Introduction

The following are the events for OpenJDK 24 (jdk-24+24, permalink, 15-November-2024), and Graal VM 24.2.0 (jdk-24+24) . 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

default profiling startTime 11 17 21 23 24

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:

static void post_events(bool exception_handler, Thread* thread) {
  if (exception_handler) {
    EventShutdown e;
    e.set_reason("VM Error");
    e.commit();
  } else {
    // OOM
    LeakProfiler::emit_events(max_jlong, false, false);
  }
  EventDumpReason event;
  event.set_reason(exception_handler ? "Crash" : "Out of Memory");
  event.set_recordingId(-1);
  event.commit();
}

void JfrEmergencyDump::on_vm_shutdown(bool exception_handler) {
  if (!guard_reentrancy()) {
    return;
  }
  Thread* thread = Thread::current_or_null_safe();
  if (thread == nullptr) {

Configuration enabled
default true
profiling 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

default profiling startTime 11 17 21 23 24 graal vm

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/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();

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

JVM_ENTRY_NO_ENV(jlong, jfr_host_total_swap_memory(JNIEnv* env, jclass jvm))
#ifdef LINUX
  // We want the host swap memory, not the container value.
  return os::Linux::host_swap();
#else
  return os::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))

Configuration enabled
default true
profiling 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 23 24

Category: Flight Recorder

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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
default false 0 ns
profiling false 0 ns

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

Examples 3
elements ulong
3039
flushId ulong
641
size ulong: bytes
611382
startTime long: millis
853254851833
elements ulong
795
flushId ulong
57
size ulong: bytes
280649
startTime long: millis
60476668667
elements ulong
121
flushId ulong
57
size ulong: bytes
80352
startTime long: millis
63802914917

ActiveRecording

default profiling startTime duration stackTrace 11 17 21 23 24

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

Category: Flight Recorder

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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/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,

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()) {
                    WriteableUserPath 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()
                    );

Configuration enabled
default true
profiling true

Field Type Description
id long Id
name string Name Consider contributing a description to jfreventcollector.
destination string Destination Consider contributing a description to jfreventcollector.
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
[...]/code/experiments/jfreventcollector/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
1702899886817
stackTrace StackTrace
null
startTime long: millis
17888392958
destination string
[...]/code/experiments/jfreventcollector/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
1727266203142
startTime long: millis
842439355708
destination string
[...]/code/experiments/jfreventcollector/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
1702899981921
stackTrace StackTrace
null
startTime long: millis
84412629542

ActiveSetting

default profiling startTime duration stackTrace 11 17 21 23 24

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

Category: Flight Recorder

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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/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,

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/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/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")

Configuration enabled
default true
profiling true

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

Examples 3
id long
13
name string
threshold
stackTrace StackTrace
null
startTime long: millis
360834042
value string
10 ms
id long
62
name string
enabled
startTime long: millis
791746993083
value string
true
id long
40
name string
stackTrace
stackTrace StackTrace
null
startTime long: millis
416785542
value string
true

JVM

JVMInformation

default profiling startTime duration end of every chunk 11 17 21 23 24 graal vm

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
default true beginChunk
profiling 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
[...]/code/experiments/jfreventcollector/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=[...]/code/experiments/jfreventcollector/jfr/sample_UseParallelGC.jfr,settings=[...]/code/experiments/jfreventcollector/.cache/jfc.jfc -XX:+UseParallelGC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1702899886436
jvmVersion string
OpenJDK 64-Bit Server VM (21.0.1+12-LTS) for bsd-aarch64 JRE (21.0.1+12-LTS), built on 2023-10-17T00:00:00Z by "admin" with clang Apple LLVM 12.0.0 (clang-1200.0.32.29)
pid long
13981
startTime long: millis
30585938083
javaArguments string
[...]/code/experiments/jfreventcollector/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=[...]/code/experiments/jfreventcollector/jfr/sample_UseG1GC.jfr,settings=[...]/code/experiments/jfreventcollector/.cache/jfc.jfc -XX:+UseG1GC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1727266202802
jvmVersion string
OpenJDK 64-Bit Server VM (22+36) for bsd-aarch64 JRE (22+36), built on 2024-03-13T13:18:01Z by "sapmachine" with clang Apple LLVM 13.0.0 (clang-1300.0.29.3)
pid long
26284
startTime long: millis
889511371750
javaArguments string
[...]/code/experiments/jfreventcollector/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=[...]/code/experiments/jfreventcollector/jfr/sample_UseSerialGC.jfr,settings=[...]/code/experiments/jfreventcollector/.cache/jfc.jfc -XX:+UseSerialGC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1702899981604
jvmVersion string
OpenJDK 64-Bit Server VM (21.0.1+12-LTS) for bsd-aarch64 JRE (21.0.1+12-LTS), built on 2023-10-17T00:00:00Z by "admin" with clang Apple LLVM 12.0.0 (clang-1200.0.32.29)
pid long
14273
startTime long: millis
364229792

