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
scala/concurrent/stm/ccstm/TxnLevelImpl
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/concurrent/stm/ccstm
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
319446542966
address ulong: address
139845144791808
monitorClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Object
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
previousOwner Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
rpc-server-4-3
javaThreadId long
1377
osName string
rpc-server-4-3
osThreadId long
4645
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
7
lineNumber int
573
method Method
descriptor string
(Ljava/lang/String;Z)Ljava/lang/Class;
hidden boolean
false
modifiers int
4
name string
loadClass
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1025
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
435414128428

JavaMonitorWait

profiling default startTime duration eventThread stackTrace 11 17 21 25 26 27

Category: Java Application

Waiting on a Java monitor

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/objectMonitor.cpp:

// Otherwise returns false and throws IllegalMonitorStateException
// (IMSE). If there is a pending exception and the specified thread
// is not the owner, that exception will be replaced by the IMSE.
bool ObjectMonitor::check_owner(TRAPS) {
  JavaThread* current = THREAD;
  int64_t cur = owner_raw();
  if (cur == owner_id_from(current)) {
    return true;
  }
  THROW_MSG_(vmSymbols::java_lang_IllegalMonitorStateException(),
             "current thread is not owner", false);
}

static void post_monitor_wait_event(EventJavaMonitorWait* event,
                                    ObjectMonitor* monitor,
                                    uint64_t notifier_tid,
                                    jlong timeout,
                                    bool timedout) {
  assert(event != nullptr, "invariant");
  assert(monitor != nullptr, "invariant");
  const Klass* monitor_klass = monitor->object()->klass();
  if (ObjectMonitor::is_jfr_excluded(monitor_klass)) {
    return;
  }
  event->set_monitorClass(monitor_klass);
  event->set_timeout(timeout);
  // Set an address that is 'unique enough', such that events close in
  // time and with the same address are likely (but not guaranteed) to
  // belong to the same object.
  event->set_address((uintptr_t)monitor);
  event->set_notifier(notifier_tid);
  event->set_timedOut(timedout);
  event->commit();
}

static void vthread_monitor_waited_event(JavaThread* current, ObjectWaiter* node, ContinuationWrapper& cont, EventJavaMonitorWait* event, jboolean timed_out) {
  // Since we might safepoint set the anchor so that the stack can we walked.
  assert(current->last_continuation() != nullptr, "");
  JavaFrameAnchor* anchor = current->frame_anchor();
  anchor->set_last_Java_sp(current->last_continuation()->entry_sp());
  anchor->set_last_Java_pc(current->last_continuation()->entry_pc());

  ContinuationWrapper::SafepointOp so(current, cont);

  JRT_BLOCK
    if (event->should_commit()) {
      long timeout = java_lang_VirtualThread::timeout(current->vthread());

src/hotspot/share/runtime/objectMonitor.cpp:

// -----------------------------------------------------------------------------
// Wait/Notify/NotifyAll
//
// Note: a subset of changes to ObjectMonitor::wait()
// will need to be replicated in complete_exit
void ObjectMonitor::wait(jlong millis, bool interruptible, TRAPS) {
  JavaThread* current = THREAD;

  assert(InitDone, "Unexpectedly not initialized");

  CHECK_OWNER();  // Throws IMSE if not owner.

  EventJavaMonitorWait wait_event;
  EventVirtualThreadPinned vthread_pinned_event;

  // check for a pending interrupt
  if (interruptible && current->is_interrupted(true) && !HAS_PENDING_EXCEPTION) {
    JavaThreadInObjectWaitState jtiows(current, millis != 0, interruptible);

    if (JvmtiExport::should_post_monitor_wait()) {
      JvmtiExport::post_monitor_wait(current, object(), millis);
    }
    // post monitor waited event.  Note that this is past-tense, we are done waiting.
    if (JvmtiExport::should_post_monitor_waited()) {

src/hotspot/share/runtime/objectMonitor.cpp:

      node->TState = ObjectWaiter::TS_RUN;
    }
  }

  // If this was an interrupted case, set the _interrupted boolean so that
  // once we re-acquire the monitor we know if we need to throw IE or not.
  ObjectWaiter::TStates state = node->TState;
  bool was_notified = state == ObjectWaiter::TS_ENTER;
  assert(was_notified || state == ObjectWaiter::TS_RUN, "");
  node->_interrupted = node->_interruptible && !was_notified && current->is_interrupted(false);

  // Post JFR and JVMTI events. If non-interruptible we are in
  // ObjectLocker case so we don't post anything.
  EventJavaMonitorWait wait_event;
  if (node->_interruptible && (wait_event.should_commit() || JvmtiExport::should_post_monitor_waited())) {
    vthread_monitor_waited_event(current, node, cont, &wait_event, !was_notified && !node->_interrupted);
  }

  // Mark that we are at reenter so that we don't call this method again.
  node->_at_reenter = true;

  if (!was_notified) {
    bool acquired = vthread_monitor_enter(current, node);
    if (acquired) {
      guarantee(_recursions == 0, "invariant");

Configuration enabled stackTrace threshold
profiling true true 10 ms
default true true 20 ms

Field Type Description
monitorClass Class Monitor Class Class of object waited on
notifier Thread Notifier Thread Notifying Thread
timeout long: millis Timeout Maximum wait time
timedOut boolean Timed Out Wait has been timed out
address ulong: address Monitor Address Address of object waited on

Examples 3
address ulong: address
139844471116544
monitorClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/util/TaskQueue
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util
notifier Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
main
javaThreadId long
1
osName string
main
osThreadId long
2926
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(J)V
hidden boolean
false
modifiers int
274
name string
wait0
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Object
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
327456483249
timedOut boolean
false
timeout long: millis
0
address ulong: address
140018417806752
monitorClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
scala/concurrent/stm/ccstm/TxnLevelImpl
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/concurrent/stm/ccstm
notifier Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
Thread-257
javaThreadId long
1385
osName string
Thread-257
osThreadId long
3995
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(J)V
hidden boolean
false
modifiers int
274
name string
wait0
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Object
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
316820770022
timedOut boolean
false
timeout long: millis
0
address ulong: address
140430648842912
monitorClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/renaissance/twitter/finagle/FinagleChirper$Client
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/renaissance/twitter/finagle
notifier Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
Thread-294
javaThreadId long
1922
osName string
Thread-294
osThreadId long
4572
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(J)V
hidden boolean
false
modifiers int
274
name string
wait0
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Object
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
493373802026
timedOut boolean
false
timeout long: millis
0

JavaMonitorNotify

startTime duration eventThread stackTrace 25 26 27

Category: Java Application

Notifying a Java monitor

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/objectMonitor.cpp:

        // If the target was interrupted or the wait timed-out at the same time, it could
        // have reached reenter_internal and read a false value of has_unmounted_vthreads()
        // before we added it to the _entry_list above. To deal with that case, we set _do_timed_park
        // which will be read by the target on the next loop iteration in reenter_internal.
        iterator->_do_timed_park = true;
        JavaThread* t = iterator->thread();
        t->_ParkEvent->unpark();
      }
    }
  }
  return did_notify;
}

static void post_monitor_notify_event(EventJavaMonitorNotify* event,
                                      ObjectMonitor* monitor,
                                      int notified_count) {
  assert(event != nullptr, "invariant");
  assert(monitor != nullptr, "invariant");
  const Klass* monitor_klass = monitor->object()->klass();
  if (ObjectMonitor::is_jfr_excluded(monitor_klass)) {
    return;
  }
  event->set_monitorClass(monitor_klass);
  // Set an address that is 'unique enough', such that events close in
  // time and with the same address are likely (but not guaranteed) to

src/hotspot/share/runtime/objectMonitor.cpp:

void ObjectMonitor::notify(TRAPS) {
  JavaThread* current = THREAD;
  CHECK_OWNER();  // Throws IMSE if not owner.
  if (_wait_set == nullptr) {
    return;
  }

  quick_notify(current);
}

void ObjectMonitor::quick_notify(JavaThread* current) {
  assert(has_owner(current), "Precondition");

  EventJavaMonitorNotify event;
  DTRACE_MONITOR_PROBE(notify, this, object(), current);
  int tally = notify_internal(current) ? 1 : 0;

  if ((tally > 0) && event.should_commit()) {
    post_monitor_notify_event(&event, this, /* notified_count = */ tally);
  }
}

// notifyAll() transfers the waiters one-at-a-time from the waitset to
// the entry_list. If the waitset is "ABCD" (where A was added first
// and D last) and the entry_list is ->X->Y->Z. After a notifyAll()

src/hotspot/share/runtime/objectMonitor.cpp:

void ObjectMonitor::notifyAll(TRAPS) {
  JavaThread* current = THREAD;
  CHECK_OWNER();  // Throws IMSE if not owner.
  if (_wait_set == nullptr) {
    return;
  }

  quick_notifyAll(current);
}

void ObjectMonitor::quick_notifyAll(JavaThread* current) {
  assert(has_owner(current), "Precondition");

  EventJavaMonitorNotify event;
  DTRACE_MONITOR_PROBE(notifyAll, this, object(), current);
  int tally = 0;
  while (_wait_set != nullptr) {
    if (notify_internal(current)) {
      tally++;
    }
  }

  if ((tally > 0) && event.should_commit()) {
    post_monitor_notify_event(&event, this, /* notified_count = */ tally);
  }

Configuration enabled stackTrace threshold
profiling false true 0 ms
default false true 0 ms

Field Type Description
monitorClass Class Monitor Class Class of object waited on
notifiedCount uint Notified Threads Number of actually notified threads
address ulong: address Monitor Address Address of object waited on

JavaMonitorInflate

startTime duration eventThread stackTrace 11 17 21 25 26 27

Category: Java Application

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/synchronizer.cpp:

static void log_inflate(Thread* current, oop object, ObjectSynchronizer::InflateCause cause) {
  if (log_is_enabled(Trace, monitorinflation)) {
    ResourceMark rm(current);
    log_trace(monitorinflation)("inflate: object=" INTPTR_FORMAT ", mark="
                                INTPTR_FORMAT ", type='%s' cause=%s", p2i(object),
                                object->mark().value(), object->klass()->external_name(),
                                ObjectSynchronizer::inflate_cause_name(cause));
  }
}

static void post_monitor_inflate_event(EventJavaMonitorInflate* event,
                                       const oop obj,
                                       ObjectSynchronizer::InflateCause cause) {
  assert(event != nullptr, "invariant");
  const Klass* monitor_klass = obj->klass();
  if (ObjectMonitor::is_jfr_excluded(monitor_klass)) {
    return;
  }
  event->set_monitorClass(monitor_klass);
  event->set_address((uintptr_t)(void*)obj);
  event->set_cause((u1)cause);
  event->commit();
}

ObjectMonitor* ObjectSynchronizer::get_or_insert_monitor(oop object, JavaThread* current, ObjectSynchronizer::InflateCause cause) {
  assert(UseObjectMonitorTable, "must be");

  EventJavaMonitorInflate event;

  bool inserted;
  ObjectMonitor* monitor = get_or_insert_monitor_from_table(object, current, &inserted);

  if (inserted) {
    log_inflate(current, object, cause);
    if (event.should_commit()) {
      post_monitor_inflate_event(&event, object, cause);
    }

    // The monitor has an anonymous owner so it is safe from async deflation.

src/hotspot/share/runtime/synchronizer.cpp:

ObjectMonitor* ObjectSynchronizer::inflate_into_object_header(oop object, ObjectSynchronizer::InflateCause cause, JavaThread* locking_thread, Thread* current) {

  // The JavaThread* locking parameter requires that the locking_thread == JavaThread::current,
  // or is suspended throughout the call by some other mechanism.
  // Even with fast locking the thread might be nullptr when called from a non
  // JavaThread. (As may still be the case from FastHashCode). However it is only
  // important for the correctness of the fast locking algorithm that the thread
  // is set when called from ObjectSynchronizer::enter from the owning thread,
  // ObjectSynchronizer::enter_for from any thread, or ObjectSynchronizer::exit.
  EventJavaMonitorInflate event;

  for (;;) {
    const markWord mark = object->mark_acquire();

    // The mark can be in one of the following states:
    // *  inflated     - Just return if using stack-locking.
    //                   If using fast-locking and the ObjectMonitor owner
    //                   is anonymous and the locking_thread owns the
    //                   object lock, then we make the locking_thread
    //                   the ObjectMonitor owner and remove the lock from
    //                   the locking_thread's lock stack.

Configuration enabled stackTrace threshold
profiling false true 0 ms
default false true 0 ms

Field Type Description
monitorClass Class Monitor Class
address ulong: address Monitor Address
cause InflateCause Monitor Inflation Cause Cause of inflation

JavaMonitorDeflate

startTime duration 25 26 27

Category: Java Application

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/objectMonitor.cpp:

    // Interference - the CAS failed because _entry_list changed.  Before
    // retrying the CAS retry taking the lock as it may now be free.
    if (try_lock(current) == TryLockResult::Success) {
      assert(!has_successor(current), "invariant");
      assert(has_owner(current), "invariant");
      node->TState = ObjectWaiter::TS_RUN;
      return true;
    }
  }
}

static void post_monitor_deflate_event(EventJavaMonitorDeflate* event,
                                       const oop obj) {
  assert(event != nullptr, "invariant");
  if (obj == nullptr) {
    // Accept the case when obj was already garbage-collected.
    // Emit the event anyway, but without details.
    event->set_monitorClass(nullptr);
    event->set_address(0);
  } else {
    const Klass* monitor_klass = obj->klass();
    if (ObjectMonitor::is_jfr_excluded(monitor_klass)) {
      return;

src/hotspot/share/runtime/objectMonitor.cpp:

// as part of the protocol to make sure that the calling thread has
// not lost the race to a contending thread.
//
// The ObjectMonitor has been successfully async deflated when:
//   (contentions < 0)
// Contending threads that see that condition know to retry their operation.
//
bool ObjectMonitor::deflate_monitor(Thread* current) {
  if (is_busy()) {
    // Easy checks are first - the ObjectMonitor is busy so no deflation.
    return false;
  }

  EventJavaMonitorDeflate event;

  const oop obj = object_peek();

  if (obj == nullptr) {
    // If the object died, we can recycle the monitor without racing with
    // Java threads. The GC already broke the association with the object.
    set_owner_from_raw(NO_OWNER, DEFLATER_MARKER);
    assert(contentions() >= 0, "must be non-negative: contentions=%d", contentions());
    _contentions = INT_MIN; // minimum negative int
  } else {
    // Attempt async deflation protocol.

Configuration enabled threshold
profiling false 0 ms
default false 0 ms

Field Type Description
monitorClass Class Monitor Class Class of the object deflated. If null or N/A, the object has been garbage collected.
address ulong: address Monitor Address Address of the object deflated. If null or N/A, the object has been garbage collected.

VirtualThreadPinned

profiling default startTime duration eventThread stackTrace 19 21 25 26 27

Category: Java Application

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/runtime/objectMonitor.cpp:

  assert(!has_owner(current), "must be");
  assert(cm._monitor == this, "must be");
  assert(!is_being_async_deflated(), "must be");

  JFR_ONLY(JfrConditionalFlush<EventJavaMonitorEnter> flush(current);)
  EventJavaMonitorEnter enter_event;
  if (enter_event.is_started()) {
    enter_event.set_monitorClass(object()->klass());
    // Set an address that is 'unique enough', such that events close in
    // time and with the same address are likely (but not guaranteed) to
    // belong to the same object.
    enter_event.set_address((uintptr_t)this);
  }
  EventVirtualThreadPinned vthread_pinned_event;

  freeze_result result;

  assert(current->current_pending_monitor() == nullptr, "invariant");

  ContinuationEntry* ce = current->last_continuation();
  bool is_virtual = ce != nullptr && ce->is_virtual_thread();
  if (is_virtual) {
    notify_contended_enter(current);
    result = Continuation::try_preempt(current, ce->cont_oop(current));
    if (result == freeze_ok) {

src/hotspot/share/runtime/objectMonitor.cpp:

// -----------------------------------------------------------------------------
// Wait/Notify/NotifyAll
//
// Note: a subset of changes to ObjectMonitor::wait()
// will need to be replicated in complete_exit
void ObjectMonitor::wait(jlong millis, bool interruptible, TRAPS) {
  JavaThread* current = THREAD;

  assert(InitDone, "Unexpectedly not initialized");

  CHECK_OWNER();  // Throws IMSE if not owner.

  EventJavaMonitorWait wait_event;
  EventVirtualThreadPinned vthread_pinned_event;

  // check for a pending interrupt
  if (interruptible && current->is_interrupted(true) && !HAS_PENDING_EXCEPTION) {
    JavaThreadInObjectWaitState jtiows(current, millis != 0, interruptible);

    if (JvmtiExport::should_post_monitor_wait()) {
      JvmtiExport::post_monitor_wait(current, object(), millis);
    }
    // post monitor waited event.  Note that this is past-tense, we are done waiting.
    if (JvmtiExport::should_post_monitor_waited()) {
      // Note: 'false' parameter is passed here because the

src/hotspot/share/runtime/javaThread.cpp:

  new_head->add(_scopedValueCache);
  _oop_handle_list = new_head;
  Service_lock->notify_all();
}

#if INCLUDE_JFR
void JavaThread::set_last_freeze_fail_result(freeze_result result) {
  assert(result != freeze_ok, "sanity check");
  _last_freeze_fail_result = result;
  _last_freeze_fail_time = Ticks::now();
}

// Post jdk.VirtualThreadPinned event
void JavaThread::post_vthread_pinned_event(EventVirtualThreadPinned* event, const char* op, freeze_result result) {
  assert(result != freeze_ok, "sanity check");
  if (event->should_commit()) {
    char reason[256];
    if (class_to_be_initialized() != nullptr) {
      ResourceMark rm(this);
      jio_snprintf(reason, sizeof reason, "Waited for initialization of %s by another thread",
                   class_to_be_initialized()->external_name());
      event->set_pinnedReason(reason);
    } else if (class_being_initialized() != nullptr) {
      ResourceMark rm(this);
      jio_snprintf(reason, sizeof(reason), "VM call to %s.<clinit> on stack",

src/hotspot/share/runtime/javaThread.hpp:

class OSThread;

class ThreadsList;
class ThreadSafepointState;
class ThreadStatistics;

class vframeArray;
class vframe;
class javaVFrame;

class JavaThread;
typedef void (*ThreadFunction)(JavaThread*, TRAPS);

class EventVirtualThreadPinned;

class JavaThread: public Thread {
  friend class VMStructs;
  friend class JVMCIVMStructs;
  friend class WhiteBox;
  friend class ThreadsSMRSupport; // to access _threadObj for exiting_threads_oops_do
  friend class HandshakeState;
  friend class Continuation;
  friend class Threads;
  friend class ServiceThread; // for deferred OopHandle release access
 private:

src/hotspot/share/runtime/javaThread.hpp:

  bool sleep(jlong millis);
  bool sleep_nanos(jlong nanos);

  // java.lang.Thread interruption support
  void interrupt();
  bool is_interrupted(bool clear_interrupted);

#if INCLUDE_JFR
  // Support for jdk.VirtualThreadPinned event
  freeze_result last_freeze_fail_result() { return _last_freeze_fail_result; }
  Ticks& last_freeze_fail_time() { return _last_freeze_fail_time; }
  void set_last_freeze_fail_result(freeze_result result);
#endif
  void post_vthread_pinned_event(EventVirtualThreadPinned* event, const char* op, freeze_result result) NOT_JFR_RETURN();


  // This is only for use by JVMTI RawMonitorWait. It emulates the actions of
  // the Java code in Object::wait which are not present in RawMonitorWait.
  bool get_and_clear_interrupted();

private:
  LockStack _lock_stack;
  OMCache _om_cache;

public:

src/hotspot/share/prims/jvm.cpp:

    assert(!JvmtiExport::can_support_virtual_threads(), "sanity check");
    return;
  }
  assert(thread->is_disable_suspend() != (bool)enter,
         "nested or unbalanced monitor enter/exit is not allowed");
  thread->toggle_is_disable_suspend();
#endif
JVM_END

JVM_ENTRY(void, JVM_VirtualThreadPinnedEvent(JNIEnv* env, jclass ignored, jstring op))
#if INCLUDE_JFR
  freeze_result result = THREAD->last_freeze_fail_result();
  assert(result != freeze_ok, "sanity check");
  EventVirtualThreadPinned event(UNTIMED);
  event.set_starttime(THREAD->last_freeze_fail_time());
  if (event.should_commit()) {
    ResourceMark rm(THREAD);
    const char *str = java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(op));
    THREAD->post_vthread_pinned_event(&event, str, result);
  }
#endif
JVM_END

JVM_ENTRY(jobject, JVM_TakeVirtualThreadListToUnblock(JNIEnv* env, jclass ignored))
  ParkEvent* parkEvent = ObjectMonitor::vthread_unparker_ParkEvent();

Configuration enabled stackTrace threshold
profiling true true 20 ms
default true true 20 ms

Field Type Description
blockingOperation string 24+ Blocking Operation
pinnedReason string 24+ Pinned Reason
carrierThread Thread 24+ Carrier Thread

ObjectAllocationInNewTLAB

startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Application

Allocation in new Thread Local Allocation Buffer

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/allocTracer.cpp:

void AllocTracer::send_allocation_outside_tlab(Klass* klass, HeapWord* obj, size_t alloc_size, JavaThread* thread) {
  JFR_ONLY(JfrAllocationTracer tracer(klass, obj, alloc_size, true, thread);)
  EventObjectAllocationOutsideTLAB event;
  if (event.should_commit()) {
    event.set_objectClass(klass);
    event.set_allocationSize(alloc_size);
    event.commit();
  }
}

void AllocTracer::send_allocation_in_new_tlab(Klass* klass, HeapWord* obj, size_t tlab_size, size_t alloc_size, JavaThread* thread) {
  JFR_ONLY(JfrAllocationTracer tracer(klass, obj, alloc_size, false, thread);)
  EventObjectAllocationInNewTLAB event;
  if (event.should_commit()) {
    event.set_objectClass(klass);
    event.set_allocationSize(alloc_size);
    event.set_tlabSize(tlab_size);
    event.commit();
  }
}

void AllocTracer::send_allocation_requiring_gc_event(size_t size, uint gcId) {
  EventAllocationRequiringGC event;
  if (event.should_commit()) {

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
objectClass Class Object Class Class of allocated object
allocationSize ulong: bytes Allocation Size
tlabSize ulong: bytes TLAB Size

Examples 3
allocationSize ulong: bytes
56
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[F
package Package
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
2
lineNumber int
78
method Method
descriptor string
(Ljava/lang/Class;I)Ljava/lang/Object;
hidden boolean
false
modifiers int
9
name string
newInstance
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/reflect/Array
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang/reflect
type FrameType
Inlined
truncated boolean
true
startTime long: millis
278775783402
tlabSize ulong: bytes
196136
allocationSize ulong: bytes
16
objectClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
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modifiers int
17
name string
scala/runtime/ObjectRef
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/runtime
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
23
method Method
descriptor string
(Ljava/lang/Object;)Lscala/runtime/ObjectRef;
hidden boolean
false
modifiers int
9
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create
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
17
name string
scala/runtime/ObjectRef
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/runtime
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
366278066611
tlabSize ulong: bytes
183568
allocationSize ulong: bytes
56
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[F
package Package
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
2
lineNumber int
78
method Method
descriptor string
(Ljava/lang/Class;I)Ljava/lang/Object;
hidden boolean
false
modifiers int
9
name string
newInstance
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/reflect/Array
package Package
exported boolean
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module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang/reflect
type FrameType
Inlined
truncated boolean
true
startTime long: millis
379225980532
tlabSize ulong: bytes
422800

ObjectAllocationOutsideTLAB

startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Application

Allocation outside Thread Local Allocation Buffers

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/gc/shared/allocTracer.cpp:

#if INCLUDE_JFR
#include "jfr/support/jfrAllocationTracer.hpp"
#endif

void AllocTracer::send_allocation_outside_tlab(Klass* klass, HeapWord* obj, size_t alloc_size, JavaThread* thread) {
  JFR_ONLY(JfrAllocationTracer tracer(klass, obj, alloc_size, true, thread);)
  EventObjectAllocationOutsideTLAB event;
  if (event.should_commit()) {
    event.set_objectClass(klass);
    event.set_allocationSize(alloc_size);
    event.commit();
  }
}

void AllocTracer::send_allocation_in_new_tlab(Klass* klass, HeapWord* obj, size_t tlab_size, size_t alloc_size, JavaThread* thread) {
  JFR_ONLY(JfrAllocationTracer tracer(klass, obj, alloc_size, false, thread);)
  EventObjectAllocationInNewTLAB event;
  if (event.should_commit()) {
    event.set_objectClass(klass);
    event.set_allocationSize(alloc_size);

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
objectClass Class Object Class Class of allocated object
allocationSize ulong: bytes Allocation Size

Examples 3
allocationSize ulong: bytes
4194320
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[B
package Package
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
6
lineNumber int
71
method Method
descriptor string
(IILjava/lang/foreign/MemorySegment;)V
hidden boolean
false
modifiers int
0
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/nio/HeapByteBuffer
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/nio
type FrameType
Inlined
truncated boolean
false
startTime long: millis
375016259126
allocationSize ulong: bytes
32784
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[B
package Package
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
52
lineNumber int
94
method Method
descriptor string
(Ljava/io/OutputStream;II)V
hidden boolean
false
modifiers int
2
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/io/BufferedOutputStream
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/io
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
379425058945
allocationSize ulong: bytes
32952
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[B
package Package
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
50
lineNumber int
104
method Method
descriptor string
(Ljava/io/OutputStream;ILnet/jpountz/lz4/LZ4Compressor;Ljava/util/zip/Checksum;Z)V
hidden boolean
false
modifiers int
1
name string
<init>
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
net/jpountz/lz4/LZ4BlockOutputStream
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
net/jpountz/lz4
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
279243228178

ObjectAllocationSample

throttle profiling default startTime eventThread stackTrace 16 17 21 25 26 27

Category: Java Application

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/support/jfrObjectAllocationSample.cpp:

inline bool send_allocation_sample(const Klass* klass, int64_t allocated_bytes, JfrThreadLocal* tl) {
  EventObjectAllocationSample event;
  if (event.should_commit()) {
    const int64_t weight = allocated_bytes - tl->last_allocated_bytes();
    assert(weight > 0, "invariant");
    event.set_objectClass(klass);
    event.set_weight(weight);
    event.commit();
    tl->set_last_allocated_bytes(allocated_bytes);
    return true;
  }
  return false;
}

inline int64_t estimate_tlab_size_bytes(JavaThread* jt) {
  const size_t desired_tlab_size_bytes = jt->tlab().desired_size() * HeapWordSize;
  const size_t alignment_reserve_bytes = jt->tlab().alignment_reserve_in_bytes();

src/hotspot/share/jfr/support/jfrAllocationTracer.cpp:

JfrAllocationTracer::JfrAllocationTracer(const Klass* klass, HeapWord* obj, size_t alloc_size, bool outside_tlab, JavaThread* thread) {
  if (LeakProfiler::is_running()) {
    LeakProfiler::sample(obj, alloc_size, thread);
  }
  if (EventObjectAllocationSample::is_enabled()) {
    JfrObjectAllocationSample::send_event(klass, alloc_size, outside_tlab, thread);
  }
}

Configuration enabled stackTrace throttle
profiling true true 300/s
default true true 150/s

Field Type Description
objectClass Class Object Class Class of allocated object
weight long: bytes Sample Weight The relative weight of the sample. Aggregating the weights for a large number of samples, for a particular class, thread or stack trace, gives a statistically accurate representation of the allocation pressure