InitialSystemProperty

default profiling startTime end of every chunk 11 17 21 23 24 graal vm

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
default true beginChunk
profiling true beginChunk

Field Type Description
key string Key
value string Value

Examples 3
key string
java.class.path
startTime long: millis
75961241583
value string
[...]/code/experiments/jfreventcollector/.cache/renaissance.jar
key string
java.vm.compressedOopsMode
startTime long: millis
30585953875
value string
Zero based
key string
sun.java.command
startTime long: millis
839577529750
value string
[...]/code/experiments/jfreventcollector/.cache/renaissance.jar -t 5 -r 1 all

JVM: Class Loading

ClassLoad

startTime duration eventThread stackTrace 11 17 21 23 24

Category: Java Virtual Machine / Class Loading

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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/classfile/systemDictionaryShared.cpp:

  InstanceKlass* loaded_lambda =
    SystemDictionary::load_shared_lambda_proxy_class(lambda_ik, class_loader, protection_domain, pkg_entry, CHECK_NULL);

  if (loaded_lambda == nullptr) {
    return nullptr;
  }

  // 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_start_event;

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

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

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

        InstanceKlass* check = loader_data->dictionary()->find_class(current, name);
        if (check != nullptr) {
          // Klass is already loaded, so just return it
          return check;
        }
        // check if other thread failed to load and cleaned up
        oldprobe = PlaceholderTable::get_entry(name, loader_data);
      }
    }
  }
  return nullptr;
}

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();
}

// 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,
                                                                Handle protection_domain,
                                                                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_start_event;

  HandleMark hm(THREAD);

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

  // Do lookup to see if class already exists and the protection domain
  // has the right access.
  // This call uses find which checks protection domain already matches
  // All subsequent calls use find_class, and set loaded_class so that
  // before we return a result, we call out to java to check for valid protection domain.

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_start_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");
  assert(st->need_verify(), "invariant");

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;

class SystemDictionary : AllStatic {
  friend class BootstrapInfo;
  friend class vmClasses;
  friend class VMStructs;

 public:

  // Returns a class with a given class name and class loader.  Loads the
  // class if needed. If not found a NoClassDefFoundError or a

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

  static bool check_shared_class_super_type(InstanceKlass* klass, InstanceKlass* super,
                                            Handle class_loader,  Handle protection_domain,
                                            bool is_superclass, TRAPS);
  static bool check_shared_class_super_types(InstanceKlass* ik, Handle class_loader,
                                               Handle protection_domain, TRAPS);
  // Second part of load_shared_class
  static void load_shared_class_misc(InstanceKlass* ik, ClassLoaderData* loader_data) NOT_CDS_RETURN;

protected:
  // Used by SystemDictionaryShared

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

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

Field Type Description
loadedClass Class Loaded Class Consider contributing a description to jfreventcollector.
definingClassLoader ClassLoader Defining Class Loader Consider contributing a description to jfreventcollector.
initiatingClassLoader ClassLoader Initiating Class Loader Consider contributing a description to jfreventcollector.

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
22
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
22
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
22
name string
java/net
hidden boolean
true
modifiers int
4112
name string
org.apache.spark.ml.recommendation.ALS$$$Lambda+0x000007f8063848c0/738672526
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
22
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/ml/recommendation
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/Class;Ljava/lang/String;[BIILjava/security/ProtectionDomain;ZILjava/lang/Object;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass0
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
22
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
842421122542
definingClassLoader ClassLoader
name string
bootstrap
type Class
null
initiatingClassLoader ClassLoader
name string
bootstrap
type Class
null
loadedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1057
name string
java/text/spi/DecimalFormatSymbolsProvider
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
21.0.1
name string
java/text/spi
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
181
method Method
descriptor string
(Ljava/util/Locale;)Ljava/text/DecimalFormatSymbols;
hidden boolean
false
modifiers int
25
name string
getInstance
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/text/DecimalFormatSymbols
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
21.0.1
name string
java/text
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
398629792
definingClassLoader ClassLoader
name string
bootstrap
type Class
null
initiatingClassLoader ClassLoader
name string
bootstrap
type Class
null
loadedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/util/logging/StreamHandler
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.logging
name string
java.logging
version string
21.0.1
name string
java/util/logging
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/String;)Ljava/lang/Class;
hidden boolean
false
modifiers int
266
name string
findBootstrapClass
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1057
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
21.0.1
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
450472583

ClassDefine

startTime eventThread stackTrace 11 17 21 23 24

Category: Java Virtual Machine / Class Loading

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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/classfile/systemDictionary.cpp:

    // before references to the initiating class loader.
    loader_data->record_dependency(loaded_class);

    update_dictionary(THREAD, loaded_class, loader_data);

    if (JvmtiExport::should_post_class_load()) {
      JvmtiExport::post_class_load(THREAD, loaded_class);
    }
  }
  return loaded_class;
}

static void post_class_define_event(InstanceKlass* k, const ClassLoaderData* def_cld) {
  EventClassDefine event;
  if (event.should_commit()) {
    event.set_definedClass(k);
    event.set_definingClassLoader(def_cld);
    event.commit();
  }
}

void SystemDictionary::define_instance_class(InstanceKlass* k, Handle class_loader, TRAPS) {

  ClassLoaderData* loader_data = k->class_loader_data();
  assert(loader_data->class_loader() == class_loader(), "they must be the same");

Configuration enabled stackTrace
default false true
profiling false true

Field Type Description
definedClass Class Defined Class Consider contributing a description to jfreventcollector.
definingClassLoader ClassLoader Defining Class Loader Consider contributing a description to jfreventcollector.

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
22
name string
java/net
hidden boolean
false
modifiers int
17
name string
org/apache/spark/sql/SQLImplicits$$typecreator1$18
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
22
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/sql
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
22
name string
java/net
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass1
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1025
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
22
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
843436850500
definedClass Class
classLoader ClassLoader
name string
app
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
jdk/internal/loader/ClassLoaders$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
21.0.1
name string
jdk/internal/loader
hidden boolean
false
modifiers int
48
name string
org/renaissance/core/ModuleLoader$ModuleLoadingException
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
app
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
jdk/internal/loader/ClassLoaders$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
21.0.1
name string
jdk/internal/loader
location string
null
name string
null
version string
null
name string
org/renaissance/core
definingClassLoader ClassLoader
name string
app
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
jdk/internal/loader/ClassLoaders$AppClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
jdk/internal/loader
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass1
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1057
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.1
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
449276708
definedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
32
name string
java/util/jar/Manifest$FastInputStream
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
21.0.1
name string
java/util/jar
definingClassLoader ClassLoader
name string
bootstrap
type Class
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
287
method Method
descriptor string
(Ljava/io/InputStream;Ljava/lang/String;)V
hidden boolean
false
modifiers int
2
name string
read
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
java/util/jar/Manifest
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
21.0.1
name string
java/util/jar
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
380962583

ClassRedefinition

default profiling startTime 15 17 21 23 24

Category: Java Virtual Machine / Class Loading

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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
    log_info(redefine, class, load)

Configuration enabled
default true
profiling true

Field Type Description
redefinedClass Class Redefined Class Consider contributing a description to jfreventcollector.
classModificationCount int Class Modification Count The number of times the class has changed
redefinitionId ulong Class Redefinition Id

RedefineClasses

default profiling startTime duration eventThread stackTrace 15 17 21 23 24

Category: Java Virtual Machine / Class Loading

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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
default true true 0 ms
profiling true true 0 ms

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

RetransformClasses

default profiling startTime duration eventThread stackTrace 15 17 21 23 24

Category: Java Virtual Machine / Class Loading

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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
default true true 0 ms
profiling true true 0 ms

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

ClassUnload

startTime eventThread 11 17 21 23 24

Category: Java Virtual Machine / Class Loading

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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
default false
profiling false

Field Type Description
unloadedClass Class Unloaded Class Consider contributing a description to jfreventcollector.
definingClassLoader ClassLoader Defining Class Loader Consider contributing a description to jfreventcollector.

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
22
name string
java/net
startTime long: millis
852482750250
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
22
name string
java/net
hidden boolean
false
modifiers int
25
name string
scala/collection/mutable/ArraySeq$ofDouble
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
22
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection/mutable
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
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
21.0.1
name string
java/net
startTime long: millis
3889474167
unloadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
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
21.0.1
name string
java/net
hidden boolean
false
modifiers int
48
name string
org/sparkproject/guava/collect/Hashing
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
33
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
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
org/sparkproject/guava/collect
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
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
21.0.1
name string
java/net
startTime long: millis
4558828458
unloadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
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
21.0.1
name string
java/net
hidden boolean
false
modifiers int
1057
name string
org/sparkproject/guava/collect/ImmutableList
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
33
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
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
org/sparkproject/guava/collect

JVM: Code Cache

CodeCacheFull

default profiling startTime eventThread 11 17 21 23 24

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
default true
profiling true

Field Type Description
codeBlobType CodeBlobType Code Heap Consider contributing a description to jfreventcollector.
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

default profiling startTime every chunk 11 17 21 23 24

Category: Java Virtual Machine / Code Cache

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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
default true everyChunk
profiling true everyChunk

Field Type Description
codeBlobType CodeBlobType Code Heap Consider contributing a description to jfreventcollector.
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
627
codeBlobType CodeBlobType
CodeHeap 'non-nmethods'
entryCount int
718
fullCount int
0
methodCount int
0
reservedTopAddress ulong: address
5094801408
startAddress ulong: address
5088952320
startTime long: millis
39031425083
unallocatedCapacity ulong: bytes
4356352
adaptorCount int
0
codeBlobType CodeBlobType
CodeHeap 'profiled nmethods'
entryCount int
5962
fullCount int
0
methodCount int
5962
reservedTopAddress ulong: address
4604248064
startAddress ulong: address
4481351680
startTime long: millis
96451884375
unallocatedCapacity ulong: bytes
106338560
adaptorCount int
0
codeBlobType CodeBlobType
CodeHeap 'profiled nmethods'
entryCount int
7008
fullCount int
0
methodCount int
7008
reservedTopAddress ulong: address
4668653568
startAddress ulong: address
4545757184
startTime long: millis
881142797625
unallocatedCapacity ulong: bytes
101689088