Examples 3
objectClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1041
name string
[Lscala/Enumeration$Value;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
19
lineNumber int
965
method Method
descriptor string
()V
hidden boolean
false
modifiers int
1
name string
<init>
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1025
name string
org/apache/spark/sql/catalyst/expressions/BinaryComparison
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/sql/catalyst/expressions
type FrameType
JIT compiled
truncated boolean
true
startTime long: millis
375031881461
weight long: bytes
422216
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[B
package Package
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
50
lineNumber int
104
method Method
descriptor string
(Ljava/io/OutputStream;ILnet/jpountz/lz4/LZ4Compressor;Ljava/util/zip/Checksum;Z)V
hidden boolean
false
modifiers int
1
name string
<init>
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
net/jpountz/lz4/LZ4BlockOutputStream
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
net/jpountz/lz4
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
366813824521
weight long: bytes
3880768
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[I
package Package
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
11
lineNumber int
2371
method Method
descriptor string
()V
hidden boolean
false
modifiers int
2
name string
growEntries
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
26
name string
java/io/ObjectOutputStream$HandleTable
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/io
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
279440730626
weight long: bytes
395112

MethodTrace

profiling default startTime duration eventThread stackTrace 25 26 27

Category: Java Application

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/MethodTraceEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Contextual;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.StackTrace;

@Name("jdk.MethodTrace")
@Label("Method Trace")
@Category({ "Java Virtual Machine", "Method Tracing" })
@StackTrace(true)
public final class MethodTraceEvent extends AbstractJDKEvent {

    @Contextual
    @Label("Method")
    private long method;

    public static void commit(long start, long duration, long method) {
        // Generated by JFR
    }

    public static long timestamp() {
        // Generated by JFR
        return 0;

src/jdk.jfr/share/classes/jdk/jfr/events/MethodTraceEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Contextual;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.StackTrace;

@Name("jdk.MethodTrace")
@Label("Method Trace")
@Category({ "Java Virtual Machine", "Method Tracing" })
@StackTrace(true)
public final class MethodTraceEvent extends AbstractJDKEvent {

    @Contextual
    @Label("Method")
    private long method;

    public static void commit(long start, long duration, long method) {
        // Generated by JFR
    }

    public static long timestamp() {
        // Generated by JFR
        return 0;

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void traceObjectInit(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTraceEvent.shouldCommit(duration) && JVM.getEventWriter() != null) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
    }

    public static void timingObjectInit(long startTime, long methodId) {

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void traceTimingObjectInit(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTraceEvent.shouldCommit(duration) && JVM.getEventWriter() != null) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addObjectTiming(duration);
        }

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void trace(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTraceEvent.shouldCommit(duration)) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
    }

    public static void timing(long startTime, long methodId) {

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addTiming(methodId, duration);
        }
        if (MethodTraceEvent.shouldCommit(duration)) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
    }
}

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void traceObjectInit(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTraceEvent.shouldCommit(duration) && JVM.getEventWriter() != null) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
    }

    public static void timingObjectInit(long startTime, long methodId) {

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void traceTimingObjectInit(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTraceEvent.shouldCommit(duration) && JVM.getEventWriter() != null) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addObjectTiming(duration);
        }

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void trace(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTraceEvent.shouldCommit(duration)) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
    }

    public static void timing(long startTime, long methodId) {

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addTiming(methodId, duration);
        }
        if (MethodTraceEvent.shouldCommit(duration)) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
    }
}

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

        jdk.internal.event.SerializationMisdeclarationEvent.class,
        jdk.internal.event.SocketReadEvent.class,
        jdk.internal.event.SocketWriteEvent.class,
        jdk.internal.event.ThreadSleepEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.VirtualThreadStartEvent.class,
        jdk.internal.event.VirtualThreadEndEvent.class,
        jdk.internal.event.VirtualThreadSubmitFailedEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class,
        jdk.internal.event.FinalFieldMutationEvent.class,
        DirectBufferStatisticsEvent.class,
        InitialSecurityPropertyEvent.class,
        MethodTraceEvent.class,
        MethodTimingEvent.class,
    };

    private static final Runnable emitExceptionStatistics = JDKEvents::emitExceptionStatistics;
    private static final Runnable emitDirectBufferStatistics = JDKEvents::emitDirectBufferStatistics;
    private static final Runnable emitContainerConfiguration = JDKEvents::emitContainerConfiguration;
    private static final Runnable emitContainerCPUUsage = JDKEvents::emitContainerCPUUsage;
    private static final Runnable emitContainerCPUThrottling = JDKEvents::emitContainerCPUThrottling;
    private static final Runnable emitContainerMemoryUsage = JDKEvents::emitContainerMemoryUsage;
    private static final Runnable emitContainerIOUsage = JDKEvents::emitContainerIOUsage;
    private static final Runnable emitInitialSecurityProperties = JDKEvents::emitInitialSecurityProperties;

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

        jdk.internal.event.SerializationMisdeclarationEvent.class,
        jdk.internal.event.SocketReadEvent.class,
        jdk.internal.event.SocketWriteEvent.class,
        jdk.internal.event.ThreadSleepEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.VirtualThreadStartEvent.class,
        jdk.internal.event.VirtualThreadEndEvent.class,
        jdk.internal.event.VirtualThreadSubmitFailedEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class,
        jdk.internal.event.FinalFieldMutationEvent.class,
        DirectBufferStatisticsEvent.class,
        InitialSecurityPropertyEvent.class,
        MethodTraceEvent.class,
        MethodTimingEvent.class,
    };

    private static final Runnable emitExceptionStatistics = JDKEvents::emitExceptionStatistics;
    private static final Runnable emitDirectBufferStatistics = JDKEvents::emitDirectBufferStatistics;
    private static final Runnable emitContainerConfiguration = JDKEvents::emitContainerConfiguration;
    private static final Runnable emitContainerCPUUsage = JDKEvents::emitContainerCPUUsage;
    private static final Runnable emitContainerCPUThrottling = JDKEvents::emitContainerCPUThrottling;
    private static final Runnable emitContainerMemoryUsage = JDKEvents::emitContainerMemoryUsage;
    private static final Runnable emitContainerIOUsage = JDKEvents::emitContainerIOUsage;
    private static final Runnable emitInitialSecurityProperties = JDKEvents::emitInitialSecurityProperties;

Configuration enabled filter stackTrace threshold
profiling true null true 0 ms
default true null true 0 ms

Field Type Description
method Method Method

MethodTiming

profiling default startTime every chunk 25 26 27

Category: Java Application

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/MethodTimingEvent.java:

@Name("jdk.MethodTiming")
@Label("Method Timing")
@Category({ "Java Virtual Machine", "Method Tracing" })
@RemoveFields({ "duration", "eventThread", "stackTrace" })
@Description("Measures the approximate time it takes for a method to execute, including all delays, not just CPU processing time")
public final class MethodTimingEvent extends AbstractJDKEvent {

    @Label("Method")
    public long method;

    @Label("Invocations")
    public long invocations;

    @Label("Minimum Time")
    @Description("The value may be missing (Long.MIN_VALUE) if the clock-resolution is too low to establish a minimum time")
    @Timespan(Timespan.TICKS)
    public long minimum;

src/jdk.jfr/share/classes/jdk/jfr/events/MethodTimingEvent.java:

@Name("jdk.MethodTiming")
@Label("Method Timing")
@Category({ "Java Virtual Machine", "Method Tracing" })
@RemoveFields({ "duration", "eventThread", "stackTrace" })
@Description("Measures the approximate time it takes for a method to execute, including all delays, not just CPU processing time")
public final class MethodTimingEvent extends AbstractJDKEvent {

    @Label("Method")
    public long method;

    @Label("Invocations")
    public long invocations;

    @Label("Minimum Time")
    @Description("The value may be missing (Long.MIN_VALUE) if the clock-resolution is too low to establish a minimum time")
    @Timespan(Timespan.TICKS)
    public long minimum;

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void timingObjectInit(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addObjectTiming(duration);
        }
    }

    public static void traceTimingObjectInit(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTraceEvent.shouldCommit(duration) && JVM.getEventWriter() != null) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addObjectTiming(duration);
        }
    }

    public static void trace(long startTime, long methodId) {

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void timing(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addTiming(methodId, duration);
        }
    }

    public static void traceTiming(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addTiming(methodId, duration);
        }
        if (MethodTraceEvent.shouldCommit(duration)) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void timingObjectInit(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addObjectTiming(duration);
        }
    }

    public static void traceTimingObjectInit(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTraceEvent.shouldCommit(duration) && JVM.getEventWriter() != null) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addObjectTiming(duration);
        }
    }

    public static void trace(long startTime, long methodId) {

src/jdk.jfr/share/classes/jdk/jfr/tracing/MethodTracer.java:

    public static void timing(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addTiming(methodId, duration);
        }
    }

    public static void traceTiming(long startTime, long methodId) {
        long endTime = JVM.counterTime();
        long duration = endTime - startTime;
        if (MethodTimingEvent.enabled()) {
            PlatformTracer.addTiming(methodId, duration);
        }
        if (MethodTraceEvent.shouldCommit(duration)) {
            MethodTraceEvent.commit(startTime, duration, methodId);
        }

src/jdk.jfr/share/classes/jdk/jfr/internal/tracing/TimedClass.java:

    public void emit(long timestamp) {
        for (var tm : methods.values()) {
            if (tm.published().get()) {
                long methodId = tm.method().methodId();
                long invocations = tm.invocations().get();
                long time = tm.time().get();
                long min = tm.minimum().get();
                long max = tm.maximum().get();
                if (time == 0 || invocations == 0) {
                    // If time is zero, it's a low resolution clock and more invocations are needed.
                    MethodTimingEvent.commit(timestamp, methodId, invocations, MISSING, MISSING, MISSING);
                } else {
                    long average = (time + invocations / 2) / invocations;
                    if (min == Long.MAX_VALUE) {
                        min = average;
                    }
                    if (max == Long.MIN_VALUE) {
                        max = average;
                    }
                    min = Math.min(min, average);
                    max = Math.max(max, average);
                    MethodTimingEvent.commit(timestamp, methodId, invocations, min, average, max);
                }
                tm.method().log("Emitted event");
            }
        }
    }
}

src/jdk.jfr/share/classes/jdk/jfr/internal/tracing/TimedClass.java:

    public void emit(long timestamp) {
        for (var tm : methods.values()) {
            if (tm.published().get()) {
                long methodId = tm.method().methodId();
                long invocations = tm.invocations().get();
                long time = tm.time().get();
                long min = tm.minimum().get();
                long max = tm.maximum().get();
                if (time == 0 || invocations == 0) {
                    // If time is zero, it's a low resolution clock and more invocations are needed.
                    MethodTimingEvent.commit(timestamp, methodId, invocations, MISSING, MISSING, MISSING);
                } else {
                    long average = (time + invocations / 2) / invocations;
                    if (min == Long.MAX_VALUE) {
                        min = average;
                    }
                    if (max == Long.MIN_VALUE) {
                        max = average;
                    }
                    min = Math.min(min, average);
                    max = Math.max(max, average);
                    MethodTimingEvent.commit(timestamp, methodId, invocations, min, average, max);
                }
                tm.method().log("Emitted event");
            }
        }
    }
}

src/jdk.jfr/share/classes/jdk/jfr/internal/tracing/PlatformTracer.java:

        s.append(message);
        s.append(" for ");
        s.append(className.replace("/", "."));
        s.append(" in module ");
        s.append(module.getName());
        s.append(" and class loader " + module.getClassLoader());
        Logger.log(LogTag.JFR_METHODTRACE, level, s.toString());
    }

    public static void emitTiming() {
        // Metadata lock prevents rotation/flush while emitting events.
        synchronized (MetadataRepository.getInstance()) {
            removeClasses(JVM.drainStaleMethodTracerIds());
            long timestamp = MethodTimingEvent.timestamp();
            for (var tc : timedClasses.values()) {
                tc.emit(timestamp);
            }
        }
    }

    public static void addObjectTiming(long duration) {
        OBJECT.invocations().getAndIncrement();
        OBJECT.time().addAndGet(duration);
        OBJECT.updateMinMax(duration);
    }

src/jdk.jfr/share/classes/jdk/jfr/internal/tracing/PlatformTracer.java:

        s.append(message);
        s.append(" for ");
        s.append(className.replace("/", "."));
        s.append(" in module ");
        s.append(module.getName());
        s.append(" and class loader " + module.getClassLoader());
        Logger.log(LogTag.JFR_METHODTRACE, level, s.toString());
    }

    public static void emitTiming() {
        // Metadata lock prevents rotation/flush while emitting events.
        synchronized (MetadataRepository.getInstance()) {
            removeClasses(JVM.drainStaleMethodTracerIds());
            long timestamp = MethodTimingEvent.timestamp();
            for (var tc : timedClasses.values()) {
                tc.emit(timestamp);
            }
        }
    }

    public static void addObjectTiming(long duration) {
        OBJECT.invocations().getAndIncrement();
        OBJECT.time().addAndGet(duration);
        OBJECT.updateMinMax(duration);
    }

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

        jdk.internal.event.VirtualThreadEndEvent.class,
        jdk.internal.event.VirtualThreadSubmitFailedEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class,
        jdk.internal.event.FinalFieldMutationEvent.class,
        DirectBufferStatisticsEvent.class,
        InitialSecurityPropertyEvent.class,
        MethodTraceEvent.class,
        MethodTimingEvent.class,
    };

    private static final Runnable emitExceptionStatistics = JDKEvents::emitExceptionStatistics;
    private static final Runnable emitDirectBufferStatistics = JDKEvents::emitDirectBufferStatistics;
    private static final Runnable emitContainerConfiguration = JDKEvents::emitContainerConfiguration;
    private static final Runnable emitContainerCPUUsage = JDKEvents::emitContainerCPUUsage;
    private static final Runnable emitContainerCPUThrottling = JDKEvents::emitContainerCPUThrottling;

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

        try {
            if (initializationTriggered == false) {
                for (Class<?> eventClass : eventClasses) {
                    MetadataRepository.getInstance().register((Class<? extends Event>) eventClass);
                }
                PeriodicEvents.addJavaEvent(jdk.internal.event.ExceptionStatisticsEvent.class, emitExceptionStatistics);
                PeriodicEvents.addJavaEvent(DirectBufferStatisticsEvent.class, emitDirectBufferStatistics);
                PeriodicEvents.addJavaEvent(InitialSecurityPropertyEvent.class, emitInitialSecurityProperties);
                PeriodicEvents.addJavaEvent(MethodTimingEvent.class, emitMethodTiming);

                initializeContainerEvents();
                JFRTracing.enable();
                initializationTriggered = true;
            }
        } catch (Exception e) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.WARN, "Could not initialize JDK events. " + e.getMessage());

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

            for (String key : p.stringPropertyNames()) {
                InitialSecurityPropertyEvent e = new InitialSecurityPropertyEvent();
                e.key = key;
                e.value = p.getProperty(key);
                e.commit();
            }
        }
    }

    private static void emitMethodTiming() {
        if (MethodSetting.isInitialized() && MethodTimingEvent.enabled()) {
            PlatformTracer.emitTiming();
        }
    }
}

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

        jdk.internal.event.VirtualThreadEndEvent.class,
        jdk.internal.event.VirtualThreadSubmitFailedEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class,
        jdk.internal.event.FinalFieldMutationEvent.class,
        DirectBufferStatisticsEvent.class,
        InitialSecurityPropertyEvent.class,
        MethodTraceEvent.class,
        MethodTimingEvent.class,
    };

    private static final Runnable emitExceptionStatistics = JDKEvents::emitExceptionStatistics;
    private static final Runnable emitDirectBufferStatistics = JDKEvents::emitDirectBufferStatistics;
    private static final Runnable emitContainerConfiguration = JDKEvents::emitContainerConfiguration;
    private static final Runnable emitContainerCPUUsage = JDKEvents::emitContainerCPUUsage;
    private static final Runnable emitContainerCPUThrottling = JDKEvents::emitContainerCPUThrottling;

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

        try {
            if (initializationTriggered == false) {
                for (Class<?> eventClass : eventClasses) {
                    MetadataRepository.getInstance().register((Class<? extends Event>) eventClass);
                }
                PeriodicEvents.addJavaEvent(jdk.internal.event.ExceptionStatisticsEvent.class, emitExceptionStatistics);
                PeriodicEvents.addJavaEvent(DirectBufferStatisticsEvent.class, emitDirectBufferStatistics);
                PeriodicEvents.addJavaEvent(InitialSecurityPropertyEvent.class, emitInitialSecurityProperties);
                PeriodicEvents.addJavaEvent(MethodTimingEvent.class, emitMethodTiming);

                initializeContainerEvents();
                JFRTracing.enable();
                initializationTriggered = true;
            }
        } catch (Exception e) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.WARN, "Could not initialize JDK events. " + e.getMessage());

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

            for (String key : p.stringPropertyNames()) {
                InitialSecurityPropertyEvent e = new InitialSecurityPropertyEvent();
                e.key = key;
                e.value = p.getProperty(key);
                e.commit();
            }
        }
    }

    private static void emitMethodTiming() {
        if (MethodSetting.isInitialized() && MethodTimingEvent.enabled()) {
            PlatformTracer.emitTiming();
        }
    }
}

Configuration enabled filter period
profiling true null endChunk
default true null endChunk

Field Type Description
method Method Method
invocations long Invocations The number of times the method was invoked
minimum Tickspan Minimum An approximation of the minimum wall-clock time it took for the method to execute
average Tickspan Average An approximation of the average wall-clock time it took for the method to execute
maximum Tickspan Maximum An approximation of the maximum wall-clock time it took for the method to execute

FileWrite

throttle profiling default startTime duration 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/FileWriteEvent.java

Category: Java Application

Excludes in stack trace: java.nio.channels.FileChannel, java.io.DataOutputStream, java.io.FileOutputStream, java.io.OutputStream, java.io.RandomAccessFile, sun.nio.ch.ChannelOutputStream, sun.nio.ch.FileChannelImpl

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

Writing data to a file

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/FileWriteEvent.java:

@Name(Type.EVENT_NAME_PREFIX + "FileWrite")
@Label("File Write")
@Category("Java Application")
@Description("Writing data to a file")
@StackFilter({"java.nio.channels.FileChannel",
              "java.io.DataOutputStream",
              "java.io.FileOutputStream",
              "java.io.OutputStream",
              "java.io.RandomAccessFile",
              "sun.nio.ch.ChannelOutputStream",
              "sun.nio.ch.FileChannelImpl"})
@Throttle
public final class FileWriteEvent extends MirrorEvent {

    @Label("Path")
    @Description("Full path of the file, or N/A if a file descriptor was used to create the stream, for example System.out and System.err")
    public String path;

    @Label("Bytes Written")
    @Description("Number of bytes written to the file")
    @DataAmount
    public long bytesWritten;
}

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

/**
 * This class registers all mirror events.
 */
final class MirrorEvents {
    private static final Map<String, Class<? extends MirrorEvent>> mirrorLookup = new ConcurrentHashMap<>();

    // Add mirror event mapping here. See MirrorEvent class for details.
    static {
        register("jdk.internal.event.DeserializationEvent", DeserializationEvent.class);
        register("jdk.internal.event.FileForceEvent", FileForceEvent.class);
        register("jdk.internal.event.FileReadEvent", FileReadEvent.class);
        register("jdk.internal.event.FileWriteEvent", FileWriteEvent.class);
        register("jdk.internal.event.ProcessStartEvent", ProcessStartEvent.class);
        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);
        register("jdk.internal.event.VirtualThreadEndEvent", VirtualThreadEndEvent.class);
        register("jdk.internal.event.VirtualThreadSubmitFailedEvent", VirtualThreadSubmitFailedEvent.class);

src/java.base/share/classes/sun/nio/ch/FileChannelImpl.java:

    @Override
    public int write(ByteBuffer src) throws IOException {
        if (jfrTracing && FileWriteEvent.enabled()) {
            return traceImplWrite(src);
        }
        return implWrite(src);
    }

src/java.base/share/classes/sun/nio/ch/FileChannelImpl.java:

    private int traceImplWrite(ByteBuffer src) throws IOException {
        int bytesWritten = 0;
        long start = FileWriteEvent.timestamp();
        try {
            bytesWritten = implWrite(src);
        } finally {
            FileWriteEvent.offer(start, path, bytesWritten);
        }
        return bytesWritten;
    }

    @Override
    public long write(ByteBuffer[] srcs, int offset, int length) throws IOException {
        if (jfrTracing && FileWriteEvent.enabled()) {
            return traceImplWrite(srcs, offset, length);
        }
        return implWrite(srcs, offset, length);
    }

src/java.base/share/classes/sun/nio/ch/FileChannelImpl.java:

    private long traceImplWrite(ByteBuffer[] srcs, int offset, int length) throws IOException {
        long bytesWritten = 0;
        long start = FileWriteEvent.timestamp();
        try {
            bytesWritten = implWrite(srcs, offset, length);
        } finally {
            FileWriteEvent.offer(start, path, bytesWritten);
        }
        return bytesWritten;
    }

src/java.base/share/classes/sun/nio/ch/FileChannelImpl.java:

    private int traceImplWrite(ByteBuffer src, long position) throws IOException {
        int bytesWritten = 0;
        long start = FileWriteEvent.timestamp();
        try {
            bytesWritten = implWrite(src, position);
        } finally {
            FileWriteEvent.offer(start, path, bytesWritten);
        }
        return bytesWritten;
    }

src/java.base/share/classes/java/io/RandomAccessFile.java:

     * Writes the specified byte to this file. The write starts at
     * the current file pointer.
     *
     * @param      b   the {@code byte} to be written.
     * @throws     IOException  if an I/O error occurs.
     */
    public void write(int b) throws IOException {
        if (jfrTracing && FileWriteEvent.enabled()) {
            traceImplWrite(b);
            return;
        }
        implWrite(b);
    }

src/java.base/share/classes/java/io/RandomAccessFile.java:

        } finally {
            Blocker.end(attempted);
        }
    }

    private void traceImplWrite(int b) throws IOException {
        long bytesWritten = 0;
        long start = FileWriteEvent.timestamp();
        try {
            implWrite(b);
            bytesWritten = 1;
        } finally {
            FileWriteEvent.offer(start, path, bytesWritten);
        }
    }

    private native void write0(int b) throws IOException;

src/java.base/share/classes/java/io/RandomAccessFile.java:

     *
     * @param     b the data to be written
     * @param     off the start offset in the data
     * @param     len the number of bytes that are written
     * @throws    IOException If an I/O error has occurred.
     */
    private void writeBytes(byte[] b, int off, int len) throws IOException {
        if (jfrTracing && FileWriteEvent.enabled()) {
            traceImplWriteBytes(b, off, len);
            return;
        }
        implWriteBytes(b, off, len);
    }

src/java.base/share/classes/java/io/RandomAccessFile.java:

        } finally {
            Blocker.end(attempted);
        }
    }

    private void traceImplWriteBytes(byte b[], int off, int len) throws IOException {
        long bytesWritten = 0;
        long start = FileWriteEvent.timestamp();
        try {
            implWriteBytes(b, off, len);
            bytesWritten = len;
        } finally {
            FileWriteEvent.offer(start, path, bytesWritten);
        }
    }

    private native void writeBytes0(byte[] b, int off, int len) throws IOException;

src/java.base/share/classes/java/io/FileOutputStream.java:

     *     advances the position to the end of file
     */
    private native void write(int b, boolean append) throws IOException;

    private void traceWrite(int b, boolean append) throws IOException {
        long bytesWritten = 0;
        long start = FileWriteEvent.timestamp();
        try {
            write(b, append);
            bytesWritten = 1;
        } finally {
            FileWriteEvent.offer(start, path, bytesWritten);
        }
    }

    /**

src/java.base/share/classes/java/io/FileOutputStream.java:

     * @param      b   the byte to be written.
     * @throws     IOException  if an I/O error occurs.
     */
    @Override
    public void write(int b) throws IOException {
        boolean append = FD_ACCESS.getAppend(fd);
        if (jfrTracing && FileWriteEvent.enabled()) {
            traceWrite(b, append);
            return;
        }
        write(b, append);

src/java.base/share/classes/java/io/FileOutputStream.java:

     */
    private native void writeBytes(byte[] b, int off, int len, boolean append)
        throws IOException;

    private void traceWriteBytes(byte b[], int off, int len, boolean append) throws IOException {
        long bytesWritten = 0;
        long start = FileWriteEvent.timestamp();
        try {
            writeBytes(b, off, len, append);
            bytesWritten = len;
        } finally {
            FileWriteEvent.offer(start, path, bytesWritten);
        }
    }

    /**

src/java.base/share/classes/java/io/FileOutputStream.java:

     * @param      b   {@inheritDoc}
     * @throws     IOException  {@inheritDoc}
     */
    @Override
    public void write(byte[] b) throws IOException {
        boolean append = FD_ACCESS.getAppend(fd);
        if (jfrTracing && FileWriteEvent.enabled()) {
            traceWriteBytes(b, 0, b.length, append);
            return;
        }
        writeBytes(b, 0, b.length, append);

src/java.base/share/classes/java/io/FileOutputStream.java:

     * @throws     IOException  if an I/O error occurs.
     * @throws     IndexOutOfBoundsException {@inheritDoc}
     */
    @Override
    public void write(byte[] b, int off, int len) throws IOException {
        boolean append = FD_ACCESS.getAppend(fd);
        if (jfrTracing && FileWriteEvent.enabled()) {
            traceWriteBytes(b, off, len, append);
            return;
        }
        writeBytes(b, off, len, append);

src/java.base/share/classes/jdk/internal/event/FileWriteEvent.java:

package jdk.internal.event;

/**
 * Event recording file writes.
 */
public final class FileWriteEvent extends Event {

    // The order of these fields must be the same as the parameters in
    // commit(..., String, long)
    public String path;
    public long bytesWritten;

    public static boolean enabled() {
        // Generated by JFR
        return false;
    }

    public static long timestamp() {
        // Generated by JFR
        return 0L;
    }

    public static boolean shouldThrottleCommit(long duration, long end) {
        // Generated by JFR
        return false;

Configuration enabled stackTrace threshold throttle
profiling true true 1 ms 300/s 25+
default true true 1 ms 100/s 25+

Field Type Description
path string Path Full path of the file, or N/A if a file descriptor was used to create the stream, for example System.out and System.err
bytesWritten long: bytes Bytes Written Number of bytes written to the file

Examples 2
bytesWritten long: bytes
28112
path string
/home/runner/work/jfrevents/jfrevents/harness-003927-11018005009666797249/apache-spark/als/blockmgr-8e66d520-4bed-4a10-a35a-3b794a9b4dcb/33/temp_shuffle_d4341960-d619-437f-9c2b-0dfb3ad1ef14
startTime long: millis
302040747617
bytesWritten long: bytes
85805
path string
/home/runner/work/jfrevents/jfrevents/harness-003928-7951762178349451551/apache-spark/als/blockmgr-2bb2e5d4-fda1-4c72-8c69-c810458aa118/3e/shuffle_6_202_0.data.aecc1fe2-0c0f-4b5c-b06a-c169419e5048
startTime long: millis
398117182764

SocketWrite

throttle profiling default startTime duration 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/SocketWriteEvent.java

Category: Java Application

Excludes in stack trace: java.io.OutputStream, java.net.Socket$SocketOutputStream, java.nio.channels.SocketChannel, sun.nio.ch.SocketOutputStream

Writing data to a socket

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/SocketWriteEvent.java:

@Name(Type.EVENT_NAME_PREFIX + "SocketWrite")
@Label("Socket Write")
@Category("Java Application")
@Description("Writing data to a socket")
@StackFilter({"java.io.OutputStream",
              "java.net.Socket$SocketOutputStream",
              "java.nio.channels.SocketChannel",
              "sun.nio.ch.SocketOutputStream"})
@Throttle
public final class SocketWriteEvent extends MirrorEvent {