CodeCacheConfiguration

default profiling startTime end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Code Cache

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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
default true beginChunk
profiling 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
5839564
nonProfiledSize ulong: bytes
122909338
profiledSize ulong: bytes
122909338
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
5217714176
startAddress ulong: address
4966055936
startTime long: millis
93747386417
expansionSize ulong: bytes
65536
initialSize ulong: bytes
2555904
minBlockLength ulong: bytes
6
nonNMethodSize ulong: bytes
5839564
nonProfiledSize ulong: bytes
122909338
profiledSize ulong: bytes
122909338
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
4733009920
startAddress ulong: address
4481351680
startTime long: millis
96717754667
expansionSize ulong: bytes
65536
initialSize ulong: bytes
2555904
minBlockLength ulong: bytes
6
nonNMethodSize ulong: bytes
5839564
nonProfiledSize ulong: bytes
122909338
profiledSize ulong: bytes
122909338
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
4797415424
startAddress ulong: address
4545757184
startTime long: millis
917994311208

JVM: Compiler

JITRestart

default profiling startTime eventThread 17 21 23 24

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
default true
profiling true

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

Compilation

default profiling startTime duration eventThread 11 17 21 23 24

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/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/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.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/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);

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;
        }

Configuration enabled threshold
default true 1000 ms
profiling true 100 ms

Field Type Description
compileId int Compilation Identifier
compiler CompilerType 14+ Compiler Consider contributing a description to jfreventcollector.
method Method Method Consider contributing a description to jfreventcollector.
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
188648
compileId int
6965
compileLevel ushort
2
compiler CompilerType
c1
inlinedBytes ulong: bytes
8029
isOsr boolean
false
method Method
descriptor string
()V
hidden boolean
false
modifiers int
2
name string
finishTerminate
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
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
21.0.1
name string
java/net
hidden boolean
false
modifiers int
1537
name string
akka/actor/dungeon/FaultHandling
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
33
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
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
akka/actor/dungeon
startTime long: millis
14262930583
succeded boolean
true
codeSize ulong: bytes
4528
compileId int
16161
compileLevel ushort
4
compiler CompilerType
c2
inlinedBytes ulong: bytes
502
isOsr boolean
false
method Method
descriptor string
(Lcom/twitter/finagle/http/HeaderMap;)V
hidden boolean
false
modifiers int
2
name string
removeAllHeaders
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
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
21.0.1
name string
java/net
hidden boolean
false
modifiers int
49
name string
com/twitter/finagle/http/TraceInfo$
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
33
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
21.0.1
name string
java/net
location string
null
name string
null
version string
null
name string
com/twitter/finagle/http
startTime long: millis
50112762750
succeded boolean
true
codeSize ulong: bytes
6536
compileId int
85884
compileLevel ushort
3
compiler CompilerType
c1
inlinedBytes ulong: bytes
131
isOsr boolean
false
method Method
descriptor string
(Lscala/concurrent/duration/Duration;)Lscala/util/Try;
hidden boolean
false
modifiers int
18
name string
tryAwait0
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
22
name string
java/net
hidden boolean
false
modifiers int
9
name string
scala/concurrent/impl/Promise$DefaultPromise
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
22
name string
java/net
location string
null
name string
null
version string
null
name string
scala/concurrent/impl
startTime long: millis
795912961375
succeded boolean
true

CompilerPhase

default profiling startTime duration eventThread 11 17 21 23 24

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
default true 60 s
profiling true 10 s

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

CompilationFailure

profiling startTime eventThread 11 17 21 23 24

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:

// ------------------------------------------------------------------
// ciEnv::record_failure()
void ciEnv::record_failure(const char* reason) {
  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
default false
profiling true

Field Type Description
failureMessage string Failure Message
compileId int Compilation Identifier

Examples 3
compileId int
22930
failureMessage string
concurrent class loading
startTime long: millis
74091028458
compileId int
3706
failureMessage string
concurrent class loading
startTime long: millis
3613493750
compileId int
99696
failureMessage string
concurrent class loading
startTime long: millis
890105317542

CompilerInlining

startTime eventThread 11 17 21 23 24

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/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/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/opto/bytecodeInfo.cpp:

  CompileTask::print_inlining_ul(callee_method, inline_level(),
                                 caller_bci, inlining_result_of(success), inline_msg);
  if (C->print_inlining()) {
    C->print_inlining(callee_method, inline_level(), caller_bci, inlining_result_of(success), inline_msg);
    guarantee(callee_method != nullptr, "would crash in CompilerEvent::InlineEvent::post");
    if (Verbose) {
      const InlineTree *top = this;
      while (top->caller_tree() != nullptr) { top = top->caller_tree(); }
      //tty->print("  bcs: %d+%d  invoked: %d", top->count_inline_bcs(), callee_method->code_size(), callee_method->interpreter_invocation_count());
    }
  }
  EventCompilerInlining event;
  if (event.should_commit()) {
    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!");
  // Make sure the incoming jvms has the same information content as me.

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
default false
profiling 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
64
callee CalleeMethod
descriptor string
()Ljava/lang/Object;
name string
value
type string
scala/collection/mutable/LinkedHashMap$LinkedEntry
caller Method
descriptor string
(Ljava/lang/Object;)Lscala/Option;
hidden boolean
false
modifiers int
1
name string
get
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
22
name string
java/net
hidden boolean
false
modifiers int
1
name string
scala/collection/mutable/LinkedHashMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
22
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection/mutable
compileId int
85847
message string
accessor
startTime long: millis
794959214917
succeeded boolean
true
bci int
6
callee CalleeMethod
descriptor string
()V
name string
<init>
type string
java/lang/Object
caller Method
descriptor string
(Ljava/util/HashMap;)V
hidden boolean
false
modifiers int
0
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1056
name string
java/util/HashMap$HashIterator
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
21.0.1
name string
java/util
compileId int
1461
message string
inline
startTime long: millis
413531125
succeeded boolean
true
bci int
70
callee CalleeMethod
descriptor string
(D)J
name string
doubleToRawLongBits
type string
java/lang/Double
caller Method
descriptor string
(DDDD)D
hidden boolean
false
modifiers int
10
name string
floorOrCeil
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
49
name string
java/lang/StrictMath
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
21.0.1
name string
java/lang
compileId int
1424
message string
intrinsic
startTime long: millis
361516000
succeeded boolean
true

Deoptimization

default profiling startTime eventThread stackTrace 14 17 21 23 24

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
default true false
profiling true true

Field Type Description
compileId int Compilation Identifier
compiler CompilerType Compiler Consider contributing a description to jfreventcollector.
method Method Method Consider contributing a description to jfreventcollector.
lineNumber int Line Number
bci int Bytecode Index
instruction Bytecode Instruction Consider contributing a description to jfreventcollector.
reason DeoptimizationReason Reason Consider contributing a description to jfreventcollector.
action DeoptimizationAction Action Consider contributing a description to jfreventcollector.

Examples 3
action DeoptimizationAction
maybe_recompile
bci int
19
compileId int
3410
compiler CompilerType
c2
instruction Bytecode
if_icmpge
lineNumber int
285
method Method
descriptor string
(Ljava/nio/ByteBuffer;ILjava/lang/String;I)I
hidden boolean
false
modifiers int
8
name string
stringFromByteBufferMatches
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
jdk/internal/jimage/ImageStringsReader
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
21.0.1
name string
jdk/internal/jimage
reason DeoptimizationReason
profile_predicate
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
19
lineNumber int
285
method Method
descriptor string
(Ljava/nio/ByteBuffer;ILjava/lang/String;I)I
hidden boolean
false
modifiers int
8
name string
stringFromByteBufferMatches
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
33
name string
jdk/internal/jimage/ImageStringsReader
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
21.0.1
name string
jdk/internal/jimage
type FrameType
Inlined
truncated boolean
false
startTime long: millis
2842585875
action DeoptimizationAction
reinterpret
bci int
128
compileId int
88221
compiler CompilerType
c2
instruction Bytecode
ifnonnull
lineNumber int
463
method Method
descriptor string
(Ljava/lang/Object;Lscala/Function0;)Ljava/lang/Object;
hidden boolean
false
modifiers int
1
name string
getOrElseUpdate
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
22
name string
java/net
hidden boolean
false
modifiers int
1
name string
scala/collection/mutable/HashMap
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
22
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection/mutable
reason DeoptimizationReason
unstable_if
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
128
lineNumber int
463
method Method
descriptor string
(Ljava/lang/Object;Lscala/Function0;)Ljava/lang/Object;
hidden boolean
false
modifiers int
1
name string
getOrElseUpdate
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
22
name string
java/net
hidden boolean
false
modifiers int
1
name string
scala/collection/mutable/HashMap
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
22
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection/mutable
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
852249351042
action DeoptimizationAction
maybe_recompile
bci int
19
compileId int
3137
compiler CompilerType
c2
instruction Bytecode
invokeinterface
lineNumber int
526
method Method
descriptor string
(Ljava/util/stream/Sink;Ljava/util/Spliterator;)Z
hidden boolean
false
modifiers int
16
name string
copyIntoWithCancel
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1056
name string
java/util/stream/AbstractPipeline
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
21.0.1
name string
java/util/stream
reason DeoptimizationReason
class_check
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
19
lineNumber int
526
method Method
descriptor string
(Ljava/util/stream/Sink;Ljava/util/Spliterator;)Z
hidden boolean
false
modifiers int
16
name string
copyIntoWithCancel
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1056
name string
java/util/stream/AbstractPipeline
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
21.0.1
name string
java/util/stream
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
2225661375