    @Label("Remote Host")
    public String host;

    @Label("Remote Address")
    public String address;

    @Label("Remote Port")
    public int port;

    @Label("Bytes Written")

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

    private static final Map<String, Class<? extends MirrorEvent>> mirrorLookup = new ConcurrentHashMap<>();

    // Add mirror event mapping here. See MirrorEvent class for details.
    static {
        register("jdk.internal.event.DeserializationEvent", DeserializationEvent.class);
        register("jdk.internal.event.FileForceEvent", FileForceEvent.class);
        register("jdk.internal.event.FileReadEvent", FileReadEvent.class);
        register("jdk.internal.event.FileWriteEvent", FileWriteEvent.class);
        register("jdk.internal.event.ProcessStartEvent", ProcessStartEvent.class);
        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);
        register("jdk.internal.event.VirtualThreadEndEvent", VirtualThreadEndEvent.class);
        register("jdk.internal.event.VirtualThreadSubmitFailedEvent", VirtualThreadSubmitFailedEvent.class);
        register("jdk.internal.event.X509CertificateEvent", X509CertificateEvent.class);
        register("jdk.internal.event.X509ValidationEvent", X509ValidationEvent.class);
        register("jdk.internal.event.ErrorThrownEvent", ErrorThrownEvent.class);
        register("jdk.internal.event.ExceptionStatisticsEvent", ExceptionStatisticsEvent.class);
        register("jdk.internal.event.ExceptionThrownEvent", ExceptionThrownEvent.class);
        register("jdk.internal.event.FinalFieldMutationEvent", FinalFieldMutationEvent.class);

src/java.base/share/classes/java/net/Socket.java:

        private final Socket parent;
        private final OutputStream out;
        SocketOutputStream(Socket parent, OutputStream out) {
            this.parent = parent;
            this.out = out;
        }
        @Override
        public void write(int b) throws IOException {
            byte[] a = new byte[] { (byte) b };
            write(a, 0, 1);
        }
        @Override
        public void write(byte[] b, int off, int len) throws IOException {
            if (!SocketWriteEvent.enabled()) {
                implWrite(b, off, len);
                return;
            }
            long start = SocketWriteEvent.timestamp();
            implWrite(b, off, len);
            SocketWriteEvent.offer(start, len, parent.getRemoteSocketAddress());
        }

        private void implWrite(byte[] b, int off, int len) throws IOException {
            try {
                out.write(b, off, len);
            } catch (InterruptedIOException e) {
                Thread thread = Thread.currentThread();
                if (thread.isVirtual() && thread.isInterrupted()) {
                    close();
                    throw new SocketException("Closed by interrupt");
                }

src/java.base/share/classes/sun/nio/ch/SocketChannelImpl.java:

        } finally {
            writeLock.unlock();
        }
    }

    @Override
    public int write(ByteBuffer buf) throws IOException {
        if (!SocketWriteEvent.enabled()) {
            return implWrite(buf);
        }
        long start = SocketWriteEvent.timestamp();
        int nbytes = implWrite(buf);
        SocketWriteEvent.offer(start, nbytes, remoteAddress());
        return nbytes;
    }

    @Override
    public long write(ByteBuffer[] srcs, int offset, int length)
        throws IOException
    {
        if (!SocketWriteEvent.enabled()) {
            return implWrite(srcs, offset, length);
        }
        long start = SocketWriteEvent.timestamp();
        long nbytes = implWrite(srcs, offset, length);
        SocketWriteEvent.offer(start, nbytes, remoteAddress());
        return nbytes;
    }

    /**
     * Writes a byte of out of band data.

src/java.base/share/classes/sun/nio/ch/SocketOutputStream.java:

     */
    SocketChannelImpl channel() {
        return sc;
    }

    @Override
    public void write(int b) throws IOException {
        byte[] a = new byte[]{(byte) b};
        write(a, 0, 1);
    }

    @Override
    public void write(byte[] b, int off, int len) throws IOException {
        if (!SocketWriteEvent.enabled()) {
            sc.blockingWriteFully(b, off, len);
            return;
        }
        long start = SocketWriteEvent.timestamp();
        sc.blockingWriteFully(b, off, len);
        SocketWriteEvent.offer(start, len, sc.remoteAddress());
    }

    @Override
    public void close() throws IOException {
        sc.close();
    }
}

src/java.base/share/classes/jdk/internal/event/SocketWriteEvent.java:

/**
 * A JFR event for socket write operations.  This event is mirrored in
 * {@code jdk.jfr.events.SocketWriteEvent } where the metadata for the event is
 * provided with annotations.  Some of the methods are replaced by generated
 * methods when jfr is enabled.  Note that the order of the arguments of the
 * {@link #commit(long, long, String, String, int, long)} method
 * must be the same as the order of the fields.
 */
public class SocketWriteEvent extends Event {

    // THE ORDER OF THE FOLLOWING FIELDS IS IMPORTANT!
    // The order must match the argument order of the generated commit method.
    public String host;
    public String address;
    public int port;
    public long bytesWritten;

    /**
     * Actually commit a socket write event.  This is generated automatically.
     * The order of the fields must be the same as the parameters in this method.

Configuration enabled stackTrace threshold throttle
profiling true true 1 ms 300/s 25+
default true true 1 ms 100/s 25+

Field Type Description
host string Remote Host
address string Remote Address
port int Remote Port
bytesWritten long: bytes Bytes Written Number of bytes written to the socket

JavaExceptionThrow

throttle profiling default startTime duration 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/ExceptionThrownEvent.java

Category: Java Application

An object derived from java.lang.Exception has been created

Configuration enabled stackTrace throttle
profiling true true 300/s 25+
default true true 100/s 25+

Field Type Description
message string Message
thrownClass Class Class

Examples 3
message string
null
startTime long: millis
367133728707
thrownClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/io/EOFException
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/io
message string
null
startTime long: millis
374913085253
thrownClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/io/EOFException
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/io
message string
null
startTime long: millis
278744692944
thrownClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/io/EOFException
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/io

FinalFieldMutation

profiling default startTime duration 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/FinalFieldMutationEvent.java

Category: Java Application

Excludes in stack trace: java.lang.reflect.Field, java.lang.reflect.ReflectAccess, java.lang.invoke.MethodHandles$Lookup

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/FinalFieldMutationEvent.java:

@Category("Java Application")
@Label("Final Field Mutation")
@Name(Type.EVENT_NAME_PREFIX + "FinalFieldMutation")
@RemoveFields("duration")
@StackFilter({
        "java.lang.reflect.Field",
        "java.lang.reflect.ReflectAccess",
        "java.lang.invoke.MethodHandles$Lookup"
})
public final class FinalFieldMutationEvent extends MirrorEvent {

    @Label("Declaring Class")
    @Description("Declaring class with final field")
    public Class<?> declaringClass;

    @Label("Field Name")
    @Description("Field name of final field")
    public String fieldName;

}

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);
        register("jdk.internal.event.VirtualThreadEndEvent", VirtualThreadEndEvent.class);
        register("jdk.internal.event.VirtualThreadSubmitFailedEvent", VirtualThreadSubmitFailedEvent.class);
        register("jdk.internal.event.X509CertificateEvent", X509CertificateEvent.class);
        register("jdk.internal.event.X509ValidationEvent", X509ValidationEvent.class);
        register("jdk.internal.event.ErrorThrownEvent", ErrorThrownEvent.class);
        register("jdk.internal.event.ExceptionStatisticsEvent", ExceptionStatisticsEvent.class);
        register("jdk.internal.event.ExceptionThrownEvent", ExceptionThrownEvent.class);
        register("jdk.internal.event.FinalFieldMutationEvent", FinalFieldMutationEvent.class);
    };

    private static void register(String eventClassName, Class<? extends MirrorEvent> mirrorClass) {
        mirrorLookup.put(eventClassName, mirrorClass);
    }

    static Class<? extends MirrorEvent> find(Class<? extends jdk.internal.event.Event> eventClass) {
        return find(Utils.isJDKClass(eventClass), eventClass.getName());
    }

    static Class<? extends MirrorEvent> find(boolean bootClassLoader, String name) {

src/java.base/share/classes/jdk/internal/event/FinalFieldMutationEvent.java:

package jdk.internal.event;

public class FinalFieldMutationEvent extends Event {
    public Class<?> declaringClass;
    public String fieldName;

    /**
     * Commit a FinalFieldMutationEvent if enabled.
     */
    public static void offer(Class<?> declaringClass, String fieldName) {
        if (enabled()) {
            var event = new FinalFieldMutationEvent();
            event.declaringClass = declaringClass;
            event.fieldName = fieldName;
            event.commit();
        }
    }

    public static boolean enabled() {
        // Generated by JFR
        return false;
    }
}

src/java.base/share/classes/java/lang/reflect/Field.java:

                        """, warningMsg, targetModule);
            }
        } else if (mode == ModuleBootstrap.IllegalFinalFieldMutation.DEBUG) {
            // print warning and stack trace
            var sb = new StringBuilder(finalFieldMutationWarning(caller, unreflect));
            StackWalker.getInstance(StackWalker.Option.RETAIN_CLASS_REFERENCE)
                    .forEach(sf -> {
                        sb.append(System.lineSeparator()).append("\tat " + sf);
                    });
            VM.initialErr().println(sb);
        }

        // record JFR event
        FinalFieldMutationEvent.offer(getDeclaringClass(), getName());
    }

    /**
     * Returns true if this final field is "deeply accessible" to the caller.
     * The field is deeply accessible if declaring class is in a package that is open
     * to the caller's module, or the field is public in a public class that is exported
     * to the caller's module.
     *
     * Updates to the module of the declaring class at runtime with {@code Module.addExports}
     * or {@code Module.addOpens} have no impact on the result of this method.
     */

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
declaringClass Class Declaring Class Declaring class with final field
fieldName string Field Name Field name of final field

FileForce

profiling default startTime duration 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/FileForceEvent.java

Category: Java Application

Force updates to be written to file

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/FileForceEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.internal.MirrorEvent;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "FileForce")
@Label("File Force")
@Category("Java Application")
@Description("Force updates to be written to file")
public final class FileForceEvent extends MirrorEvent {

    // The order of these fields must be the same as the parameters in
    // commit(..., String, boolean)

    @Label("Path")
    @Description("Full path of the file")
    public String path;

    @Label("Update Metadata")
    @Description("Whether the file metadata is updated")
    public boolean metaData;

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

/**
 * This class registers all mirror events.
 */
final class MirrorEvents {
    private static final Map<String, Class<? extends MirrorEvent>> mirrorLookup = new ConcurrentHashMap<>();

    // Add mirror event mapping here. See MirrorEvent class for details.
    static {
        register("jdk.internal.event.DeserializationEvent", DeserializationEvent.class);
        register("jdk.internal.event.FileForceEvent", FileForceEvent.class);
        register("jdk.internal.event.FileReadEvent", FileReadEvent.class);
        register("jdk.internal.event.FileWriteEvent", FileWriteEvent.class);
        register("jdk.internal.event.ProcessStartEvent", ProcessStartEvent.class);
        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);

src/java.base/windows/classes/sun/nio/ch/WindowsAsynchronousFileChannelImpl.java:

    private void implForce(boolean metaData) throws IOException {
        try {
            begin();
            nd.force(fdObj, metaData);
        } finally {
            end();
        }
    }

    @Override
    public void force(boolean metaData) throws IOException {
        if (!FileForceEvent.enabled()) {
            implForce(metaData);
            return;
        }
        long start = FileForceEvent.timestamp();
        implForce(metaData);
        FileForceEvent.offer(start, path, metaData);
    }

    // -- file locking --

    /**
     * Task that initiates locking operation and handles completion result.
     */
    private class LockTask<A> implements Runnable, Iocp.ResultHandler {
        private final long position;
        private final FileLockImpl fli;
        private final PendingFuture<FileLock,A> result;

src/java.base/share/classes/sun/nio/ch/FileChannelImpl.java:

                } finally {
                    Blocker.end(attempted);
                }
            } while ((rv == IOStatus.INTERRUPTED) && isOpen());
        } finally {
            threads.remove(ti);
            endBlocking(rv > -1);
            assert IOStatus.check(rv);
        }
    }

    @Override
    public void force(boolean metaData) throws IOException {
        if (!FileForceEvent.enabled()) {
            implForce(metaData);
            return;
        }
        long start = FileForceEvent.timestamp();
        implForce(metaData);
        FileForceEvent.offer(start, path, metaData);
    }

    // Assume at first that the underlying kernel supports sendfile/equivalent;
    // set this to true if we find out later that it doesn't
    //
    private static volatile boolean transferToDirectNotSupported;

    // Assume at first that the underlying kernel supports copy_file_range/equivalent;
    // set this to true if we find out later that it doesn't
    //
    private static volatile boolean transferFromDirectNotSupported;

src/java.base/share/classes/sun/nio/ch/SimpleAsynchronousFileChannelImpl.java:

                do {
                    n = nd.force(fdObj, metaData);
                } while ((n == IOStatus.INTERRUPTED) && isOpen());
            } finally {
                end(n >= 0);
            }
        } finally {
            threads.remove(ti);
        }
    }

    @Override
    public void force(boolean metaData) throws IOException {
        if (!FileForceEvent.enabled()) {
            implForce(metaData);
            return;
        }
        long start = FileForceEvent.timestamp();
        implForce(metaData);
        FileForceEvent.offer(start, path, metaData);
    }

    @Override
    <A> Future<FileLock> implLock(final long position,
                                  final long size,
                                  final boolean shared,
                                  final A attachment,
                                  final CompletionHandler<FileLock,? super A> handler)
    {
        if (shared && !reading)
            throw new NonReadableChannelException();

src/java.base/share/classes/jdk/internal/event/FileForceEvent.java:

package jdk.internal.event;

/**
 * A JFR event for forced updates written to files.  This event is mirrored in
 * {@code jdk.jfr.events.FileForceEvent } where the event annotations are
 * provided.  Some of the methods are replaced by generated
 * methods when jfr is enabled.  Note that the order of the arguments of the
 * {@link #commit(long, long, String, boolean)} method
 * must be the same as the order of the fields.
 */
public class FileForceEvent extends Event {

    // THE ORDER OF THE FOLLOWING FIELDS IS IMPORTANT!
    // The order must match the argument order of the generated commit method.
    public String path;
    public boolean metaData;

    /**
     * Helper method to offer the data needed to potentially commit an event.
     * The duration of the operation is computed using the current
     * timestamp and the given start time.  If the duration is meets
     * or exceeds the configured value (determined by calling the generated method
     * {@link #shouldCommit(long)}), an event will be emitted by calling
     * {@link #commit(long, long, String, boolean)}.

Configuration enabled stackTrace threshold
profiling true true 10 ms
default true true 20 ms

Field Type Description
path string Path Full path of the file
metaData boolean Update Metadata Whether the file metadata is updated

VirtualThreadStart

startTime duration 19 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/VirtualThreadStartEvent.java

Category: Java Application

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/VirtualThreadStartEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.internal.MirrorEvent;
import jdk.jfr.internal.RemoveFields;

@Category("Java Application")
@Label("Virtual Thread Start")
@Name("jdk.VirtualThreadStart")
@RemoveFields("duration")
public final class VirtualThreadStartEvent extends MirrorEvent {

    @Label("Thread Id")
    public long javaThreadId;

}

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

    static {
        register("jdk.internal.event.DeserializationEvent", DeserializationEvent.class);
        register("jdk.internal.event.FileForceEvent", FileForceEvent.class);
        register("jdk.internal.event.FileReadEvent", FileReadEvent.class);
        register("jdk.internal.event.FileWriteEvent", FileWriteEvent.class);
        register("jdk.internal.event.ProcessStartEvent", ProcessStartEvent.class);
        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);
        register("jdk.internal.event.VirtualThreadEndEvent", VirtualThreadEndEvent.class);
        register("jdk.internal.event.VirtualThreadSubmitFailedEvent", VirtualThreadSubmitFailedEvent.class);
        register("jdk.internal.event.X509CertificateEvent", X509CertificateEvent.class);
        register("jdk.internal.event.X509ValidationEvent", X509ValidationEvent.class);
        register("jdk.internal.event.ErrorThrownEvent", ErrorThrownEvent.class);
        register("jdk.internal.event.ExceptionStatisticsEvent", ExceptionStatisticsEvent.class);
        register("jdk.internal.event.ExceptionThrownEvent", ExceptionThrownEvent.class);
        register("jdk.internal.event.FinalFieldMutationEvent", FinalFieldMutationEvent.class);
    };

    private static void register(String eventClassName, Class<? extends MirrorEvent> mirrorClass) {

src/java.base/share/classes/jdk/internal/event/VirtualThreadStartEvent.java:

package jdk.internal.event;

/**
 * Event recording that a virtual thread has been started.
 */
public class VirtualThreadStartEvent extends Event {
    private static final VirtualThreadStartEvent EVENT = new VirtualThreadStartEvent();

    /**
     * Returns {@code true} if event is enabled, {@code false} otherwise.
     */
    public static boolean isTurnedOn() {
        return EVENT.isEnabled();
    }

    public long javaThreadId;
}

src/java.base/share/classes/java/lang/VirtualThread.java:

            event.javaThreadId = threadId();
            event.exceptionMessage = ree.getMessage();
            event.commit();
        }
    }

    /**
     * Runs a task in the context of this virtual thread.
     */
    private void run(Runnable task) {
        assert Thread.currentThread() == this && state == RUNNING;

        // emit JFR event if enabled
        if (VirtualThreadStartEvent.isTurnedOn()) {
            var event = new VirtualThreadStartEvent();
            event.javaThreadId = threadId();
            event.commit();
        }

        Object bindings = Thread.scopedValueBindings();
        try {
            runWith(bindings, task);
        } catch (Throwable exc) {
            dispatchUncaughtException(exc);
        } finally {
            // pop any remaining scopes from the stack, this may block

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
javaThreadId long Thread Id

SocketRead

throttle profiling default startTime duration 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/SocketReadEvent.java

Category: Java Application

Excludes in stack trace: java.io.InputStream, java.net.Socket$SocketInputStream, java.nio.channels.SocketChannel, sun.nio.ch.SocketInputStream

Reading data from a socket

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/SocketReadEvent.java:

@Name(Type.EVENT_NAME_PREFIX + "SocketRead")
@Label("Socket Read")
@Category("Java Application")
@Description("Reading data from a socket")
@StackFilter({"java.io.InputStream",
              "java.net.Socket$SocketInputStream",
              "java.nio.channels.SocketChannel",
              "sun.nio.ch.SocketInputStream"})
@Throttle
public final class SocketReadEvent extends MirrorEvent {

    @Label("Remote Host")
    public String host;

    @Label("Remote Address")
    public String address;

    @Label("Remote Port")
    public int port;

    @Label("Timeout Value")

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

final class MirrorEvents {
    private static final Map<String, Class<? extends MirrorEvent>> mirrorLookup = new ConcurrentHashMap<>();

    // Add mirror event mapping here. See MirrorEvent class for details.
    static {
        register("jdk.internal.event.DeserializationEvent", DeserializationEvent.class);
        register("jdk.internal.event.FileForceEvent", FileForceEvent.class);
        register("jdk.internal.event.FileReadEvent", FileReadEvent.class);
        register("jdk.internal.event.FileWriteEvent", FileWriteEvent.class);
        register("jdk.internal.event.ProcessStartEvent", ProcessStartEvent.class);
        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);
        register("jdk.internal.event.VirtualThreadEndEvent", VirtualThreadEndEvent.class);
        register("jdk.internal.event.VirtualThreadSubmitFailedEvent", VirtualThreadSubmitFailedEvent.class);
        register("jdk.internal.event.X509CertificateEvent", X509CertificateEvent.class);
        register("jdk.internal.event.X509ValidationEvent", X509ValidationEvent.class);
        register("jdk.internal.event.ErrorThrownEvent", ErrorThrownEvent.class);
        register("jdk.internal.event.ExceptionStatisticsEvent", ExceptionStatisticsEvent.class);
        register("jdk.internal.event.ExceptionThrownEvent", ExceptionThrownEvent.class);

src/java.base/share/classes/java/net/Socket.java:

        private final InputStream in;
        SocketInputStream(Socket parent, InputStream in) {
            this.parent = parent;
            this.in = in;
        }
        @Override
        public int read() throws IOException {
            byte[] a = new byte[1];
            int n = read(a, 0, 1);
            return (n > 0) ? (a[0] & 0xff) : -1;
        }
        @Override
        public int read(byte[] b, int off, int len) throws IOException {
            if (!SocketReadEvent.enabled()) {
                return implRead(b, off, len);
            }
            long start = SocketReadEvent.timestamp();
            int nbytes = implRead(b, off, len);
            SocketReadEvent.offer(start, nbytes, parent.getRemoteSocketAddress(), getSoTimeout());
            return nbytes;
        }

        private int implRead(byte[] b, int off, int len) throws IOException {
            try {
                return in.read(b, off, len);
            } catch (SocketTimeoutException e) {
                throw e;
            } catch (InterruptedIOException e) {
                Thread thread = Thread.currentThread();
                if (thread.isVirtual() && thread.isInterrupted()) {

src/java.base/share/classes/sun/nio/ch/SocketChannelImpl.java:

        } finally {
            readLock.unlock();
        }
    }

    @Override
    public int read(ByteBuffer buf) throws IOException {
        if (!SocketReadEvent.enabled()) {
            return implRead(buf);
        }
        long start = SocketReadEvent.timestamp();
        int nbytes = implRead(buf);
        SocketReadEvent.offer(start, nbytes, remoteAddress(), 0);
        return nbytes;
    }


    @Override
    public long read(ByteBuffer[] dsts, int offset, int length)
        throws IOException
    {
        if (!SocketReadEvent.enabled()) {
            return implRead(dsts, offset, length);
        }
        long start = SocketReadEvent.timestamp();
        long nbytes = implRead(dsts, offset, length);
        SocketReadEvent.offer(start, nbytes, remoteAddress(), 0);
        return nbytes;
    }

    /**
     * Marks the beginning of a write operation that might block.

src/java.base/share/classes/sun/nio/ch/SocketInputStream.java:

    private int implRead(byte[] b, int off, int len, int timeout) throws IOException {
        if (timeout > 0) {
            long nanos = MILLISECONDS.toNanos(timeout);
            return sc.blockingRead(b, off, len, nanos);
        } else {
            return sc.blockingRead(b, off, len, 0);
        }
    }

    @Override
    public int read(byte[] b, int off, int len) throws IOException {
        int timeout = timeoutSupplier.getAsInt();
        if (!SocketReadEvent.enabled()) {
            return implRead(b, off, len, timeout);
        }
        long start = SocketReadEvent.timestamp();
        int n = implRead(b, off, len, timeout);
        SocketReadEvent.offer(start, n, sc.remoteAddress(), timeout);
        return n;
    }

    @Override
    public int available() throws IOException {
        return sc.available();
    }

    @Override
    public void close() throws IOException {
        sc.close();

src/java.base/share/classes/jdk/internal/event/SocketReadEvent.java:

/**
 * A JFR event for socket read operations.  This event is mirrored in
 * {@code jdk.jfr.events.SocketReadEvent } where the metadata for the event is
 * provided with annotations.  Some of the methods are replaced by generated
 * methods when jfr is enabled.  Note that the order of the arguments of the
 * {@link #commit(long, long, String, String, int, long, long, boolean)} method
 * must be the same as the order of the fields.
 */
public class SocketReadEvent extends Event {

    // THE ORDER OF THE FOLLOWING FIELDS IS IMPORTANT!
    // The order must match the argument order of the generated commit method.
    public String host;
    public String address;
    public int port;
    public long timeout;
    public long bytesRead;
    public boolean endOfStream;

    /**

Configuration enabled stackTrace threshold throttle
profiling true true 1 ms 300/s 25+
default true true 1 ms 100/s 25+

Field Type Description
host string Remote Host
address string Remote Address
port int Remote Port
timeout long: millis Timeout Value
bytesRead long: bytes Bytes Read Number of bytes read from the socket
endOfStream boolean End of Stream If end of stream was reached

ThreadSleep

profiling default startTime duration 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/ThreadSleepEvent.java

Category: Java Application

Excludes in stack trace: java.lang.Thread::afterSleep, java.lang.Thread::sleepNanos, java.lang.Thread::sleep

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/ThreadSleepEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.Timespan;
import jdk.jfr.internal.MirrorEvent;

@Category("Java Application")
@Label("Java Thread Sleep")
@Name("jdk.ThreadSleep")
@StackFilter({"java.lang.Thread::afterSleep",
              "java.lang.Thread::sleepNanos",
              "java.lang.Thread::sleep"})
public final class ThreadSleepEvent extends MirrorEvent {
    @Label("Sleep Time")
    @Timespan(Timespan.NANOSECONDS)
    public long time;
}

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

    // Add mirror event mapping here. See MirrorEvent class for details.
    static {
        register("jdk.internal.event.DeserializationEvent", DeserializationEvent.class);
        register("jdk.internal.event.FileForceEvent", FileForceEvent.class);
        register("jdk.internal.event.FileReadEvent", FileReadEvent.class);
        register("jdk.internal.event.FileWriteEvent", FileWriteEvent.class);
        register("jdk.internal.event.ProcessStartEvent", ProcessStartEvent.class);
        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);
        register("jdk.internal.event.VirtualThreadEndEvent", VirtualThreadEndEvent.class);
        register("jdk.internal.event.VirtualThreadSubmitFailedEvent", VirtualThreadSubmitFailedEvent.class);
        register("jdk.internal.event.X509CertificateEvent", X509CertificateEvent.class);
        register("jdk.internal.event.X509ValidationEvent", X509ValidationEvent.class);
        register("jdk.internal.event.ErrorThrownEvent", ErrorThrownEvent.class);
        register("jdk.internal.event.ExceptionStatisticsEvent", ExceptionStatisticsEvent.class);
        register("jdk.internal.event.ExceptionThrownEvent", ExceptionThrownEvent.class);
        register("jdk.internal.event.FinalFieldMutationEvent", FinalFieldMutationEvent.class);
    };

src/java.base/share/classes/jdk/internal/event/ThreadSleepEvent.java:

package jdk.internal.event;

/**
 * Event recording thread sleeping.
 */

public final class ThreadSleepEvent extends Event {
    public long time;
}

src/java.base/share/classes/java/lang/Thread.java:

    public static void yield() {
        if (currentThread() instanceof VirtualThread vthread) {
            vthread.tryYield();
        } else {
            yield0();
        }
    }

    private static native void yield0();

    /**
     * Called before sleeping to create a jdk.ThreadSleep event.
     */
    private static ThreadSleepEvent beforeSleep(long nanos) {
        try {
            ThreadSleepEvent event = new ThreadSleepEvent();
            if (event.isEnabled()) {
                event.time = nanos;
                event.begin();
                return event;
            }
        } catch (OutOfMemoryError e) {
            // ignore
        }
        return null;
    }


    /**
     * Called after sleeping to commit the jdk.ThreadSleep event.
     */
    private static void afterSleep(ThreadSleepEvent event) {
        if (event != null) {
            try {
                event.commit();
            } catch (OutOfMemoryError e) {
                // ignore
            }
        }
    }

    /**
     * Sleep for the specified number of nanoseconds, subject to the precision
     * and accuracy of system timers and schedulers.
     */
    private static void sleepNanos(long nanos) throws InterruptedException {
        ThreadSleepEvent event = beforeSleep(nanos);
        try {
            if (currentThread() instanceof VirtualThread vthread) {
                vthread.sleepNanos(nanos);
            } else {
                sleepNanos0(nanos);
            }
        } finally {
            afterSleep(event);
        }
    }

Configuration enabled stackTrace threshold
profiling true true 10 ms
default true true 20 ms