CompilerQueueUtilization

default profiling startTime duration every chunk 22 23 24

Category: Java Virtual Machine / Compiler

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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
default true 10 s
profiling true 5 s

Field Type Description
compiler CompilerType Compiler Consider contributing a description to jfreventcollector.
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

Examples 1
addedCount long
1753
addedRate long: hertz
317
compiler CompilerType
c1
compilerThreadCount int
1
peakQueueSize long
206
queueSize long
3
removedCount long
1750
removedRate long: hertz
316
startTime long: millis
884659135708
totalAddedCount long
73574
totalRemovedCount long
73571

CompilerStatistics

default profiling startTime every chunk 11 17 21 23 24

Category: Java Virtual Machine / Compiler

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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
default true 1000 ms
profiling 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
2
compileCount int
19439
invalidatedCount int
0
nmethodCodeSize ulong: bytes
23170752
nmethodsSize ulong: bytes
36379136
osrBytesCompiled ulong: bytes
0
osrCompileCount int
180
peakTimeSpent long: millis
1360
standardBytesCompiled ulong: bytes
0
standardCompileCount int
19259
startTime long: millis
76343286417
totalTimeSpent long: millis
63681
bailoutCount int
11
compileCount int
95597
invalidatedCount int
0
nmethodCodeSize ulong: bytes
124792200
nmethodsSize ulong: bytes
188081456
osrBytesCompiled ulong: bytes
0
osrCompileCount int
1126
peakTimeSpent long: millis
10885
standardBytesCompiled ulong: bytes
0
standardCompileCount int
94471
startTime long: millis
893921690042
totalTimeSpent long: millis
406908
bailoutCount int
4
compileCount int
32641
invalidatedCount int
0
nmethodCodeSize ulong: bytes
42788472
nmethodsSize ulong: bytes
65397632
osrBytesCompiled ulong: bytes
0
osrCompileCount int
235
peakTimeSpent long: millis
953
standardBytesCompiled ulong: bytes
0
standardCompileCount int
32406
startTime long: millis
81087491500
totalTimeSpent long: millis
60848

CompilerConfiguration

default profiling startTime end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Compiler

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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
default true beginChunk
profiling 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
30519906375
threadCount int
4
tieredCompilation boolean
true
dynamicCompilerThreadCount boolean
true
startTime long: millis
30586816333
threadCount int
4
tieredCompilation boolean
true
dynamicCompilerThreadCount boolean
true
startTime long: millis
833251960792
threadCount int
4
tieredCompilation boolean
true

JVM: Diagnostics

SyncOnValueBasedClass

experimental default profiling startTime eventThread stackTrace 16 17 21 23 24

Category: Java Virtual Machine / Diagnostics

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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
default true true
profiling true true

Field Type Description
valueBasedClass Class Value Based Class Consider contributing a description to jfreventcollector.

HeapDump

default profiling startTime duration eventThread stackTrace 15 17 21 23 24

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:

  if (_oome && num_dump_threads > 1) {
    // Each additional parallel writer requires several MB of internal memory
    // (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.
    julong max_threads = os::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
default true true 0 ns
profiling 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

default profiling startTime end of every chunk 21 23 24

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) {
  const 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(const 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
default true endChunk
profiling 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

default profiling startTime end of every chunk 21 23 24

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:

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

Configuration enabled period
default true endChunk
profiling 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

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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
default true
profiling true

Field Type Description
name string Name
oldValue int Old Value
newValue int New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

UnsignedIntFlagChanged

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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
default true
profiling true

Field Type Description
name string Name
oldValue uint Old Value
newValue uint New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

LongFlagChanged

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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=" INTX_FORMAT " is outside the allowed range "
                        "[ " INTX_FORMAT " ... " INTX_FORMAT " ]\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
default true
profiling true

Field Type Description
name string Name
oldValue long Old Value
newValue long New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

UnsignedLongFlagChanged

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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("[ " INTX_FORMAT_W(-25) " ... " INTX_FORMAT_W(25) " ]", min, max);
  }
  void print_default_range(outputStream* st) const {
    st->print("[ " INTX_FORMAT_W(-25) " ... " INTX_FORMAT_W(25) " ]", 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=" UINTX_FORMAT " is outside the allowed range "
                        "[ " UINTX_FORMAT " ... " UINTX_FORMAT " ]\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("[ " UINTX_FORMAT_W(-25) " ... " UINTX_FORMAT_W(25) " ]", min, max);
  }
  void print_default_range(outputStream* st) const {
    st->print("[ " UINTX_FORMAT_W(-25) " ... " UINTX_FORMAT_W(25) " ]", 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=" SIZE_FORMAT " is outside the allowed range "
                        "[ " SIZE_FORMAT " ... " SIZE_FORMAT " ]\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
default true
profiling true

Field Type Description
name string Name
oldValue ulong Old Value
newValue ulong New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

DoubleFlagChanged

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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("[ " SIZE_FORMAT_W(-25) " ... " SIZE_FORMAT_W(25) " ]", min, max);
  }
  void print_default_range(outputStream* st) const {
    st->print("[ " SIZE_FORMAT_W(-25) " ... " SIZE_FORMAT_W(25) " ]", 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
default true
profiling true

Field Type Description
name string Name
oldValue double Old Value
newValue double New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

BooleanFlagChanged

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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
default true
profiling true

Field Type Description
name string Name
oldValue boolean Old Value
newValue boolean New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

StringFlagChanged

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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:

JVMFlag::Error JVMFlagAccess::set_impl(JVMFlag* flag, void* value, JVMFlagOrigin origin) {
  if (flag->is_ccstr()) {
    return set_ccstr(flag, (ccstr*)value, origin);
  } else {
    return access_impl(flag)->set(flag, value, origin);
  }
}

JVMFlag::Error JVMFlagAccess::set_ccstr(JVMFlag* flag, ccstr* value, JVMFlagOrigin origin) {
  if (flag == nullptr) return JVMFlag::INVALID_FLAG;
  if (!flag->is_ccstr()) return JVMFlag::WRONG_FORMAT;
  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
default true
profiling true

Field Type Description
name string Name
oldValue string Old Value
newValue string New Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

IntFlag

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value int Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
DeoptimizeObjectsALotThreadCountAll
origin FlagValueOrigin
Default
startTime long: millis
39268373833
value int
1
name string
JavaPriority6_To_OSPriority
origin FlagValueOrigin
Default
startTime long: millis
40031147583
value int
-1
name string
UnguardOnExecutionViolation
origin FlagValueOrigin
Default
startTime long: millis
798681836333
value int
0

UnsignedIntFlag

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value uint Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
G1RemSetArrayOfCardsEntriesBase
origin FlagValueOrigin
Default
startTime long: millis
364799833
value uint
8
name string
ErrorHandlerTest
origin FlagValueOrigin
Default
startTime long: millis
30586825083
value uint
0
name string
TargetPLABWastePct
origin FlagValueOrigin
Default
startTime long: millis
791773035708
value uint
10

LongFlag

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value long Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
Tier3MinInvocationThreshold
origin FlagValueOrigin
Default
startTime long: millis
364811083
value long
100
name string
C1InlineStackLimit
origin FlagValueOrigin
Default
startTime long: millis
423468208
value long
5
name string
Tier2BackedgeNotifyFreqLog
origin FlagValueOrigin
Default
startTime long: millis
791773047292
value long
14

UnsignedLongFlag

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value ulong Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
AdaptiveSizePolicyReadyThreshold
origin FlagValueOrigin
Default
startTime long: millis
423581083
value ulong
5
name string
TenuredGenerationSizeIncrement
origin FlagValueOrigin
Default
startTime long: millis
364825125
value ulong
20
name string
ReservedCodeCacheSize
origin FlagValueOrigin
Ergonomic
startTime long: millis
791773058000
value ulong
251658240

DoubleFlag

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value double Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
CompileThresholdScaling
origin FlagValueOrigin
Default
startTime long: millis
423590875
value double
1.0
name string
EscapeAnalysisTimeout
origin FlagValueOrigin
Default
startTime long: millis
798682012708
value double
20.0
name string
EscapeAnalysisTimeout
origin FlagValueOrigin
Default
startTime long: millis
75962782208
value double
20.0

BooleanFlag

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value boolean Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
UseCRC32
origin FlagValueOrigin
Default
startTime long: millis
364836792
value boolean
true
name string
PrintInitialBlockList
origin FlagValueOrigin
Default
startTime long: millis
791773072917
value boolean
false
name string
SelectivePhiFunctions
origin FlagValueOrigin
Default
startTime long: millis
423597083
value boolean
true

StringFlag

default profiling startTime duration end of every chunk 11 17 21 23 24

Category: Java Virtual Machine / Flag

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

Configuration enabled period
default true beginChunk
profiling true beginChunk

Field Type Description
name string Name
value string Value
origin FlagValueOrigin Origin Consider contributing a description to jfreventcollector.

Examples 3
name string
ArchiveClassesAtExit
origin FlagValueOrigin
Default
startTime long: millis
817390663417
value string
null
name string
DumpLoadedClassList
origin FlagValueOrigin
Default
startTime long: millis
30586897083
value string
null
name string
ErrorFile
origin FlagValueOrigin
Default
startTime long: millis
40031308583
value string
null

JVM: GC: Collector

GarbageCollection

default profiling startTime duration eventThread 11 17 21 23 24 graal vm

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
default true 0 ms
profiling 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
Heap Inspection Initiated GC
gcId uint
945
longestPause Tickspan
334260583
name GCName
G1Full
startTime long: millis
880609883542
sumOfPauses Tickspan
334260583
cause GCCause
Allocation Failure
gcId uint
32
longestPause Tickspan
100032791
name GCName
ParallelScavenge
startTime long: millis
19624623292
sumOfPauses Tickspan
100032791
cause GCCause
Allocation Failure
gcId uint
59
longestPause Tickspan
19405083
name GCName
DefNew
startTime long: millis
6015857917
sumOfPauses Tickspan
19405083

SystemGC

default profiling startTime duration eventThread stackTrace 17 21 23 24 graal vm

Category: Java Virtual Machine / GC / Collector

No additional description available. Write your own and contribute it to jfreventcollector or directly to the OpenJDK.