Field Type Description
time long: nanos Sleep Time

Examples 3
startTime long: millis
275187464247
time long: nanos
10000000
startTime long: millis
374261807691
time long: nanos
200000000
startTime long: millis
367135134866
time long: nanos
10000000

JavaErrorThrow

profiling default startTime duration 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/ErrorThrownEvent.java

Category: Java Application

An object derived from java.lang.Error has been created. OutOfMemoryErrors are ignored

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
message string Message
thrownClass Class Class

Examples 3
message string
static Ljava/lang/Object;.<clinit>()V
startTime long: millis
445705854411
thrownClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/NoSuchMethodError
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
message string
static Lorg/apache/spark/NarrowDependency;.<clinit>()V
startTime long: millis
324557933551
thrownClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/NoSuchMethodError
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
message string
static Lorg/apache/spark/sql/catalyst/analysis/GetColumnByOrdinal;.<clinit>()V
startTime long: millis
452441955539
thrownClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/NoSuchMethodError
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang

VirtualThreadEnd

startTime duration 19 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/VirtualThreadEndEvent.java

Category: Java Application

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/VirtualThreadEndEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.internal.MirrorEvent;
import jdk.jfr.internal.RemoveFields;

@Category("Java Application")
@Label("Virtual Thread End")
@Name("jdk.VirtualThreadEnd")
@RemoveFields({"duration", "stackTrace"})
public final class VirtualThreadEndEvent extends MirrorEvent {

    @Label("Thread Id")
    public long javaThreadId;

}

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

        register("jdk.internal.event.DeserializationEvent", DeserializationEvent.class);
        register("jdk.internal.event.FileForceEvent", FileForceEvent.class);
        register("jdk.internal.event.FileReadEvent", FileReadEvent.class);
        register("jdk.internal.event.FileWriteEvent", FileWriteEvent.class);
        register("jdk.internal.event.ProcessStartEvent", ProcessStartEvent.class);
        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);
        register("jdk.internal.event.VirtualThreadEndEvent", VirtualThreadEndEvent.class);
        register("jdk.internal.event.VirtualThreadSubmitFailedEvent", VirtualThreadSubmitFailedEvent.class);
        register("jdk.internal.event.X509CertificateEvent", X509CertificateEvent.class);
        register("jdk.internal.event.X509ValidationEvent", X509ValidationEvent.class);
        register("jdk.internal.event.ErrorThrownEvent", ErrorThrownEvent.class);
        register("jdk.internal.event.ExceptionStatisticsEvent", ExceptionStatisticsEvent.class);
        register("jdk.internal.event.ExceptionThrownEvent", ExceptionThrownEvent.class);
        register("jdk.internal.event.FinalFieldMutationEvent", FinalFieldMutationEvent.class);
    };

    private static void register(String eventClassName, Class<? extends MirrorEvent> mirrorClass) {
        mirrorLookup.put(eventClassName, mirrorClass);

src/java.base/share/classes/jdk/internal/event/VirtualThreadEndEvent.java:

package jdk.internal.event;

/**
 * Event recording that a virtual thread has terminated.
 */
public class VirtualThreadEndEvent extends Event {
    private static final VirtualThreadEndEvent EVENT = new VirtualThreadEndEvent();

    /**
     * Returns {@code true} if event is enabled, {@code false} otherwise.
     */
    public static boolean isTurnedOn() {
        return EVENT.isEnabled();
    }

    public long javaThreadId;
}

src/java.base/share/classes/java/lang/VirtualThread.java:

            event.commit();
        }

        Object bindings = Thread.scopedValueBindings();
        try {
            runWith(bindings, task);
        } catch (Throwable exc) {
            dispatchUncaughtException(exc);
        } finally {
            // pop any remaining scopes from the stack, this may block
            StackableScope.popAll();

            // emit JFR event if enabled
            if (VirtualThreadEndEvent.isTurnedOn()) {
                var event = new VirtualThreadEndEvent();
                event.javaThreadId = threadId();
                event.commit();
            }
        }
    }

    /**
     * Mounts this virtual thread onto the current platform thread. On
     * return, the current thread is the virtual thread.
     */
    @ChangesCurrentThread

Configuration enabled
profiling false
default false

Field Type Description
javaThreadId long Thread Id

FileRead

throttle profiling default startTime duration 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/FileReadEvent.java

Category: Java Application

Excludes in stack trace: java.nio.channels.FileChannel, java.io.DataInputStream, java.io.FileInputStream, java.io.InputStream, java.io.RandomAccessFile, sun.nio.ch.ChannelInputStream, sun.nio.ch.FileChannelImpl

Appearing in: SerialGC, ZGC

Missing in: G1GC, ParallelGC, ShenandoahGC

Reading data from a file

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/FileReadEvent.java:

@Name(Type.EVENT_NAME_PREFIX + "FileRead")
@Label("File Read")
@Category("Java Application")
@Description("Reading data from a file")
@StackFilter({"java.nio.channels.FileChannel",
              "java.io.DataInputStream",
              "java.io.FileInputStream",
              "java.io.InputStream",
              "java.io.RandomAccessFile",
              "sun.nio.ch.ChannelInputStream",
              "sun.nio.ch.FileChannelImpl"})
@Throttle
public final class FileReadEvent extends MirrorEvent {

    @Label("Path")
    @Description("Full path of the file, or N/A if a file descriptor was used to create the stream, for example System.in")
    public String path;

    @Label("Bytes Read")
    @Description("Number of bytes read from the file (possibly 0)")
    @DataAmount
    public long bytesRead;

    @Label("End of File")

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

/**
 * This class registers all mirror events.
 */
final class MirrorEvents {
    private static final Map<String, Class<? extends MirrorEvent>> mirrorLookup = new ConcurrentHashMap<>();

    // Add mirror event mapping here. See MirrorEvent class for details.
    static {
        register("jdk.internal.event.DeserializationEvent", DeserializationEvent.class);
        register("jdk.internal.event.FileForceEvent", FileForceEvent.class);
        register("jdk.internal.event.FileReadEvent", FileReadEvent.class);
        register("jdk.internal.event.FileWriteEvent", FileWriteEvent.class);
        register("jdk.internal.event.ProcessStartEvent", ProcessStartEvent.class);
        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);
        register("jdk.internal.event.VirtualThreadEndEvent", VirtualThreadEndEvent.class);

src/java.base/share/classes/sun/nio/ch/FileChannelImpl.java:

    @Override
    public int read(ByteBuffer dst) throws IOException {
        if (jfrTracing && FileReadEvent.enabled()) {
            return traceImplRead(dst);
        }
        return implRead(dst);

src/java.base/share/classes/sun/nio/ch/FileChannelImpl.java:

    private int traceImplRead(ByteBuffer dst) throws IOException {
        int bytesRead = 0;
        long start = FileReadEvent.timestamp();
        try {
            bytesRead = implRead(dst);
        } finally {
            FileReadEvent.offer(start, path, bytesRead);
        }
        return bytesRead;
    }

    @Override
    public long read(ByteBuffer[] dsts, int offset, int length) throws IOException {
        if (jfrTracing && FileReadEvent.enabled()) {
            return traceImplRead(dsts, offset, length);
        }
        return implRead(dsts, offset, length);

src/java.base/share/classes/sun/nio/ch/FileChannelImpl.java:

    private long traceImplRead(ByteBuffer[] dsts, int offset, int length) throws IOException {
        long bytesRead = 0;
        long start = FileReadEvent.timestamp();
        try {
            bytesRead = implRead(dsts, offset, length);
        } finally {
            FileReadEvent.offer(start, path, bytesRead);
        }
        return bytesRead;
    }

src/java.base/share/classes/sun/nio/ch/FileChannelImpl.java:

    @Override
    public int read(ByteBuffer dst, long position) throws IOException {
        if (jfrTracing && FileReadEvent.enabled()) {
            return traceImplRead(dst, position);
        }
        return implRead(dst, position);

src/java.base/share/classes/sun/nio/ch/FileChannelImpl.java:

    private int traceImplRead(ByteBuffer dst, long position) throws IOException {
        int bytesRead = 0;
        long start = FileReadEvent.timestamp();
        try {
            bytesRead = implRead(dst, position);
        } finally {
            FileReadEvent.offer(start, path, bytesRead);
        }
        return bytesRead;
    }

src/java.base/share/classes/sun/nio/ch/FileChannelImpl.java:

    @Override
    public int write(ByteBuffer src, long position) throws IOException {
        if (jfrTracing && FileReadEvent.enabled()) {
            return traceImplWrite(src, position);
        }
        return implWrite(src, position);

src/java.base/share/classes/java/io/FileInputStream.java:

     * @return     the next byte of data, or {@code -1} if the end of the
     *             file is reached.
     * @throws     IOException {@inheritDoc}
     */
    @Override
    public int read() throws IOException {
        if (jfrTracing && FileReadEvent.enabled()) {
            return traceRead0();
        }
        return read0();
    }

src/java.base/share/classes/java/io/FileInputStream.java:

    private native int read0() throws IOException;

    private int traceRead0() throws IOException {
        int result = 0;
        long bytesRead = 0;
        long start = FileReadEvent.timestamp();
        try {
            result = read0();
            if (result < 0) {
                bytesRead = -1;
            } else {
                bytesRead = 1;
            }
        } finally {
            FileReadEvent.offer(start, path, bytesRead);
        }
        return result;
    }

src/java.base/share/classes/java/io/FileInputStream.java:

     * @throws    IOException If an I/O error has occurred.
     */
    private native int readBytes(byte[] b, int off, int len) throws IOException;

    private int traceReadBytes(byte b[], int off, int len) throws IOException {
        int bytesRead = 0;
        long start = FileReadEvent.timestamp();
        try {
            bytesRead = readBytes(b, off, len);
        } finally {
            FileReadEvent.offer(start, path, bytesRead);
        }
        return bytesRead;
    }

src/java.base/share/classes/java/io/FileInputStream.java:

     *             {@code -1} if there is no more data because the end of
     *             the file has been reached.
     * @throws     IOException  if an I/O error occurs.
     */
    @Override
    public int read(byte[] b) throws IOException {
        if (jfrTracing && FileReadEvent.enabled()) {
            return traceReadBytes(b, 0, b.length);
        }
        return readBytes(b, 0, b.length);
    }

src/java.base/share/classes/java/io/FileInputStream.java:

     * @throws     NullPointerException {@inheritDoc}
     * @throws     IndexOutOfBoundsException {@inheritDoc}
     * @throws     IOException  if an I/O error occurs.
     */
    @Override
    public int read(byte[] b, int off, int len) throws IOException {
        if (jfrTracing && FileReadEvent.enabled()) {
            return traceReadBytes(b, off, len);
        }
        return readBytes(b, off, len);
    }

src/java.base/share/classes/java/io/RandomAccessFile.java:

     *             file has been reached.
     * @throws     IOException  if an I/O error occurs. Not thrown if
     *                          end-of-file has been reached.
     */
    public int read() throws IOException {
        if (jfrTracing && FileReadEvent.enabled()) {
            return traceRead0();
        }
        return read0();

src/java.base/share/classes/java/io/RandomAccessFile.java:

    private native int read0() throws IOException;

    private int traceRead0() throws IOException {
        int result = 0;
        long bytesRead = 0;
        long start = FileReadEvent.timestamp();
        try {
            result = read0();
            if (result < 0) {

src/java.base/share/classes/java/io/RandomAccessFile.java:

                bytesRead = -1;
            } else {
                bytesRead = 1;
            }
        } finally {
            FileReadEvent.offer(start, path, bytesRead);
        }
        return result;
    }

src/java.base/share/classes/java/io/RandomAccessFile.java:

     * @param     off the start offset of the data.
     * @param     len the number of bytes to read.
     * @throws    IOException If an I/O error has occurred.
     */
    private int readBytes(byte[] b, int off, int len) throws IOException {
        if (jfrTracing && FileReadEvent.enabled()) {
            return traceReadBytes0(b, off, len);
        }
        return readBytes0(b, off, len);

src/java.base/share/classes/java/io/RandomAccessFile.java:

    private native int readBytes0(byte[] b, int off, int len) throws IOException;

    private int traceReadBytes0(byte b[], int off, int len) throws IOException {
        int bytesRead = 0;
        long start = FileReadEvent.timestamp();
        try {
            bytesRead = readBytes0(b, off, len);
        } finally {
            FileReadEvent.offer(start, path, bytesRead);
        }
        return bytesRead;
    }

src/java.base/share/classes/java/io/RandomAccessFile.java:

     *             of file is encountered before even one byte is read.
     * @throws     IOException  if an I/O error occurs.
     */

    public final String readLine() throws IOException {
        if (jfrTracing && FileReadEvent.enabled()) {
            long bytesRead = 0;
            long start = FileReadEvent.timestamp();
            try {
                String result = implReadLine();
                bytesRead = result == null ? 0 : result.length();
                return result;
            } finally {
                FileReadEvent.offer(start, path, bytesRead);
            }
        }
        return implReadLine();

src/java.base/share/classes/jdk/internal/event/FileReadEvent.java:

package jdk.internal.event;

/**
 * Event recording file reads.
 */
public final class FileReadEvent extends Event {

    // The order of these fields must be the same as the parameters in
    // commit(..., String, long, boolean)
    public String path;
    public long bytesRead;
    public boolean endOfFile;

    public static boolean enabled() {
        // Generated by JFR
        return false;
    }

    public static long timestamp() {
        // Generated by JFR
        return 0L;
    }

    public static boolean shouldThrottleCommit(long duration, long end) {
        // Generated by JFR

Configuration enabled stackTrace threshold throttle
profiling true true 1 ms 300/s 25+
default true true 1 ms 100/s 25+

Field Type Description
path string Path Full path of the file, or N/A if a file descriptor was used to create the stream, for example System.in
bytesRead long: bytes Bytes Read Number of bytes read from the file (possibly 0)
endOfFile boolean End of File If end of file was reached

Examples 2
bytesRead long: bytes
1
endOfFile boolean
false
path string
harness-003931-5537147875304790524/scala-dotty/dotty/out/scala/tools/scalap/scalax/rules/scalasig/AnnotatedWithSelfType.tasty
startTime long: millis
491828405582
bytesRead long: bytes
27935
endOfFile boolean
false
path string
/home/runner/work/jfrevents/jfrevents/harness-003916-17833306698725904421/apache-spark/als/blockmgr-f7fac2eb-c7cf-4f2a-9591-0f39ec4a6b4a/16/shuffle_12_137_0.data
startTime long: millis
389966578659

Java Application Statistics

JavaMonitorStatistics

profiling default startTime duration every chunk 25 26 27

Category: Java Application / Statistics

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

TRACE_REQUEST_FUNC(FinalizerStatistics) {
#if INCLUDE_MANAGEMENT
  JfrFinalizerStatisticsEvent::generate_events();
#else
  log_debug(jfr, system)("Unable to generate requestable event FinalizerStatistics. The required jvm feature 'management' is missing.");
#endif
}

TRACE_REQUEST_FUNC(NativeMemoryUsage) {
  JfrNativeMemoryEvent::send_type_events(timestamp());
}

TRACE_REQUEST_FUNC(NativeMemoryUsageTotal) {
  JfrNativeMemoryEvent::send_total_event(timestamp());
}

TRACE_REQUEST_FUNC(JavaMonitorStatistics) {
  EventJavaMonitorStatistics event;
  event.set_count(ObjectSynchronizer::in_use_list_count());
  event.commit();
}

Configuration enabled period
profiling true everyChunk
default true everyChunk

Field Type Description
count ulong Monitors in Use Current number of in-use monitors

JavaThreadStatistics

profiling default startTime duration every chunk 11 17 21 25 26 27

Category: Java Application / Statistics

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  EventSwapSpace event;
  physical_memory_size_type total_swap_space = 0;
  // Return value ignored - defaulting to 0 on failure.
  (void)os::total_swap_space(total_swap_space);
  event.set_totalSize(static_cast<s8>(total_swap_space));
  physical_memory_size_type free_swap_space = 0;
  // Return value ignored - defaulting to 0 on failure.
  (void)os::free_swap_space(free_swap_space);
  event.set_freeSize(static_cast<s8>(free_swap_space));
  event.commit();
}

TRACE_REQUEST_FUNC(JavaThreadStatistics) {
  EventJavaThreadStatistics event;
  event.set_activeCount(ThreadService::get_live_thread_count());
  event.set_daemonCount(ThreadService::get_daemon_thread_count());
  event.set_accumulatedCount(ThreadService::get_total_thread_count());
  event.set_peakCount(ThreadService::get_peak_thread_count());
  event.commit();
}

TRACE_REQUEST_FUNC(GCHeapMemoryUsage) {
  MemoryUsage usage = Universe::heap()->memory_usage();
  EventGCHeapMemoryUsage event(UNTIMED);
  event.set_used(usage.used());

Configuration enabled period
profiling true 1000 ms
default true 1000 ms

Field Type Description
activeCount long Active Threads Number of live active threads including both daemon and non-daemon threads
daemonCount long Daemon Threads Number of live daemon threads
accumulatedCount long Accumulated Threads Number of threads created and also started since JVM start
peakCount long Peak Threads Peak live thread count since JVM start or when peak count was reset

Examples 3
accumulatedCount long
1373
activeCount long
53
daemonCount long
52
peakCount long
273
startTime long: millis
440490449848
accumulatedCount long
1655
activeCount long
103
daemonCount long
102
peakCount long
293
startTime long: millis
458494046575
accumulatedCount long
1348
activeCount long
45
daemonCount long
39
peakCount long
273
startTime long: millis
319600817738

ClassLoadingStatistics

profiling default startTime duration every chunk 11 17 21 25 26 27

Category: Java Application / Statistics

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

      event.set_used(usage.used());
      event.set_committed(usage.committed());
      event.set_max(usage.max_size());
      event.set_starttime(timestamp());
      event.set_endtime(timestamp());
      event.commit();
    }
  }
}


TRACE_REQUEST_FUNC(ClassLoadingStatistics) {
#if INCLUDE_MANAGEMENT
  EventClassLoadingStatistics event;
  event.set_loadedClassCount(ClassLoadingService::loaded_class_count());
  event.set_unloadedClassCount(ClassLoadingService::unloaded_class_count());
  event.commit();
#else
  log_debug(jfr, system)("Unable to generate requestable event ClassLoadingStatistics. The required jvm feature 'management' is missing.");
#endif
}

class JfrClassLoaderStatsClosure : public ClassLoaderStatsClosure {
public:
  JfrClassLoaderStatsClosure() : ClassLoaderStatsClosure(nullptr) {}

Configuration enabled period
profiling true 1000 ms
default true 1000 ms

Field Type Description
loadedClassCount long Loaded Class Count Number of classes loaded since JVM start
unloadedClassCount long Unloaded Class Count Number of classes unloaded since JVM start

Examples 3
loadedClassCount long
125299
startTime long: millis
464834833724
unloadedClassCount long
4663
loadedClassCount long
96776
startTime long: millis
442698306932
unloadedClassCount long
2376
loadedClassCount long
109621
startTime long: millis
327013654041
unloadedClassCount long
3173

ClassLoaderStatistics

profiling default startTime duration every chunk 11 17 21 25 26 27

Category: Java Application / Statistics

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  log_debug(jfr, system)("Unable to generate requestable event ClassLoadingStatistics. The required jvm feature 'management' is missing.");
#endif
}

class JfrClassLoaderStatsClosure : public ClassLoaderStatsClosure {
public:
  JfrClassLoaderStatsClosure() : ClassLoaderStatsClosure(nullptr) {}

  bool do_entry(oop const& key, ClassLoaderStats const& cls) {
    const ClassLoaderData* this_cld = cls._class_loader != nullptr ?
      java_lang_ClassLoader::loader_data_acquire(cls._class_loader) : nullptr;
    const ClassLoaderData* parent_cld = cls._parent != nullptr ?
      java_lang_ClassLoader::loader_data_acquire(cls._parent) : nullptr;
    EventClassLoaderStatistics event;
    event.set_classLoader(this_cld);
    event.set_parentClassLoader(parent_cld);
    event.set_classLoaderData((intptr_t)cls._cld);
    event.set_classCount(cls._classes_count);
    event.set_chunkSize(cls._chunk_sz);
    event.set_blockSize(cls._block_sz);
    event.set_hiddenClassCount(cls._hidden_classes_count);
    event.set_hiddenChunkSize(cls._hidden_chunk_sz);
    event.set_hiddenBlockSize(cls._hidden_block_sz);
    event.commit();
    return true;

Configuration enabled period
profiling true everyChunk
default true everyChunk

Field Type Description
classLoader ClassLoader Class Loader
parentClassLoader ClassLoader Parent Class Loader
classLoaderData ulong: address ClassLoaderData Pointer Pointer to the ClassLoaderData structure in the JVM
classCount long Classes Number of loaded classes
chunkSize ulong: bytes Total Chunk Size Total size of all allocated metaspace chunks (each chunk has several blocks)
blockSize ulong: bytes Total Block Size Total size of all allocated metaspace blocks (each chunk has several blocks)
hiddenClassCount long 15+ Hidden Classes Number of hidden classes
hiddenChunkSize ulong: bytes 15+ Total Hidden Classes Chunk Size Total size of all allocated metaspace chunks for hidden classes (each chunk has several blocks)
hiddenBlockSize ulong: bytes 15+ Total Hidden Classes Block Size Total size of all allocated metaspace blocks for hidden classes (each chunk has several blocks)

Examples 3
blockSize ulong: bytes
5488
chunkSize ulong: bytes
10240
classCount long
2
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
0
name string
org/neo4j/codegen/CodeLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/neo4j/codegen
classLoaderData ulong: address
139843208389280
hiddenBlockSize ulong: bytes
0
hiddenChunkSize ulong: bytes
0
hiddenClassCount long
0
parentClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
startTime long: millis
371359387785
blockSize ulong: bytes
1424
chunkSize ulong: bytes
6144
classCount long
1
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/codehaus/commons/compiler/util/reflect/ByteArrayClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/codehaus/commons/compiler/util/reflect
classLoaderData ulong: address
140017185670192
hiddenBlockSize ulong: bytes
0
hiddenChunkSize ulong: bytes
0
hiddenClassCount long
0
parentClassLoader ClassLoader
null
startTime long: millis
278182146546
blockSize ulong: bytes
4704
chunkSize ulong: bytes
6144
classCount long
2
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
0
name string
org/neo4j/codegen/CodeLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/neo4j/codegen
classLoaderData ulong: address
140431215635312
hiddenBlockSize ulong: bytes
0
hiddenChunkSize ulong: bytes
0
hiddenClassCount long
0
parentClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
startTime long: millis
378912613724

ThreadAllocationStatistics

profiling default startTime every chunk 11 17 21 25 26 27

Category: Java Application / Statistics

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  GrowableArray<jlong> allocated(initial_size);
  GrowableArray<traceid> thread_ids(initial_size);
  JfrTicks time_stamp = JfrTicks::now();
  JfrJavaThreadIterator iter;
  while (iter.has_next()) {
    JavaThread* const jt = iter.next();
    assert(jt != nullptr, "invariant");
    allocated.append(jt->cooked_allocated_bytes());
    thread_ids.append(JFR_JVM_THREAD_ID(jt));
  }

  // Write allocation statistics to buffer.
  for(int i = 0; i < thread_ids.length(); i++) {
    EventThreadAllocationStatistics event(UNTIMED);
    event.set_allocated(allocated.at(i));
    event.set_thread(thread_ids.at(i));
    event.set_starttime(time_stamp);
    event.set_endtime(time_stamp);
    event.commit();
  }
}

/**
 *  PhysicalMemory event represents:
 *

Configuration enabled period
profiling true everyChunk
default true everyChunk

Field Type Description
allocated ulong: bytes Allocated Approximate number of bytes allocated since thread start
thread Thread Thread

Examples 3
allocated ulong: bytes
624936
startTime long: millis
378913010243
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
executor-heartbeater
javaThreadId long
1152
osName string
executor-heartbeater
osThreadId long
3738
virtual boolean
false
allocated ulong: bytes
134208
startTime long: millis
278185390348
thread Thread
group ThreadGroup
name string
finagle/netty4/boss
parent ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
finagle/netty4/boss-1
javaThreadId long
853
osName string
finagle/netty4/boss-1
osThreadId long
3365
virtual boolean
false
allocated ulong: bytes
32
startTime long: millis
371363060942
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
map-output-dispatcher-3
javaThreadId long
1141
osName string
map-output-dispatcher-3
osThreadId long
4372
virtual boolean
false

FinalizerStatistics

profiling default startTime end of every chunk 18 21 25 26 27

Category: Java Application / Statistics

Per class statistics about finalizers

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrFinalizerStatisticsEvent.cpp:

static void send_event(const FinalizerEntry* fe, const InstanceKlass* ik, const JfrTicks& timestamp, Thread* thread) {
  assert(ik != nullptr, "invariant");
  assert(ik->has_finalizer(), "invariant");
  assert(thread != nullptr, "invariant");
  const char* const url = fe != nullptr ? fe->codesource() : nullptr;
  const traceid url_symbol_id = url != nullptr ? JfrSymbolTable::add(url) : 0;
  EventFinalizerStatistics event(UNTIMED);
  event.set_starttime(timestamp);
  event.set_endtime(timestamp);
  event.set_finalizableClass(ik);
  event.set_codeSource(url_symbol_id);
  if (fe == nullptr) {
    event.set_objects(0);
    event.set_totalFinalizersRun(0);
  } else {
    assert(fe->klass() == ik, "invariant");
    event.set_objects(fe->objects_on_heap());
    event.set_totalFinalizersRun(fe->total_finalizers_run());
  }
  event.commit();
}

void JfrFinalizerStatisticsEvent::send_unload_event(const InstanceKlass* ik) {
  if (!EventFinalizerStatistics::is_enabled()) {
    return;
  }
  Thread* const thread = Thread::current();
  ResourceMark rm(thread);
  send_event(FinalizerService::lookup(ik, thread), ik, JfrTicks::now(), thread);
}

// Finalizer events generated by the periodic task will all have the same timestamp.

class FinalizerStatisticsEventClosure : public FinalizerEntryClosure {
 private:

Configuration enabled period
profiling true endChunk
default true endChunk

Field Type Description
finalizableClass Class Class Overriding Finalize
codeSource Symbol Code Source URL from where the class was loaded
objects ulong Finalizable Objects on Heap Number of objects on heap that can be finalized
totalFinalizersRun ulong Finalizers Run Total number of finalizers run since JVM start

Examples 3
codeSource Symbol
file:///home/runner/work/jfrevents/jfrevents/harness-003927-11018005009666797249/apache-spark/lib/netty-buffer-4.1.99.Final.jar
finalizableClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
24
name string
io/netty/buffer/PoolArena$DirectArena
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
io/netty/buffer
objects ulong
16
startTime long: millis
282992929523
totalFinalizersRun ulong
0
codeSource Symbol
file:///home/runner/work/jfrevents/jfrevents/harness-003916-17833306698725904421/apache-spark/lib/netty-buffer-4.1.99.Final.jar
finalizableClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
24
name string
io/netty/buffer/PoolArena$HeapArena
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
io/netty/buffer
objects ulong
16
startTime long: millis
390307226901
totalFinalizersRun ulong
0
codeSource Symbol
file:///home/runner/work/jfrevents/jfrevents/harness-003928-7951762178349451551/twitter-finagle/lib/netty-buffer-4.1.99.Final.jar
finalizableClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
24
name string
io/netty/buffer/PoolArena$HeapArena
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
io/netty/buffer
objects ulong
8
startTime long: millis
374807905603
totalFinalizersRun ulong
0

DeprecatedInvocation

profiling default startTime stackTrace 22 25 26 27

Category: Java Application / Statistics

A unique invocation of a method that is annotated with @Deprecated. Packages and modules that are deprecated are ignored. At most 10 000 invocation sites and only the first invocation from a class is guaranteed to be included.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/jni/jfrJniMethod.cpp:

  JfrEventSetting::set_enabled(JfrCPUTimeSampleEvent, rate > 0);
  JfrCPUTimeThreadSampling::set_rate(rate);
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_set_cpu_period(JNIEnv* env, jclass jvm, jlong period_nanos))
  assert(period_nanos >= 0, "invariant");
  JfrEventSetting::set_enabled(JfrCPUTimeSampleEvent, period_nanos > 0);
  JfrCPUTimeThreadSampling::set_period(period_nanos);
JVM_END

NO_TRANSITION(void, jfr_set_miscellaneous(JNIEnv* env, jclass jvm, jlong event_type_id, jlong value))
  JfrEventSetting::set_miscellaneous(event_type_id, value);
  const JfrEventId typed_event_id = (JfrEventId)event_type_id;
  if (EventDeprecatedInvocation::eventId == typed_event_id) {
    JfrDeprecationManager::on_level_setting_update(value);
  }
NO_TRANSITION_END

NO_TRANSITION(jboolean, jfr_should_rotate_disk(JNIEnv* env, jclass jvm))
  return JfrChunkRotation::should_rotate() ? JNI_TRUE : JNI_FALSE;
NO_TRANSITION_END

NO_TRANSITION(jlong, jfr_get_type_id_from_string(JNIEnv * env, jclass jvm, jstring type))
  const char* type_name = env->GetStringUTFChars(type, nullptr);
  jlong id = JfrType::name_to_id(type_name);

Configuration enabled level stackTrace
profiling true forRemoval true
default true forRemoval true

Field Type Description
method Method Deprecated Method
invocationTime Ticks Invocation Time The time the deprecated method was invoked for the first time
forRemoval boolean For Removal

ExceptionStatistics

profiling default startTime duration 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/ExceptionStatisticsEvent.java

Category: Java Application / Statistics

Number of objects derived from java.lang.Throwable that have been created

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/ExceptionStatisticsEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.internal.MirrorEvent;
import jdk.jfr.internal.RemoveFields;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "ExceptionStatistics")
@Label("Exception Statistics")
@Category({ "Java Application", "Statistics" })
@Description("Number of objects derived from java.lang.Throwable that have been created")
@RemoveFields({"duration", "eventThread", "stackTrace"})
public final class ExceptionStatisticsEvent extends MirrorEvent {

    @Label("Exceptions Created")
    public long throwables;
}

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);
        register("jdk.internal.event.VirtualThreadEndEvent", VirtualThreadEndEvent.class);
        register("jdk.internal.event.VirtualThreadSubmitFailedEvent", VirtualThreadSubmitFailedEvent.class);
        register("jdk.internal.event.X509CertificateEvent", X509CertificateEvent.class);
        register("jdk.internal.event.X509ValidationEvent", X509ValidationEvent.class);
        register("jdk.internal.event.ErrorThrownEvent", ErrorThrownEvent.class);
        register("jdk.internal.event.ExceptionStatisticsEvent", ExceptionStatisticsEvent.class);
        register("jdk.internal.event.ExceptionThrownEvent", ExceptionThrownEvent.class);
        register("jdk.internal.event.FinalFieldMutationEvent", FinalFieldMutationEvent.class);
    };

    private static void register(String eventClassName, Class<? extends MirrorEvent> mirrorClass) {
        mirrorLookup.put(eventClassName, mirrorClass);
    }

    static Class<? extends MirrorEvent> find(Class<? extends jdk.internal.event.Event> eventClass) {
        return find(Utils.isJDKClass(eventClass), eventClass.getName());
    }

src/java.base/share/classes/jdk/internal/event/ThrowableTracer.java:

                ErrorThrownEvent.commit(timestamp, message, clazz);
            }
            if (ExceptionThrownEvent.shouldThrottleCommit(timestamp)) {
                ExceptionThrownEvent.commit(timestamp, message, clazz);
            }
        }
        numThrowables.incrementAndGet();
    }

    public static void traceThrowable(Class<?> clazz, String message) {
        if (ExceptionThrownEvent.enabled()) {
            long timestamp = ErrorThrownEvent.timestamp();
            if (ExceptionThrownEvent.shouldThrottleCommit(timestamp)) {
                ExceptionThrownEvent.commit(timestamp, message, clazz);
            }
        }
        numThrowables.incrementAndGet();
    }

    public static void emitStatistics() {
        long timestamp = ExceptionStatisticsEvent.timestamp();
        ExceptionStatisticsEvent.commit(timestamp, numThrowables.get());
    }
}

src/java.base/share/classes/jdk/internal/event/ExceptionStatisticsEvent.java:

package jdk.internal.event;

/**
 * Event recording number of exceptions that has been created.
 */
public class ExceptionStatisticsEvent extends Event {

    public long throwables;

    public static void commit(long timestamp, long throwables) {
        // Generated by JFR
    }

    public static boolean enabled() {
        // Generated by JFR
        return false;
    }

    public static long timestamp() {
        // Generated by JFR
        return 0;
    }
}

Configuration enabled period
profiling true 1000 ms
default true 1000 ms

Field Type Description
throwables long Exceptions Created

Examples 3
startTime long: millis
305317098035
throwables long
2202697
startTime long: millis
487742220408
throwables long
2259941
startTime long: millis
446615129252
throwables long
2219377

DirectBufferStatistics

profiling default startTime duration stackTrace 15 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/DirectBufferStatisticsEvent.java

Category: Java Application / Statistics

Statistics of direct buffer

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/DirectBufferStatisticsEvent.java:

package jdk.jfr.events;

import jdk.internal.misc.VM;
import jdk.internal.misc.VM.BufferPool;

import jdk.jfr.*;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "DirectBufferStatistics")
@Label("Direct Buffer Statistics")
@Description("Statistics of direct buffer")
public final class DirectBufferStatisticsEvent extends AbstractBufferStatisticsEvent {

    private static final BufferPool DIRECT_BUFFER_POOL = findPoolByName("direct");

    public DirectBufferStatisticsEvent() {
        super(DIRECT_BUFFER_POOL);
        this.maxCapacity = VM.maxDirectMemory();
    }

    @Label("Maximum Capacity")
    @Description("Maximum direct buffer capacity the process can use")
    @DataAmount
    final long maxCapacity;
}

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.SecurityProviderServiceEvent.class,
        jdk.internal.event.SerializationMisdeclarationEvent.class,
        jdk.internal.event.SocketReadEvent.class,
        jdk.internal.event.SocketWriteEvent.class,
        jdk.internal.event.ThreadSleepEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.VirtualThreadStartEvent.class,
        jdk.internal.event.VirtualThreadEndEvent.class,
        jdk.internal.event.VirtualThreadSubmitFailedEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class,
        jdk.internal.event.FinalFieldMutationEvent.class,
        DirectBufferStatisticsEvent.class,
        InitialSecurityPropertyEvent.class,
        MethodTraceEvent.class,
        MethodTimingEvent.class,
    };

    private static final Runnable emitExceptionStatistics = JDKEvents::emitExceptionStatistics;
    private static final Runnable emitDirectBufferStatistics = JDKEvents::emitDirectBufferStatistics;
    private static final Runnable emitContainerConfiguration = JDKEvents::emitContainerConfiguration;
    private static final Runnable emitContainerCPUUsage = JDKEvents::emitContainerCPUUsage;
    private static final Runnable emitContainerCPUThrottling = JDKEvents::emitContainerCPUThrottling;
    private static final Runnable emitContainerMemoryUsage = JDKEvents::emitContainerMemoryUsage;

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

    private static final Runnable emitInitialSecurityProperties = JDKEvents::emitInitialSecurityProperties;
    private static final Runnable emitMethodTiming = JDKEvents::emitMethodTiming;
    private static Metrics containerMetrics = null;
    private static boolean initializationTriggered;

    @SuppressWarnings("unchecked")
    public static synchronized void initialize() {
        try {
            if (initializationTriggered == false) {
                for (Class<?> eventClass : eventClasses) {
                    MetadataRepository.getInstance().register((Class<? extends Event>) eventClass);
                }
                PeriodicEvents.addJavaEvent(jdk.internal.event.ExceptionStatisticsEvent.class, emitExceptionStatistics);
                PeriodicEvents.addJavaEvent(DirectBufferStatisticsEvent.class, emitDirectBufferStatistics);
                PeriodicEvents.addJavaEvent(InitialSecurityPropertyEvent.class, emitInitialSecurityProperties);
                PeriodicEvents.addJavaEvent(MethodTimingEvent.class, emitMethodTiming);

                initializeContainerEvents();
                JFRTracing.enable();
                initializationTriggered = true;
            }
        } catch (Exception e) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.WARN, "Could not initialize JDK events. " + e.getMessage());
        }
    }

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

        PeriodicEvents.removeEvent(emitExceptionStatistics);
        PeriodicEvents.removeEvent(emitDirectBufferStatistics);
        PeriodicEvents.removeEvent(emitInitialSecurityProperties);
        PeriodicEvents.removeEvent(emitMethodTiming);

        PeriodicEvents.removeEvent(emitContainerConfiguration);
        PeriodicEvents.removeEvent(emitContainerCPUUsage);
        PeriodicEvents.removeEvent(emitContainerCPUThrottling);
        PeriodicEvents.removeEvent(emitContainerMemoryUsage);
        PeriodicEvents.removeEvent(emitContainerIOUsage);
    }

    private static void emitDirectBufferStatistics() {
        DirectBufferStatisticsEvent e = new DirectBufferStatisticsEvent();
        e.commit();
    }

    private static void emitInitialSecurityProperties() {
        Properties p = SharedSecrets.getJavaSecurityPropertiesAccess().getInitialProperties();
        if (p != null) {
            for (String key : p.stringPropertyNames()) {
                InitialSecurityPropertyEvent e = new InitialSecurityPropertyEvent();
                e.key = key;
                e.value = p.getProperty(key);
                e.commit();

Configuration enabled period
profiling true 5 s
default true 5 s

Examples 3
stackTrace StackTrace
null
startTime long: millis
435409006720
stackTrace StackTrace
null
startTime long: millis
286627234844
stackTrace StackTrace
null
startTime long: millis
439466330871

Java Development Kit

Deserialization

startTime duration 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/DeserializationEvent.java

Category: Java Development Kit / Serialization

Results of deserialization and ObjectInputFilter checks

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/DeserializationEvent.java:

@Category({"Java Development Kit", "Serialization"})
@Label("Deserialization")
@Name("jdk.Deserialization")
@Description("Results of deserialization and ObjectInputFilter checks")
@RemoveFields("duration")
public final class DeserializationEvent extends MirrorEvent {

    @Label("Filter Configured")
    public boolean filterConfigured;

    @Label("Filter Status")
    public String filterStatus;

    @Label ("Type")
    public Class<?> type;

    @Label ("Array Length")

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

/**
 * This class registers all mirror events.
 */
final class MirrorEvents {
    private static final Map<String, Class<? extends MirrorEvent>> mirrorLookup = new ConcurrentHashMap<>();

    // Add mirror event mapping here. See MirrorEvent class for details.
    static {
        register("jdk.internal.event.DeserializationEvent", DeserializationEvent.class);
        register("jdk.internal.event.FileForceEvent", FileForceEvent.class);
        register("jdk.internal.event.FileReadEvent", FileReadEvent.class);
        register("jdk.internal.event.FileWriteEvent", FileWriteEvent.class);
        register("jdk.internal.event.ProcessStartEvent", ProcessStartEvent.class);
        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);

src/java.base/share/classes/java/io/ObjectInputStream.java:

        ObjectInputFilter next = Config.getSerialFilterFactory()
                .apply(serialFilter, filter);
        if (serialFilter != null && next == null) {
            throw new IllegalStateException("filter can not be replaced with null filter");
        }
        serialFilter = next;
    }

    /**
     * Invokes the deserialization filter if non-null.
     *
     * If the filter rejects or an exception is thrown, throws InvalidClassException.
     *
     * Logs and/or commits a {@code DeserializationEvent}, if configured.
     *
     * @param clazz the class; may be null
     * @param arrayLength the array length requested; use {@code -1} if not creating an array
     * @throws InvalidClassException if it rejected by the filter or
     *        a {@link RuntimeException} is thrown
     */
    private void filterCheck(Class<?> clazz, int arrayLength)
            throws InvalidClassException {
        // Info about the stream is not available if overridden by subclass, return 0
        long bytesRead = (bin == null) ? 0 : bin.getBytesRead();
        RuntimeException ex = null;

src/java.base/share/classes/java/io/ObjectInputStream.java:

                status = ObjectInputFilter.Status.REJECTED;
                ex = e;
            }
            if (Logging.filterLogger != null) {
                // Debug logging of filter checks that fail; Tracing for those that succeed
                Logging.filterLogger.log(status == null || status == ObjectInputFilter.Status.REJECTED
                                ? Logger.Level.DEBUG
                                : Logger.Level.TRACE,
                        "ObjectInputFilter {0}: {1}, array length: {2}, nRefs: {3}, depth: {4}, bytes: {5}, ex: {6}",
                        status, clazz, arrayLength, totalObjectRefs, depth, bytesRead,
                        Objects.toString(ex, "n/a"));
            }
        }
        DeserializationEvent event = new DeserializationEvent();
        if (event.shouldCommit()) {
            event.filterConfigured = serialFilter != null;
            event.filterStatus = status != null ? status.name() : null;
            event.type = clazz;
            event.arrayLength = arrayLength;
            event.objectReferences = totalObjectRefs;
            event.depth = depth;
            event.bytesRead = bytesRead;
            event.exceptionType = ex != null ? ex.getClass() : null;
            event.exceptionMessage = ex != null ? ex.getMessage() : null;
            event.commit();

src/java.base/share/classes/jdk/internal/event/DeserializationEvent.java:

package jdk.internal.event;

/**
 * Event details relating to deserialization.
 */

public final class DeserializationEvent extends Event {
    public boolean filterConfigured;
    public String filterStatus;
    public Class<?> type;
    public int arrayLength;
    public long objectReferences;
    public long depth;
    public long bytesRead;
    public Class<?> exceptionType;
    public String exceptionMessage;
}

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
filterConfigured boolean Filter Configured
filterStatus string Filter Status
type Class Type
arrayLength int Array Length
objectReferences long Object References
depth long Depth
bytesRead long Bytes Read
exceptionType Class Exception Type
exceptionMessage string Exception Message

Examples 3
arrayLength int
-1
bytesRead long
23649
depth long
3
exceptionMessage string
null
exceptionType Class
null
filterConfigured boolean
false
filterStatus string
null
objectReferences long
479
startTime long: millis
275178389026
type Class
null
arrayLength int
10
bytesRead long
37448
depth long
3
exceptionMessage string
null
exceptionType Class
null
filterConfigured boolean
false
filterStatus string
null
objectReferences long
755
startTime long: millis
366275154874
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[F
package Package
null
arrayLength int
-1
bytesRead long
41178
depth long
50
exceptionMessage string
null
exceptionType Class
null
filterConfigured boolean
false
filterStatus string
null
objectReferences long
1876
startTime long: millis
374276696479
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/apache/spark/HashPartitioner
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark

X509Certificate

startTime duration 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/X509CertificateEvent.java

Category: Java Development Kit / Security

Details of X.509 Certificate parsed by JDK

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/X509CertificateEvent.java:

package jdk.jfr.events;

import jdk.jfr.*;
import jdk.jfr.internal.MirrorEvent;
import jdk.jfr.internal.RemoveFields;

@Category({"Java Development Kit", "Security"})
@Label("X509 Certificate")
@Name("jdk.X509Certificate")
@Description("Details of X.509 Certificate parsed by JDK")
@RemoveFields("duration")
public final class X509CertificateEvent extends MirrorEvent {
    @Label("Signature Algorithm")
    public String algorithm;

    @Label("Serial Number")
    public String serialNumber;

    @Label("Subject")
    public String subject;

    @Label("Issuer")
    public String issuer;

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

        register("jdk.internal.event.FileReadEvent", FileReadEvent.class);
        register("jdk.internal.event.FileWriteEvent", FileWriteEvent.class);
        register("jdk.internal.event.ProcessStartEvent", ProcessStartEvent.class);
        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);
        register("jdk.internal.event.VirtualThreadEndEvent", VirtualThreadEndEvent.class);
        register("jdk.internal.event.VirtualThreadSubmitFailedEvent", VirtualThreadSubmitFailedEvent.class);
        register("jdk.internal.event.X509CertificateEvent", X509CertificateEvent.class);
        register("jdk.internal.event.X509ValidationEvent", X509ValidationEvent.class);
        register("jdk.internal.event.ErrorThrownEvent", ErrorThrownEvent.class);
        register("jdk.internal.event.ExceptionStatisticsEvent", ExceptionStatisticsEvent.class);
        register("jdk.internal.event.ExceptionThrownEvent", ExceptionThrownEvent.class);
        register("jdk.internal.event.FinalFieldMutationEvent", FinalFieldMutationEvent.class);
    };

    private static void register(String eventClassName, Class<? extends MirrorEvent> mirrorClass) {
        mirrorLookup.put(eventClassName, mirrorClass);
    }

src/java.base/share/classes/sun/security/jca/JCAUtil.java:

        SecureRandom result = def;
        if (result == null) {
            synchronized (JCAUtil.class) {
                result = def;
                if (result == null) {
                    def = result = new SecureRandom();
                }
            }
        }
        return result;
    }

    public static void tryCommitCertEvent(Certificate cert) {
        if ((X509CertificateEvent.isTurnedOn() || EventHelper.isLoggingSecurity()) &&
                (cert instanceof X509Certificate x509)) {
            PublicKey pKey = x509.getPublicKey();
            String algId = x509.getSigAlgName();
            String serNum = Debug.toString(x509.getSerialNumber());
            String subject = x509.getSubjectX500Principal().toString();
            String issuer = x509.getIssuerX500Principal().toString();
            String keyType = pKey.getAlgorithm();
            int length = KeyUtil.getKeySize(pKey);
            int hashCode = x509.hashCode();
            long certifcateId = Integer.toUnsignedLong(hashCode);
            long beginDate = x509.getNotBefore().getTime();
            long endDate = x509.getNotAfter().getTime();
            if (X509CertificateEvent.isTurnedOn()) {
                X509CertificateEvent xce = new X509CertificateEvent();
                xce.algorithm = algId;
                xce.serialNumber = serNum;
                xce.subject = subject;
                xce.issuer = issuer;
                xce.keyType = keyType;
                xce.keyLength = length;
                xce.certificateId = certifcateId;
                xce.validFrom = beginDate;
                xce.validUntil = endDate;
                xce.commit();
            }

src/java.base/share/classes/jdk/internal/event/X509CertificateEvent.java:

package jdk.internal.event;


/**
 * Event recording details of X.509 Certificate.
 */

public final class X509CertificateEvent extends Event {
    private static final X509CertificateEvent EVENT = new X509CertificateEvent();

    /**
     * Returns {@code true} if event is enabled, {@code false} otherwise.
     */
    public static boolean isTurnedOn() {
        return EVENT.isEnabled();
    }

    public String algorithm;
    public String serialNumber;
    public String subject;
    public String issuer;
    public String keyType;
    public int keyLength;
    public long certificateId;

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
algorithm string Signature Algorithm
serialNumber string Serial Number
subject string Subject
issuer string Issuer
keyType string Key Type
keyLength int Key Length
certificateId ulong: certificateId Certificate Id
validFrom long: epochmillis Valid From
validUntil long: epochmillis Valid Until

Examples 3
algorithm string
SHA1withDSA
certificateId ulong: certificateId
3045411335
issuer string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
keyLength int
1024
keyType string
DSA
serialNumber string
46:10:1f:71
startTime long: millis
323674348680
subject string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
validFrom long: epochmillis
1175461745000
validUntil long: epochmillis
4329061745000
algorithm string
SHA1withDSA
certificateId ulong: certificateId
3045411335
issuer string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
keyLength int
1024
keyType string
DSA
serialNumber string
46:10:1f:71
startTime long: millis
441957310824
subject string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
validFrom long: epochmillis
1175461745000
validUntil long: epochmillis
4329061745000
algorithm string
SHA1withDSA
certificateId ulong: certificateId
3045411335
issuer string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
keyLength int
1024
keyType string
DSA
serialNumber string
46:10:1f:71
startTime long: millis
449306982013
subject string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
validFrom long: epochmillis
1175461745000
validUntil long: epochmillis
4329061745000

SerializationMisdeclaration

profiling startTime duration 23 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/SerializationMisdeclarationEvent.java

Category: Java Development Kit / Serialization

Methods and fields misdeclarations. The checks are usually performed just once per serializable class, the first time it is used by serialization. Under high memory pressure, a class might be re-checked again.

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/SerializationMisdeclarationEvent.java:

@Name(Type.EVENT_NAME_PREFIX + "SerializationMisdeclaration")
@Label("Serialization Misdeclaration")
@Category({"Java Development Kit", "Serialization"})
@Description("Methods and fields misdeclarations." +
        " The checks are usually performed just once per serializable class," +
        " the first time it is used by serialization." +
        " Under high memory pressure, a class might be re-checked again.")
@RemoveFields({"duration", "stackTrace", "eventThread"})
public final class SerializationMisdeclarationEvent extends MirrorEvent {

    @Label("Misdeclared Class")
    public Class<?> misdeclaredClass;

    @Label("Message")
    public String message;

}

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

 */
final class MirrorEvents {
    private static final Map<String, Class<? extends MirrorEvent>> mirrorLookup = new ConcurrentHashMap<>();

    // Add mirror event mapping here. See MirrorEvent class for details.
    static {
        register("jdk.internal.event.DeserializationEvent", DeserializationEvent.class);
        register("jdk.internal.event.FileForceEvent", FileForceEvent.class);
        register("jdk.internal.event.FileReadEvent", FileReadEvent.class);
        register("jdk.internal.event.FileWriteEvent", FileWriteEvent.class);
        register("jdk.internal.event.ProcessStartEvent", ProcessStartEvent.class);
        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);
        register("jdk.internal.event.VirtualThreadEndEvent", VirtualThreadEndEvent.class);
        register("jdk.internal.event.VirtualThreadSubmitFailedEvent", VirtualThreadSubmitFailedEvent.class);
        register("jdk.internal.event.X509CertificateEvent", X509CertificateEvent.class);
        register("jdk.internal.event.X509ValidationEvent", X509ValidationEvent.class);
        register("jdk.internal.event.ErrorThrownEvent", ErrorThrownEvent.class);
        register("jdk.internal.event.ExceptionStatisticsEvent", ExceptionStatisticsEvent.class);

src/java.base/share/classes/java/io/ObjectStreamClass.java:

        if (isRecord && canonicalCtr == null) {
            deserializeEx = new ExceptionInfo(name, "record canonical constructor not found");
        } else {
            for (int i = 0; i < fields.length; i++) {
                if (fields[i].getField() == null) {
                    defaultSerializeEx = new ExceptionInfo(
                        name, "unmatched serializable field(s) declared");
                }
            }
        }
        initialized = true;

        if (SerializationMisdeclarationEvent.enabled() && serializable) {
            SerializationMisdeclarationChecker.checkMisdeclarations(cl);
        }
    }

    /**
     * Creates blank class descriptor which should be initialized via a
     * subsequent call to initProxy(), initNonProxy() or readNonProxy().
     */
    ObjectStreamClass() {
    }

src/java.base/share/classes/jdk/internal/event/SerializationMisdeclarationEvent.java:

package jdk.internal.event;

/**
 * A JFR event for serialization misdeclarations.
 * This event is mirrored in {@code jdk.jfr.events.SerializationMisdeclarationEvent}
 * where the metadata for the event is provided with annotations.
 * Some of the methods are replaced by generated methods when jfr is enabled.
 * Note that the order of the arguments of the {@link #commit(long,Class,String)}
 * method must be the same as the order of the fields.
 */
public class SerializationMisdeclarationEvent extends Event {

    public Class<?> misdeclaredClass;
    public String message;

    /**
     * Commit a serialization misdeclaration event.
     * The implementation of this method is generated automatically if jfr is enabled.
     * The order of the fields must be the same as the parameters in this method.
     * {@code commit(long,Class,String)}
     *
     * @param start             timestamp of the start of the operation
     * @param misdeclaredClass  the affected class
     * @param message           the specific event message

Configuration enabled
profiling true
default false

Field Type Description
misdeclaredClass Class Misdeclared Class
message string Message

TLSHandshake

startTime duration 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/TLSHandshakeEvent.java

Category: Java Development Kit / Security

Excludes in stack trace: sun.security.ssl.Finished::recordEvent

Parameters used in TLS Handshake

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/TLSHandshakeEvent.java:

@Category({"Java Development Kit", "Security"})
@Label("TLS Handshake")
@Name("jdk.TLSHandshake")
@Description("Parameters used in TLS Handshake")
@RemoveFields("duration")
@StackFilter("sun.security.ssl.Finished::recordEvent")
public final class TLSHandshakeEvent extends MirrorEvent {
    @Label("Peer Host")
    public String peerHost;

    @Label("Peer Port")
    public int peerPort;

    @Label("Protocol Version")
    public String protocolVersion;

    @Label("Cipher Suite")
    public String cipherSuite;

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

    // Add mirror event mapping here. See MirrorEvent class for details.
    static {
        register("jdk.internal.event.DeserializationEvent", DeserializationEvent.class);
        register("jdk.internal.event.FileForceEvent", FileForceEvent.class);
        register("jdk.internal.event.FileReadEvent", FileReadEvent.class);
        register("jdk.internal.event.FileWriteEvent", FileWriteEvent.class);
        register("jdk.internal.event.ProcessStartEvent", ProcessStartEvent.class);
        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);
        register("jdk.internal.event.VirtualThreadEndEvent", VirtualThreadEndEvent.class);
        register("jdk.internal.event.VirtualThreadSubmitFailedEvent", VirtualThreadSubmitFailedEvent.class);
        register("jdk.internal.event.X509CertificateEvent", X509CertificateEvent.class);
        register("jdk.internal.event.X509ValidationEvent", X509ValidationEvent.class);
        register("jdk.internal.event.ErrorThrownEvent", ErrorThrownEvent.class);
        register("jdk.internal.event.ExceptionStatisticsEvent", ExceptionStatisticsEvent.class);
        register("jdk.internal.event.ExceptionThrownEvent", ExceptionThrownEvent.class);
        register("jdk.internal.event.FinalFieldMutationEvent", FinalFieldMutationEvent.class);
    };

src/java.base/share/classes/sun/security/ssl/Finished.java:

                shc.conContext.finishHandshake();
            }
            recordEvent(shc.conContext.conSession);

            //
            // produce
            if (SSLConfiguration.serverNewSessionTicketCount > 0) {
                NewSessionTicket.t13PosthandshakeProducer.produce(shc);
            }
        }
    }

    private static void recordEvent(SSLSessionImpl session) {
        TLSHandshakeEvent event = new TLSHandshakeEvent();
        if (event.shouldCommit() || EventHelper.isLoggingSecurity()) {
            int hash = 0;
            try {
                // use hash code for Id
                hash = session
                        .getCertificateChain()[0]
                        .hashCode();
            } catch (SSLPeerUnverifiedException e) {
                 // not verified msg
            }
            long peerCertificateId = Integer.toUnsignedLong(hash);

src/java.base/share/classes/jdk/internal/event/TLSHandshakeEvent.java:

package jdk.internal.event;

/**
 * Event recording details of successful TLS handshakes.
 */

public final class TLSHandshakeEvent extends Event {
    public String peerHost;
    public int peerPort;
    public String protocolVersion;
    public String cipherSuite;
    public long certificateId;
}

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
peerHost string Peer Host
peerPort int Peer Port
protocolVersion string Protocol Version
cipherSuite string Cipher Suite
certificateId ulong: certificateId Certificate Id Peer Certificate Id

SecurityPropertyModification

startTime duration 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/SecurityPropertyModificationEvent.java

Category: Java Development Kit / Security

Excludes in stack trace: java.security.Security::setProperty

Modification of Security property

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/SecurityPropertyModificationEvent.java:

package jdk.jfr.events;

import jdk.jfr.*;
import jdk.jfr.internal.MirrorEvent;
import jdk.jfr.internal.RemoveFields;

@Category({"Java Development Kit", "Security"})
@Label("Security Property Modification")
@Name("jdk.SecurityPropertyModification")
@Description("Modification of Security property")
@RemoveFields("duration")
@StackFilter({"java.security.Security::setProperty"})
public final class SecurityPropertyModificationEvent extends MirrorEvent {
    @Label("Key")
    public String key;

    @Label("Value")
    public String value;
}

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

/**
 * This class registers all mirror events.
 */
final class MirrorEvents {
    private static final Map<String, Class<? extends MirrorEvent>> mirrorLookup = new ConcurrentHashMap<>();

    // Add mirror event mapping here. See MirrorEvent class for details.
    static {
        register("jdk.internal.event.DeserializationEvent", DeserializationEvent.class);
        register("jdk.internal.event.FileForceEvent", FileForceEvent.class);
        register("jdk.internal.event.FileReadEvent", FileReadEvent.class);
        register("jdk.internal.event.FileWriteEvent", FileWriteEvent.class);
        register("jdk.internal.event.ProcessStartEvent", ProcessStartEvent.class);
        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);
        register("jdk.internal.event.VirtualThreadEndEvent", VirtualThreadEndEvent.class);
        register("jdk.internal.event.VirtualThreadSubmitFailedEvent", VirtualThreadSubmitFailedEvent.class);
        register("jdk.internal.event.X509CertificateEvent", X509CertificateEvent.class);
        register("jdk.internal.event.X509ValidationEvent", X509ValidationEvent.class);

src/java.base/share/classes/java/security/Security.java:

     * @param datum the value of the property to be set.
     *
     * @throws  NullPointerException if key or datum is {@code null}
     * @throws  IllegalArgumentException if key is reserved and cannot be
     *          used as a Security property name. Reserved keys are:
     *          "include".
     *
     * @see #getProperty
     */
    public static void setProperty(String key, String datum) {
        SecPropLoader.checkReservedKey(key);
        props.put(key, datum);

        SecurityPropertyModificationEvent spe = new SecurityPropertyModificationEvent();
        // following is a no-op if event is disabled
        spe.key = key;
        spe.value = datum;
        spe.commit();

        if (EventHelper.isLoggingSecurity()) {
            EventHelper.logSecurityPropertyEvent(key, datum);
        }
    }

    private static class Criteria {

src/java.base/share/classes/jdk/internal/event/SecurityPropertyModificationEvent.java:

package jdk.internal.event;

/**
 * Event details relating to the modification of a Security property.
 */

public final class SecurityPropertyModificationEvent extends Event {
    public String key;
    public String value;
}

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
key string Key
value string Value

VirtualThreadSubmitFailed

profiling default startTime duration 19 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/VirtualThreadSubmitFailedEvent.java

Category: Java Development Kit / Threading

Submit of task for virtual thread failed

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/VirtualThreadSubmitFailedEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.internal.MirrorEvent;
import jdk.jfr.internal.RemoveFields;

@Category({"Java Development Kit", "Threading"})
@Label("Virtual Thread Submit Failed")
@Name("jdk.VirtualThreadSubmitFailed")
@Description("Submit of task for virtual thread failed")
@RemoveFields("duration")
public final class VirtualThreadSubmitFailedEvent extends MirrorEvent {

    @Label("Thread Id")
    public long javaThreadId;

    @Label("Exception Message")
    public String exceptionMessage;

}

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

        register("jdk.internal.event.FileForceEvent", FileForceEvent.class);
        register("jdk.internal.event.FileReadEvent", FileReadEvent.class);
        register("jdk.internal.event.FileWriteEvent", FileWriteEvent.class);
        register("jdk.internal.event.ProcessStartEvent", ProcessStartEvent.class);
        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);
        register("jdk.internal.event.VirtualThreadEndEvent", VirtualThreadEndEvent.class);
        register("jdk.internal.event.VirtualThreadSubmitFailedEvent", VirtualThreadSubmitFailedEvent.class);
        register("jdk.internal.event.X509CertificateEvent", X509CertificateEvent.class);
        register("jdk.internal.event.X509ValidationEvent", X509ValidationEvent.class);
        register("jdk.internal.event.ErrorThrownEvent", ErrorThrownEvent.class);
        register("jdk.internal.event.ExceptionStatisticsEvent", ExceptionStatisticsEvent.class);
        register("jdk.internal.event.ExceptionThrownEvent", ExceptionThrownEvent.class);
        register("jdk.internal.event.FinalFieldMutationEvent", FinalFieldMutationEvent.class);
    };

    private static void register(String eventClassName, Class<? extends MirrorEvent> mirrorClass) {
        mirrorLookup.put(eventClassName, mirrorClass);
    }

src/java.base/share/classes/jdk/internal/event/VirtualThreadSubmitFailedEvent.java:

package jdk.internal.event;

/**
 * Event recording when an attempt to submit the task for a virtual thread failed.
 */
public class VirtualThreadSubmitFailedEvent extends Event {
    public long javaThreadId;
    public String exceptionMessage;
}

src/java.base/share/classes/java/lang/VirtualThread.java:

        if (scheduler == DEFAULT_SCHEDULER && currentCarrierThread() instanceof CarrierThread ct) {
            try {
                ct.getPool().externalSubmit(ForkJoinTask.adapt(runContinuation));
            } catch (RejectedExecutionException ree) {
                submitFailed(ree);
                throw ree;
            }
        } else {
            submitRunContinuation(scheduler, false);
        }
    }

    /**
     * If enabled, emits a JFR VirtualThreadSubmitFailedEvent.
     */
    private void submitFailed(RejectedExecutionException ree) {
        var event = new VirtualThreadSubmitFailedEvent();
        if (event.isEnabled()) {
            event.javaThreadId = threadId();
            event.exceptionMessage = ree.getMessage();
            event.commit();
        }
    }

    /**
     * Runs a task in the context of this virtual thread.
     */
    private void run(Runnable task) {

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
javaThreadId long Thread Id
exceptionMessage string Exception Message

X509Validation

startTime duration 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/X509ValidationEvent.java

Category: Java Development Kit / Security

Serial numbers from X.509 Certificates forming chain of trust

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/X509ValidationEvent.java:

package jdk.jfr.events;

import jdk.jfr.*;
import jdk.jfr.internal.MirrorEvent;
import jdk.jfr.internal.RemoveFields;

@Category({"Java Development Kit", "Security"})
@Label("X509 Validation")
@Name("jdk.X509Validation")
@Description("Serial numbers from X.509 Certificates forming chain of trust")
@RemoveFields("duration")
public final class X509ValidationEvent extends MirrorEvent {
    @CertificateId
    @Label("Certificate Id")
    @Unsigned
    public long certificateId;

    @Label("Certificate Position")
    @Description("Certificate position in chain of trust, 1 = trust anchor")
    public int certificatePosition;

    @Label("Validation Counter")
    public long validationCounter;
}

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

        register("jdk.internal.event.FileWriteEvent", FileWriteEvent.class);
        register("jdk.internal.event.ProcessStartEvent", ProcessStartEvent.class);
        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);
        register("jdk.internal.event.VirtualThreadEndEvent", VirtualThreadEndEvent.class);
        register("jdk.internal.event.VirtualThreadSubmitFailedEvent", VirtualThreadSubmitFailedEvent.class);
        register("jdk.internal.event.X509CertificateEvent", X509CertificateEvent.class);
        register("jdk.internal.event.X509ValidationEvent", X509ValidationEvent.class);
        register("jdk.internal.event.ErrorThrownEvent", ErrorThrownEvent.class);
        register("jdk.internal.event.ExceptionStatisticsEvent", ExceptionStatisticsEvent.class);
        register("jdk.internal.event.ExceptionThrownEvent", ExceptionThrownEvent.class);
        register("jdk.internal.event.FinalFieldMutationEvent", FinalFieldMutationEvent.class);
    };

    private static void register(String eventClassName, Class<? extends MirrorEvent> mirrorClass) {
        mirrorLookup.put(eventClassName, mirrorClass);
    }

    static Class<? extends MirrorEvent> find(Class<? extends jdk.internal.event.Event> eventClass) {

src/java.base/share/classes/sun/security/provider/certpath/PKIXCertPathValidator.java:

        // only add a RevocationChecker if revocation is enabled and
        // a PKIXRevocationChecker has not already been added
        if (params.revocationEnabled() && !revCheckerAdded) {
            certPathCheckers.add(new RevocationChecker(anchor, params));
        }
        // add user-specified checkers
        certPathCheckers.addAll(checkers);

        PKIXMasterCertPathValidator.validate(params.certPath(),
                                             params.certificates(),
                                             certPathCheckers);

        X509ValidationEvent xve = new X509ValidationEvent();
        if (xve.shouldCommit() || EventHelper.isLoggingSecurity()) {
            long[] certIds = params.certificates().stream()
                    .mapToInt(Certificate::hashCode)
                    .mapToLong(Integer::toUnsignedLong)
                    .toArray();
            int hash = (anchorCert != null) ?
                anchorCert.hashCode() : anchor.getCAPublicKey().hashCode();
            long anchorCertId = Integer.toUnsignedLong(hash);
            if (xve.shouldCommit()) {
                xve.certificateId = anchorCertId;
                int certificatePos = 1; // most trusted CA

src/java.base/share/classes/jdk/internal/event/X509ValidationEvent.java:

package jdk.internal.event;

/**
 * Event recording details of X.509 Certificate serial numbers
 * used in X509 cert path validation.
 */

public final class X509ValidationEvent extends Event {
    public long certificateId;
    public int certificatePosition;
    public long validationCounter;
}

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
certificateId ulong: certificateId Certificate Id
certificatePosition int Certificate Position Certificate position in chain of trust, 1 = trust anchor
validationCounter long Validation Counter

SecurityProviderService

startTime duration 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/SecurityProviderServiceEvent.java

Category: Java Development Kit / Security

Excludes in stack trace: java.security.Provider::getService

Details of Provider.getInstance(String type, String algorithm) calls

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/SecurityProviderServiceEvent.java:

@Category({"Java Development Kit", "Security"})
@Label("Security Provider Instance Request")
@Name("jdk.SecurityProviderService")
@Description("Details of Provider.getInstance(String type, String algorithm) calls")
@RemoveFields("duration")
@StackFilter({"java.security.Provider::getService"})
public final class SecurityProviderServiceEvent extends MirrorEvent {
    @Label("Type of Service")
    public String type;

    @Label("Algorithm Name")
    public String algorithm;

    @Label("Security Provider")
    public String provider;
}

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

 * This class registers all mirror events.
 */
final class MirrorEvents {
    private static final Map<String, Class<? extends MirrorEvent>> mirrorLookup = new ConcurrentHashMap<>();

    // Add mirror event mapping here. See MirrorEvent class for details.
    static {
        register("jdk.internal.event.DeserializationEvent", DeserializationEvent.class);
        register("jdk.internal.event.FileForceEvent", FileForceEvent.class);
        register("jdk.internal.event.FileReadEvent", FileReadEvent.class);
        register("jdk.internal.event.FileWriteEvent", FileWriteEvent.class);
        register("jdk.internal.event.ProcessStartEvent", ProcessStartEvent.class);
        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);
        register("jdk.internal.event.VirtualThreadEndEvent", VirtualThreadEndEvent.class);
        register("jdk.internal.event.VirtualThreadSubmitFailedEvent", VirtualThreadSubmitFailedEvent.class);
        register("jdk.internal.event.X509CertificateEvent", X509CertificateEvent.class);
        register("jdk.internal.event.X509ValidationEvent", X509ValidationEvent.class);
        register("jdk.internal.event.ErrorThrownEvent", ErrorThrownEvent.class);

src/java.base/share/classes/java/security/Provider.java:

            key = new ServiceKey(type, algorithm, false);
            previousKey.set(key);
        }

        Service s = serviceMap.get(key);
        if (s == null) {
            s = legacyMap.get(key);
            if (s != null && !s.isValid()) {
                legacyMap.remove(key, s);
                return null;
            }
        }

        if (s != null && SecurityProviderServiceEvent.isTurnedOn()) {
            var e  = new SecurityProviderServiceEvent();
            e.provider = getName();
            e.type = type;
            e.algorithm = algorithm;
            e.commit();
        }

        return s;
    }

    // ServiceKey from previous getService() call
    // by re-using it if possible we avoid allocating a new object

src/java.base/share/classes/jdk/internal/event/SecurityProviderServiceEvent.java:

package jdk.internal.event;

/**
 * Event recording details of Provider.getService(String type, String algorithm) calls
 */

public final class SecurityProviderServiceEvent extends Event {
    private static final SecurityProviderServiceEvent EVENT = new SecurityProviderServiceEvent();

    /**
     * Returns {@code true} if event is enabled, {@code false} otherwise.
     */
    public static boolean isTurnedOn() {
        return EVENT.isEnabled();
    }

    public String type;
    public String algorithm;
    public String provider;
}

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
type string Type of Service
algorithm string Algorithm Name
provider string Security Provider

Examples 3
algorithm string
SHA-256
provider string
SUN
startTime long: millis
443547541614
type string
MessageDigest
algorithm string
SHA-256
provider string
SUN
startTime long: millis
324830411140
type string
MessageDigest
algorithm string
SHA
provider string
SUN
startTime long: millis
449161558717
type string
MessageDigest

InitialSecurityProperty

profiling default startTime duration stackTrace 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/InitialSecurityPropertyEvent.java

Category: Java Development Kit / Security

Initial Security Properties

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/InitialSecurityPropertyEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.Name;

@Category({"Java Development Kit", "Security"})
@Label("Initial Security Property")
@Name("jdk.InitialSecurityProperty")
@Description("Initial Security Properties")
public final class InitialSecurityPropertyEvent extends AbstractPeriodicEvent {
    @Label("Key")
    public String key;

    @Label("Value")
    public String value;
}

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

        jdk.internal.event.SecurityProviderServiceEvent.class,
        jdk.internal.event.SerializationMisdeclarationEvent.class,
        jdk.internal.event.SocketReadEvent.class,
        jdk.internal.event.SocketWriteEvent.class,
        jdk.internal.event.ThreadSleepEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.VirtualThreadStartEvent.class,
        jdk.internal.event.VirtualThreadEndEvent.class,
        jdk.internal.event.VirtualThreadSubmitFailedEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class,
        jdk.internal.event.FinalFieldMutationEvent.class,
        DirectBufferStatisticsEvent.class,
        InitialSecurityPropertyEvent.class,
        MethodTraceEvent.class,
        MethodTimingEvent.class,
    };

    private static final Runnable emitExceptionStatistics = JDKEvents::emitExceptionStatistics;
    private static final Runnable emitDirectBufferStatistics = JDKEvents::emitDirectBufferStatistics;
    private static final Runnable emitContainerConfiguration = JDKEvents::emitContainerConfiguration;
    private static final Runnable emitContainerCPUUsage = JDKEvents::emitContainerCPUUsage;
    private static final Runnable emitContainerCPUThrottling = JDKEvents::emitContainerCPUThrottling;
    private static final Runnable emitContainerMemoryUsage = JDKEvents::emitContainerMemoryUsage;
    private static final Runnable emitContainerIOUsage = JDKEvents::emitContainerIOUsage;

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

    private static final Runnable emitMethodTiming = JDKEvents::emitMethodTiming;
    private static Metrics containerMetrics = null;
    private static boolean initializationTriggered;

    @SuppressWarnings("unchecked")
    public static synchronized void initialize() {
        try {
            if (initializationTriggered == false) {
                for (Class<?> eventClass : eventClasses) {
                    MetadataRepository.getInstance().register((Class<? extends Event>) eventClass);
                }
                PeriodicEvents.addJavaEvent(jdk.internal.event.ExceptionStatisticsEvent.class, emitExceptionStatistics);
                PeriodicEvents.addJavaEvent(DirectBufferStatisticsEvent.class, emitDirectBufferStatistics);
                PeriodicEvents.addJavaEvent(InitialSecurityPropertyEvent.class, emitInitialSecurityProperties);
                PeriodicEvents.addJavaEvent(MethodTimingEvent.class, emitMethodTiming);

                initializeContainerEvents();
                JFRTracing.enable();
                initializationTriggered = true;
            }
        } catch (Exception e) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.WARN, "Could not initialize JDK events. " + e.getMessage());
        }
    }

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

        PeriodicEvents.removeEvent(emitContainerMemoryUsage);
        PeriodicEvents.removeEvent(emitContainerIOUsage);
    }

    private static void emitDirectBufferStatistics() {
        DirectBufferStatisticsEvent e = new DirectBufferStatisticsEvent();
        e.commit();
    }

    private static void emitInitialSecurityProperties() {
        Properties p = SharedSecrets.getJavaSecurityPropertiesAccess().getInitialProperties();
        if (p != null) {
            for (String key : p.stringPropertyNames()) {
                InitialSecurityPropertyEvent e = new InitialSecurityPropertyEvent();
                e.key = key;
                e.value = p.getProperty(key);
                e.commit();
            }
        }
    }

    private static void emitMethodTiming() {
        if (MethodSetting.isInitialized() && MethodTimingEvent.enabled()) {
            PlatformTracer.emitTiming();
        }

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
key string Key
value string Value

Examples 3
key string
jdk.io.permissionsUseCanonicalPath
stackTrace StackTrace
null
startTime long: millis
380959306161
value string
false
key string
sun.security.krb5.disableReferrals
stackTrace StackTrace
null
startTime long: millis
280827752095
value string
false
key string
krb5.kdc.bad.policy
stackTrace StackTrace
null
startTime long: millis
388495938878
value string
tryLast

Operating System

OSInformation

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Operating System

Description of the OS the JVM runs on, for example, a uname-like output

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.set_jvmVersion(VM_Version::internal_vm_info_string());
  event.set_javaArguments(Arguments::java_command());
  event.set_jvmArguments(Arguments::jvm_args());
  event.set_jvmFlags(Arguments::jvm_flags());
  event.set_jvmStartTime(Management::vm_init_done_time());
  event.set_pid(os::current_process_id());
  event.commit();
 }

TRACE_REQUEST_FUNC(OSInformation) {
  ResourceMark rm;
  char* os_version = nullptr;
  JfrOSInterface::os_version(&os_version);
  EventOSInformation event;
  event.set_osVersion(os_version);
  event.commit();
}

TRACE_REQUEST_FUNC(VirtualizationInformation) {
  EventVirtualizationInformation event;
  event.set_name(JfrOSInterface::virtualization_name());
  event.commit();
}

TRACE_REQUEST_FUNC(ModuleRequire) {

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
osVersion string OS Version

Examples 3
osVersion string
DISTRIB_ID=Ubuntu DISTRIB_RELEASE=24.04 DISTRIB_CODENAME=noble DISTRIB_DESCRIPTION="Ubuntu 24.04.3 LTS" uname: Linux 6.11.0-1018-azure #18~24.04.1-Ubuntu SMP Sat Jun 28 04:46:03 UTC 2025 x86_64 libc: glibc 2.39 NPTL 2.39
startTime long: millis
450857917751
osVersion string
DISTRIB_ID=Ubuntu DISTRIB_RELEASE=24.04 DISTRIB_CODENAME=noble DISTRIB_DESCRIPTION="Ubuntu 24.04.3 LTS" uname: Linux 6.11.0-1018-azure #18~24.04.1-Ubuntu SMP Sat Jun 28 04:46:03 UTC 2025 x86_64 libc: glibc 2.39 NPTL 2.39
startTime long: millis
303912183838
osVersion string
DISTRIB_ID=Ubuntu DISTRIB_RELEASE=24.04 DISTRIB_CODENAME=noble DISTRIB_DESCRIPTION="Ubuntu 24.04.3 LTS" uname: Linux 6.11.0-1018-azure #18~24.04.1-Ubuntu SMP Sat Jun 28 04:46:03 UTC 2025 x86_64 libc: glibc 2.39 NPTL 2.39
startTime long: millis
426578587164

VirtualizationInformation

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Operating System

Description of the virtualization technology the JVM runs on

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  event.commit();
 }

TRACE_REQUEST_FUNC(OSInformation) {
  ResourceMark rm;
  char* os_version = nullptr;
  JfrOSInterface::os_version(&os_version);
  EventOSInformation event;
  event.set_osVersion(os_version);
  event.commit();
}

TRACE_REQUEST_FUNC(VirtualizationInformation) {
  EventVirtualizationInformation event;
  event.set_name(JfrOSInterface::virtualization_name());
  event.commit();
}

TRACE_REQUEST_FUNC(ModuleRequire) {
  JfrModuleEvent::generate_module_dependency_events();
}

TRACE_REQUEST_FUNC(ModuleExport) {
  JfrModuleEvent::generate_module_export_events();
}

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
name string Name

Examples 3
name string
Hyper-V virtualization
startTime long: millis
371346712864
name string
Hyper-V virtualization
startTime long: millis
331112846304
name string
Hyper-V virtualization
startTime long: millis
392328865842

InitialEnvironmentVariable

profiling default startTime end of every chunk 11 17 21 25 26 27

Category: Operating System

Key-value pairs for environment variables at JVM startup

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrOSInterface.cpp:

  } else if (vrt == PowerFullPartitionMode) {
    return "Power full partition";
  }

  return "No virtualization detected";
}

int JfrOSInterface::generate_initial_environment_variable_events() {
  if (os::get_environ() == nullptr) {
    return OS_ERR;
  }

  if (EventInitialEnvironmentVariable::is_enabled()) {
    // One time stamp for all events, so they can be grouped together
    JfrTicks time_stamp = JfrTicks::now();
    for (char** p = os::get_environ(); *p != nullptr; p++) {
      char* variable = *p;
      char* equal_sign = strchr(variable, '=');
      if (equal_sign != nullptr) {
        // Extract key/value
        ResourceMark rm;
        ptrdiff_t key_length = equal_sign - variable;
        char* key = NEW_RESOURCE_ARRAY(char, key_length + 1);
        char* value = equal_sign + 1;
        strncpy(key, variable, key_length);
        key[key_length] = '\0';
        EventInitialEnvironmentVariable event(UNTIMED);
        event.set_starttime(time_stamp);
        event.set_endtime(time_stamp);
        event.set_key(key);
        event.set_value(value);
        event.commit();
      }
    }
  }
  return OS_OK;
}

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
key string Key
value string Value

Examples 3
key string
GITHUB_REF_NAME
startTime long: millis
371346718444
value string
main
key string
GITHUB_ACTIONS
startTime long: millis
378900894646
value string
true
key string
VCPKG_INSTALLATION_ROOT
startTime long: millis
278169438967
value string
/usr/local/share/vcpkg

SystemProcess

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Operating System

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

    while (processes != nullptr) {
      SystemProcess* tmp = processes;
      const char* info = processes->command_line();
      if (info == nullptr) {
         info = processes->path();
      }
      if (info == nullptr) {
         info = processes->name();
      }
      if (info == nullptr) {
         info = "?";
      }
      jio_snprintf(pid_buf, sizeof(pid_buf), "%d", processes->pid());
      EventSystemProcess event(UNTIMED);
      event.set_pid(pid_buf);
      event.set_commandLine(info);
      event.set_starttime(start_time);
      event.set_endtime(end_time);
      event.commit();
      processes = processes->next();
      delete tmp;
    }
  }
}

Configuration enabled period
profiling true endChunk
default true endChunk

Field Type Description
pid string Process Identifier
commandLine string Command Line

CPUInformation

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Operating System / Processor

Characteristics and descriptions of the processor(s) the JVM is running on

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

TRACE_REQUEST_FUNC(CPUInformation) {
  CPUInformation cpu_info;
  int ret_val = JfrOSInterface::cpu_information(cpu_info);
  if (ret_val == OS_ERR) {
    log_debug(jfr, system)( "Unable to generate requestable event CPUInformation");
    return;
  }
  if (ret_val == FUNCTIONALITY_NOT_IMPLEMENTED) {
     return;
  }
  if (ret_val == OS_OK) {
    EventCPUInformation event;
    event.set_cpu(cpu_info.cpu_name());
    event.set_description(cpu_info.cpu_description());
    event.set_sockets(cpu_info.number_of_sockets());
    event.set_cores(cpu_info.number_of_cores());
    event.set_hwThreads(cpu_info.number_of_hardware_threads());
    event.commit();
  }
}

TRACE_REQUEST_FUNC(CPULoad) {
  double u = 0; // user time

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
cpu string Type
description string Description
sockets uint Sockets
cores uint Cores Approximation on a hybrid CPU
hwThreads uint Hardware Threads

Examples 3
cores uint
16
cpu string
AMD Unknown x86 (HT) SSE SSE2 SSE3 SSSE3 SSE4.1 SSE4.2 SSE4A AMD64
description string
Brand: AMD EPYC 7763 64-Core Processor , Vendor: AuthenticAMD Family: Unknown x86 (0x19), Model: <unknown> (0x1), Stepping: 0x1 Ext. family: 0xa, Ext. model: 0x0, Type: 0x0, Signature: 0x00a00f11 Features: ebx: 0x02100800, ecx: 0xfeda3203, edx: 0x178bfbff Ext. features: eax: 0x00a00f1
hwThreads uint
4
sockets uint
1
startTime long: millis
451341062403
cores uint
16
cpu string
AMD Unknown x86 (HT) SSE SSE2 SSE3 SSSE3 SSE4.1 SSE4.2 SSE4A AMD64
description string
Brand: AMD EPYC 7763 64-Core Processor , Vendor: AuthenticAMD Family: Unknown x86 (0x19), Model: <unknown> (0x1), Stepping: 0x1 Ext. family: 0xa, Ext. model: 0x0, Type: 0x0, Signature: 0x00a00f11 Features: ebx: 0x01100800, ecx: 0xfeda3203, edx: 0x178bfbff Ext. features: eax: 0x00a00f1
hwThreads uint
4
sockets uint
1
startTime long: millis
349029082752
cores uint
16
cpu string
AMD Unknown x86 (HT) SSE SSE2 SSE3 SSSE3 SSE4.1 SSE4.2 SSE4A AMD64
description string
Brand: AMD EPYC 7763 64-Core Processor , Vendor: AuthenticAMD Family: Unknown x86 (0x19), Model: <unknown> (0x1), Stepping: 0x1 Ext. family: 0xa, Ext. model: 0x0, Type: 0x0, Signature: 0x00a00f11 Features: ebx: 0x03100800, ecx: 0xfeda3203, edx: 0x178bfbff Ext. features: eax: 0x00a00f1
hwThreads uint
4
sockets uint
1
startTime long: millis
392328885829

CPUTimeStampCounter

profiling default startTime duration end of every chunk 11 17 21 25 26 27

Category: Operating System / Processor

Information about the CPU time stamp mechanism / (RD)TSC

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

TRACE_REQUEST_FUNC(ThreadCPULoad) {
  JfrThreadCPULoadEvent::send_events();
}

TRACE_REQUEST_FUNC(CompilerQueueUtilization) {
  JfrCompilerQueueUtilization::send_events();
}

TRACE_REQUEST_FUNC(NetworkUtilization) {
  JfrNetworkUtilization::send_events();
}

TRACE_REQUEST_FUNC(CPUTimeStampCounter) {
  EventCPUTimeStampCounter event;
  event.set_fastTimeEnabled(JfrTime::is_ft_enabled());
  event.set_fastTimeAutoEnabled(JfrTime::is_ft_supported());
  event.set_osFrequency(os::elapsed_frequency());
  event.set_fastTimeFrequency(JfrTime::frequency());
  event.commit();
}

TRACE_REQUEST_FUNC(SystemProcess) {
  char pid_buf[16];
  SystemProcess* processes = nullptr;
  int num_of_processes = 0;

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
fastTimeEnabled boolean Fast Time
fastTimeAutoEnabled boolean Trusted Platform
osFrequency long: hertz OS Frequency
fastTimeFrequency long: hertz Fast Time Frequency

Examples 3
fastTimeAutoEnabled boolean
true
fastTimeEnabled boolean
false
fastTimeFrequency long: hertz
1000000000
osFrequency long: hertz
1000000000
startTime long: millis
299758402266
fastTimeAutoEnabled boolean
true
fastTimeEnabled boolean
false
fastTimeFrequency long: hertz
1000000000
osFrequency long: hertz
1000000000
startTime long: millis
470672582465
fastTimeAutoEnabled boolean
true
fastTimeEnabled boolean
false
fastTimeFrequency long: hertz
1000000000
osFrequency long: hertz
1000000000
startTime long: millis
380779420199

CPULoad

profiling default startTime duration every chunk 11 17 21 25 26 27

Category: Operating System / Processor

Information about the recent CPU usage of the JVM process

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

  double t = 0; // total time
  int ret_val = OS_ERR;
  {
    // Can take some time on certain platforms, especially under heavy load.
    // Transition to native to avoid unnecessary stalls for pending safepoint synchronizations.
    ThreadToNativeFromVM transition(JavaThread::current());
    ret_val = JfrOSInterface::cpu_loads_process(&u, &s, &t);
  }
  if (ret_val == OS_ERR) {
    log_debug(jfr, system)( "Unable to generate requestable event CPULoad");
    return;
  }
  if (ret_val == OS_OK) {
    EventCPULoad event;
    event.set_jvmUser((float)u);
    event.set_jvmSystem((float)s);
    event.set_machineTotal((float)t);
    event.commit();
  }
}

TRACE_REQUEST_FUNC(ThreadCPULoad) {
  JfrThreadCPULoadEvent::send_events();
}

Configuration enabled period
profiling true 1000 ms
default true 1000 ms

Field Type Description
jvmUser float: percentage JVM User
jvmSystem float: percentage JVM System
machineTotal float: percentage Machine Total

Examples 3
jvmSystem float: percentage
0.009603841
jvmUser float: percentage
0.52340937
machineTotal float: percentage
0.53421366
startTime long: millis
392663345921
jvmSystem float: percentage
0.006772009
jvmUser float: percentage
0.4524347
machineTotal float: percentage
0.46017414
startTime long: millis
398279282965
jvmSystem float: percentage
0.01459854
jvmUser float: percentage
0.9002433
machineTotal float: percentage
0.93430656
startTime long: millis
337420475661

ThreadCPULoad

profiling default startTime duration eventThread every chunk 11 17 21 25 26 27

Category: Operating System / Processor

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrThreadCPULoadEvent.hpp:

#ifndef SHARE_JFR_PERIODIC_JFRTHREADCPULOADEVENT_HPP
#define SHARE_JFR_PERIODIC_JFRTHREADCPULOADEVENT_HPP

#include "jni.h"
#include "memory/allStatic.hpp"

class JavaThread;
class EventThreadCPULoad;

class JfrThreadCPULoadEvent : public AllStatic {
  static int _last_active_processor_count;
 public:
  static jlong get_wallclock_time();
  static int get_processor_count();
  static bool update_event(EventThreadCPULoad& event, JavaThread* thread, jlong cur_wallclock_time, int processor_count);
  static void send_events();
  static void send_event_for_thread(JavaThread* jt);
};

#endif // SHARE_JFR_PERIODIC_JFRTHREADCPULOADEVENT_HPP

src/hotspot/share/jfr/periodic/jfrThreadCPULoadEvent.cpp:

int JfrThreadCPULoadEvent::get_processor_count() {
  int cur_processor_count = os::active_processor_count();
  int last_processor_count = _last_active_processor_count;
  _last_active_processor_count = cur_processor_count;

  // If the number of processors decreases, we don't know at what point during
  // the sample interval this happened, so use the largest number to try
  // to avoid percentages above 100%
  return MAX2(cur_processor_count, last_processor_count);
}

// Returns false if the thread has not been scheduled since the last call to updateEvent
// (i.e. the delta for both system and user time is 0 milliseconds)
bool JfrThreadCPULoadEvent::update_event(EventThreadCPULoad& event, JavaThread* thread, jlong cur_wallclock_time, int processor_count) {
  JfrThreadLocal* const tl = thread->jfr_thread_local();

  jlong cur_cpu_time = os::thread_cpu_time(thread, true);
  jlong prev_cpu_time = tl->get_cpu_time();

  jlong prev_wallclock_time = tl->get_wallclock_time();
  tl->set_wallclock_time(cur_wallclock_time);

  // Threshold of 1 ms
  if (cur_cpu_time - prev_cpu_time < 1 * NANOSECS_PER_MILLISEC) {
    return false;

src/hotspot/share/jfr/periodic/jfrThreadCPULoadEvent.cpp:

void JfrThreadCPULoadEvent::send_events() {
  Thread* periodic_thread = Thread::current();
  traceid periodic_thread_id = JfrThreadLocal::thread_id(periodic_thread);
  const int processor_count = JfrThreadCPULoadEvent::get_processor_count();
  JfrTicks event_time = JfrTicks::now();
  jlong cur_wallclock_time = JfrThreadCPULoadEvent::get_wallclock_time();

  JfrJavaThreadIterator iter;
  int number_of_threads = 0;
  while (iter.has_next()) {
    JavaThread* const jt = iter.next();
    assert(jt != nullptr, "invariant");
    ++number_of_threads;
    EventThreadCPULoad event(UNTIMED);
    if (JfrThreadCPULoadEvent::update_event(event, jt, cur_wallclock_time, processor_count)) {
      event.set_starttime(event_time);
      event.set_endtime(event_time);
      if (jt != periodic_thread) {
        // Commit reads the thread id from this thread's trace data, so put it there temporarily
        JfrThreadLocal::impersonate(periodic_thread, JFR_JVM_THREAD_ID(jt));
      } else {
        JfrThreadLocal::impersonate(periodic_thread, periodic_thread_id);
      }
      event.commit();
    }
  }
  log_trace(jfr)("Measured CPU usage for %d threads in %.3f milliseconds", number_of_threads,
    (double)(JfrTicks::now() - event_time).milliseconds());
  JfrThreadLocal::stop_impersonating(periodic_thread);
}

void JfrThreadCPULoadEvent::send_event_for_thread(JavaThread* jt) {
  EventThreadCPULoad event;
  if (event.should_commit()) {
    if (update_event(event, jt, get_wallclock_time(), get_processor_count())) {
      event.commit();
    }
  }
}

Configuration enabled period
profiling true 10 s
default true 10 s

Field Type Description
user float: percentage User Mode CPU Load User mode thread CPU load
system float: percentage System Mode CPU Load System mode thread CPU load

Examples 3
startTime long: millis
313085016727
system float: percentage
1.3045633E-4
user float: percentage
0.0
startTime long: millis
445726697546
system float: percentage
3.4149786E-4
user float: percentage
0.008855208
startTime long: millis
433402539969
system float: percentage
6.1710402E-6
user float: percentage
0.0

ThreadContextSwitchRate

profiling default startTime duration every chunk 11 17 21 25 26 27

Category: Operating System / Processor

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

    // Can take some time on certain platforms, especially under heavy load.
    // Transition to native to avoid unnecessary stalls for pending safepoint synchronizations.
    ThreadToNativeFromVM transition(JavaThread::current());
    ret_val = JfrOSInterface::context_switch_rate(&rate);
  }
  if (ret_val == OS_ERR) {
    log_debug(jfr, system)( "Unable to generate requestable event ThreadContextSwitchRate");
    return;
  }
  if (ret_val == FUNCTIONALITY_NOT_IMPLEMENTED) {
    return;
  }
  if (ret_val == OS_OK) {
    EventThreadContextSwitchRate event;
    event.set_switchRate((float)rate + 0.0f);
    event.commit();
  }
}

#define SEND_FLAGS_OF_TYPE(eventType, flagType)                   \
  do {                                                            \
    JVMFlag *flag = JVMFlag::flags;                               \
    while (flag->name() != nullptr) {                             \
      if (flag->is_ ## flagType()) {                              \
        if (flag->is_unlocked()) {                                \

Configuration enabled period
profiling true 10 s
default true 10 s

Field Type Description
switchRate float: hertz Switch Rate Number of context switches per second

Examples 3
startTime long: millis
445542742096
switchRate float: hertz
10912.365
startTime long: millis
363563656372
switchRate float: hertz
6984.4907
startTime long: millis
472108918423
switchRate float: hertz
3372.7505

NetworkUtilization

profiling default startTime every chunk 11 17 21 25 26 27

Category: Operating System / Network

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrNetworkUtilization.cpp:

  static JfrTicks last_sample_instant;
  const JfrTicks cur_time = JfrTicks::now();
  if (cur_time > last_sample_instant) {
    const JfrTickspan interval = cur_time - last_sample_instant;
    for (NetworkInterface *cur = network_interfaces; cur != nullptr; cur = cur->next()) {
      InterfaceEntry& entry = get_entry(cur);
      const uint64_t current_bytes_in = cur->get_bytes_in();
      const uint64_t current_bytes_out = cur->get_bytes_out();
      const uint64_t read_rate = rate_per_second(current_bytes_in, entry.bytes_in, interval);
      const uint64_t write_rate = rate_per_second(current_bytes_out, entry.bytes_out, interval);
      if (read_rate > 0 || write_rate > 0) {
        write_interface_constant(entry);
        EventNetworkUtilization event(UNTIMED);
        event.set_starttime(cur_time);
        event.set_endtime(cur_time);
        event.set_networkInterface(entry.id);
        event.set_readRate(8 * read_rate);
        event.set_writeRate(8 * write_rate);
        event.commit();
      }
      // update existing entry with new values
      entry.bytes_in = current_bytes_in;
      entry.bytes_out = current_bytes_out;
    }

Configuration enabled period
profiling true 5 s
default true 5 s

Field Type Description
networkInterface NetworkInterfaceName Network Interface Network Interface Name
readRate long: bits-per-second Read Rate Number of incoming bits per second
writeRate long: bits-per-second Write Rate Number of outgoing bits per second

Examples 3
networkInterface NetworkInterfaceName
eth0
readRate long: bits-per-second
8264
startTime long: millis
440490683592
writeRate long: bits-per-second
4664
networkInterface NetworkInterfaceName
eth0
readRate long: bits-per-second
14248
startTime long: millis
449942967699
writeRate long: bits-per-second
17280
networkInterface NetworkInterfaceName
eth0
readRate long: bits-per-second
14496
startTime long: millis
321605660824
writeRate long: bits-per-second
37464

PhysicalMemory

profiling default startTime duration every chunk 11 17 21 25 26 27

Category: Operating System / Memory

OS Physical Memory

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

 *  PhysicalMemory event represents:
 *
 *  @totalSize == The amount of physical memory (hw) installed and reported by the OS, in bytes.
 *  @usedSize  == The amount of physical memory currently in use in the system (reserved/committed), in bytes.
 *
 *  Both fields are systemwide, i.e. represents the entire OS/HW environment.
 *  These fields do not include virtual memory.
 *
 *  If running inside a guest OS on top of a hypervisor in a virtualized environment,
 *  the total memory reported is the amount of memory configured for the guest OS by the hypervisor.
 */
TRACE_REQUEST_FUNC(PhysicalMemory) {
  physical_memory_size_type totalPhysicalMemory = os::physical_memory();
  EventPhysicalMemory event;
  event.set_totalSize(totalPhysicalMemory);
  physical_memory_size_type avail_mem = 0;
  // Return value ignored - defaulting to 0 on failure.
  (void)os::available_memory(avail_mem);
  event.set_usedSize(totalPhysicalMemory - avail_mem);
  event.commit();
}

TRACE_REQUEST_FUNC(SwapSpace) {
  EventSwapSpace event;
  physical_memory_size_type total_swap_space = 0;

Configuration enabled period
profiling true everyChunk
default true everyChunk

Field Type Description
totalSize ulong: bytes Total Size Total amount of physical memory available to OS
usedSize ulong: bytes Used Size Total amount of physical memory in use

Examples 3
startTime long: millis
404635067960
totalSize ulong: bytes
16772575232
usedSize ulong: bytes
3971964928
startTime long: millis
426593990934
totalSize ulong: bytes
16772579328
usedSize ulong: bytes
5919973376
startTime long: millis
279631409671
totalSize ulong: bytes
16772579328
usedSize ulong: bytes
3749142528

SwapSpace

profiling default startTime duration every chunk 23 25 26 27

Category: Operating System / Memory

OS Swap Space

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/hotspot/share/jfr/periodic/jfrPeriodic.cpp:

 */
TRACE_REQUEST_FUNC(PhysicalMemory) {
  physical_memory_size_type totalPhysicalMemory = os::physical_memory();
  EventPhysicalMemory event;
  event.set_totalSize(totalPhysicalMemory);
  physical_memory_size_type avail_mem = 0;
  // Return value ignored - defaulting to 0 on failure.
  (void)os::available_memory(avail_mem);
  event.set_usedSize(totalPhysicalMemory - avail_mem);
  event.commit();
}

TRACE_REQUEST_FUNC(SwapSpace) {
  EventSwapSpace event;
  physical_memory_size_type total_swap_space = 0;
  // Return value ignored - defaulting to 0 on failure.
  (void)os::total_swap_space(total_swap_space);
  event.set_totalSize(static_cast<s8>(total_swap_space));
  physical_memory_size_type free_swap_space = 0;
  // Return value ignored - defaulting to 0 on failure.
  (void)os::free_swap_space(free_swap_space);
  event.set_freeSize(static_cast<s8>(free_swap_space));
  event.commit();
}

Configuration enabled period
profiling true everyChunk
default true everyChunk

Field Type Description
totalSize long: bytes Total Size Total swap space available to the OS
freeSize long: bytes Free Size Free swap space

ProcessStart

profiling default startTime duration 15 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/ProcessStartEvent.java

Category: Operating System

Excludes in stack trace: java.lang.ProcessBuilder, java.lang.Runtime::exec

Operating system process started

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/ProcessStartEvent.java:

@Category({"Operating System"})
@Label("Process Start")
@Name("jdk.ProcessStart")
@Description("Operating system process started")
@RemoveFields("duration")
@StackFilter({"java.lang.ProcessBuilder", "java.lang.Runtime::exec"})
public final class ProcessStartEvent extends MirrorEvent {
    @Label("Process Id")
    public long pid;

    @Label("Directory")
    public String directory;

    @Label("Command")
    public String command;
}

src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java:

/**
 * This class registers all mirror events.
 */
final class MirrorEvents {
    private static final Map<String, Class<? extends MirrorEvent>> mirrorLookup = new ConcurrentHashMap<>();

    // Add mirror event mapping here. See MirrorEvent class for details.
    static {
        register("jdk.internal.event.DeserializationEvent", DeserializationEvent.class);
        register("jdk.internal.event.FileForceEvent", FileForceEvent.class);
        register("jdk.internal.event.FileReadEvent", FileReadEvent.class);
        register("jdk.internal.event.FileWriteEvent", FileWriteEvent.class);
        register("jdk.internal.event.ProcessStartEvent", ProcessStartEvent.class);
        register("jdk.internal.event.SecurityPropertyModificationEvent", SecurityPropertyModificationEvent.class);
        register("jdk.internal.event.SecurityProviderServiceEvent", SecurityProviderServiceEvent.class);
        register("jdk.internal.event.SerializationMisdeclarationEvent", SerializationMisdeclarationEvent.class);
        register("jdk.internal.event.SocketReadEvent", SocketReadEvent.class);
        register("jdk.internal.event.SocketWriteEvent", SocketWriteEvent.class);
        register("jdk.internal.event.ThreadSleepEvent", ThreadSleepEvent.class);
        register("jdk.internal.event.TLSHandshakeEvent", TLSHandshakeEvent.class);
        register("jdk.internal.event.VirtualThreadStartEvent", VirtualThreadStartEvent.class);
        register("jdk.internal.event.VirtualThreadEndEvent", VirtualThreadEndEvent.class);
        register("jdk.internal.event.VirtualThreadSubmitFailedEvent", VirtualThreadSubmitFailedEvent.class);
        register("jdk.internal.event.X509CertificateEvent", X509CertificateEvent.class);

src/java.base/share/classes/jdk/internal/event/ProcessStartEvent.java:

package jdk.internal.event;

/**
 * Event for the start of an OS procsss
 */

public final class ProcessStartEvent extends Event {
    public long pid;
    public String directory;
    public String command;
}

src/java.base/share/classes/java/lang/ProcessBuilder.java:

        for (String s : cmdarray) {
            if (s.indexOf('\u0000') >= 0) {
                throw new IOException("invalid null character in command");
            }
        }

        try {
            Process process = ProcessImpl.start(cmdarray,
                                     environment,
                                     dir,
                                     redirects,
                                     redirectErrorStream);
            ProcessStartEvent event = new ProcessStartEvent();
            if (event.isEnabled()) {
                event.directory = dir;
                event.command = String.join(" ", cmdarray);
                event.pid = process.pid();
                event.commit();
            }
            // Racy initialization for logging; errors in configuration may throw exceptions
            System.Logger logger = LOGGER;
            if (logger == null) {
                LOGGER = logger = System.getLogger("java.lang.ProcessBuilder");
            }

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
pid long Process Id
directory string Directory
command string Command

Examples 3
command string
setsid bash -c echo $$
directory string
null
pid long
4667
startTime long: millis
440170736498
command string
rm -rf /home/runner/work/jfrevents/jfrevents/harness-003916-17833306698725904421/apache-spark/gauss-mix/spark-3378aa9e-5662-4829-8f01-7a423fb3bcbc/userFiles-933c2f2b-1cca-4878-8bfc-63048f619f7d
directory string
null
pid long
4550
startTime long: millis
463221796162
command string
rm -rf /home/runner/work/jfrevents/jfrevents/harness-003927-11018005009666797249/apache-spark/als/spark-31ac7d2e-7b4f-4019-821d-3e32fa5116be/userFiles-1c2f544a-8214-4be9-bf4b-52cf3814319d
directory string
null
pid long
3985
startTime long: millis
311022574779

ContainerCPUThrottling

profiling default startTime duration stackTrace 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/ContainerCPUThrottlingEvent.java

Category: Operating System / Processor

Container CPU throttling related information

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/ContainerCPUThrottlingEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.Timespan;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "ContainerCPUThrottling")
@Label("CPU Throttling")
@Category({"Operating System", "Processor"})
@Description("Container CPU throttling related information")
public class ContainerCPUThrottlingEvent extends AbstractPeriodicEvent {
  @Label("CPU Elapsed Slices")
  @Description("Number of time-slice periods that have elapsed if a CPU quota has been setup for the container")
  public long cpuElapsedSlices;

  @Label("CPU Throttled Slices")
  @Description("Number of time-slice periods that the CPU has been throttled or limited due to exceeding CPU quota")
  public long cpuThrottledSlices;

  @Label("CPU Throttled Time")
  @Description("Total time duration, in nanoseconds, that the CPU has been throttled or limited due to exceeding CPU quota")
  @Timespan

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

    private static void initializeContainerEvents() {
        if (JVM.isContainerized() ) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.DEBUG, "JVM is containerized");
            containerMetrics = Container.metrics();
            if (containerMetrics != null) {
                Logger.log(LogTag.JFR_SYSTEM, LogLevel.DEBUG, "Container metrics are available");
            }
        }
        // The registration of events and hooks are needed to provide metadata,
        // even when not running in a container
        registerEvent(ContainerConfigurationEvent.class);
        registerEvent(ContainerCPUUsageEvent.class);
        registerEvent(ContainerCPUThrottlingEvent.class);
        registerEvent(ContainerMemoryUsageEvent.class);
        registerEvent(ContainerIOUsageEvent.class);

        PeriodicEvents.addJavaEvent(ContainerConfigurationEvent.class, emitContainerConfiguration);
        PeriodicEvents.addJavaEvent(ContainerCPUUsageEvent.class, emitContainerCPUUsage);
        PeriodicEvents.addJavaEvent(ContainerCPUThrottlingEvent.class, emitContainerCPUThrottling);
        PeriodicEvents.addJavaEvent(ContainerMemoryUsageEvent.class, emitContainerMemoryUsage);
        PeriodicEvents.addJavaEvent(ContainerIOUsageEvent.class, emitContainerIOUsage);
    }

    private static void registerEvent(Class<? extends jdk.internal.event.Event> eventClass) {
        MetadataRepository.getInstance().register(eventClass);
    }

    private static void emitExceptionStatistics() {
        ThrowableTracer.emitStatistics();
    }

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

    private static void emitContainerIOUsage() {
        if (containerMetrics != null) {
            ContainerIOUsageEvent event = new ContainerIOUsageEvent();

            event.serviceRequests = containerMetrics.getBlkIOServiceCount();
            event.dataTransferred = containerMetrics.getBlkIOServiced();
            event.commit();
        }
    }

    private static void emitContainerCPUThrottling() {
        if (containerMetrics != null) {
            ContainerCPUThrottlingEvent event = new ContainerCPUThrottlingEvent();

            event.cpuElapsedSlices = containerMetrics.getCpuNumPeriods();
            event.cpuThrottledSlices = containerMetrics.getCpuNumThrottled();
            event.cpuThrottledTime = containerMetrics.getCpuThrottledTime();
            event.commit();
        }
    }

    public static void remove() {
        PeriodicEvents.removeEvent(emitExceptionStatistics);
        PeriodicEvents.removeEvent(emitDirectBufferStatistics);

Configuration enabled period
profiling true 30 s
default true 30 s

Field Type Description
cpuElapsedSlices long CPU Elapsed Slices Number of time-slice periods that have elapsed if a CPU quota has been setup for the container
cpuThrottledSlices long CPU Throttled Slices Number of time-slice periods that the CPU has been throttled or limited due to exceeding CPU quota
cpuThrottledTime long: nanos CPU Throttled Time Total time duration, in nanoseconds, that the CPU has been throttled or limited due to exceeding CPU quota

ContainerMemoryUsage

profiling default startTime duration stackTrace 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/ContainerMemoryUsageEvent.java

Category: Operating System / Memory

Container memory usage related information

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/ContainerMemoryUsageEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.DataAmount;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "ContainerMemoryUsage")
@Label("Container Memory Usage")
@Category({"Operating System", "Memory"})
@Description("Container memory usage related information")
public final class ContainerMemoryUsageEvent extends AbstractPeriodicEvent {
    @Label("Memory Fail Count")
    @Description("Number of times that user memory requests in the container have exceeded the memory limit")
    public long memoryFailCount;

    @Label("Memory Usage")
    @Description("Amount of physical memory, in bytes, that is currently allocated in the current container")
    @DataAmount
    public long memoryUsage;

    @Label("Memory and Swap Usage")
    @Description("Amount of physical memory and swap space, in bytes, that is currently allocated in the current container")

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

    private static void initializeContainerEvents() {
        if (JVM.isContainerized() ) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.DEBUG, "JVM is containerized");
            containerMetrics = Container.metrics();
            if (containerMetrics != null) {
                Logger.log(LogTag.JFR_SYSTEM, LogLevel.DEBUG, "Container metrics are available");
            }
        }
        // The registration of events and hooks are needed to provide metadata,
        // even when not running in a container
        registerEvent(ContainerConfigurationEvent.class);
        registerEvent(ContainerCPUUsageEvent.class);
        registerEvent(ContainerCPUThrottlingEvent.class);
        registerEvent(ContainerMemoryUsageEvent.class);
        registerEvent(ContainerIOUsageEvent.class);

        PeriodicEvents.addJavaEvent(ContainerConfigurationEvent.class, emitContainerConfiguration);
        PeriodicEvents.addJavaEvent(ContainerCPUUsageEvent.class, emitContainerCPUUsage);
        PeriodicEvents.addJavaEvent(ContainerCPUThrottlingEvent.class, emitContainerCPUThrottling);
        PeriodicEvents.addJavaEvent(ContainerMemoryUsageEvent.class, emitContainerMemoryUsage);
        PeriodicEvents.addJavaEvent(ContainerIOUsageEvent.class, emitContainerIOUsage);
    }

    private static void registerEvent(Class<? extends jdk.internal.event.Event> eventClass) {
        MetadataRepository.getInstance().register(eventClass);
    }

    private static void emitExceptionStatistics() {
        ThrowableTracer.emitStatistics();
    }

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

    private static void emitContainerCPUUsage() {
        if (containerMetrics != null) {
            ContainerCPUUsageEvent event = new ContainerCPUUsageEvent();

            event.cpuTime = containerMetrics.getCpuUsage();
            event.cpuSystemTime = containerMetrics.getCpuSystemUsage();
            event.cpuUserTime = containerMetrics.getCpuUserUsage();
            event.commit();
        }
    }
    private static void emitContainerMemoryUsage() {
        if (containerMetrics != null) {
            ContainerMemoryUsageEvent event = new ContainerMemoryUsageEvent();

            event.memoryFailCount = containerMetrics.getMemoryFailCount();
            event.memoryUsage = containerMetrics.getMemoryUsage();
            event.swapMemoryUsage = containerMetrics.getMemoryAndSwapUsage();
            event.commit();
        }
    }

    private static void emitContainerIOUsage() {
        if (containerMetrics != null) {
            ContainerIOUsageEvent event = new ContainerIOUsageEvent();

Configuration enabled period
profiling true 30 s
default true 30 s

Field Type Description
memoryFailCount long Memory Fail Count Number of times that user memory requests in the container have exceeded the memory limit
memoryUsage long: bytes Memory Usage Amount of physical memory, in bytes, that is currently allocated in the current container
swapMemoryUsage long: bytes Memory and Swap Usage Amount of physical memory and swap space, in bytes, that is currently allocated in the current container

ContainerConfiguration

profiling default startTime duration stackTrace 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/ContainerConfigurationEvent.java

Category: Operating System

A set of container specific attributes

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/ContainerConfigurationEvent.java:

@Name(Type.EVENT_NAME_PREFIX + "ContainerConfiguration")
@Label("Container Configuration")
@Category({"Operating System"})
@Description("A set of container specific attributes")
public final class ContainerConfigurationEvent extends AbstractPeriodicEvent {
    @Label("Container Type")
    @Description("Container type information")
    public String containerType;

    @Label("CPU Slice Period")
    @Description("Length of the scheduling period for processes within the container")
    @Timespan(Timespan.MICROSECONDS)
    public long cpuSlicePeriod;

    @Label("CPU Quota")
    @Description("Total available run-time allowed during each scheduling period for all tasks in the container")

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

    private static void initializeContainerEvents() {
        if (JVM.isContainerized() ) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.DEBUG, "JVM is containerized");
            containerMetrics = Container.metrics();
            if (containerMetrics != null) {
                Logger.log(LogTag.JFR_SYSTEM, LogLevel.DEBUG, "Container metrics are available");
            }
        }
        // The registration of events and hooks are needed to provide metadata,
        // even when not running in a container
        registerEvent(ContainerConfigurationEvent.class);
        registerEvent(ContainerCPUUsageEvent.class);
        registerEvent(ContainerCPUThrottlingEvent.class);
        registerEvent(ContainerMemoryUsageEvent.class);
        registerEvent(ContainerIOUsageEvent.class);

        PeriodicEvents.addJavaEvent(ContainerConfigurationEvent.class, emitContainerConfiguration);
        PeriodicEvents.addJavaEvent(ContainerCPUUsageEvent.class, emitContainerCPUUsage);
        PeriodicEvents.addJavaEvent(ContainerCPUThrottlingEvent.class, emitContainerCPUThrottling);
        PeriodicEvents.addJavaEvent(ContainerMemoryUsageEvent.class, emitContainerMemoryUsage);
        PeriodicEvents.addJavaEvent(ContainerIOUsageEvent.class, emitContainerIOUsage);
    }

    private static void registerEvent(Class<? extends jdk.internal.event.Event> eventClass) {
        MetadataRepository.getInstance().register(eventClass);
    }

    private static void emitExceptionStatistics() {
        ThrowableTracer.emitStatistics();
    }

    private static void emitContainerConfiguration() {
        if (containerMetrics != null) {
            ContainerConfigurationEvent t = new ContainerConfigurationEvent();
            t.containerType = containerMetrics.getProvider();
            t.cpuSlicePeriod = containerMetrics.getCpuPeriod();
            t.cpuQuota = containerMetrics.getCpuQuota();
            t.cpuShares = containerMetrics.getCpuShares();
            t.effectiveCpuCount = containerMetrics.getEffectiveCpuCount();
            t.memorySoftLimit = containerMetrics.getMemorySoftLimit();
            t.memoryLimit = containerMetrics.getMemoryLimit();
            t.swapMemoryLimit = containerMetrics.getMemoryAndSwapLimit();
            t.hostTotalMemory = JVM.hostTotalMemory();
            t.hostTotalSwapMemory = JVM.hostTotalSwapMemory();
            t.commit();

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
containerType string Container Type Container type information
cpuSlicePeriod long: microseconds CPU Slice Period Length of the scheduling period for processes within the container
cpuQuota long: microseconds CPU Quota Total available run-time allowed during each scheduling period for all tasks in the container
cpuShares long CPU Shares Relative weighting of processes with the container used for prioritizing the scheduling of processes across all containers running on a host
effectiveCpuCount long Effective CPU Count Number of effective processors that this container has available to it
memorySoftLimit long: bytes Memory Soft Limit Hint to the operating system that allows groups to specify the minimum required amount of physical memory
memoryLimit long: bytes Memory Limit Maximum amount of physical memory that can be allocated in the container
swapMemoryLimit long: bytes Memory and Swap Limit Maximum amount of physical memory and swap space, in bytes, that can be allocated in the container
hostTotalMemory long: bytes 20+ Container Host Total Memory Total memory of the host running the container
hostTotalSwapMemory long: bytes 23+ Container Host Total Swap Memory Total swap memory of the host running the container

ContainerCPUUsage

profiling default startTime duration stackTrace 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/ContainerCPUUsageEvent.java

Category: Operating System / Processor

Container CPU usage related information

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/ContainerCPUUsageEvent.java:

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.Timespan;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "ContainerCPUUsage")
@Label("CPU Usage")
@Category({"Operating System", "Processor"})
@Description("Container CPU usage related information")
public class ContainerCPUUsageEvent extends AbstractPeriodicEvent {
  @Label("CPU Time")
  @Description("Aggregate time consumed by all tasks in the container")
  @Timespan
  public long cpuTime;

  @Label("CPU User Time")
  @Description("Aggregate user time consumed by all tasks in the container")
  @Timespan
  public long cpuUserTime;

  @Label("CPU System Time")

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

    private static void initializeContainerEvents() {
        if (JVM.isContainerized() ) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.DEBUG, "JVM is containerized");
            containerMetrics = Container.metrics();
            if (containerMetrics != null) {
                Logger.log(LogTag.JFR_SYSTEM, LogLevel.DEBUG, "Container metrics are available");
            }
        }
        // The registration of events and hooks are needed to provide metadata,
        // even when not running in a container
        registerEvent(ContainerConfigurationEvent.class);
        registerEvent(ContainerCPUUsageEvent.class);
        registerEvent(ContainerCPUThrottlingEvent.class);
        registerEvent(ContainerMemoryUsageEvent.class);
        registerEvent(ContainerIOUsageEvent.class);

        PeriodicEvents.addJavaEvent(ContainerConfigurationEvent.class, emitContainerConfiguration);
        PeriodicEvents.addJavaEvent(ContainerCPUUsageEvent.class, emitContainerCPUUsage);
        PeriodicEvents.addJavaEvent(ContainerCPUThrottlingEvent.class, emitContainerCPUThrottling);
        PeriodicEvents.addJavaEvent(ContainerMemoryUsageEvent.class, emitContainerMemoryUsage);
        PeriodicEvents.addJavaEvent(ContainerIOUsageEvent.class, emitContainerIOUsage);
    }

    private static void registerEvent(Class<? extends jdk.internal.event.Event> eventClass) {
        MetadataRepository.getInstance().register(eventClass);
    }

    private static void emitExceptionStatistics() {
        ThrowableTracer.emitStatistics();

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

            t.cpuShares = containerMetrics.getCpuShares();
            t.effectiveCpuCount = containerMetrics.getEffectiveCpuCount();
            t.memorySoftLimit = containerMetrics.getMemorySoftLimit();
            t.memoryLimit = containerMetrics.getMemoryLimit();
            t.swapMemoryLimit = containerMetrics.getMemoryAndSwapLimit();
            t.hostTotalMemory = JVM.hostTotalMemory();
            t.hostTotalSwapMemory = JVM.hostTotalSwapMemory();
            t.commit();
        }
    }

    private static void emitContainerCPUUsage() {
        if (containerMetrics != null) {
            ContainerCPUUsageEvent event = new ContainerCPUUsageEvent();

            event.cpuTime = containerMetrics.getCpuUsage();
            event.cpuSystemTime = containerMetrics.getCpuSystemUsage();
            event.cpuUserTime = containerMetrics.getCpuUserUsage();
            event.commit();
        }
    }
    private static void emitContainerMemoryUsage() {
        if (containerMetrics != null) {
            ContainerMemoryUsageEvent event = new ContainerMemoryUsageEvent();

Configuration enabled period
profiling true 30 s
default true 30 s

Field Type Description
cpuTime long: nanos CPU Time Aggregate time consumed by all tasks in the container
cpuUserTime long: nanos CPU User Time Aggregate user time consumed by all tasks in the container
cpuSystemTime long: nanos CPU System Time Aggregate system time consumed by all tasks in the container

ContainerIOUsage

profiling default startTime duration stackTrace 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/ContainerIOUsageEvent.java

Category: Operating System / File System

Container IO usage related information

Code Context

The event is likely defined and utilized in the following locations within the OpenJDK source code, which is licensed under the GPLv2, excluding any XML or configuration files:

src/jdk.jfr/share/classes/jdk/jfr/events/ContainerIOUsageEvent.java:

@Name(Type.EVENT_NAME_PREFIX + "ContainerIOUsage")
@Label("Container IO Usage")
@Category({"Operating System", "File System"})
@Description("Container IO usage related information")
public class ContainerIOUsageEvent extends AbstractPeriodicEvent {

  @Label("Block IO Request Count")
  @Description("Number of block IO requests to the disk that have been issued by the container")
  public long serviceRequests;

  @Label("Block IO Transfer")
  @Description("Number of block IO bytes that have been transferred to/from the disk by the container")
  @DataAmount
  public long dataTransferred;
}

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

        if (JVM.isContainerized() ) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.DEBUG, "JVM is containerized");
            containerMetrics = Container.metrics();
            if (containerMetrics != null) {
                Logger.log(LogTag.JFR_SYSTEM, LogLevel.DEBUG, "Container metrics are available");
            }
        }
        // The registration of events and hooks are needed to provide metadata,
        // even when not running in a container
        registerEvent(ContainerConfigurationEvent.class);
        registerEvent(ContainerCPUUsageEvent.class);
        registerEvent(ContainerCPUThrottlingEvent.class);
        registerEvent(ContainerMemoryUsageEvent.class);
        registerEvent(ContainerIOUsageEvent.class);

        PeriodicEvents.addJavaEvent(ContainerConfigurationEvent.class, emitContainerConfiguration);
        PeriodicEvents.addJavaEvent(ContainerCPUUsageEvent.class, emitContainerCPUUsage);
        PeriodicEvents.addJavaEvent(ContainerCPUThrottlingEvent.class, emitContainerCPUThrottling);
        PeriodicEvents.addJavaEvent(ContainerMemoryUsageEvent.class, emitContainerMemoryUsage);
        PeriodicEvents.addJavaEvent(ContainerIOUsageEvent.class, emitContainerIOUsage);
    }

    private static void registerEvent(Class<? extends jdk.internal.event.Event> eventClass) {
        MetadataRepository.getInstance().register(eventClass);
    }

    private static void emitExceptionStatistics() {
        ThrowableTracer.emitStatistics();
    }

    private static void emitContainerConfiguration() {

src/jdk.jfr/share/classes/jdk/jfr/internal/JDKEvents.java:

    private static void emitContainerMemoryUsage() {
        if (containerMetrics != null) {
            ContainerMemoryUsageEvent event = new ContainerMemoryUsageEvent();

            event.memoryFailCount = containerMetrics.getMemoryFailCount();
            event.memoryUsage = containerMetrics.getMemoryUsage();
            event.swapMemoryUsage = containerMetrics.getMemoryAndSwapUsage();
            event.commit();
        }
    }

    private static void emitContainerIOUsage() {
        if (containerMetrics != null) {
            ContainerIOUsageEvent event = new ContainerIOUsageEvent();

            event.serviceRequests = containerMetrics.getBlkIOServiceCount();
            event.dataTransferred = containerMetrics.getBlkIOServiced();
            event.commit();
        }
    }

    private static void emitContainerCPUThrottling() {
        if (containerMetrics != null) {
            ContainerCPUThrottlingEvent event = new ContainerCPUThrottlingEvent();

Configuration enabled period
profiling true 30 s
default true 30 s

Field Type Description
serviceRequests long Block IO Request Count Number of block IO requests to the disk that have been issued by the container
dataTransferred long: bytes Block IO Transfer Number of block IO bytes that have been transferred to/from the disk by the container

Types

Bytecode

14+

Bytecode Instruction

Field Type Description
bytecode string Instruction

Examples 3
invokeinterface
invokevirtual
if_icmpne

CalleeMethod

Field Type Description
type string Class
name string Method Name
descriptor string Method Descriptor

Examples 3
descriptor string
(ILjava/lang/Object;)Ljava/util/concurrent/ConcurrentHashMap$Node;
name string
find
type string
java/util/concurrent/ConcurrentHashMap$TreeBin
descriptor string
(Ljava/lang/Object;)Ljava/lang/Object;
name string
allocateInstance
type string
java/lang/invoke/DirectMethodHandle
descriptor string
(Lscala/collection/mutable/LinkedHashMap$LinkedEntry;)V
name string
next_$eq
type string
scala/collection/mutable/LinkedHashMap$LinkedEntry

ChunkHeader

14+

Chunk Header

Field Type Description
payload array byte Payload

Class

Java Class

Field Type Description
classLoader ClassLoader Class Loader
name Symbol Name
package Package Package
modifiers int Access Modifiers
hidden boolean 15+ Hidden

ClassLoader

Java Class Loader

Field Type Description
type Class Type
name Symbol Name

CodeBlobType

Code Blob Type

Field Type Description
type string Type

Examples 3
CodeHeap 'non-profiled nmethods'
CodeHeap 'non-profiled nmethods'
CodeHeap 'non-nmethods'

CompilerPhaseType

Compiler Phase Type

Field Type Description
phase string Phase

CompilerType

14+

Compiler Type

Field Type Description
compiler string Compiler

Examples 3

CopyFailed

Field Type Description
objectCount ulong Object Count
firstSize ulong: bytes First Failed Object Size
smallestSize ulong: bytes Smallest Failed Object Size
totalSize ulong: bytes Total Object Size

DeoptimizationAction

14+

Deoptimization Action

Field Type Description
action string Action

Examples 3
reinterpret
maybe_recompile
maybe_recompile

DeoptimizationReason

14+

Deoptimization Reason

Field Type Description
reason string Reason

Examples 3
class_check
unstable_if
class_check

FlagValueOrigin

Flag Value Origin

Field Type Description
origin string Origin

Examples 3
Default
Default
Default

FrameType

Frame type

Field Type Description
description string Description

Examples 3
JIT compiled
Inlined
Inlined

G1EvacuationStatistics

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Field Type Description
gcId uint GC Identifier
allocated ulong: bytes Allocated Total memory allocated by PLABs
wasted ulong: bytes Wasted Total memory wasted within PLABs due to alignment or refill
used ulong: bytes Used Total memory occupied by objects within PLABs
undoWaste ulong: bytes Undo Wasted Total memory wasted due to allocation undo within PLABs
regionEndWaste ulong: bytes Region End Wasted Total memory wasted at the end of regions due to refill
regionsRefilled uint Region Refills Number of regions refilled
numPlabsFilled ulong 17+ PLAB Fills Number of PLABs filled
directAllocated ulong: bytes Allocated (Direct) Total memory allocated using direct allocation outside of PLABs
numDirectAllocated ulong 17+ Direct Allocations Number of direct allocations
failureUsed ulong: bytes Used (Failure) Total memory occupied by objects in regions where evacuation failed
failureWaste ulong: bytes Wasted (Failure) Total memory left unused in regions where evacuation failed

Examples 2
allocated ulong: bytes
460576
directAllocated ulong: bytes
0
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
950
numDirectAllocated ulong
0
numPlabsFilled ulong
0
regionEndWaste ulong: bytes
0
regionsRefilled uint
1
undoWaste ulong: bytes
0
used ulong: bytes
127272
wasted ulong: bytes
0
allocated ulong: bytes
924672
directAllocated ulong: bytes
188272
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
1078
numDirectAllocated ulong
0
numPlabsFilled ulong
0
regionEndWaste ulong: bytes
0
regionsRefilled uint
1
undoWaste ulong: bytes
0
used ulong: bytes
884536
wasted ulong: bytes
4552

G1HeapRegionType

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

G1 Heap Region Type

Field Type Description
type string Type

Examples 1
Free

G1YCType

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

G1 YC Type

Field Type Description
type string Type

Examples 1
Concurrent Start

GCCause

GC Cause

Field Type Description
cause string Cause

Examples 3
Allocation Failure
Heap Inspection Initiated GC
Heap Inspection Initiated GC

GCName

GC Name

Field Type Description
name string Name

Examples 3
G1Full
G1New
G1Old

GCThresholdUpdater

GC Threshold Updater

Field Type Description
updater string Updater

Examples 3
compute_new_size
compute_new_size
compute_new_size

GCWhen

GC When

Field Type Description
when string When

Examples 3
Before GC
After GC
Before GC

InflateCause

Inflation Cause

Field Type Description
cause string Cause

MetadataType

Metadata Type

Field Type Description
type string Type

Examples 3
Class
Class
Class

MetaspaceObjectType

Metaspace Object Type

Field Type Description
type string Type

MetaspaceSizes

Field Type Description
committed ulong: bytes Committed Committed memory for this space
used ulong: bytes Used Bytes allocated by objects in the space
reserved ulong: bytes Reserved Reserved memory for this space

Examples 3
committed ulong: bytes
571080704
reserved ulong: bytes
603979776
used ulong: bytes
569170248
committed ulong: bytes
88080384
reserved ulong: bytes
1073741824
used ulong: bytes
86220768
committed ulong: bytes
659161088
reserved ulong: bytes
1677721600
used ulong: bytes
655391016

Method

Java Method

Field Type Description
type Class Type
name Symbol Name
descriptor Symbol Descriptor
modifiers int Access Modifiers
hidden boolean Hidden

Module

Module

Field Type Description
name Symbol Name
version Symbol Version
location Symbol Location
classLoader ClassLoader Class Loader

NMTType

21+

Native Memory Tracking Type

Field Type Description
name string Name

NarrowOopMode

Narrow Oop Mode

Field Type Description
mode string Mode

Examples 3
Zero based
Zero based
Zero based

NetworkInterfaceName

Network Interface

Field Type Description
networkInterface string Network Interface Network Interface Name

Examples 3
eth0
eth0
eth0

ObjectSpace

Appearing in: ParallelGC

Missing in: G1GC, SerialGC, ShenandoahGC, ZGC

Field Type Description
start ulong: address Start Address Start address of the space
end ulong: address End Address End address of the space
used ulong: bytes Used Bytes allocated by objects in the space
size ulong: bytes Size Size of the space

Examples 3
end ulong: address
34234433536
size ulong: bytes
4194304
start ulong: address
34230239232
used ulong: bytes
0
end ulong: address
34230239232
size ulong: bytes
1268252672
start ulong: address
32961986560
used ulong: bytes
12540504
end ulong: address
31729909760
size ulong: bytes
1564475392
start ulong: address
30165434368
used ulong: bytes
210748448

OldObject

Appearing in: G1GC, ParallelGC, SerialGC, ZGC

Missing in: ShenandoahGC

Old Object

Field Type Description
address ulong: address Memory Address
type Class Java Class
description string Object Description Object description
referrer Reference Referrer Object Object referencing this object

Examples 3
address ulong: address
30384410024
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/String
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
address ulong: address
31812930656
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[Ljava/util/concurrent/ForkJoinTask;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent
address ulong: address
30351632312
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/reflect/Method
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang/reflect

OldObjectArray

Old Object Array

Field Type Description
size int Array Size Size of array
index int Index Index in the array

OldObjectField

Old Object Field

Field Type Description
name string Field Name of field
modifiers short Field Modifiers Field modifiers

OldObjectGcRoot

Appearing in: G1GC, ParallelGC, SerialGC, ZGC

Missing in: ShenandoahGC

GC Root

Field Type Description
description string Root Description Root information
system OldObjectRootSystem System The subsystem of origin for the root
type OldObjectRootType Type The root type

Examples 3
null
null
null

OldObjectRootSystem

GC Root System

Field Type Description
system string System

OldObjectRootType

GC Root Type

Field Type Description
type string Type

Package

Package

Field Type Description
name Symbol Name
module Module Module
exported boolean Exported

Reference

Appearing in: G1GC, ParallelGC, SerialGC, ZGC

Missing in: ShenandoahGC

Reference

Field Type Description
array OldObjectArray Array Information Array or null if it is not an array
field OldObjectField Field Information Field or null if it is an array
object OldObject Object Object holder for this reference
skip int Skip Value The object is this many hops away

Examples 3
null
null
null

ReferenceType

Reference Type

Field Type Description
type string Type

Examples 3
Soft reference
Soft reference
Soft reference

ShenandoahHeapRegionState

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

Shenandoah Heap Region State

Field Type Description
state string State

Examples 3
Regular
Empty Uncommitted
Empty Committed

StackFrame

Field Type Description
method Method Java Method
lineNumber int Line Number
bytecodeIndex int Bytecode Index
type FrameType Frame Type

Examples 3
bytecodeIndex int
2
lineNumber int
2577
method Method
descriptor string
(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden boolean
false
modifiers int
1
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/lang/System$2
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Inlined
bytecodeIndex int
11
lineNumber int
2371
method Method
descriptor string
()V
hidden boolean
false
modifiers int
2
name string
growEntries
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
26
name string
java/io/ObjectOutputStream$HandleTable
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/io
type FrameType
JIT compiled
bytecodeIndex int
2
lineNumber int
78
method Method
descriptor string
(Ljava/lang/Class;I)Ljava/lang/Object;
hidden boolean
false
modifiers int
9
name string
newInstance
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/reflect/Array
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang/reflect
type FrameType
Inlined

StackTrace

Stacktrace

Field Type Description
truncated boolean Truncated
frames array StackFrame struct Stack Frames

Symbol

Symbol

Field Type Description
string string String

Examples 3
file:///home/runner/work/jfrevents/jfrevents/harness-003928-7951762178349451551/twitter-finagle/lib/netty-buffer-4.1.99.Final.jar
file:///home/runner/work/jfrevents/jfrevents/harness-003927-11018005009666797249/apache-spark/lib/netty-buffer-4.1.99.Final.jar
file:///home/runner/work/jfrevents/jfrevents/harness-003916-17833306698725904421/apache-spark/lib/netty-buffer-4.1.99.Final.jar

Thread

Thread

Field Type Description
osName string OS Thread Name
osThreadId long OS Thread Id
javaName string Java Thread Name
javaThreadId long Java Thread Id
group ThreadGroup Java Thread Group
virtual boolean 19+ Virtual Thread

ThreadGroup

Thread Group

Field Type Description
parent ThreadGroup Parent
name string Name

Examples 3
null
name string
system
parent ThreadGroup
null
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null

ThreadState

Java Thread State

Field Type Description
name string Name

Examples 3
STATE_RUNNABLE
STATE_RUNNABLE
STATE_RUNNABLE

VMOperationType

VM Operation Type

Field Type Description
type string Type

Examples 3
HandshakeAllThreads
ClassLoaderStatsOperation
GC_HeapInspection

VMThreadState

25+

JVM Thread State

Field Type Description
state string State

VirtualSpace

Field Type Description
start ulong: address Start Address Start address of the virtual space
committedEnd ulong: address Committed End Address End address of the committed memory for the virtual space
committedSize ulong: bytes Committed Size Size of the committed memory for the virtual space
reservedEnd ulong: address Reserved End Address End address of the reserved memory for the virtual space
reservedSize ulong: bytes Reserved Size Size of the reserved memory for the virtual space

Examples 3
committedEnd ulong: address
31729909760
committedSize ulong: bytes
1564475392
reservedEnd ulong: address
32961986560
reservedSize ulong: bytes
2796552192
start ulong: address
30165434368
committedEnd ulong: address
31144804352
committedSize ulong: bytes
979369984
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4194304000
start ulong: address
30165434368
committedEnd ulong: address
33047445504
committedSize ulong: bytes
2882011136
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4194304000
start ulong: address
30165434368

ZPageTypeType

15+

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Z Page Type

Field Type Description
type string Type

Examples 1
Small

ZStatisticsCounterType

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Z Statistics Counter

Field Type Description
counter string Counter

Examples 1
Allocation Rate

ZStatisticsSamplerType

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Z Statistics Sampler

Field Type Description
sampler string Sampler

Examples 1
Page Cache Hit L2

XML Content Types

address

Annotation: jdk.jfr.MemoryAddress

Examples 3
30454841344
30318888256
30165434368

bits-per-second

Annotation: jdk.jfr.DataAmount(BITS), jdk.jfr.Frequency

Examples 3
37464
14496
8264

bytes

Annotation: jdk.jfr.DataAmount(BYTES)

Examples 3
196136
56
0

bytes-per-second

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Annotation: jdk.jfr.DataAmount(BYTES), jdk.jfr.Frequency

Examples 2
0.0
2.4814065956924498E8

certificateId

Annotation: jdk.jfr.events.CertificateId

Examples 3
3045411335
3045411335
3045411335

epochmillis

Annotation: jdk.jfr.Timestamp(MILLISECONDS_SINCE_EPOCH)

Examples 3
1767487166908
1767487167450
-9223372036854775808

hertz

Annotation: jdk.jfr.Frequency

Examples 3
1000000000
1000000000
6984.4907

microseconds

17+

Annotation: jdk.jfr.Timespan(MICROSECONDS)

millis

Annotation: jdk.jfr.Timespan(MILLISECONDS)

Examples 3
275178389026
305062413344
278744692944

nanos

Annotation: jdk.jfr.Timespan(NANOSECONDS)

Examples 3
199999999
99999910
10000000

percentage

Annotation: jdk.jfr.Percentage

Examples 3
0.93430656
0.01459854
0.9002433

tickspan

Annotation: jdk.jfr.Timespan(TICKS)

Examples 3
159030622
3186709
10848898807

tickstamp

Annotation: jdk.jfr.Timestamp(TICKS)

XML Types

Class

Parameter Type const Klass*
Field Type const Klass*
Java Type java.lang.Class
Examples 3
null
null
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[F
package Package
null

ClassLoader

Parameter Type const ClassLoaderData*
Field Type const ClassLoaderData*
Examples 3
name string
bootstrap
type Class
null
name string
bootstrap
type Class
null
name string
bootstrap
type Class
null

Method

Parameter Type const Method*
Field Type const Method*
Examples 3
descriptor string
()V
hidden boolean
false
modifiers int
2
name string
growEntries
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
26
name string
java/io/ObjectOutputStream$HandleTable
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/io
descriptor string
(Ljava/lang/Class;I)Ljava/lang/Object;
hidden boolean
false
modifiers int
9
name string
newInstance
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/reflect/Array
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang/reflect
descriptor string
(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden boolean
false
modifiers int
1
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/lang/System$2
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang

Module

Parameter Type const ModuleEntry*
Field Type const ModuleEntry*
Examples 3
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9

Package

Parameter Type const PackageEntry*
Field Type const PackageEntry*
Examples 3
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/io
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
null

StackTrace

15+

Parameter Type u8
Field Type u8
Java Type jdk.types.StackTrace
Examples 3
frames StackFrame
bytecodeIndex int
2
lineNumber int
2577
method Method
descriptor string
(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden boolean
false
modifiers int
1
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/lang/System$2
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Inlined
truncated boolean
false
frames StackFrame
bytecodeIndex int
2
lineNumber int
78
method Method
descriptor string
(Ljava/lang/Class;I)Ljava/lang/Object;
hidden boolean
false
modifiers int
9
name string
newInstance
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/reflect/Array
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang/reflect
type FrameType
Inlined
truncated boolean
true
frames StackFrame
bytecodeIndex int
11
lineNumber int
2371
method Method
descriptor string
()V
hidden boolean
false
modifiers int
2
name string
growEntries
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
26
name string
java/io/ObjectOutputStream$HandleTable
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/io
type FrameType
JIT compiled
truncated boolean
false

Thread

Parameter Type u8
Field Type u8
Java Type java.lang.Thread
Examples 3
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-75
javaThreadId long
1319
osName string
block-manager-storage-async-thread-pool-75
osThreadId long
3921
virtual boolean
false
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-77
javaThreadId long
1321
osName string
block-manager-storage-async-thread-pool-77
osThreadId long
3923
virtual boolean
false
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-71
javaThreadId long
1308
osName string
block-manager-storage-async-thread-pool-71
osThreadId long
4565
virtual boolean
false

Ticks

unsigned

Appearing in: G1GC, ParallelGC, SerialGC, ZGC

Missing in: ShenandoahGC

Parameter Type const Ticks&
Field Type Ticks
Java Type long
Content Type tickstamp
Examples 3
330226165751
356487792667
484304776660

Tickspan

unsigned

Parameter Type const Tickspan&
Field Type Tickspan
Java Type long
Content Type tickspan

boolean

Parameter Type bool
Field Type bool
Java Type boolean
Examples 3
false
true
false

byte

Parameter Type s1
Field Type s1
Java Type byte

char

Parameter Type char
Field Type char
Java Type char

double

Parameter Type double
Field Type double
Java Type double
Examples 3
1.5625
1.5625
10.0

float

Parameter Type float
Field Type float
Java Type float
Examples 3
4.3608637
4.3553925
2.088268

int

Parameter Type s4
Field Type s4
Java Type int
Examples 3
-1
0
1

long

Parameter Type s8
Field Type s8
Java Type long
Examples 3
3
23649
479

short

Parameter Type s2
Field Type s2
Java Type short

string

Parameter Type const char*
Field Type const char*
Java Type java.lang.String
Examples 3
bootstrap
null
null

ubyte

unsigned

Parameter Type u1
Field Type u1
Java Type byte
Examples 3
32
7
15

uint

unsigned

Parameter Type unsigned
Field Type unsigned
Java Type int
Examples 3
973
138
962

ulong

unsigned

Parameter Type u8
Field Type u8
Java Type long
Examples 3

ushort

unsigned

Parameter Type u2
Field Type u2
Java Type short
Examples 3