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
default true true 0 ms
profiling 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
33
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
21.0.1
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
38514425792
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
22
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
890268499208
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
33
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
21.0.1
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
63970686125

ParallelOldGarbageCollection

default profiling startTime duration 11 17 21 23 24

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
default true 0 ms
profiling 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
30160715776
gcId uint
95
startTime long: millis
67843911042

YoungGarbageCollection

default profiling startTime duration 11 17 21 23 24

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
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier
tenuringThreshold uint Tenuring Threshold

Examples 3
gcId uint
79
startTime long: millis
11989342458
tenuringThreshold uint
1
gcId uint
921
startTime long: millis
869476276000
tenuringThreshold uint
15
gcId uint
66
startTime long: millis
49106537792
tenuringThreshold uint
15

OldGarbageCollection

default profiling startTime duration 11 17 21 23 24

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
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier

Examples 3
gcId uint
146
startTime long: millis
28586542000
gcId uint
52
startTime long: millis
29661553625
gcId uint
905
startTime long: millis
846704085250

G1GarbageCollection

default profiling startTime duration 11 17 21 23 24

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
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier
type G1YCType Type Consider contributing a description to jfreventcollector.

Examples 1
gcId uint
868
startTime long: millis
798559098542
type G1YCType
Concurrent Start

ZYoungGarbageCollection

default profiling startTime duration eventThread 21 23 24

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
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier
tenuringThreshold uint Tenuring Threshold

ZOldGarbageCollection

default profiling startTime duration eventThread 21 23 24

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
default true 0 ms
profiling true 0 ms

Field Type Description
gcId uint GC Identifier

JVM: GC: Configuration

GCConfiguration

default profiling startTime duration end of every chunk 11 17 21 23 24

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
default true everyChunk
profiling 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
ParallelOld
parallelGCThreads uint
8
pauseTarget long: millis
-9223372036854775808
startTime long: millis
39156311500
usesDynamicGCThreads boolean
true
youngCollector GCName
ParallelScavenge
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
88354585375
usesDynamicGCThreads boolean
true
youngCollector GCName
DefNew
concurrentGCThreads uint
2
gcTimeRatio uint
12
isExplicitGCConcurrent boolean
false
isExplicitGCDisabled boolean
false
oldCollector GCName
G1Old
parallelGCThreads uint
8
pauseTarget long: millis
-9223372036854775808
startTime long: millis
833403462458
usesDynamicGCThreads boolean
true
youngCollector GCName
G1New

GCSurvivorConfiguration

default profiling startTime duration end of every chunk 11 17 21 23 24

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
default true beginChunk
profiling 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
60476332542
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
96932669292
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
881475920833

GCTLABConfiguration

default profiling startTime duration end of every chunk 11 17 21 23 24

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
default true beginChunk
profiling 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
84639716708
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true
minTLABSize ulong: bytes
2048
startTime long: millis
18250636333
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true
minTLABSize ulong: bytes
2048
startTime long: millis
871662544792
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true

GCHeapConfiguration

default profiling startTime duration end of every chunk 11 17 21 23 24

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
default true beginChunk
profiling 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
268435456
maxSize ulong: bytes
4294967296
minSize ulong: bytes
8388608
objectAlignment ulong: bytes
8
startTime long: millis
30586924375
usesCompressedOops boolean
true
compressedOopsMode NarrowOopMode
Zero based
heapAddressBits ubyte
32
initialSize ulong: bytes
268435456
maxSize ulong: bytes
4294967296
minSize ulong: bytes
8388608
objectAlignment ulong: bytes
8
startTime long: millis
52241834458
usesCompressedOops boolean
true
compressedOopsMode NarrowOopMode
Zero based
heapAddressBits ubyte
32
initialSize ulong: bytes
268435456
maxSize ulong: bytes
4294967296
minSize ulong: bytes
8388608
objectAlignment ulong: bytes
8
startTime long: millis
833403464792
usesCompressedOops boolean
true

YoungGenerationConfiguration

default profiling startTime duration end of every chunk 11 17 21 23 24

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
default true beginChunk
profiling 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
1431633920
minSize ulong: bytes
89456640
newRatio uint
2
startTime long: millis
96932670917
maxSize ulong: bytes
2575302656
minSize ulong: bytes
1363144
newRatio uint
2
startTime long: millis
884658800875
maxSize ulong: bytes
1431306240
minSize ulong: bytes
89128960
newRatio uint
2
startTime long: millis
39413199875

JVM: GC: Detailed

ZThreadDebug

internal startTime duration eventThread 18 21 23 24

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.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();
  }
}

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());
}

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

G1MMU

default profiling startTime 11 17 21 23 24

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC,