Introduction

The following are the events for OpenJDK 16 (jdk-16.0.2+7, permalink, 18-January-2026). The events are collected from the event configuration and the source code. Visit the jfreventcollector repository for more information. This is also the place you can contribute additional event descriptions, if you don't want to contribute them directly to the OpenJDK. The site generator lives on GitHub, too.

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

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

Flight Recorder

DumpReason

profiling default startTime 11 17 21 25 26 27

Category: Flight Recorder

Who requested the recording and why

Code Context

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

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

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 == NULL) {

Configuration enabled
profiling true
default true

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

DataLoss

profiling default startTime 11 17 21 25 26 27

Category: Flight Recorder

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

Code Context

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

src/hotspot/share/jfr/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 != NULL, "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 != NULL, "invariant");
  const size_t unflushed_size = buffer->unflushed_size();
  buffer->reinitialize();

Configuration enabled
profiling true
default true

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

Flush

experimental startTime duration 14 17 21 25 26 27

Category: Flight Recorder

Code Context

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

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

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

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

class StackTraceRepository : public StackObj {
 private:

Configuration enabled threshold
profiling false 0 ns
default false 0 ns

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

Examples 3
elements ulong
2709
flushId ulong
213
size ulong: bytes
1008438
startTime long: millis
280829003275
elements ulong
13542
flushId ulong
209
size ulong: bytes
2401312
startTime long: millis
432436098031
elements ulong
12474
flushId ulong
187
size ulong: bytes
2758071
startTime long: millis
442516586897

ActiveRecording

profiling default startTime duration stackTrace 11 17 21 25 26 27

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

Category: Flight Recorder

Code Context

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

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

    private RepositoryChunk currentChunk;
    private boolean inShutdown;

    public PlatformRecorder() throws Exception {
        repository = Repository.getRepository();
        Logger.log(JFR_SYSTEM, INFO, "Initialized disk repository");
        repository.ensureRepository();
        jvm.createNativeJFR();
        Logger.log(JFR_SYSTEM, INFO, "Created native");
        JDKEvents.initialize();
        Logger.log(JFR_SYSTEM, INFO, "Registered JDK events");
        JDKEvents.addInstrumentation();
        startDiskMonitor();
        activeRecordingEvent = EventType.getEventType(ActiveRecordingEvent.class);
        activeSettingEvent = EventType.getEventType(ActiveSettingEvent.class);
        shutdownHook = SecuritySupport.createThreadWitNoPermissions("JFR Shutdown Hook", new ShutdownHook(this));
        SecuritySupport.setUncaughtExceptionHandler(shutdownHook, new ShutdownHook.ExceptionHandler());
        SecuritySupport.registerShutdownHook(shutdownHook);

    }


    private static Timer createTimer() {
        try {
            List<Timer> result = new CopyOnWriteArrayList<>();

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

    private void finishChunk(RepositoryChunk chunk, Instant time, PlatformRecording ignoreMe) {
        chunk.finish(time);
        for (PlatformRecording r : getRecordings()) {
            if (r != ignoreMe && r.getState() == RecordingState.RUNNING) {
                r.appendChunk(chunk);
            }
        }
        FilePurger.purge();
    }

    private void writeMetaEvents() {
        if (activeRecordingEvent.isEnabled()) {
            ActiveRecordingEvent event = ActiveRecordingEvent.EVENT.get();
            for (PlatformRecording r : getRecordings()) {
                if (r.getState() == RecordingState.RUNNING && r.shouldWriteMetadataEvent()) {
                    event.id = r.getId();
                    event.name = r.getName();
                    WriteableUserPath p = r.getDestination();
                    event.destination = p == null ? null : p.getRealPathText();
                    Duration d = r.getDuration();
                    event.recordingDuration = d == null ? Long.MAX_VALUE : d.toMillis();
                    Duration age = r.getMaxAge();
                    event.maxAge = age == null ? Long.MAX_VALUE : age.toMillis();
                    Long size = r.getMaxSize();

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

        ProcessStartEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class,
        jdk.internal.event.ProcessStartEvent.class,
        DirectBufferStatisticsEvent.class
    };

    // This is a list of the classes with instrumentation code that should be applied.
    private static final Class<?>[] instrumentationClasses = new Class<?>[] {
        FileInputStreamInstrumentor.class,

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

@Name(Type.EVENT_NAME_PREFIX + "ActiveRecording")
@Label("Flight Recording")
@Category("Flight Recorder")
@StackTrace(false)
public final class ActiveRecordingEvent extends AbstractJDKEvent {

    public static final ThreadLocal<ActiveRecordingEvent> EVENT = new ThreadLocal<ActiveRecordingEvent>() {
        @Override
        protected ActiveRecordingEvent initialValue() {
            return new ActiveRecordingEvent();
        }
    };

    @Label("Id")
    public long id;

    @Label("Name")
    public String name;

    @Label("Destination")
    public String destination;

Configuration enabled
profiling true
default true

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

Examples 3
destination string
/home/runner/work/jfrevents/jfrevents/jfr/sample_UseParallelGC.jfr
flushInterval long: millis
1000
id long
1
maxAge long: millis
9223372036854775807
maxSize long: bytes
262144000
name string
1
recordingDuration long: millis
9223372036854775807
recordingStart long: epochmillis
1767487168217
stackTrace StackTrace
null
startTime long: millis
398077595618
destination string
/home/runner/work/jfrevents/jfrevents/jfr/sample_UseG1GC.jfr
flushInterval long: millis
1000
id long
1
maxAge long: millis
9223372036854775807
maxSize long: bytes
262144000
name string
1
recordingDuration long: millis
9223372036854775807
recordingStart long: epochmillis
1767487167450
stackTrace StackTrace
null
startTime long: millis
366516605544
destination string
/home/runner/work/jfrevents/jfrevents/jfr/sample_UseSerialGC.jfr
flushInterval long: millis
1000
id long
1
maxAge long: millis
9223372036854775807
maxSize long: bytes
262144000
name string
1
recordingDuration long: millis
9223372036854775807
recordingStart long: epochmillis
1767487156514
stackTrace StackTrace
null
startTime long: millis
428280826825

ActiveSetting

profiling default startTime duration stackTrace 11 17 21 25 26 27

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

Category: Flight Recorder

Code Context

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

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

    private boolean inShutdown;

    public PlatformRecorder() throws Exception {
        repository = Repository.getRepository();
        Logger.log(JFR_SYSTEM, INFO, "Initialized disk repository");
        repository.ensureRepository();
        jvm.createNativeJFR();
        Logger.log(JFR_SYSTEM, INFO, "Created native");
        JDKEvents.initialize();
        Logger.log(JFR_SYSTEM, INFO, "Registered JDK events");
        JDKEvents.addInstrumentation();
        startDiskMonitor();
        activeRecordingEvent = EventType.getEventType(ActiveRecordingEvent.class);
        activeSettingEvent = EventType.getEventType(ActiveSettingEvent.class);
        shutdownHook = SecuritySupport.createThreadWitNoPermissions("JFR Shutdown Hook", new ShutdownHook(this));
        SecuritySupport.setUncaughtExceptionHandler(shutdownHook, new ShutdownHook.ExceptionHandler());
        SecuritySupport.registerShutdownHook(shutdownHook);

    }


    private static Timer createTimer() {
        try {
            List<Timer> result = new CopyOnWriteArrayList<>();
            Thread t = SecuritySupport.createThreadWitNoPermissions("Permissionless thread", ()-> {

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

        X509ValidationEvent.class,
        ProcessStartEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class,
        jdk.internal.event.ProcessStartEvent.class,
        DirectBufferStatisticsEvent.class
    };

    // This is a list of the classes with instrumentation code that should be applied.
    private static final Class<?>[] instrumentationClasses = new Class<?>[] {

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.StackTrace;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "ActiveSetting")
@Label("Recording Setting")
@Category("Flight Recorder")
@StackTrace(false)
public final class ActiveSettingEvent extends AbstractJDKEvent {

    public static final ThreadLocal<ActiveSettingEvent> EVENT = new ThreadLocal<ActiveSettingEvent>() {
        @Override
        protected ActiveSettingEvent initialValue() {
            return new ActiveSettingEvent();
        }
    };

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

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

    @Label("Setting Value")
    public String value;

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

    void disable() {
        for (NamedControl nc : namedControls) {
            if (nc.control.isType(EnabledSetting.class)) {
                nc.control.setValue("false");
                return;
            }
        }
    }

    void writeActiveSettingEvent() {
        if (!type.isRegistered()) {
            return;
        }
        ActiveSettingEvent event = ActiveSettingEvent.EVENT.get();
        for (NamedControl nc : namedControls) {
            if (Utils.isSettingVisible(nc.control, type.hasEventHook())) {
                String value = nc.control.getLastValue();
                if (value == null) {
                    value = nc.control.getDefaultValue();
                }
                event.id = type.getId();
                event.name = nc.name;
                event.value = value;
                event.commit();
            }

Configuration enabled
profiling true
default true

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

Examples 3
id long
1523
name string
enabled
stackTrace StackTrace
null
startTime long: millis
371338931988
value string
true
id long
26
name string
enabled
stackTrace StackTrace
null
startTime long: millis
378896523380
value string
true
id long
37
name string
period
stackTrace StackTrace
null
startTime long: millis
278162944220
value string
everyChunk

JVM

JVMInformation

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

Category: Java Virtual Machine

Description of JVM and the Java application

Code Context

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

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

#if INCLUDE_SHENANDOAHGC
#include "gc/shenandoah/shenandoahJfrSupport.hpp"
#endif
/**
 *  JfrPeriodic class
 *  Implementation of declarations in
 *  xsl generated traceRequestables.hpp
 */
#define TRACE_REQUEST_FUNC(id)    void JfrPeriodicEventSet::request##id(void)

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

TRACE_REQUEST_FUNC(OSInformation) {

Configuration enabled period
profiling true beginChunk
default true beginChunk

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

Examples 3
javaArguments string
/home/runner/work/jfrevents/jfrevents/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=/home/runner/work/jfrevents/jfrevents/jfr/sample_UseSerialGC.jfr,settings=/home/runner/work/jfrevents/jfrevents/.cache/jfc.jfc -XX:+UseSerialGC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1767487156005
jvmVersion string
OpenJDK 64-Bit Server VM (21.0.9+10-LTS) for linux-amd64 JRE (21.0.9+10-LTS), built on 2025-10-17T14:44:04Z by "jenkinsi" with gcc 11.3.0
pid long
2254
startTime long: millis
413436337949
javaArguments string
/home/runner/work/jfrevents/jfrevents/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=/home/runner/work/jfrevents/jfrevents/jfr/sample_UseG1GC.jfr,settings=/home/runner/work/jfrevents/jfrevents/.cache/jfc.jfc -XX:+UseG1GC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1767487166908
jvmVersion string
OpenJDK 64-Bit Server VM (21.0.9+10-LTS) for linux-amd64 JRE (21.0.9+10-LTS), built on 2025-10-17T14:44:04Z by "jenkinsi" with gcc 11.3.0
pid long
2289
startTime long: millis
334749585036
javaArguments string
/home/runner/work/jfrevents/jfrevents/.cache/renaissance.jar -t 5 -r 1 all
jvmArguments string
-XX:StartFlightRecording=filename=/home/runner/work/jfrevents/jfrevents/jfr/sample_UseParallelGC.jfr,settings=/home/runner/work/jfrevents/jfrevents/.cache/jfc.jfc -XX:+UseParallelGC
jvmFlags string
null
jvmName string
OpenJDK 64-Bit Server VM
jvmStartTime long: epochmillis
1767487167754
jvmVersion string
OpenJDK 64-Bit Server VM (21.0.9+10-LTS) for linux-amd64 JRE (21.0.9+10-LTS), built on 2025-10-17T14:44:04Z by "jenkinsi" with gcc 11.3.0
pid long
2925
startTime long: millis
451340978237

InitialSystemProperty

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

Category: Java Virtual Machine

System Property at JVM start

Code Context

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

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

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

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

TRACE_REQUEST_FUNC(ThreadAllocationStatistics) {
  ResourceMark rm;

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
key string Key
value string Value

Examples 3
key string
sun.java.command
startTime long: millis
406888458245
value string
/home/runner/work/jfrevents/jfrevents/.cache/renaissance.jar -t 5 -r 1 all
key string
sun.java.command
startTime long: millis
383169991067
value string
/home/runner/work/jfrevents/jfrevents/.cache/renaissance.jar -t 5 -r 1 all
key string
java.vm.specification.version
startTime long: millis
278169436152
value string
21

JVM: Class Loading

ClassLoad

startTime duration eventThread stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / Class Loading

Code Context

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

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

class BootstrapInfo;
class ClassFileStream;
class ClassLoadInfo;
class Dictionary;
class PlaceholderTable;
class LoaderConstraintTable;
template <MEMFLAGS F> class HashtableBucket;
class ResolutionErrorTable;
class SymbolPropertyTable;
class PackageEntry;
class ProtectionDomainCacheTable;
class ProtectionDomainCacheEntry;
class GCTimer;
class EventClassLoad;
class Symbol;
class TableStatistics;

#define WK_KLASS_ENUM_NAME(kname)    kname##_knum

// Certain classes, such as java.lang.Object and java.lang.String,
// are "well-known", in the sense that no class loader is allowed
// to provide a different definition.
//
// Each well-known class has a short klass name (like object_klass),
// and a vmSymbol name (like java_lang_Object).

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

  static ProtectionDomainCacheTable*   _pd_cache_table;

protected:
  static void validate_protection_domain(InstanceKlass* klass,
                                         Handle class_loader,
                                         Handle protection_domain, TRAPS);

  friend class VM_PopulateDumpSharedSpace;
  friend class TraversePlaceholdersClosure;
  static PlaceholderTable*   placeholders() { return _placeholders; }
  static LoaderConstraintTable* constraints() { return _loader_constraints; }
  static ResolutionErrorTable* resolution_errors() { return _resolution_errors; }
  static SymbolPropertyTable* invoke_method_table() { return _invoke_method_table; }
  static void post_class_load_event(EventClassLoad* event, const InstanceKlass* k, const ClassLoaderData* init_cld);

  // Basic loading operations
  static InstanceKlass* resolve_instance_class_or_null_helper(Symbol* name,
                                                              Handle class_loader,
                                                              Handle protection_domain,
                                                              TRAPS);
  static InstanceKlass* resolve_instance_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
  static Klass* resolve_array_class_or_null(Symbol* class_name, Handle class_loader, Handle protection_domain, TRAPS);
  static InstanceKlass* handle_parallel_super_load(Symbol* class_name, Symbol* supername, Handle class_loader, Handle protection_domain, Handle lockObject, TRAPS);
  // Wait on SystemDictionary_lock; unlocks lockObject before
  // waiting; relocks lockObject with correct recursion count

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

          SystemDictionary_lock->wait();
        } else {
          double_lock_wait(lockObject, THREAD);
        }
      } else {
        // If not in SD and not in PH, other thread's load must have failed
        super_load_in_progress = false;
      }
    }
  }
  return NULL;
}

void SystemDictionary::post_class_load_event(EventClassLoad* event, const InstanceKlass* k, const ClassLoaderData* init_cld) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_loadedClass(k);
  event->set_definingClassLoader(k->class_loader_data());
  event->set_initiatingClassLoader(init_cld);
  event->commit();
}


// Be careful when modifying this code: once you have run
// placeholders()->find_and_add(PlaceholderTable::LOAD_INSTANCE),
// you need to find_and_remove it before returning.
// So be careful to not exit with a CHECK_ macro betweeen these calls.
//
// name must be in the form of "java/lang/Object" -- cannot be "Ljava/lang/Object;"
InstanceKlass* SystemDictionary::resolve_instance_class_or_null(Symbol* name,
                                                                Handle class_loader,
                                                                Handle protection_domain,
                                                                TRAPS) {
  assert(name != NULL && !Signature::is_array(name) &&
         !Signature::has_envelope(name), "invalid class name");

  EventClassLoad class_load_start_event;

  HandleMark hm(THREAD);

  // Fix for 4474172; see evaluation for more details
  class_loader = Handle(THREAD, java_lang_ClassLoader::non_reflection_class_loader(class_loader()));
  ClassLoaderData* loader_data = register_loader(class_loader);
  Dictionary* dictionary = loader_data->dictionary();
  unsigned int d_hash = dictionary->compute_hash(name);

  // Do lookup to see if class already exist and the protection domain
  // has the right access

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

// Note: this method is much like resolve_from_stream, but
// does not publish the classes via the SystemDictionary.
// Handles Lookup.defineClass hidden, unsafe_DefineAnonymousClass
// and redefineclasses. RedefinedClasses do not add to the class hierarchy.
InstanceKlass* SystemDictionary::parse_stream(Symbol* class_name,
                                              Handle class_loader,
                                              ClassFileStream* st,
                                              const ClassLoadInfo& cl_info,
                                              TRAPS) {

  EventClassLoad class_load_start_event;
  ClassLoaderData* loader_data;
  bool is_unsafe_anon_class = cl_info.unsafe_anonymous_host() != NULL;

  // - for unsafe anonymous class: create a new CLD whith a class holder that uses
  //                               the same class loader as the unsafe_anonymous_host.
  // - 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.
  if (is_unsafe_anon_class || cl_info.is_hidden()) {
    guarantee(!is_unsafe_anon_class || cl_info.unsafe_anonymous_host()->class_loader() == class_loader(),
              "should be NULL or the same");

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 == NULL) {
    return NULL;
  }

  // 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;
  {
    MutexLocker mu_r(THREAD, Compile_lock);

    // Add to class hierarchy, initialize vtables, and do possible
    // deoptimizations.
    SystemDictionary::add_to_hierarchy(loaded_lambda, CHECK_NULL); // No exception, but can block
    // But, do not add to dictionary.
  }
  loaded_lambda->link_class(CHECK_NULL);
  // notify jvmti
  if (JvmtiExport::should_post_class_load()) {

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

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

Examples 3
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
initiatingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
loadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
true
modifiers int
4112
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org.apache.spark.ml.recommendation.ALS$$$Lambda/0x00007f3075282600
package Package
exported boolean
true
module Module
classLoader ClassLoader
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null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
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
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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
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false
modifiers int
1025
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
426575328286
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
initiatingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
loadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/apache/spark/sql/SparkSession$implicits$
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/sql
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
12
lineNumber int
825
method Method
descriptor string
()V
hidden boolean
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modifiers int
18
name string
implicits$lzycompute$1
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/apache/spark/sql/SparkSession
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/sql
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
310088270701
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
initiatingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
loadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
true
modifiers int
4112
name string
org.apache.spark.ml.recommendation.ALS$$$Lambda/0x00007fb961446ca0
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/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
21.0.9
name string
java/lang
type FrameType
Native
truncated boolean
true
startTime long: millis
424120299173

ClassDefine

startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / Class Loading

Code Context

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

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

      // For user defined Java class loaders, check that the name returned is
      // the same as that requested.  This check is done for the bootstrap
      // loader when parsing the class file.
      if (class_name == k->name()) {
        return k;
      }
    }
    // Class is not found or has the wrong name, return NULL
    return NULL;
  }
}

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, TRAPS) {

  HandleMark hm(THREAD);
  ClassLoaderData* loader_data = k->class_loader_data();

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
definedClass Class Defined Class
definingClassLoader ClassLoader Defining Class Loader

Examples 3
definedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1537
name string
scala/reflect/internal/Symbols
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/reflect/internal
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass1
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1025
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Native
truncated boolean
true
startTime long: millis
431324630755
definedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
17
name string
org/apache/spark/sql/SQLImplicits$$typecreator1$3
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/sql
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass1
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1025
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Native
truncated boolean
false
startTime long: millis
428486663793
definedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1537
name string
scala/reflect/internal/tpe/GlbLubs
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/reflect/internal/tpe
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/ClassLoader;Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
hidden boolean
false
modifiers int
264
name string
defineClass1
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1025
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Native
truncated boolean
true
startTime long: millis
310150055759

ClassRedefinition

profiling default startTime 15 17 21 25 26 27

Category: Java Virtual Machine / Class Loading

Code Context

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

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

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

  if (the_class->oop_map_cache() != NULL) {
    // 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((InstanceKlass *)the_class, THREAD);

  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(THREAD);
    // increment the classRedefinedCount field in the_class and in any
    // direct and indirect subclasses of the_class
    log_info(redefine, class, load)

Configuration enabled
profiling true
default true

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

RedefineClasses

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

Category: Java Virtual Machine / Class Loading

Code Context

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

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

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


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

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

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

RetransformClasses

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

Category: Java Virtual Machine / Class Loading

Code Context

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

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

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

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

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

ClassUnload

startTime eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Class Loading

Code Context

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

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

  if (Arguments::is_dumping_archive()) {
    SystemDictionaryShared::remove_dumptime_info(ik);
  }

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

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

#if INCLUDE_JFR
  assert(ik != NULL, "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();
}

void InstanceKlass::release_C_heap_structures() {

Configuration enabled
profiling false
default false

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

Examples 3
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
startTime long: millis
437054598152
unloadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
true
modifiers int
4112
name string
org.renaissance.jdk.streams.MnemonicsCoderWithStream$$Lambda/0x00007f3075423b50
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/renaissance/jdk/streams
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
startTime long: millis
443004822981
unloadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
17
name string
org/renaissance/jdk/streams/MnemonicsCoderWithStream
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/renaissance/jdk/streams
definingClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
startTime long: millis
316588411059
unloadedClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
true
modifiers int
4112
name string
org.renaissance.scala.stdlib.KmeansUtilities$$Lambda/0x00007f58d9617b90
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/renaissance/scala/stdlib

JVM: Code Cache

CodeCacheFull

profiling default startTime eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Code Cache

Code Context

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

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

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

    if (heap->full_count() == 0) {
      if (PrintCodeHeapAnalytics) {
        CompileBroker::print_heapinfo(tty, "all", 4096); // details, may be a lot!
      }
    }
  }

  heap->report_full();

  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.commit();

Configuration enabled
profiling true
default true

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

CodeCacheStatistics

profiling default startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Code Cache

Code Context

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

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

TRACE_REQUEST_FUNC(CompilerConfiguration) {
  EventCompilerConfiguration event;
  event.set_threadCount(CICompilerCount);
  event.set_tieredCompilation(TieredCompilation);
  event.commit();
}

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

Configuration enabled period
profiling true everyChunk
default true everyChunk

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

Examples 3
adaptorCount int
0
codeBlobType CodeBlobType
CodeHeap 'profiled nmethods'
entryCount int
7486
fullCount int
0
methodCount int
7486
reservedTopAddress ulong: address
139847420571648
startAddress ulong: address
139847297662976
startTime long: millis
387701425735
unallocatedCapacity ulong: bytes
100465536
adaptorCount int
0
codeBlobType CodeBlobType
CodeHeap 'non-profiled nmethods'
entryCount int
8830
fullCount int
0
methodCount int
8830
reservedTopAddress ulong: address
140021361278976
startAddress ulong: address
140021238366208
startTime long: millis
348779477688
unallocatedCapacity ulong: bytes
106661504
adaptorCount int
0
codeBlobType CodeBlobType
CodeHeap 'non-profiled nmethods'
entryCount int
9843
fullCount int
0
methodCount int
9843
reservedTopAddress ulong: address
140435422969856
startAddress ulong: address
140435300057088
startTime long: millis
470155460465
unallocatedCapacity ulong: bytes
107323008

CodeCacheConfiguration

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

Category: Java Virtual Machine / Code Cache

Code Context

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

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

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

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

Configuration enabled period
profiling true beginChunk
default true beginChunk

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

Examples 3
expansionSize ulong: bytes
65536
initialSize ulong: bytes
2555904
minBlockLength ulong: bytes
6
nonNMethodSize ulong: bytes
5832780
nonProfiledSize ulong: bytes
122912730
profiledSize ulong: bytes
122912730
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
140435422969856
startAddress ulong: address
140435171311616
startTime long: millis
404635134354
expansionSize ulong: bytes
65536
initialSize ulong: bytes
2555904
minBlockLength ulong: bytes
6
nonNMethodSize ulong: bytes
5832780
nonProfiledSize ulong: bytes
122912730
profiledSize ulong: bytes
122912730
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
139847549321216
startAddress ulong: address
139847297662976
startTime long: millis
461166585174
expansionSize ulong: bytes
65536
initialSize ulong: bytes
2555904
minBlockLength ulong: bytes
6
nonNMethodSize ulong: bytes
5832780
nonProfiledSize ulong: bytes
122912730
profiledSize ulong: bytes
122912730
reservedSize ulong: bytes
251658240
reservedTopAddress ulong: address
140021361278976
startAddress ulong: address
140021109620736
startTime long: millis
303924617115

JVM: Code Sweeper

SweepCodeCache

profiling default startTime duration eventThread 11 17 until JDK 20

Category: Java Virtual Machine / Code Sweeper

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/sweeper.cpp:

  sweep_code_cache();

  // We are done with sweeping the code cache once.
  _total_nof_code_cache_sweeps++;

  if (_force_sweep) {
    // Notify requester that forced sweep finished
    MutexLocker mu(CodeSweeper_lock, Mutex::_no_safepoint_check_flag);
    _force_sweep = false;
    CodeSweeper_lock->notify();
  }
}

static void post_sweep_event(EventSweepCodeCache* event,
                             const Ticks& start,
                             const Ticks& end,
                             s4 traversals,
                             int swept,
                             int flushed,
                             int zombified) {
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_starttime(start);
  event->set_endtime(end);
  event->set_sweepId(traversals);

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

  const Ticks sweep_end_counter = Ticks::now();
  const Tickspan sweep_time = sweep_end_counter - sweep_start_counter;
  {
    MutexLocker mu(NMethodSweeperStats_lock, Mutex::_no_safepoint_check_flag);
    _total_time_sweeping  += sweep_time;
    _total_time_this_sweep += sweep_time;
    _peak_sweep_fraction_time = MAX2(sweep_time, _peak_sweep_fraction_time);
    _total_flushed_size += freed_memory;
    _total_nof_methods_reclaimed += flushed_count;
    _total_nof_c2_methods_reclaimed += flushed_c2_count;
    _peak_sweep_time = MAX2(_peak_sweep_time, _total_time_this_sweep);
  }

  EventSweepCodeCache event(UNTIMED);
  if (event.should_commit()) {
    post_sweep_event(&event, sweep_start_counter, sweep_end_counter, (s4)_traversals, swept_count, flushed_count, zombified_count);
  }

#ifdef ASSERT
  if(PrintMethodFlushing) {
    tty->print_cr("### sweeper:      sweep time(" JLONG_FORMAT "): ", sweep_time.value());
  }
#endif

  Log(codecache, sweep) log;

Configuration enabled threshold
profiling true 100 ms
default true 100 ms

Field Type Description
sweepId int Sweep Identifier
sweptCount uint Methods Swept
flushedCount uint Methods Flushed
zombifiedCount uint Methods Zombified

CodeSweeperStatistics

profiling default startTime every chunk 11 17 until JDK 20

Category: Java Virtual Machine / Code Sweeper

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_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();
}

TRACE_REQUEST_FUNC(CodeSweeperStatistics) {
  EventCodeSweeperStatistics event;
  event.set_sweepCount(NMethodSweeper::traversal_count());
  event.set_methodReclaimedCount(NMethodSweeper::total_nof_methods_reclaimed());
  event.set_totalSweepTime(NMethodSweeper::total_time_sweeping());
  event.set_peakFractionTime(NMethodSweeper::peak_sweep_fraction_time());
  event.set_peakSweepTime(NMethodSweeper::peak_sweep_time());
  event.commit();
}

TRACE_REQUEST_FUNC(CodeSweeperConfiguration) {
  EventCodeSweeperConfiguration event;
  event.set_sweeperEnabled(MethodFlushing);

Configuration enabled period
profiling true everyChunk
default true everyChunk

Field Type Description
sweepCount int Sweeps
methodReclaimedCount int Methods Reclaimed
totalSweepTime Tickspan Time Spent Sweeping
peakFractionTime Tickspan Peak Time Fraction Sweep
peakSweepTime Tickspan Peak Time Full Sweep

CodeSweeperConfiguration

profiling default startTime end of every chunk 11 17 until JDK 20

Category: Java Virtual Machine / Code Sweeper

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(CodeSweeperStatistics) {
  EventCodeSweeperStatistics event;
  event.set_sweepCount(NMethodSweeper::traversal_count());
  event.set_methodReclaimedCount(NMethodSweeper::total_nof_methods_reclaimed());
  event.set_totalSweepTime(NMethodSweeper::total_time_sweeping());
  event.set_peakFractionTime(NMethodSweeper::peak_sweep_fraction_time());
  event.set_peakSweepTime(NMethodSweeper::peak_sweep_time());
  event.commit();
}

TRACE_REQUEST_FUNC(CodeSweeperConfiguration) {
  EventCodeSweeperConfiguration event;
  event.set_sweeperEnabled(MethodFlushing);
  event.set_flushingEnabled(UseCodeCacheFlushing);
  event.set_sweepThreshold(NMethodSweeper::sweep_threshold_bytes());
  event.commit();
}


TRACE_REQUEST_FUNC(ShenandoahHeapRegionInformation) {
#if INCLUDE_SHENANDOAHGC
  if (UseShenandoahGC) {
    VM_ShenandoahSendHeapRegionInfoEvents op;

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
sweeperEnabled boolean Code Sweeper Enabled
flushingEnabled boolean Code Cache Flushing Enabled
sweepThreshold ulong: bytes 17 until JDK 20 Sweep Threshold

JVM: Compiler

Compilation

profiling default startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Compiler

Code Context

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

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

  } else if (AbortVMOnCompilationFailure) {
    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);
    }
  }
  // simulate crash during compilation
  assert(task->compile_id() != CICrashAt, "just as planned");
}

static void post_compilation_event(EventCompilation& event, CompileTask* task) {
  assert(task != NULL, "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->code() == NULL) ? 0 : task->code()->total_size(),
                                        task->num_inlined_bytecodes());
}

int DirectivesStack::_depth = 0;

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

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

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

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

    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 == NULL) {
      ci_env.record_method_not_compilable("no compiler", !TieredCompilation);
    } else if (!ci_env.failing()) {
      if (WhiteBoxAPI && WhiteBox::compilation_locked) {
        MonitorLocker locker(Compilation_lock, Mutex::_no_safepoint_check_flag);
        while (WhiteBox::compilation_locked) {
          locker.wait();
        }
      }
      comp->compile_method(&ci_env, target, osr_bci, true, directive);

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) 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:

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

  if (register_jfr_serializer) {
    JfrSerializer::register_serializer(TYPE_COMPILERPHASETYPE, false, new CompilerPhaseTypeConstant());
  } else if (Jfr::is_recording()) {
    // serialize new phase.
    JfrCheckpointWriter writer;
    writer.write_type(TYPE_COMPILERPHASETYPE);
    writer.write_count(1);
    writer.write_key(index);
    writer.write(phase_name);
  }
  return index;
}

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) {
  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.commit();
}

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

package jdk.vm.ci.hotspot;

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

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

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

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

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

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

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

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

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

        void setCompileId(int compileId);

        void setCompileLevel(int compileLevel);

        void setSucceeded(boolean succeeded);

Configuration enabled threshold
profiling true 100 ms
default true 1000 ms

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

Examples 3
codeSize ulong: bytes
8400
compileId uint
74533
compileLevel ushort
3
compiler CompilerType
c1
inlinedBytes ulong: bytes
101
isOsr boolean
false
method Method
descriptor string
(Lorg/apache/spark/ContextCleaner;Lorg/apache/spark/CleanupTaskWeakReference;)V
hidden boolean
false
modifiers int
4121
name string
$anonfun$keepCleaning$3
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/apache/spark/ContextCleaner
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark
startTime long: millis
420635381909
succeded boolean
true
codeSize ulong: bytes
264
compileId uint
72758
compileLevel ushort
1
compiler CompilerType
c1
inlinedBytes ulong: bytes
0
isOsr boolean
false
method Method
descriptor string
(Ljava/lang/String;)V
hidden boolean
false
modifiers int
2
name string
host__$eq
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/apache/spark/storage/BlockManagerId
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/storage
startTime long: millis
395931388158
succeded boolean
true
codeSize ulong: bytes
42592
compileId uint
89114
compileLevel ushort
4
compiler CompilerType
c2
inlinedBytes ulong: bytes
11010
isOsr boolean
false
method Method
descriptor string
()Ldotty/tools/dotc/core/Names$Name;
hidden boolean
false
modifiers int
4161
name string
mangled
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
25
name string
dotty/tools/dotc/core/Names$TypeName
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
dotty/tools/dotc/core
startTime long: millis
344696888204
succeded boolean
true

CompilerPhase

profiling default startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Compiler

Code Context

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

src/hotspot/share/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_succeded(success);
  event.set_isOsr(is_osr);
  event.set_codeSize(code_size);
  event.set_inlinedBytes(inlined_bytecodes);
  event.commit();
}

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

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

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

    Node* n = macro_node(i);
    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, const char *name, int level, int idx) {
  EventCompilerPhase event;
  if (event.should_commit()) {
    CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, cpt, C->_compile_id, level);
  }
#ifndef PRODUCT
  if (should_print(level)) {
    _printer->print_method(name, level);
  }
#endif
  C->_latest_stage_start_counter.stamp();
}

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

void Compile::print_method(CompilerPhaseType cpt, Node* n, int level) {
  ResourceMark rm;
  stringStream ss;
  ss.print_raw(CompilerPhaseTypeHelper::to_string(cpt));
  if (n != NULL) {
    ss.print(": %d %s ", n->_idx, NodeClassNames[n->Opcode()]);
  } else {
    ss.print_raw(": NULL");
  }
  C->print_method(cpt, ss.as_string(), level);
}

void Compile::end_method(int level) {
  EventCompilerPhase event;
  if (event.should_commit()) {
    CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, PHASE_END, C->_compile_id, level);
  }

#ifndef PRODUCT
  if (_method != NULL && should_print(level)) {
    _printer->end_method();
  }
#endif
}

src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.hotspot/src/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 {see @code src/share/jfr/metadata/metadata.xml}.
     */
    public static final class CompilerPhaseEvent {

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

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

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

Configuration enabled threshold
profiling true 10 s
default true 60 s

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

CompilationFailure

profiling startTime eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Compiler

Code Context

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

src/hotspot/share/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) 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:

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) {
  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.commit();
}

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 == NULL) {
    // Record the first failure reason.
    _failure_reason = reason;
  }
}

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

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

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

Configuration enabled
profiling true
default false

Field Type Description
failureMessage string Failure Message
compileId uint Compilation Identifier

Examples 3
compileId uint
97569
failureMessage string
retry without subsuming loads
startTime long: millis
479401566257
compileId uint
97175
failureMessage string
concurrent class loading
startTime long: millis
351309237748
compileId uint
102550
failureMessage string
retry without subsuming loads
startTime long: millis
473186528304

CompilerInlining

startTime eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Compiler / Optimization

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);
  event.commit();
}

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

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

#define CC (char*)  /*cast a literal from (const char*)*/
#define FN_PTR(f) CAST_FROM_FN_PTR(void*, &(c2v_ ## f))

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

void GraphBuilder::print_inlining(ciMethod* callee, const char* msg, bool success) {
  CompileLog* log = compilation()->log();
  if (log != NULL) {
    assert(msg != NULL, "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(), msg);

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

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

  CompileTask::print_inlining_ul(callee_method, inline_level(),
                                               caller_bci, inline_msg);
  if (C->print_inlining()) {
    C->print_inlining(callee_method, inline_level(), caller_bci, inline_msg);
    guarantee(callee_method != NULL, "would crash in CompilerEvent::InlineEvent::post");
    if (Verbose) {
      const InlineTree *top = this;
      while (top->caller_tree() != NULL) { 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-----------------------------------
WarmCallInfo* InlineTree::ok_to_inline(ciMethod* callee_method, JVMState* jvms, ciCallProfile& profile, WarmCallInfo* initial_wci, bool& should_delay) {
  assert(callee_method != NULL, "caller checks for optimized virtual!");
  assert(!should_delay, "should be initialized to false");
#ifdef ASSERT
  // Make sure the incoming jvms has the same information content as me.

src/jdk.internal.vm.ci/share/classes/jdk.vm.ci.hotspot/src/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 {see @code
     * src/share/jfr/metadata/metadata.xml}.
     */
    public static final class CompilerInliningEvent {

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

Configuration enabled
profiling false
default false

Field Type Description
compileId uint 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
95
callee CalleeMethod
descriptor string
(ILjava/lang/Object;)Ljava/util/HashMap$TreeNode;
name string
getTreeNode
type string
java/util/HashMap$TreeNode
caller Method
descriptor string
(Ljava/lang/Object;)Ljava/util/HashMap$Node;
hidden boolean
false
modifiers int
16
name string
getNode
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/HashMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util
compileId uint
73542
message string
low call site frequency
startTime long: millis
371345325605
succeeded boolean
false
bci int
32
callee CalleeMethod
descriptor string
(Ljava/lang/String;)Ljava/lang/StringBuilder;
name string
append
type string
java/lang/StringBuilder
caller Method
descriptor string
(I)V
hidden boolean
false
modifiers int
2
name string
growTable
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
scala/collection/mutable/LinkedHashMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/collection/mutable
compileId uint
72214
message string
inline
startTime long: millis
378898455633
succeeded boolean
true
bci int
50
callee CalleeMethod
descriptor string
(Lscala/Function1;)V
name string
foreach$mVc$sp
type string
scala/collection/immutable/Range
caller Method
descriptor string
(Lorg/apache/spark/scheduler/TaskSetManager;Lscala/Enumeration$Value;Lscala/collection/immutable/Seq;[I[Lscala/collection/immutable/Map;Lscala/collection/immutable/IndexedSeq;)Lscala/Tuple2;
hidden boolean
false
modifiers int
2
name string
resourceOfferSingleTaskSet
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/apache/spark/scheduler/TaskSchedulerImpl
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/scheduler
compileId uint
73380
message string
inlining prohibited by policy
startTime long: millis
278182861044
succeeded boolean
false

Deoptimization

profiling default startTime eventThread stackTrace 14 17 21 25 26 27

Category: Java Virtual Machine / Compiler

Code Context

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

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

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

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

Configuration enabled stackTrace
profiling true true
default true false

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

Examples 3
action DeoptimizationAction
maybe_recompile
bci int
52
compileId uint
76567
compiler CompilerType
c2
instruction Bytecode
getstatic
lineNumber int
76
method Method
descriptor string
(Lscala/concurrent/stm/ccstm/Handle;)Ljava/lang/Object;
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
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1025
name string
scala/concurrent/stm/ccstm/InTxnRefOps
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/concurrent/stm/ccstm
reason DeoptimizationReason
predicate
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
52
lineNumber int
76
method Method
descriptor string
(Lscala/concurrent/stm/ccstm/Handle;)Ljava/lang/Object;
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
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1025
name string
scala/concurrent/stm/ccstm/InTxnRefOps
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/concurrent/stm/ccstm
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
437954693633
action DeoptimizationAction
maybe_recompile
bci int
17
compileId uint
72732
compiler CompilerType
c2
instruction Bytecode
checkcast
lineNumber int
2395
method Method
descriptor string
(I)Lorg/sparkproject/guava/collect/MapMakerInternalMap$ReferenceEntry;
hidden boolean
false
modifiers int
0
name string
getFirst
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
8
name string
org/sparkproject/guava/collect/MapMakerInternalMap$Segment
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/sparkproject/guava/collect
reason DeoptimizationReason
class_check
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
17
lineNumber int
2395
method Method
descriptor string
(I)Lorg/sparkproject/guava/collect/MapMakerInternalMap$ReferenceEntry;
hidden boolean
false
modifiers int
0
name string
getFirst
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
8
name string
org/sparkproject/guava/collect/MapMakerInternalMap$Segment
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/sparkproject/guava/collect
type FrameType
Inlined
truncated boolean
false
startTime long: millis
428925149353
action DeoptimizationAction
maybe_recompile
bci int
71
compileId uint
76801
compiler CompilerType
c2
instruction Bytecode
invokevirtual
lineNumber int
78
method Method
descriptor string
(Lscala/concurrent/stm/ccstm/Handle;)Ljava/lang/Object;
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
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1025
name string
scala/concurrent/stm/ccstm/InTxnRefOps
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/concurrent/stm/ccstm
reason DeoptimizationReason
class_check
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
71
lineNumber int
78
method Method
descriptor string
(Lscala/concurrent/stm/ccstm/Handle;)Ljava/lang/Object;
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
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1025
name string
scala/concurrent/stm/ccstm/InTxnRefOps
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/concurrent/stm/ccstm
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
320109938399

CompilerStatistics

profiling default startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Compiler

Code Context

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

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

TRACE_REQUEST_FUNC(LoaderConstraintsTableStatistics) {
  TableStatistics statistics = SystemDictionary::loader_constraints_statistics();
  emit_table_statistics<EventLoaderConstraintsTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(ProtectionDomainCacheTableStatistics) {
  TableStatistics statistics = SystemDictionary::protection_domain_cache_statistics();
  emit_table_statistics<EventProtectionDomainCacheTableStatistics>(statistics);
}

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

Configuration enabled period
profiling true 1000 ms
default true 1000 ms

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

Examples 3
bailoutCount int
13
compileCount int
85236
invalidatedCount int
0
nmethodCodeSize ulong: bytes
119656464
nmethodsSize ulong: bytes
173110256
osrBytesCompiled ulong: bytes
0
osrCompileCount int
986
peakTimeSpent long: millis
5268
standardBytesCompiled ulong: bytes
0
standardCompileCount int
84250
startTime long: millis
341445155043
totalTimeSpent long: millis
344826
bailoutCount int
13
compileCount int
78470
invalidatedCount int
0
nmethodCodeSize ulong: bytes
103200192
nmethodsSize ulong: bytes
152663568
osrBytesCompiled ulong: bytes
0
osrCompileCount int
898
peakTimeSpent long: millis
12707
standardBytesCompiled ulong: bytes
0
standardCompileCount int
77572
startTime long: millis
444521282828
totalTimeSpent long: millis
740170
bailoutCount int
16
compileCount int
104681
invalidatedCount int
0
nmethodCodeSize ulong: bytes
146693512
nmethodsSize ulong: bytes
218424592
osrBytesCompiled ulong: bytes
0
osrCompileCount int
993
peakTimeSpent long: millis
10482
standardBytesCompiled ulong: bytes
0
standardCompileCount int
103688
startTime long: millis
490753671581
totalTimeSpent long: millis
699259

CompilerConfiguration

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

Category: Java Virtual Machine / Compiler

Code Context

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

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

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

TRACE_REQUEST_FUNC(CompilerConfiguration) {
  EventCompilerConfiguration event;
  event.set_threadCount(CICompilerCount);
  event.set_tieredCompilation(TieredCompilation);
  event.commit();
}

TRACE_REQUEST_FUNC(CodeCacheStatistics) {
  // Emit stats for all available code heaps
  for (int bt = 0; bt < CodeBlobType::NumTypes; ++bt) {
    if (CodeCache::heap_available(bt)) {
      EventCodeCacheStatistics event;
      event.set_codeBlobType((u1)bt);

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
threadCount int Thread Count
tieredCompilation boolean Tiered Compilation

Examples 3
startTime long: millis
461166582378
threadCount int
3
tieredCompilation boolean
true
startTime long: millis
352206811708
threadCount int
3
tieredCompilation boolean
true
startTime long: millis
413449080534
threadCount int
3
tieredCompilation boolean
true

JVM: Diagnostics

SyncOnValueBasedClass

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

Category: Java Virtual Machine / Diagnostics

Code Context

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

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

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

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

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

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

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
valueBasedClass Class Value Based Class

HeapDump

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

Category: Java Virtual Machine / Diagnostics

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:

// dump the heap to given path.
int HeapDumper::dump(const char* path, outputStream* out, int compression) {
  assert(path != NULL && strlen(path) > 0, "path missing");

  // print message in interactive case
  if (out != NULL) {
    out->print_cr("Dumping heap to %s ...", path);
    timer()->start();
  }

  // create JFR event
  EventHeapDump event;

  AbstractCompressor* compressor = NULL;

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

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

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

Field Type Description
destination string Destination
size long Size
gcBeforeDump boolean GC Before Dump
onOutOfMemoryError boolean On Out of Memory Error

JVM: Flag

IntFlagChanged

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Code Context

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

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

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

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

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

Configuration enabled
profiling true
default true

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

UnsignedIntFlagChanged

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Code Context

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

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

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

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

Configuration enabled
profiling true
default true

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

LongFlagChanged

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Code Context

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

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

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

class FlagAccessImpl_intx : public RangedFlagAccessImpl<JVM_FLAG_TYPE(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
profiling true
default true

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

UnsignedLongFlagChanged

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Code Context

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

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

                        name, value, min, max);
  }
  JVMFlag::Error typed_check_constraint(void* func, intx value, bool verbose) const {
    return ((JVMFlagConstraintFunc_intx)func)(value, verbose);
  }
  void print_range_impl(outputStream* st, intx min, intx max) const {
    st->print("[ " 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<JVM_FLAG_TYPE(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<JVM_FLAG_TYPE(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<JVM_FLAG_TYPE(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
profiling true
default true

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

DoubleFlagChanged

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Code Context

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

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

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

Configuration enabled
profiling true
default true

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

BooleanFlagChanged

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Code Context

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

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

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

    return JVMFlag::SUCCESS;
  }

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

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

class FlagAccessImpl_bool : public TypedFlagAccessImpl<JVM_FLAG_TYPE(bool), EventBooleanFlagChanged> {
public:
  JVMFlag::Error set_impl(JVMFlag* flag, void* value_addr, JVMFlagOrigin origin) const {
    bool verbose = JVMFlagLimit::verbose_checks_needed();
    return TypedFlagAccessImpl<JVM_FLAG_TYPE(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, int type_enum, typename EVENT>
class RangedFlagAccessImpl : public TypedFlagAccessImpl<T, type_enum, EVENT> {
public:

Configuration enabled
profiling true
default true

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

StringFlagChanged

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / Flag

Code Context

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

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

  if (flag == NULL) {
    return JVMFlag::INVALID_FLAG;
  }
  if (flag->type() != type_enum) {
    return JVMFlag::WRONG_FORMAT;
  }
  return access_impl(flag)->set(flag, value, origin);
}

JVMFlag::Error JVMFlagAccess::ccstrAtPut(JVMFlag* flag, ccstr* value, JVMFlagOrigin origin) {
  if (flag == NULL) 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 = NULL;
  if (*value != NULL) {
    new_value = os::strdup_check_oom(*value);
  }
  flag->set_ccstr(new_value);
  if (flag->is_default() && old_value != NULL) {
    // Prior value is NOT heap allocated, but was a literal constant.
    old_value = os::strdup_check_oom(old_value);
  }
  *value = old_value;
  flag->set_origin(origin);

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

  JVMFlag* flag = JVMFlag::flag_from_enum(flag_enum);
  assert(flag->type() == type_enum, "wrong flag type");
  return set_impl(flag, type_enum, value, origin);
}

// This is called by the FLAG_SET_XXX macros.
JVMFlag::Error JVMFlagAccess::ccstrAtPut(JVMFlagsEnum flag, ccstr value, JVMFlagOrigin origin) {
  JVMFlag* faddr = JVMFlag::flag_from_enum(flag);
  assert(faddr->is_ccstr(), "wrong flag type");
  ccstr old_value = faddr->get_ccstr();
  trace_flag_changed<ccstr, EventStringFlagChanged>(faddr, old_value, value, origin);
  char* new_value = os::strdup_check_oom(value);
  faddr->set_ccstr(new_value);
  if (!faddr->is_default() && old_value != NULL) {
    // Prior value is heap allocated so free it.
    FREE_C_HEAP_ARRAY(char, old_value);
  }
  faddr->set_origin(origin);
  return JVMFlag::SUCCESS;
}

JVMFlag::Error JVMFlagAccess::check_range(const JVMFlag* flag, bool verbose) {

Configuration enabled
profiling true
default true

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

IntFlag

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

Category: Java Virtual Machine / Flag

Configuration enabled period
profiling true beginChunk
default true beginChunk

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

Examples 3
name string
JavaPriority4_To_OSPriority
origin FlagValueOrigin
Default
startTime long: millis
404635139233
value int
-1
name string
DeoptimizeObjectsALotThreadCountAll
origin FlagValueOrigin
Default
startTime long: millis
280663476501
value int
1
name string
UseSSE
origin FlagValueOrigin
Default
startTime long: millis
386025194909
value int
4

UnsignedIntFlag

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

Category: Java Virtual Machine / Flag

Configuration enabled period
profiling true beginChunk
default true beginChunk

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

Examples 3
name string
SharedSymbolTableBucketSize
origin FlagValueOrigin
Default
startTime long: millis
398111957222
value uint
4
name string
G1ConcRefinementThreads
origin FlagValueOrigin
Ergonomic
startTime long: millis
280663485077
value uint
4
name string
G1RemSetArrayOfCardsEntriesBase
origin FlagValueOrigin
Default
startTime long: millis
378913109577
value uint
8

LongFlag

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

Category: Java Virtual Machine / Flag

Configuration enabled period
profiling true beginChunk
default true beginChunk

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

Examples 3
name string
LoopOptsCount
origin FlagValueOrigin
Default
startTime long: millis
278185500763
value long
43
name string
MaxRecursiveInlineLevel
origin FlagValueOrigin
Default
startTime long: millis
378913120959
value long
1
name string
MaxVectorSize
origin FlagValueOrigin
Default
startTime long: millis
371363180474
value long
32

UnsignedLongFlag

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

Category: Java Virtual Machine / Flag

Configuration enabled period
profiling true beginChunk
default true beginChunk

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

Examples 3
name string
G1ConfidencePercent
origin FlagValueOrigin
Default
startTime long: millis
378913146917
value ulong
50
name string
SurvivorRatio
origin FlagValueOrigin
Default
startTime long: millis
371363221510
value ulong
8
name string
MaxMetaspaceFreeRatio
origin FlagValueOrigin
Default
startTime long: millis
278185527223
value ulong
70

DoubleFlag

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

Category: Java Virtual Machine / Flag

Configuration enabled period
profiling true beginChunk
default true beginChunk

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

Examples 3
name string
G1ConcMarkStepDurationMillis
origin FlagValueOrigin
Default
startTime long: millis
286474505938
value double
10.0
name string
MinRAMPercentage
origin FlagValueOrigin
Default
startTime long: millis
392343958789
value double
50.0
name string
ZCollectionIntervalMajor
origin FlagValueOrigin
Default
startTime long: millis
383182394352
value double
-1.0

BooleanFlag

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

Category: Java Virtual Machine / Flag

Configuration enabled period
profiling true beginChunk
default true beginChunk

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

Examples 3
name string
PrintSimpleStubs
origin FlagValueOrigin
Default
startTime long: millis
378913179688
value boolean
false
name string
DebugDeoptimization
origin FlagValueOrigin
Default
startTime long: millis
278185617391
value boolean
false
name string
ProfileTraps
origin FlagValueOrigin
Default
startTime long: millis
371363298192
value boolean
true

StringFlag

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

Category: Java Virtual Machine / Flag

Configuration enabled period
profiling true beginChunk
default true beginChunk

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

Examples 3
name string
ReplayDataFile
origin FlagValueOrigin
Default
startTime long: millis
380799334722
value string
null
name string
ArchiveHeapTestClass
origin FlagValueOrigin
Default
startTime long: millis
388178055344
value string
null
name string
InlineDataFile
origin FlagValueOrigin
Default
startTime long: millis
285196734607
value string
null

JVM: GC: Collector

GarbageCollection

profiling default startTime duration 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Collector

Garbage collection performed by the JVM

Code Context

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

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

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

typedef uintptr_t TraceAddress;

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

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

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

Examples 3
cause GCCause
Heap Inspection Initiated GC
gcId uint
398
longestPause Tickspan
2208901
name GCName
ParallelScavenge
startTime long: millis
380799386438
sumOfPauses Tickspan
2208901
cause GCCause
G1 Evacuation Pause
gcId uint
1019
longestPause Tickspan
7469435
name GCName
G1New
startTime long: millis
313728496244
sumOfPauses Tickspan
7469435
cause GCCause
Allocation Failure
gcId uint
928
longestPause Tickspan
8058965
name GCName
DefNew
startTime long: millis
446096318995
sumOfPauses Tickspan
8058965

ParallelOldGarbageCollection

profiling default startTime duration 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Collector

Appearing in: ParallelGC

Missing in: G1GC, SerialGC, ShenandoahGC, ZGC

Extra information specific to Parallel Old Garbage Collections

Code Context

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

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

    e.set_smallChunksTotalSize(summary.small_chunks_size_in_bytes());

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

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

    e.commit();
  }
}

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

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

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

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

Examples 1
densePrefix ulong: address
30427054080
gcId uint
403
startTime long: millis
383184614003

YoungGarbageCollection

profiling default startTime duration 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Collector

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Extra information specific to Young Garbage Collections

Code Context

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

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

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

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

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

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
tenuringThreshold uint Tenuring Threshold

Examples 3
gcId uint
437
startTime long: millis
435445184573
tenuringThreshold uint
15
gcId uint
933
startTime long: millis
451522035612
tenuringThreshold uint
15
gcId uint
1079
startTime long: millis
341921782665
tenuringThreshold uint
15

OldGarbageCollection

profiling default startTime duration 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Collector

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Extra information specific to Old Garbage Collections

Code Context

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

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

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

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

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

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier

Examples 3
gcId uint
997
startTime long: millis
482614681858
gcId uint
1037
startTime long: millis
325838879134
gcId uint
495
startTime long: millis
482471857014

G1GarbageCollection

profiling default startTime duration 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Collector

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Extra information specific to G1 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:

                                                  double predicted_allocation_rate,
                                                  double predicted_marking_length,
                                                  bool prediction_active) {
  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() {
  EventG1GarbageCollection e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_type(_g1_young_gc_info.type());
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

void G1NewTracer::send_evacuation_info_event(G1EvacuationInfo* info) {
  EventEvacuationInformation e;

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
type G1YCType Type

Examples 1
gcId uint
1020
startTime long: millis
313929695520
type G1YCType
Prepare Mixed

JVM: GC: Configuration

GCConfiguration

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

Category: Java Virtual Machine / GC / Configuration

The configuration of the garbage collector

Code Context

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

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

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

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

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

Configuration enabled period
profiling true everyChunk
default true everyChunk

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

Examples 3
concurrentGCThreads uint
0
gcTimeRatio uint
99
isExplicitGCConcurrent boolean
false
isExplicitGCDisabled boolean
false
oldCollector GCName
SerialOld
parallelGCThreads uint
0
pauseTarget long: millis
-9223372036854775808
startTime long: millis
388495621977
usesDynamicGCThreads boolean
true
youngCollector GCName
DefNew
concurrentGCThreads uint
1
gcTimeRatio uint
12
isExplicitGCConcurrent boolean
false
isExplicitGCDisabled boolean
false
oldCollector GCName
G1Old
parallelGCThreads uint
4
pauseTarget long: millis
-9223372036854775808
startTime long: millis
280827556420
usesDynamicGCThreads boolean
true
youngCollector GCName
G1New
concurrentGCThreads uint
0
gcTimeRatio uint
99
isExplicitGCConcurrent boolean
false
isExplicitGCDisabled boolean
false
oldCollector GCName
ParallelOld
parallelGCThreads uint
4
pauseTarget long: millis
-9223372036854775808
startTime long: millis
482664306958
usesDynamicGCThreads boolean
true
youngCollector GCName
ParallelScavenge

GCSurvivorConfiguration

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

Category: Java Virtual Machine / GC / Configuration

The configuration of the survivors of garbage collection

Code Context

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

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

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

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

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

Configuration enabled period
profiling true beginChunk
default true beginChunk

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

Examples 3
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
357327566327
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
443487066359
initialTenuringThreshold ubyte
7
maxTenuringThreshold ubyte
15
startTime long: millis
413773111761

GCTLABConfiguration

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

Category: Java Virtual Machine / GC / Configuration

The configuration of the Thread Local Allocation Buffers (TLABs)

Code Context

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

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

  event.set_oldCollector(conf.old_collector());
  event.set_parallelGCThreads(conf.num_parallel_gc_threads());
  event.set_concurrentGCThreads(conf.num_concurrent_gc_threads());
  event.set_usesDynamicGCThreads(conf.uses_dynamic_gc_threads());
  event.set_isExplicitGCConcurrent(conf.is_explicit_gc_concurrent());
  event.set_isExplicitGCDisabled(conf.is_explicit_gc_disabled());
  event.set_gcTimeRatio(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(conf.max_tenuring_threshold());
  event.set_initialTenuringThreshold(conf.initial_tenuring_threshold());

Configuration enabled period
profiling true beginChunk
default true beginChunk

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

Examples 3
minTLABSize ulong: bytes
2048
startTime long: millis
428614576850
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true
minTLABSize ulong: bytes
2048
startTime long: millis
390507144523
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true
minTLABSize ulong: bytes
2048
startTime long: millis
299932217800
tlabRefillWasteLimit ulong: bytes
64
usesTLABs boolean
true

GCHeapConfiguration

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

Category: Java Virtual Machine / GC / Configuration

The configuration of the garbage collected heap

Code Context

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

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

  event.commit();
}

TRACE_REQUEST_FUNC(GCSurvivorConfiguration) {
  GCSurvivorConfiguration conf;
  EventGCSurvivorConfiguration event;
  event.set_maxTenuringThreshold(conf.max_tenuring_threshold());
  event.set_initialTenuringThreshold(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(conf.heap_address_size_in_bits());
  event.commit();
}

TRACE_REQUEST_FUNC(YoungGenerationConfiguration) {

Configuration enabled period
profiling true beginChunk
default true beginChunk

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

Examples 3
compressedOopsMode NarrowOopMode
Zero based
heapAddressBits ubyte
32
initialSize ulong: bytes
262144000
maxSize ulong: bytes
4194304000
minSize ulong: bytes
8388608
objectAlignment ulong: bytes
8
startTime long: millis
471106617033
usesCompressedOops boolean
true
compressedOopsMode NarrowOopMode
Zero based
heapAddressBits ubyte
32
initialSize ulong: bytes
262144000
maxSize ulong: bytes
4194304000
minSize ulong: bytes
8388608
objectAlignment ulong: bytes
8
startTime long: millis
443487067321
usesCompressedOops boolean
true
compressedOopsMode NarrowOopMode
Zero based
heapAddressBits ubyte
32
initialSize ulong: bytes
262144000
maxSize ulong: bytes
4194304000
minSize ulong: bytes
8388608
objectAlignment ulong: bytes
8
startTime long: millis
285352592554
usesCompressedOops boolean
true

YoungGenerationConfiguration

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

Category: Java Virtual Machine / GC / Configuration

The configuration of the young generation of the garbage collected heap

Code Context

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

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

  event.set_minSize(conf.min_size());
  event.set_maxSize(conf.max_size());
  event.set_initialSize(conf.initial_size());
  event.set_usesCompressedOops(conf.uses_compressed_oops());
  event.set_compressedOopsMode(conf.narrow_oop_mode());
  event.set_objectAlignment(conf.object_alignment_in_bytes());
  event.set_heapAddressBits(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(conf.new_ratio());
  event.commit();
}

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

Configuration enabled period
profiling true beginChunk
default true beginChunk

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

Examples 3
maxSize ulong: bytes
1397751808
minSize ulong: bytes
87031808
newRatio uint
2
startTime long: millis
407159182382
maxSize ulong: bytes
1398079488
minSize ulong: bytes
87359488
newRatio uint
2
startTime long: millis
422343701250
maxSize ulong: bytes
2516582400
minSize ulong: bytes
1363144
newRatio uint
2
startTime long: millis
299932219553

JVM: GC: Detailed

G1MMU

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Code Context

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

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

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

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

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

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

Configuration enabled
profiling true
default true

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

Examples 1
gcId uint
986
gcTime long: millis
4
pauseTarget long: millis
200
startTime long: millis
301054123335
timeSlice long: millis
201

EvacuationInformation

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Code Context

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

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

void G1NewTracer::send_g1_young_gc_event() {
  EventG1GarbageCollection e(UNTIMED);
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_type(_g1_young_gc_info.type());
    e.set_starttime(_shared_gc_info.start_timestamp());
    e.set_endtime(_shared_gc_info.end_timestamp());
    e.commit();
  }
}

void G1NewTracer::send_evacuation_info_event(G1EvacuationInfo* info) {
  EventEvacuationInformation e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_cSetRegions(info->collectionset_regions());
    e.set_cSetUsedBefore(info->collectionset_used_before());
    e.set_cSetUsedAfter(info->collectionset_used_after());
    e.set_allocationRegions(info->allocation_regions());
    e.set_allocationRegionsUsedBefore(info->alloc_regions_used_before());
    e.set_allocationRegionsUsedAfter(info->alloc_regions_used_before() + info->bytes_used());
    e.set_bytesCopied(info->bytes_used());
    e.set_regionsFreed(info->regions_freed());
    e.commit();

Configuration enabled
profiling true
default true

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

Examples 1
allocationRegions uint
1
allocationRegionsUsedAfter ulong: bytes
154976
allocationRegionsUsedBefore ulong: bytes
0
bytesCopied ulong: bytes
154976
cSetRegions uint
3
cSetUsedAfter ulong: bytes
0
cSetUsedBefore ulong: bytes
6291456
gcId uint
944
regionsFreed uint
3
startTime long: millis
278676456841

ObjectCountAfterGC

startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Code Context

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

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

#if INCLUDE_SERVICES

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

bool ObjectCountEventSender::_should_send_requestable_event = false;

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

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

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

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

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

#endif // INCLUDE_SERVICES

Configuration enabled
profiling false
default false

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

Examples 3
count long
23221
gcId uint
403
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1040
name string
[Ljava/util/HashMap$Node;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util
startTime long: millis
383295230229
totalSize ulong: bytes
1851088
count long
58398
gcId uint
876
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/time/LocalDateTime
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/time
startTime long: millis
379118092812
totalSize ulong: bytes
1401552
count long
23347
gcId uint
946
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1040
name string
[Ljava/util/HashMap$Node;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util
startTime long: millis
279741338458
totalSize ulong: bytes
1879120

G1EvacuationYoungStatistics

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Memory related evacuation statistics during GC for the young generation

Code Context

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

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

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

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

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

Configuration enabled
profiling true
default true

Field Type Description
statistics G1EvacuationStatistics struct Evacuation Statistics

Examples 1
startTime long: millis
308185423817
statistics G1EvacuationStatistics
allocated ulong: bytes
3948224
directAllocated ulong: bytes
8016
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
1001
regionEndWaste ulong: bytes
0
regionsRefilled uint: bytes
2
undoWaste ulong: bytes
0
used ulong: bytes
3664208
wasted ulong: bytes
1808

G1EvacuationOldStatistics

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Memory related evacuation statistics during GC for the old generation

Code Context

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

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

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

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

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

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

Configuration enabled
profiling true
default true

Field Type Description
statistics G1EvacuationStatistics struct Evacuation Statistics

Examples 1
startTime long: millis
366187403771
statistics G1EvacuationStatistics
allocated ulong: bytes
332304
directAllocated ulong: bytes
824
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
1099
regionEndWaste ulong: bytes
0
regionsRefilled uint: bytes
1
undoWaste ulong: bytes
0
used ulong: bytes
315744
wasted ulong: bytes
4728

G1BasicIHOP

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Basic statistics related to current IHOP calculation

Code Context

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

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

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

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

Configuration enabled
profiling true
default true

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

Examples 1
currentOccupancy ulong: bytes
412099656
gcId uint
1040
lastMarkingDuration long: millis
613
recentAllocationRate double: bytes-per-second
3.4715499403522414E8
recentMutatorAllocationSize ulong: bytes
169869312
recentMutatorDuration long: millis
489
startTime long: millis
326804664134
targetOccupancy ulong: bytes
2128609280
threshold ulong: bytes
507537830
thresholdPercentage float: percentage
0.23843636

G1AdaptiveIHOP

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Statistics related to current adaptive IHOP calculation

Code Context

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

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

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

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

Configuration enabled
profiling true
default true

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

Examples 1
additionalBufferSize ulong: bytes
473956352
currentOccupancy ulong: bytes
285610152
gcId uint
998
ihopTargetOccupancy ulong: bytes
924424601
predictedAllocationRate double: bytes-per-second
2.933858826181162E8
predictedMarkingDuration long: millis
1379
predictionActive boolean
true
startTime long: millis
305729681186
threshold ulong: bytes
45615081
thresholdPercentage float: percentage
0.049344297

PromoteObjectInNewPLAB

profiling startTime eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

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

Code Context

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

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

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

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

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

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

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

Configuration enabled
profiling true
default false

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

Examples 2
gcId uint
394
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[F
package Package
null
objectSize ulong: bytes
56
plabSize ulong: bytes
32752
startTime long: millis
371365661150
tenured boolean
false
tenuringAge uint
0
gcId uint
941
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
24
name string
java/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionNode
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent/locks
objectSize ulong: bytes
32
plabSize ulong: bytes
19048
startTime long: millis
278157561896
tenured boolean
false
tenuringAge uint
0

PromoteObjectOutsidePLAB

profiling startTime eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

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

Code Context

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

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

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

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

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

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

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

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

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

void OldGCTracer::send_old_gc_event() const {

Configuration enabled
profiling true
default false

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

Examples 2
gcId uint
400
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[B
package Package
null
objectSize ulong: bytes
27976
startTime long: millis
381805572979
tenured boolean
false
tenuringAge uint
0
gcId uint
941
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1042
name string
[Ljava/io/ObjectInputStream$HandleTable$HandleList;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/io
objectSize ulong: bytes
11280
startTime long: millis
278158106540
tenured boolean
false
tenuringAge uint
0

PromotionFailed

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Promotion of an object failed

Code Context

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

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

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

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

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

Configuration enabled
profiling true
default true

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

EvacuationFailed

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Evacuation of an object failed

Code Context

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

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

    e.set_cSetRegions(info->collectionset_regions());
    e.set_cSetUsedBefore(info->collectionset_used_before());
    e.set_cSetUsedAfter(info->collectionset_used_after());
    e.set_allocationRegions(info->allocation_regions());
    e.set_allocationRegionsUsedBefore(info->alloc_regions_used_before());
    e.set_allocationRegionsUsedAfter(info->alloc_regions_used_before() + info->bytes_used());
    e.set_bytesCopied(info->bytes_used());
    e.set_regionsFreed(info->regions_freed());
    e.commit();
  }
}

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

Configuration enabled
profiling true
default true

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

ConcurrentModeFailure

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Concurrent Mode failed

Code Context

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

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

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

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

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

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier

Examples 1
gcId uint
996
startTime long: millis
305316193888

AllocationRequiringGC

startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Code Context

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

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

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

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

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

Configuration enabled stackTrace
profiling false true
default false true

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

Examples 3
gcId uint
436
size ulong: bytes
16
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
12
lineNumber int
501
method Method
descriptor string
(Ljava/lang/Object;)Ljava/lang/Object;
hidden boolean
false
modifiers int
8
name string
allocateInstance
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/lang/invoke/DirectMethodHandle
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang/invoke
type FrameType
Inlined
truncated boolean
true
startTime long: millis
434837426908
gcId uint
919
size ulong: bytes
144
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
133
lineNumber int
710
method Method
descriptor string
()[Ljava/util/HashMap$Node;
hidden boolean
false
modifiers int
16
name string
resize
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/HashMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util
type FrameType
JIT compiled
truncated boolean
true
startTime long: millis
442104320875
gcId uint
1099
size ulong: bytes
505648
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
11
lineNumber int
126
method Method
descriptor string
(Lcom/twitter/util/Promise$K;Lcom/twitter/util/Promise$WaitQueue;)Lcom/twitter/util/Promise$WaitQueue;
hidden boolean
false
modifiers int
1
name string
apply
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
9
name string
com/twitter/util/Promise$WaitQueue$
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
com/twitter/util
type FrameType
Inlined
truncated boolean
false
startTime long: millis
366182078673

TenuringDistribution

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, SerialGC

Missing in: ParallelGC, ShenandoahGC, ZGC

Code Context

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

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

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

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

Configuration enabled
profiling true
default true

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

Examples 2
age uint
1
gcId uint
894
size ulong: bytes
1751712
startTime long: millis
439112154416
age uint
7
gcId uint
944
size ulong: bytes
0
startTime long: millis
278676447213

G1HeapRegionTypeChange

startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Information about a G1 heap region type change

Code Context

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

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

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

Configuration enabled
profiling false
default false

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

Examples 1
from G1HeapRegionType
Free
index uint
454
start ulong: address
31117541376
startTime long: millis
275189933368
to G1HeapRegionType
Eden
used ulong: bytes
0

ObjectCount

startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Code Context

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

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

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

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

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

#endif // INCLUDE_SERVICES

Configuration enabled period
profiling false everyChunk
default false everyChunk

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

Examples 3
count long
81599
gcId uint
943
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
8
name string
java/util/HashMap$Node
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util
startTime long: millis
278294395695
totalSize ulong: bytes
2611168
count long
5885
gcId uint
879
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[F
package Package
null
startTime long: millis
390193059103
totalSize ulong: bytes
24324136
count long
126780
gcId uint
397
objectClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Object
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
startTime long: millis
374761390206
totalSize ulong: bytes
2028480

G1HeapRegionInformation

startTime duration every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Information about a specific heap region in the G1 GC

Code Context

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

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

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

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

Configuration enabled period
profiling false everyChunk
default false everyChunk

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

Examples 1
index uint
400
start ulong: address
31004295168
startTime long: millis
278345514459
type G1HeapRegionType
Free
used ulong: bytes
0

ZAllocationStall

profiling default startTime duration eventThread 15 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Time spent waiting for memory to become available

Code Context

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

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

  // Success
  return true;
}

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

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

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

  do {
    // Start asynchronous GC
    ZCollectedHeap::heap()->collect(GCCause::_z_allocation_stall);

    // Wait for allocation to complete, fail or request a GC
    result = allocation->wait();

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
type ZPageTypeType Type
size ulong: bytes Size

ZPageAllocation

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

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Allocation of a ZPage

Code Context

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

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

    free_page_inner(page, false /* reclaimed */);
  }

  // Adjust capacity and used to reflect the failed capacity increase
  const size_t remaining = allocation->size() - freed;
  decrease_used(remaining, false /* reclaimed */);
  decrease_capacity(remaining, true /* set_max_capacity */);

  // Try satisfy stalled allocations
  satisfy_stalled();
}

ZPage* ZPageAllocator::alloc_page(uint8_t type, size_t size, ZAllocationFlags flags) {
  EventZPageAllocation event;

retry:
  ZPageAllocation allocation(type, size, flags);

  // Allocate one or more pages from the page cache. If the allocation
  // succeeds but the returned pages don't cover the complete allocation,
  // then finalize phase is allowed to allocate the remaining memory
  // directly from the physical memory manager. Note that this call might
  // block in a safepoint if the non-blocking flag is not set.
  if (!alloc_page_or_stall(&allocation)) {
    // Out of memory

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

Field Type Description
type ZPageTypeType 15+ Type
size ulong: bytes 15+ Size
flushed ulong: bytes 17 21 until JDK 25 Flushed
committed ulong: bytes 15+ Committed
segments uint 17 21 until JDK 25 Segments
nonBlocking boolean Non-blocking

Examples 1
committed ulong: bytes
0
flushed ulong: bytes
0
nonBlocking boolean
false
segments uint
1
size ulong: bytes
2097152
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
175
lineNumber int
1425
method Method
descriptor string
(Ljava/lang/Class;I)V
hidden boolean
false
modifiers int
2
name string
filterCheck
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/io/ObjectInputStream
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/io
type FrameType
JIT compiled
truncated boolean
true
startTime long: millis
431283089322
type ZPageTypeType
Small

ZRelocationSet

profiling default startTime duration eventThread 15 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Code Context

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

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

ZRelocationSetSelector::ZRelocationSetSelector() :
    _small("Small", ZPageTypeSmall, ZPageSizeSmall, ZObjectSizeLimitSmall),
    _medium("Medium", ZPageTypeMedium, ZPageSizeMedium, ZObjectSizeLimitMedium),
    _large("Large", ZPageTypeLarge, 0 /* page_size */, 0 /* object_size_limit */),
    _empty_pages() {}

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

  EventZRelocationSet event;

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

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

ZRelocationSetSelectorStats ZRelocationSetSelector::stats() const {

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

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

Examples 1
empty ulong: bytes
0
relocate ulong: bytes
1599224
startTime long: millis
492341912093
total ulong: bytes
476053504

ZRelocationSetGroup

profiling default startTime duration eventThread 15 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Code Context

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

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

  // Update statistics
  _stats._relocate = selected_live_bytes;

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

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

  EventZRelocationSetGroup event;

  if (is_selectable()) {
    select_inner();
  }

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

ZRelocationSetSelector::ZRelocationSetSelector() :
    _small("Small", ZPageTypeSmall, ZPageSizeSmall, ZObjectSizeLimitSmall),

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
type ZPageTypeType Type
pages ulong 17 until JDK 21 Pages
total ulong: bytes Total
empty ulong: bytes Empty
relocate ulong: bytes 16+ Relocate

Examples 1
empty ulong: bytes
6291456
relocate ulong: bytes
0
startTime long: millis
466550818987
total ulong: bytes
71303168
type ZPageTypeType
Large

ZStatisticsCounter

experimental startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Code Context

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

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

#ifndef SHARE_GC_Z_ZTRACER_INLINE_HPP
#define SHARE_GC_Z_ZTRACER_INLINE_HPP

#include "gc/z/zTracer.hpp"
#include "jfr/jfrEvents.hpp"

inline ZTracer* ZTracer::tracer() {
  return _tracer;
}

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

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

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

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

ZTracer::ZTracer() :
    GCTracer(Z) {}

void ZTracer::initialize() {
  assert(_tracer == NULL, "Already initialized");
  _tracer = new (ResourceObj::C_HEAP, mtGC) ZTracer();
  JFR_ONLY(register_jfr_type_serializers());
}

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

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

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

Configuration enabled threshold
profiling false 0 ms
default false 0 ms

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

Examples 1
id ZStatisticsCounterType
Page Cache Hit L1
increment ulong
1
startTime long: millis
373309160764
value ulong
3

ZStatisticsSampler

experimental startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Code Context

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

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

inline ZTracer* ZTracer::tracer() {
  return _tracer;
}

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

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

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

inline ZTraceThreadPhase::ZTraceThreadPhase(const char* name) :

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

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

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

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

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

  EventZThreadPhase e(UNTIMED);

Configuration enabled threshold
profiling false 0 ms
default false 0 ms

Field Type Description
id ZStatisticsSamplerType Id
value ulong Value

Examples 1
id ZStatisticsSamplerType
Undo Object Allocation Failed
startTime long: millis
376093313658
value ulong
0

ZThreadPhase

experimental startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Code Context

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

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

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

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

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

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

inline ZTraceThreadPhase::~ZTraceThreadPhase() {
  ZTracer::tracer()->report_thread_phase(_name, _start, Ticks::now());
}

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

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

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

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

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

Configuration enabled threshold
profiling false 0 ms
default false 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 1
gcId uint
226
name string
Concurrent Roots OopStorageSet
startTime long: millis
377013206968

ZUncommit

profiling default startTime duration eventThread 15 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Uncommitting of memory

Code Context

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

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

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

void ZUncommitter::run_service() {
  uint64_t timeout = 0;

  while (wait(timeout)) {
    EventZUncommit event;
    size_t uncommitted = 0;

    while (should_continue()) {
      // Uncommit chunk
      const size_t flushed = _page_allocator->uncommit(&timeout);
      if (flushed == 0) {
        // Done
        break;
      }

      uncommitted += flushed;

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
uncommitted ulong: bytes Uncommitted

ZUnmap

profiling default startTime duration eventThread 17 21 until JDK 25

Category: Java Virtual Machine / GC / Detailed

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Unmapping of memory

Code Context

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

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

    ZPage* const page = _queue.remove_first();
    if (page != NULL) {
      return page;
    }

    _lock.wait();
  }
}

void ZUnmapper::do_unmap_and_destroy_page(ZPage* page) const {
  EventZUnmap event;
  const size_t unmapped = page->size();

  // Unmap and destroy
  _page_allocator->unmap_page(page);
  _page_allocator->destroy_page(page);

  // Send event
  event.commit(unmapped);
}

void ZUnmapper::unmap_and_destroy_page(ZPage* page) {

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
unmapped ulong: bytes Unmapped

Examples 1
startTime long: millis
454330336245
unmapped ulong: bytes
2097152

ShenandoahHeapRegionStateChange

startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

Information about a Shenandoah heap region state change

Code Context

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

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

void ShenandoahHeapRegion::do_uncommit() {
  ShenandoahHeap* heap = ShenandoahHeap::heap();
  if (!heap->is_heap_region_special() && !os::uncommit_memory((char *) bottom(), RegionSizeBytes)) {
    report_java_out_of_memory("Unable to uncommit region");
  }
  if (!heap->uncommit_bitmap_slice(this)) {
    report_java_out_of_memory("Unable to uncommit bitmaps for region");
  }
  heap->decrease_committed(ShenandoahHeapRegion::region_size_bytes());
}

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

Configuration enabled
profiling false
default false

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

Examples 1
from ShenandoahHeapRegionState
Empty Committed
index uint
99
start ulong: address
30270291968
startTime long: millis
293089381723
to ShenandoahHeapRegionState
Empty Uncommitted
used ulong: bytes
0

ShenandoahHeapRegionInformation

startTime duration every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Detailed

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

Information about a specific heap region in the Shenandoah GC

Code Context

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

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

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

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

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

Configuration enabled period
profiling false everyChunk
default false everyChunk

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

Examples 1
index uint
3925
start ulong: address
34282143744
startTime long: millis
294908970201
state ShenandoahHeapRegionState
Regular
used ulong: bytes
1048576

JVM: GC: Heap

GCHeapSummary

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Heap

Code Context

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

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

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

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

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

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

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

Configuration enabled
profiling true
default true

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

Examples 3
gcId uint
419
heapSpace VirtualSpace
committedEnd ulong: address
33022803968
committedSize ulong: bytes
2857369600
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4194304000
start ulong: address
30165434368
heapUsed ulong: bytes
269617440
startTime long: millis
407001863472
when GCWhen
Before GC
gcId uint
883
heapSpace VirtualSpace
committedEnd ulong: address
31159918592
committedSize ulong: bytes
994484224
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4194304000
start ulong: address
30165434368
heapUsed ulong: bytes
269855184
startTime long: millis
406049890144
when GCWhen
After GC
gcId uint
957
heapSpace VirtualSpace
committedEnd ulong: address
31144804352
committedSize ulong: bytes
979369984
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4194304000
start ulong: address
30165434368
heapUsed ulong: bytes
284560912
startTime long: millis
285175408550
when GCWhen
After GC

MetaspaceSummary

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Heap

Code Context

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

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

static JfrStructMetaspaceSizes to_struct(const MetaspaceSizes& sizes) {
  JfrStructMetaspaceSizes meta_sizes;

  meta_sizes.set_committed(sizes.committed());
  meta_sizes.set_used(sizes.used());
  meta_sizes.set_reserved(sizes.reserved());

  return meta_sizes;
}

void GCTracer::send_meta_space_summary_event(GCWhen::Type when, const MetaspaceSummary& meta_space_summary) const {
  EventMetaspaceSummary e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_when((u1) when);
    e.set_gcThreshold(meta_space_summary.capacity_until_GC());
    e.set_metaspace(to_struct(meta_space_summary.meta_space()));
    e.set_dataSpace(to_struct(meta_space_summary.data_space()));
    e.set_classSpace(to_struct(meta_space_summary.class_space()));
    e.commit();
  }
}

Configuration enabled
profiling true
default true

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

Examples 3
classSpace MetaspaceSizes
committed ulong: bytes
88080384
reserved ulong: bytes
1073741824
used ulong: bytes
86220768
dataSpace MetaspaceSizes
committed ulong: bytes
571080704
reserved ulong: bytes
603979776
used ulong: bytes
569170248
gcId uint
976
gcThreshold ulong: bytes
1098383360
metaspace MetaspaceSizes
committed ulong: bytes
659161088
reserved ulong: bytes
1677721600
used ulong: bytes
655391016
startTime long: millis
293574937833
when GCWhen
After GC
classSpace MetaspaceSizes
committed ulong: bytes
90112000
reserved ulong: bytes
1073741824
used ulong: bytes
88177368
dataSpace MetaspaceSizes
committed ulong: bytes
583729152
reserved ulong: bytes
603979776
used ulong: bytes
581802360
gcId uint
892
gcThreshold ulong: bytes
1099956224
metaspace MetaspaceSizes
committed ulong: bytes
673841152
reserved ulong: bytes
1677721600
used ulong: bytes
669979728
startTime long: millis
432433411389
when GCWhen
After GC
classSpace MetaspaceSizes
committed ulong: bytes
88276992
reserved ulong: bytes
1073741824
used ulong: bytes
86422272
dataSpace MetaspaceSizes
committed ulong: bytes
572391424
reserved ulong: bytes
603979776
used ulong: bytes
570481008
gcId uint
437
gcThreshold ulong: bytes
1100939264
metaspace MetaspaceSizes
committed ulong: bytes
660668416
reserved ulong: bytes
1677721600
used ulong: bytes
656903280
startTime long: millis
435452916347
when GCWhen
After GC

PSHeapSummary

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Heap

Appearing in: ParallelGC

Missing in: G1GC, SerialGC, ShenandoahGC, ZGC

Code Context

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

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

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

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

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

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

Configuration enabled
profiling true
default true

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

Examples 1
edenSpace ObjectSpace
end ulong: address
34230239232
size ulong: bytes
1268252672
start ulong: address
32961986560
used ulong: bytes
0
fromSpace ObjectSpace
end ulong: address
34326708224
size ulong: bytes
46137344
start ulong: address
34280570880
used ulong: bytes
0
gcId uint
399
oldObjectSpace ObjectSpace
end ulong: address
31729909760
size ulong: bytes
1564475392
start ulong: address
30165434368
used ulong: bytes
262506928
oldSpace VirtualSpace
committedEnd ulong: address
31729909760
committedSize ulong: bytes
1564475392
reservedEnd ulong: address
32961986560
reservedSize ulong: bytes
2796552192
start ulong: address
30165434368
startTime long: millis
380956002195
toSpace ObjectSpace
end ulong: address
34278473728
size ulong: bytes
48234496
start ulong: address
34230239232
used ulong: bytes
0
when GCWhen
After GC
youngSpace VirtualSpace
committedEnd ulong: address
34326708224
committedSize ulong: bytes
1364721664
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
1397751808
start ulong: address
32961986560

G1HeapSummary

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Heap

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Code Context

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

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

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

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

    EventG1HeapSummary e;
    if (e.should_commit()) {
      e.set_gcId(GCId::current());
      e.set_when((u1)_when);
      e.set_edenUsedSize(g1_heap_summary->edenUsed());
      e.set_edenTotalSize(g1_heap_summary->edenCapacity());
      e.set_survivorUsedSize(g1_heap_summary->survivorUsed());
      e.set_numberOfRegions(g1_heap_summary->numberOfRegions());
      e.commit();
    }
  }

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier
when GCWhen When
edenUsedSize ulong: bytes Eden Used Size
edenTotalSize ulong: bytes Eden Total Size
survivorUsedSize ulong: bytes Survivor Used Size
numberOfRegions uint Number of Regions

Examples 1
edenTotalSize ulong: bytes
576716800
edenUsedSize ulong: bytes
0
gcId uint
968
numberOfRegions uint
474
startTime long: millis
288057158711
survivorUsedSize ulong: bytes
0
when GCWhen
After GC

JVM: GC: Metaspace

MetaspaceGCThreshold

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Metaspace

Code Context

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

src/hotspot/share/memory/metaspaceTracer.cpp:

void MetaspaceTracer::report_gc_threshold(size_t old_val,
                                          size_t new_val,
                                          MetaspaceGCThresholdUpdater::Type updater) const {
  EventMetaspaceGCThreshold event;
  if (event.should_commit()) {
    event.set_oldValue(old_val);
    event.set_newValue(new_val);
    event.set_updater((u1)updater);
    event.commit();
  }
}

void MetaspaceTracer::report_metaspace_allocation_failure(ClassLoaderData *cld,
                                                          size_t word_size,
                                                          MetaspaceObj::Type objtype,
                                                          Metaspace::MetadataType mdtype) const {
  send_allocation_failure_event<EventMetaspaceAllocationFailure>(cld, word_size, objtype, mdtype);
}

Configuration enabled
profiling true
default true

Field Type Description
oldValue ulong: bytes Old Value
newValue ulong: bytes New Value
updater GCThresholdUpdater Updater

Examples 3
newValue ulong: bytes
1317928960
oldValue ulong: bytes
1232207872
startTime long: millis
448259778822
updater GCThresholdUpdater
compute_new_size
newValue ulong: bytes
1543176192
oldValue ulong: bytes
1533476864
startTime long: millis
352161881427
updater GCThresholdUpdater
compute_new_size
newValue ulong: bytes
1098973184
oldValue ulong: bytes
1098645504
startTime long: millis
388495414067
updater GCThresholdUpdater
compute_new_size

MetaspaceAllocationFailure

profiling default startTime stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Metaspace

Code Context

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

src/hotspot/share/memory/metaspaceTracer.cpp:

  EventMetaspaceGCThreshold event;
  if (event.should_commit()) {
    event.set_oldValue(old_val);
    event.set_newValue(new_val);
    event.set_updater((u1)updater);
    event.commit();
  }
}

void MetaspaceTracer::report_metaspace_allocation_failure(ClassLoaderData *cld,
                                                          size_t word_size,
                                                          MetaspaceObj::Type objtype,
                                                          Metaspace::MetadataType mdtype) const {
  send_allocation_failure_event<EventMetaspaceAllocationFailure>(cld, word_size, objtype, mdtype);
}

void MetaspaceTracer::report_metadata_oom(ClassLoaderData *cld,
                                         size_t word_size,
                                         MetaspaceObj::Type objtype,
                                         Metaspace::MetadataType mdtype) const {
  send_allocation_failure_event<EventMetaspaceOOM>(cld, word_size, objtype, mdtype);
}

template <typename E>
void MetaspaceTracer::send_allocation_failure_event(ClassLoaderData *cld,

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
classLoader ClassLoader Class Loader
hiddenClassLoader boolean 15+ Hidden Class Loader
size ulong: bytes Size
metadataType MetadataType Metadata Type
metaspaceObjectType MetaspaceObjectType Metaspace Object Type

MetaspaceOOM

profiling default startTime stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Metaspace

Code Context

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

src/hotspot/share/memory/metaspaceTracer.cpp:

void MetaspaceTracer::report_metaspace_allocation_failure(ClassLoaderData *cld,
                                                          size_t word_size,
                                                          MetaspaceObj::Type objtype,
                                                          Metaspace::MetadataType mdtype) const {
  send_allocation_failure_event<EventMetaspaceAllocationFailure>(cld, word_size, objtype, mdtype);
}

void MetaspaceTracer::report_metadata_oom(ClassLoaderData *cld,
                                         size_t word_size,
                                         MetaspaceObj::Type objtype,
                                         Metaspace::MetadataType mdtype) const {
  send_allocation_failure_event<EventMetaspaceOOM>(cld, word_size, objtype, mdtype);
}

template <typename E>
void MetaspaceTracer::send_allocation_failure_event(ClassLoaderData *cld,
                                                    size_t word_size,
                                                    MetaspaceObj::Type objtype,
                                                    Metaspace::MetadataType mdtype) const {
  E event;
  if (event.should_commit()) {
    event.set_classLoader(cld);
    event.set_hiddenClassLoader(cld->has_class_mirror_holder());

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
classLoader ClassLoader Class Loader
hiddenClassLoader boolean 15+ Hidden Class Loader
size ulong: bytes Size
metadataType MetadataType Metadata Type
metaspaceObjectType MetaspaceObjectType Metaspace Object Type

MetaspaceChunkFreeListSummary

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Metaspace

Code Context

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

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

void GCTracer::send_reference_stats_event(ReferenceType type, size_t count) const {
  EventGCReferenceStatistics e;
  if (e.should_commit()) {
      e.set_gcId(GCId::current());
      e.set_type((u1)type);
      e.set_count(count);
      e.commit();
  }
}

void GCTracer::send_metaspace_chunk_free_list_summary(GCWhen::Type when, Metaspace::MetadataType mdtype,
                                                      const MetaspaceChunkFreeListSummary& summary) const {
  EventMetaspaceChunkFreeListSummary e;
  if (e.should_commit()) {
    e.set_gcId(GCId::current());
    e.set_when(when);
    e.set_metadataType(mdtype);

    e.set_specializedChunks(summary.num_specialized_chunks());
    e.set_specializedChunksTotalSize(summary.specialized_chunks_size_in_bytes());

    e.set_smallChunks(summary.num_small_chunks());
    e.set_smallChunksTotalSize(summary.small_chunks_size_in_bytes());

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier
when GCWhen When
metadataType MetadataType Metadata Type
specializedChunks ulong Specialized Chunks
specializedChunksTotalSize ulong: bytes Specialized Chunks Total Size
smallChunks ulong Small Chunks
smallChunksTotalSize ulong: bytes Small Chunks Total Size
mediumChunks ulong Medium Chunks
mediumChunksTotalSize ulong: bytes Medium Chunks Total Size
humongousChunks ulong Humongous Chunks
humongousChunksTotalSize ulong: bytes Humongous Chunks Total Size

Examples 3
gcId uint
404
humongousChunks ulong
0
humongousChunksTotalSize ulong: bytes
0
mediumChunks ulong
0
mediumChunksTotalSize ulong: bytes
0
metadataType MetadataType
Metadata
smallChunks ulong
0
smallChunksTotalSize ulong: bytes
0
specializedChunks ulong
0
specializedChunksTotalSize ulong: bytes
0
startTime long: millis
384391346306
when GCWhen
After GC
gcId uint
876
humongousChunks ulong
0
humongousChunksTotalSize ulong: bytes
0
mediumChunks ulong
0
mediumChunksTotalSize ulong: bytes
0
metadataType MetadataType
Metadata
smallChunks ulong
0
smallChunksTotalSize ulong: bytes
0
specializedChunks ulong
0
specializedChunksTotalSize ulong: bytes
0
startTime long: millis
379225136832
when GCWhen
After GC
gcId uint
950
humongousChunks ulong
0
humongousChunksTotalSize ulong: bytes
0
mediumChunks ulong
0
mediumChunksTotalSize ulong: bytes
0
metadataType MetadataType
Class
smallChunks ulong
0
smallChunksTotalSize ulong: bytes
0
specializedChunks ulong
0
specializedChunksTotalSize ulong: bytes
0
startTime long: millis
282044960626
when GCWhen
Before GC

JVM: GC: Phases

GCPhasePause

profiling default startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Code Context

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

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

    e.set_gcThreshold(meta_space_summary.capacity_until_GC());
    e.set_metaspace(to_struct(meta_space_summary.meta_space()));
    e.set_dataSpace(to_struct(meta_space_summary.data_space()));
    e.set_classSpace(to_struct(meta_space_summary.class_space()));
    e.commit();
  }
}

class PhaseSender : public PhaseVisitor {
  void visit_pause(GCPhase* phase) {
    assert(phase->level() < PhasesStack::PHASE_LEVELS, "Need more event types for PausePhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 2, "There is only two levels for ConcurrentPhase");

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 3
gcId uint
427
name string
GC Pause
startTime long: millis
426597129288
gcId uint
950
name string
GC Pause
startTime long: millis
282044954815
gcId uint
888
name string
GC Pause
startTime long: millis
415717982964

GCPhasePauseLevel1

profiling default startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Missing in: ZGC

Code Context

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

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

    e.set_metaspace(to_struct(meta_space_summary.meta_space()));
    e.set_dataSpace(to_struct(meta_space_summary.data_space()));
    e.set_classSpace(to_struct(meta_space_summary.class_space()));
    e.commit();
  }
}

class PhaseSender : public PhaseVisitor {
  void visit_pause(GCPhase* phase) {
    assert(phase->level() < PhasesStack::PHASE_LEVELS, "Need more event types for PausePhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 2, "There is only two levels for ConcurrentPhase");

    switch (phase->level()) {

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 3
gcId uint
405
name string
Pre Compact
startTime long: millis
384391350543
gcId uint
960
name string
Notify PhantomReferences
startTime long: millis
285397246048
gcId uint
897
name string
Notify and keep alive finalizable
startTime long: millis
439696246141

GCPhasePauseLevel2

profiling default startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Code Context

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

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

    e.set_dataSpace(to_struct(meta_space_summary.data_space()));
    e.set_classSpace(to_struct(meta_space_summary.class_space()));
    e.commit();
  }
}

class PhaseSender : public PhaseVisitor {
  void visit_pause(GCPhase* phase) {
    assert(phase->level() < PhasesStack::PHASE_LEVELS, "Need more event types for PausePhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 2, "There is only two levels for ConcurrentPhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhaseConcurrent>(phase); break;

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 3
gcId uint
955
name string
Notify and keep alive finalizable
startTime long: millis
282550043797
gcId uint
400
name string
Notify PhantomReferences
startTime long: millis
381805841828
gcId uint
930
name string
Report Object Count
startTime long: millis
450459524924

GCPhasePauseLevel3

startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC, SerialGC

Missing in: ShenandoahGC, ZGC

Code Context

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

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

    e.set_classSpace(to_struct(meta_space_summary.class_space()));
    e.commit();
  }
}

class PhaseSender : public PhaseVisitor {
  void visit_pause(GCPhase* phase) {
    assert(phase->level() < PhasesStack::PHASE_LEVELS, "Need more event types for PausePhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 2, "There is only two levels for ConcurrentPhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhaseConcurrent>(phase); break;
      case 1: send_phase<EventGCPhaseConcurrentLevel1>(phase); break;

Configuration enabled threshold
profiling false 0 ms
default false 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 3
gcId uint
962
name string
G1 Complete Cleaning
startTime long: millis
286254139297
gcId uint
878
name string
Notify PhantomReferences
startTime long: millis
388302490163
gcId uint
399
name string
ClassLoaderData
startTime long: millis
380858361992

GCPhasePauseLevel4

startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

Code Context

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

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

    e.commit();
  }
}

class PhaseSender : public PhaseVisitor {
  void visit_pause(GCPhase* phase) {
    assert(phase->level() < PhasesStack::PHASE_LEVELS, "Need more event types for PausePhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 2, "There is only two levels for ConcurrentPhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhaseConcurrent>(phase); break;
      case 1: send_phase<EventGCPhaseConcurrentLevel1>(phase); break;
      default: /* Ignore sending this phase */ break;

Configuration enabled threshold
profiling false 0 ms
default false 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 2
gcId uint
417
name string
Balance queues
startTime long: millis
400677575090
gcId uint
1028
name string
Balance queues
startTime long: millis
316587528415

GCPhaseConcurrent

profiling default startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ShenandoahGC, ZGC

Missing in: ParallelGC, SerialGC

Code Context

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

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

      case 0: send_phase<EventGCPhasePause>(phase); break;
      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 2, "There is only two levels for ConcurrentPhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhaseConcurrent>(phase); break;
      case 1: send_phase<EventGCPhaseConcurrentLevel1>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

 public:
  template<typename T>
  void send_phase(GCPhase* phase) {
    T event(UNTIMED);
    if (event.should_commit()) {
      event.set_gcId(GCId::current());

src/hotspot/share/gc/shenandoah/shenandoahUtils.hpp:

  ShenandoahWorkerSession(uint worker_id);
  ~ShenandoahWorkerSession();
public:
  static inline uint worker_id() {
    Thread* thr = Thread::current();
    uint id = ShenandoahThreadLocalData::worker_id(thr);
    assert(id != ShenandoahThreadLocalData::INVALID_WORKER_ID, "Worker session has not been created");
    return id;
  }
};

class ShenandoahConcurrentWorkerSession : public ShenandoahWorkerSession {
private:
  EventGCPhaseConcurrent _event;

public:
  ShenandoahConcurrentWorkerSession(uint worker_id) : ShenandoahWorkerSession(worker_id) { }
  ~ShenandoahConcurrentWorkerSession();
};

class ShenandoahParallelWorkerSession : public ShenandoahWorkerSession {
private:
  EventGCPhaseParallel _event;

public:

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 3
gcId uint
227
name string
Concurrent reset
startTime long: millis
300727833824
gcId uint
973
name string
Concurrent Mark From Roots
startTime long: millis
289468517170
gcId uint
237
name string
Concurrent Process Non-Strong References
startTime long: millis
447027840706

GCPhaseConcurrentLevel1

profiling default startTime duration eventThread 15 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ShenandoahGC, ZGC

Missing in: ParallelGC, SerialGC

Code Context

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

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

      case 1: send_phase<EventGCPhasePauseLevel1>(phase); break;
      case 2: send_phase<EventGCPhasePauseLevel2>(phase); break;
      case 3: send_phase<EventGCPhasePauseLevel3>(phase); break;
      case 4: send_phase<EventGCPhasePauseLevel4>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

  void visit_concurrent(GCPhase* phase) {
    assert(phase->level() < 2, "There is only two levels for ConcurrentPhase");

    switch (phase->level()) {
      case 0: send_phase<EventGCPhaseConcurrent>(phase); break;
      case 1: send_phase<EventGCPhaseConcurrentLevel1>(phase); break;
      default: /* Ignore sending this phase */ break;
    }
  }

 public:
  template<typename T>
  void send_phase(GCPhase* phase) {
    T event(UNTIMED);
    if (event.should_commit()) {
      event.set_gcId(GCId::current());
      event.set_name(phase->name());

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
name string Name

Examples 3
gcId uint
274
name string
Trigger cleanups
startTime long: millis
493879275807
gcId uint
1055
name string
Preclean PhantomReferences
startTime long: millis
331631232395
gcId uint
242
name string
Trigger cleanups
startTime long: millis
342847662996

GCPhaseParallel

profiling default startTime duration eventThread 12 17 21 25 26 27

Category: Java Virtual Machine / GC / Phases

Appearing in: G1GC, ShenandoahGC

Missing in: ParallelGC, SerialGC, ZGC

GC phases for parallel workers

Code Context

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

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

      _worker_freelists[worker].~FreeRegionList();
    }
    FREE_C_HEAP_ARRAY(FreeRegionList, _worker_freelists);
  }

  FreeRegionList* worker_freelist(uint worker) {
    return &_worker_freelists[worker];
  }

  // Each worker creates a free list for a chunk of the heap. The chunks won't
  // be overlapping so we don't need to do any claiming.
  void work(uint worker_id) {
    Ticks start_time = Ticks::now();
    EventGCPhaseParallel event;

    uint start = worker_id * _worker_chunk_size;
    uint end = MIN2(start + _worker_chunk_size, _hrm->reserved_length());

    // If start is outside the heap, this worker has nothing to do.
    if (start > end) {
      return;
    }

    FreeRegionList *free_list = worker_freelist(worker_id);
    for (uint i = start; i < end; i++) {

src/hotspot/share/gc/g1/g1CollectedHeap.cpp:

    _evacuation_failed = true;
  }

  _evacuation_failed_info_array[worker_id].register_copy_failure(obj->size());
  _preserved_marks_set.get(worker_id)->push_if_necessary(obj, m);
}

bool G1ParEvacuateFollowersClosure::offer_termination() {
  EventGCPhaseParallel event;
  G1ParScanThreadState* const pss = par_scan_state();
  start_term_time();
  const bool res = terminator()->offer_termination();
  end_term_time();
  event.commit(GCId::current(), pss->worker_id(), G1GCPhaseTimes::phase_name(G1GCPhaseTimes::Termination));
  return res;
}

void G1ParEvacuateFollowersClosure::do_void() {
  EventGCPhaseParallel event;
  G1ParScanThreadState* const pss = par_scan_state();
  pss->trim_queue();
  event.commit(GCId::current(), pss->worker_id(), G1GCPhaseTimes::phase_name(_phase));
  do {
    EventGCPhaseParallel event;
    pss->steal_and_trim_queue(queues());
    event.commit(GCId::current(), pss->worker_id(), G1GCPhaseTimes::phase_name(_phase));
  } while (!offer_termination());
}

void G1CollectedHeap::complete_cleaning(BoolObjectClosure* is_alive,
                                        bool class_unloading_occurred) {

src/hotspot/share/gc/g1/g1CollectedHeap.cpp:

      _rs_length += r->rem_set()->occupied();
    }
  };

  // Closure applied to all regions in the collection set.
  class FreeCSetClosure : public HeapRegionClosure {
    // Helper to send JFR events for regions.
    class JFREventForRegion {
      EventGCPhaseParallel _event;
    public:
      JFREventForRegion(HeapRegion* region, uint worker_id) : _event() {
        _event.set_gcId(GCId::current());
        _event.set_gcWorkerId(worker_id);
        if (region->is_young()) {
          _event.set_name(G1GCPhaseTimes::phase_name(G1GCPhaseTimes::YoungFreeCSet));
        } else {

src/hotspot/share/gc/g1/g1CollectedHeap.cpp:

    for (uint worker = 0; worker < _active_workers; worker++) {
      _worker_stats[worker].~FreeCSetStats();
    }
    FREE_C_HEAP_ARRAY(FreeCSetStats, _worker_stats);
    _g1h->phase_times()->record_serial_free_cset_time_ms((Ticks::now() - serial_time).seconds() * 1000.0);
  }

  virtual void work(uint worker_id) {
    EventGCPhaseParallel event;
    Ticks start = Ticks::now();
    FreeCSetClosure cl(_surviving_young_words, worker_id, worker_stats(worker_id));
    _g1h->collection_set_par_iterate_all(&cl, &_claimer, worker_id);

    // Report the total parallel time along with some more detailed metrics.
    cl.report_timing(Ticks::now() - start);
    event.commit(GCId::current(), worker_id, G1GCPhaseTimes::phase_name(G1GCPhaseTimes::ParFreeCSet));

src/hotspot/share/gc/g1/g1GCParPhaseTimesTracker.hpp:

#ifndef SHARE_GC_G1_G1GCPARPHASETIMESTRACKER_HPP
#define SHARE_GC_G1_G1GCPARPHASETIMESTRACKER_HPP

#include "gc/g1/g1GCPhaseTimes.hpp"
#include "jfr/jfrEvents.hpp"
#include "utilities/ticks.hpp"

class G1GCParPhaseTimesTracker : public CHeapObj<mtGC> {
protected:
  Ticks _start_time;
  G1GCPhaseTimes::GCParPhases _phase;
  G1GCPhaseTimes* _phase_times;
  uint _worker_id;
  EventGCPhaseParallel _event;
  bool _must_record;

public:
  G1GCParPhaseTimesTracker(G1GCPhaseTimes* phase_times, G1GCPhaseTimes::GCParPhases phase, uint worker_id, bool must_record = true);
  virtual ~G1GCParPhaseTimesTracker();
};

class G1EvacPhaseTimesTracker : public G1GCParPhaseTimesTracker {
  Tickspan _total_time;
  Tickspan _trim_time;

src/hotspot/share/gc/shenandoah/shenandoahPhaseTimings.hpp:

  static const char* phase_name(Phase phase) {
    assert(phase >= 0 && phase < _num_phases, "Out of bound");
    return _phase_names[phase];
  }

  void print_cycle_on(outputStream* out) const;
  void print_global_on(outputStream* out) const;
};

class ShenandoahWorkerTimingsTracker : public StackObj {
private:
  ShenandoahPhaseTimings*          const _timings;
  ShenandoahPhaseTimings::Phase    const _phase;
  ShenandoahPhaseTimings::ParPhase const _par_phase;
  uint const _worker_id;

  double _start_time;
  EventGCPhaseParallel _event;
public:
  ShenandoahWorkerTimingsTracker(ShenandoahPhaseTimings::Phase phase, ShenandoahPhaseTimings::ParPhase par_phase, uint worker_id);
  ~ShenandoahWorkerTimingsTracker();
};

#endif // SHARE_GC_SHENANDOAH_SHENANDOAHPHASETIMINGS_HPP

src/hotspot/share/gc/shenandoah/shenandoahUtils.hpp:

class ShenandoahConcurrentWorkerSession : public ShenandoahWorkerSession {
private:
  EventGCPhaseConcurrent _event;

public:
  ShenandoahConcurrentWorkerSession(uint worker_id) : ShenandoahWorkerSession(worker_id) { }
  ~ShenandoahConcurrentWorkerSession();
};

class ShenandoahParallelWorkerSession : public ShenandoahWorkerSession {
private:
  EventGCPhaseParallel _event;

public:
  ShenandoahParallelWorkerSession(uint worker_id) : ShenandoahWorkerSession(worker_id) { }
  ~ShenandoahParallelWorkerSession();
};

class ShenandoahSuspendibleThreadSetJoiner {
private:
  SuspendibleThreadSetJoiner _joiner;
public:
  ShenandoahSuspendibleThreadSetJoiner(bool active = true) : _joiner(active) {

src/hotspot/share/gc/g1/g1RemSet.cpp:

    MemRegion mr(MAX2(card_start, _scanned_to), scan_end);
    _scanned_to = scan_memregion(region_idx_for_card, mr);

    _cards_scanned += num_cards;
  }

  ALWAYSINLINE void do_card_block(uint const region_idx, size_t const first_card, size_t const num_cards) {
    _ct->change_dirty_cards_to(first_card, num_cards, _scanned_card_value);
    do_claimed_block(region_idx, first_card, num_cards);
    _blocks_scanned++;
  }

   void scan_heap_roots(HeapRegion* r) {
    EventGCPhaseParallel event;
    uint const region_idx = r->hrm_index();

    ResourceMark rm;

    G1CardTableChunkClaimer claim(_scan_state, region_idx);

    // Set the current scan "finger" to NULL for every heap region to scan. Since
    // the claim value is monotonically increasing, the check to not scan below this
    // will filter out objects spanning chunks within the region too then, as opposed
    // to resetting this value for every claim.
    _scanned_to = NULL;

src/hotspot/share/gc/g1/g1RemSet.cpp:

  uint _worker_id;

  size_t _opt_refs_scanned;
  size_t _opt_refs_memory_used;

  Tickspan _strong_code_root_scan_time;
  Tickspan _strong_code_trim_partially_time;

  Tickspan _rem_set_opt_root_scan_time;
  Tickspan _rem_set_opt_trim_partially_time;

  void scan_opt_rem_set_roots(HeapRegion* r) {
    EventGCPhaseParallel event;

    G1OopStarChunkedList* opt_rem_set_list = _pss->oops_into_optional_region(r);

    G1ScanCardClosure scan_cl(G1CollectedHeap::heap(), _pss);
    G1ScanRSForOptionalClosure cl(G1CollectedHeap::heap(), &scan_cl);
    _opt_refs_scanned += opt_rem_set_list->oops_do(&cl, _pss->closures()->strong_oops());
    _opt_refs_memory_used += opt_rem_set_list->used_memory();

    event.commit(GCId::current(), _worker_id, G1GCPhaseTimes::phase_name(_scan_phase));
  }

src/hotspot/share/gc/g1/g1RemSet.cpp:

    _rem_set_opt_trim_partially_time() { }

  bool do_heap_region(HeapRegion* r) {
    uint const region_idx = r->hrm_index();

    // The individual references for the optional remembered set are per-worker, so we
    // always need to scan them.
    if (r->has_index_in_opt_cset()) {
      G1EvacPhaseWithTrimTimeTracker timer(_pss, _rem_set_opt_root_scan_time, _rem_set_opt_trim_partially_time);
      scan_opt_rem_set_roots(r);
    }

    if (_scan_state->claim_collection_set_region(region_idx)) {
      EventGCPhaseParallel event;

      G1EvacPhaseWithTrimTimeTracker timer(_pss, _strong_code_root_scan_time, _strong_code_trim_partially_time);
      // Scan the strong code root list attached to the current region
      r->strong_code_roots_do(_pss->closures()->weak_codeblobs());

      event.commit(GCId::current(), _worker_id, G1GCPhaseTimes::phase_name(_code_roots_phase));
    }

    return false;
  }

Configuration enabled threshold
profiling true 0 ms
default true 0 ms

Field Type Description
gcId uint GC Identifier
gcWorkerId uint GC Worker Identifier
name string Name

Examples 2
gcId uint
260
gcWorkerId uint
0
name string
Finish Mark
startTime long: millis
367830939211
gcId uint
941
gcWorkerId uint
2
name string
JNI Global
startTime long: millis
278161243152

JVM: GC: Reference

GCReferenceStatistics

profiling default startTime 11 17 21 25 26 27

Category: Java Virtual Machine / GC / Reference

Total count of processed references during GC

Code Context

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

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

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

void GCTracer::send_reference_stats_event(ReferenceType type, size_t count) const {
  EventGCReferenceStatistics e;
  if (e.should_commit()) {
      e.set_gcId(GCId::current());
      e.set_type((u1)type);
      e.set_count(count);
      e.commit();
  }
}

void GCTracer::send_metaspace_chunk_free_list_summary(GCWhen::Type when, Metaspace::MetadataType mdtype,
                                                      const MetaspaceChunkFreeListSummary& summary) const {
  EventMetaspaceChunkFreeListSummary e;

Configuration enabled
profiling true
default true

Field Type Description
gcId uint GC Identifier
type ReferenceType Type
count ulong Total Count

Examples 3
count ulong
4
gcId uint
400
startTime long: millis
381805843962
type ReferenceType
Phantom reference
count ulong
0
gcId uint
897
startTime long: millis
439696247072
type ReferenceType
Weak reference
count ulong
3022
gcId uint
962
startTime long: millis
286253126951
type ReferenceType
Phantom reference

JVM: Profiling

OldObjectSample

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

Category: Java Virtual Machine / Profiling

Appearing in: G1GC, ParallelGC, SerialGC, ZGC

Missing in: ShenandoahGC

A potential memory leak

Code Context

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

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

NO_TRANSITION(jlong, jfr_elapsed_counter(JNIEnv* env, jobject jvm))
  return JfrTicks::now();
NO_TRANSITION_END

NO_TRANSITION(void, jfr_retransform_classes(JNIEnv* env, jobject jvm, jobjectArray classes))
  JfrJvmtiAgent::retransform_classes(env, classes, JavaThread::thread_from_jni_environment(env));
NO_TRANSITION_END

NO_TRANSITION(void, jfr_set_enabled(JNIEnv* env, jobject jvm, jlong event_type_id, jboolean enabled))
  JfrEventSetting::set_enabled(event_type_id, JNI_TRUE == enabled);
  if (EventOldObjectSample::eventId == event_type_id) {
    ThreadInVMfromNative transition(JavaThread::thread_from_jni_environment(env));
    if (JNI_TRUE == enabled) {
      LeakProfiler::start(JfrOptionSet::old_object_queue_size());
    } else {
      LeakProfiler::stop();
    }
  }
NO_TRANSITION_END

NO_TRANSITION(void, jfr_set_file_notification(JNIEnv* env, jobject jvm, jlong threshold))
  JfrChunkRotation::set_threshold(threshold);

src/hotspot/share/jfr/leakprofiler/sampling/objectSampler.cpp:

  if (!tl->has_thread_blob()) {
    JfrCheckpointManager::create_thread_blob(thread);
  }
  assert(tl->has_thread_blob(), "invariant");
  return tl->thread_id();
}

class RecordStackTrace {
 private:
  JavaThread* _jt;
  bool _enabled;
 public:
  RecordStackTrace(JavaThread* jt) : _jt(jt),
    _enabled(JfrEventSetting::has_stacktrace(EventOldObjectSample::eventId)) {
    if (_enabled) {
      JfrStackTraceRepository::record_for_leak_profiler(jt);
    }
  }
  ~RecordStackTrace() {
    if (_enabled) {
      _jt->jfr_thread_local()->clear_cached_stack_trace();
    }
  }
};

src/hotspot/share/jfr/leakprofiler/checkpoint/eventEmitter.cpp:

  if (edge == NULL) {
    edge = edge_store->get(UnifiedOopRef::encode_in_native(sample->object_addr()));
  } else {
    gc_root_id = edge_store->gc_root_id(edge);
  }
  assert(edge != NULL, "invariant");
  const traceid object_id = edge_store->get_id(edge);
  assert(object_id != 0, "invariant");

  Tickspan object_age = Ticks(_start_time.value()) - sample->allocation_time();

  EventOldObjectSample e(UNTIMED);
  e.set_starttime(_start_time);
  e.set_endtime(_end_time);
  e.set_allocationTime(sample->allocation_time());
  e.set_objectAge(object_age);
  e.set_lastKnownHeapUsage(sample->heap_used_at_last_gc());
  e.set_object(object_id);
  e.set_arrayElements(array_size(edge->pointee()));
  e.set_root(gc_root_id);

  // Temporarily assigning both the stack trace id and thread id
  // onto the thread local data structure of the emitter thread (for the duration

Configuration cutoff enabled stackTrace
profiling 0 ns true true
default 0 ns true false

Field Type Description
allocationTime Ticks Allocation Time
objectAge Tickspan 14+ Object Age
lastKnownHeapUsage ulong: bytes Last Known Heap Usage
object OldObject Object
arrayElements int Array Elements If the object is an array, the number of elements, or -1 if it is not an array
root OldObjectGcRoot GC Root

Examples 3
allocationTime Ticks
227371834695
arrayElements int
512
lastKnownHeapUsage ulong: bytes
201249024
object OldObject
address ulong: address
31620103680
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1040
name string
[Ljava/util/concurrent/ConcurrentHashMap$Node;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent
objectAge Tickspan
266029870863
root OldObjectGcRoot
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
40
lineNumber int
2431
method Method
descriptor string
([Ljava/util/concurrent/ConcurrentHashMap$Node;[Ljava/util/concurrent/ConcurrentHashMap$Node;)V
hidden boolean
false
modifiers int
18
name string
transfer
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/concurrent/ConcurrentHashMap
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
493401705558
allocationTime Ticks
343658241782
arrayElements int
-2147483648
lastKnownHeapUsage ulong: bytes
257359120
object OldObject
address ulong: address
30381608600
description string
Size: 1
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/ArrayList
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util
objectAge Tickspan
23678449692
root OldObjectGcRoot
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
7
lineNumber int
738
method Method
descriptor string
(Ljava/lang/String;Ljava/nio/file/attribute/BasicFileAttributes;)V
hidden boolean
false
modifiers int
2
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
24
name string
jdk/internal/jimage/ImageReader$Directory
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
jdk/internal/jimage
type FrameType
Interpreted
truncated boolean
true
startTime long: millis
367336691474
allocationTime Ticks
309806672172
arrayElements int
20192
lastKnownHeapUsage ulong: bytes
151115608
object OldObject
address ulong: address
30325390632
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[C
package Package
null
objectAge Tickspan
172638196387
root OldObjectGcRoot
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
65
lineNumber int
141
method Method
descriptor string
(I)V
hidden boolean
false
modifiers int
1
name string
<init>
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
org/sparkproject/jetty/util/ArrayTrie
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/sparkproject/jetty/util
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
482444868559

ExecutionSample

profiling default startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Profiling

Snapshot of a threads state

Code Context

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

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

    case _thread_in_native_trans:
      break;
    case _thread_in_native:
      return true;
    default:
      ShouldNotReachHere();
      break;
  }
  return false;
}

class JfrThreadSampleClosure {
 public:
  JfrThreadSampleClosure(EventExecutionSample* events, EventNativeMethodSample* events_native);
  ~JfrThreadSampleClosure() {}
  EventExecutionSample* next_event() { return &_events[_added_java++]; }
  EventNativeMethodSample* next_event_native() { return &_events_native[_added_native++]; }
  void commit_events(JfrSampleType type);
  bool do_sample_thread(JavaThread* thread, JfrStackFrame* frames, u4 max_frames, JfrSampleType type);
  uint java_entries() { return _added_java; }
  uint native_entries() { return _added_native; }

 private:
  bool sample_thread_in_java(JavaThread* thread, JfrStackFrame* frames, u4 max_frames);
  bool sample_thread_in_native(JavaThread* thread, JfrStackFrame* frames, u4 max_frames);
  EventExecutionSample* _events;
  EventNativeMethodSample* _events_native;
  Thread* _self;
  uint _added_java;
  uint _added_native;
};

class OSThreadSampler : public os::SuspendedThreadTask {
 public:
  OSThreadSampler(JavaThread* thread,
                  JfrThreadSampleClosure& closure,
                  JfrStackFrame *frames,

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

  // Skip sample if we signaled a thread that moved to other state
  if (!thread_state_in_java(jth)) {
    return;
  }
  JfrGetCallTrace trace(true, jth);
  frame topframe;
  if (trace.get_topframe(context.ucontext(), topframe)) {
    if (_stacktrace.record_thread(*jth, topframe)) {
      /* If we managed to get a topframe and a stacktrace, create an event
      * and put it into our array. We can't call Jfr::_stacktraces.add()
      * here since it would allocate memory using malloc. Doing so while
      * the stopped thread is inside malloc would deadlock. */
      _success = true;
      EventExecutionSample *ev = _closure.next_event();
      ev->set_starttime(_suspend_time);
      ev->set_endtime(_suspend_time); // fake to not take an end time
      ev->set_sampledThread(JFR_THREAD_ID(jth));
      ev->set_state(static_cast<u8>(java_lang_Thread::get_thread_status(_thread_oop)));
    }
  }
}

void OSThreadSampler::take_sample() {
  run();
}

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

bool JfrThreadSampleClosure::sample_thread_in_java(JavaThread* thread, JfrStackFrame* frames, u4 max_frames) {
  OSThreadSampler sampler(thread, *this, frames, max_frames);
  sampler.take_sample();
  /* We don't want to allocate any memory using malloc/etc while the thread
  * is stopped, so everything is stored in stack allocated memory until this
  * point where the thread has been resumed again, if the sampling was a success
  * we need to store the stacktrace in the stacktrace repository and update
  * the event with the id that was returned. */
  if (!sampler.success()) {
    return false;
  }
  EventExecutionSample *event = &_events[_added_java - 1];
  traceid id = JfrStackTraceRepository::add(sampler.stacktrace());
  assert(id != 0, "Stacktrace id should not be 0");
  event->set_stackTrace(id);
  return true;
}

bool JfrThreadSampleClosure::sample_thread_in_native(JavaThread* thread, JfrStackFrame* frames, u4 max_frames) {
  JfrNativeSamplerCallback cb(*this, thread, frames, max_frames);
  if (JfrOptionSet::sample_protection()) {
    os::ThreadCrashProtection crash_protection;
    if (!crash_protection.call(cb)) {

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

    assert(_added_java > 0 && _added_java <= MAX_NR_OF_JAVA_SAMPLES, "invariant");
    for (uint i = 0; i < _added_java; ++i) {
      _events[i].commit();
    }
  } else {
    assert(NATIVE_SAMPLE == type, "invariant");
    assert(_added_native > 0 && _added_native <= MAX_NR_OF_NATIVE_SAMPLES, "invariant");
    for (uint i = 0; i < _added_native; ++i) {
      _events_native[i].commit();
    }
  }
}

JfrThreadSampleClosure::JfrThreadSampleClosure(EventExecutionSample* events, EventNativeMethodSample* events_native) :
  _events(events),
  _events_native(events_native),
  _self(Thread::current()),
  _added_java(0),
  _added_native(0) {
}

class JfrThreadSampler : public NonJavaThread {
  friend class JfrThreadSampling;
 private:
  Semaphore _sample;

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

      last_native_ms = get_monotonic_ms();
    }
  }
}

void JfrThreadSampler::post_run() {
  this->NonJavaThread::post_run();
  delete this;
}


void JfrThreadSampler::task_stacktrace(JfrSampleType type, JavaThread** last_thread) {
  ResourceMark rm;
  EventExecutionSample samples[MAX_NR_OF_JAVA_SAMPLES];
  EventNativeMethodSample samples_native[MAX_NR_OF_NATIVE_SAMPLES];
  JfrThreadSampleClosure sample_task(samples, samples_native);

  const uint sample_limit = JAVA_SAMPLE == type ? MAX_NR_OF_JAVA_SAMPLES : MAX_NR_OF_NATIVE_SAMPLES;
  uint num_samples = 0;
  JavaThread* start = NULL;

  {
    elapsedTimer sample_time;
    sample_time.start();
    {

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

JVM_ENTRY_NO_ENV(void, jfr_subscribe_log_level(JNIEnv* env, jobject jvm, jobject log_tag, jint id))
  JfrJavaLog::subscribe_log_level(log_tag, id, thread);
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_set_output(JNIEnv* env, jobject jvm, jstring path))
  JfrRepository::set_chunk_path(path, thread);
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_set_method_sampling_interval(JNIEnv* env, jobject jvm, jlong type, jlong intervalMillis))
  if (intervalMillis < 0) {
    intervalMillis = 0;
  }
  JfrEventId typed_event_id = (JfrEventId)type;
  assert(EventExecutionSample::eventId == typed_event_id || EventNativeMethodSample::eventId == typed_event_id, "invariant");
  if (intervalMillis > 0) {
    JfrEventSetting::set_enabled(typed_event_id, true); // ensure sampling event is enabled
  }
  if (EventExecutionSample::eventId == type) {
    JfrThreadSampling::set_java_sample_interval(intervalMillis);
  } else {
    JfrThreadSampling::set_native_sample_interval(intervalMillis);
  }
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_store_metadata_descriptor(JNIEnv* env, jobject jvm, jbyteArray descriptor))
  JfrMetadataEvent::update(descriptor);
JVM_END

// trace thread id for a thread object

Configuration enabled period
profiling true 10 ms
default true 20 ms

Field Type Description
sampledThread Thread Thread
stackTrace StackTrace Stack Trace
state ThreadState Thread State

Examples 3
sampledThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
Executor task launch worker for task 7.0 in stage 18.0 (TID 114)
javaThreadId long
1181
osName string
Executor task launch worker for task 7.0 in stage 18.0 (TID 114)
osThreadId long
4415
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
258
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/String;ID[DII[DI)V
hidden boolean
false
modifiers int
9
name string
dspr
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
17
name string
org/netlib/blas/Dspr
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/netlib/blas
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
381350717509
state ThreadState
STATE_RUNNABLE
sampledThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
Executor task launch worker for task 6.0 in stage 18.0 (TID 113)
javaThreadId long
1164
osName string
Executor task launch worker for task 6.0 in stage 18.0 (TID 113)
osThreadId long
3755
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
132
lineNumber int
58
method Method
descriptor string
([BII[BII)I
hidden boolean
false
modifiers int
8
name string
compress64k
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
16
name string
net/jpountz/lz4/LZ4JavaUnsafeCompressor
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
net/jpountz/lz4
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
382197966663
state ThreadState
STATE_RUNNABLE
sampledThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
Executor task launch worker for task 3.0 in stage 18.0 (TID 110)
javaThreadId long
1223
osName string
Executor task launch worker for task 3.0 in stage 18.0 (TID 110)
osThreadId long
3808
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
258
lineNumber int
-1
method Method
descriptor string
(Ljava/lang/String;ID[DII[DI)V
hidden boolean
false
modifiers int
9
name string
dspr
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
17
name string
org/netlib/blas/Dspr
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/netlib/blas
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
278342476859
state ThreadState
STATE_RUNNABLE

NativeMethodSample

profiling default startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Profiling

Snapshot of a threads state when in native

Code Context

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

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

    case _thread_in_native_trans:
      break;
    case _thread_in_native:
      return true;
    default:
      ShouldNotReachHere();
      break;
  }
  return false;
}

class JfrThreadSampleClosure {
 public:
  JfrThreadSampleClosure(EventExecutionSample* events, EventNativeMethodSample* events_native);
  ~JfrThreadSampleClosure() {}
  EventExecutionSample* next_event() { return &_events[_added_java++]; }
  EventNativeMethodSample* next_event_native() { return &_events_native[_added_native++]; }
  void commit_events(JfrSampleType type);
  bool do_sample_thread(JavaThread* thread, JfrStackFrame* frames, u4 max_frames, JfrSampleType type);
  uint java_entries() { return _added_java; }
  uint native_entries() { return _added_native; }

 private:
  bool sample_thread_in_java(JavaThread* thread, JfrStackFrame* frames, u4 max_frames);
  bool sample_thread_in_native(JavaThread* thread, JfrStackFrame* frames, u4 max_frames);
  EventExecutionSample* _events;
  EventNativeMethodSample* _events_native;
  Thread* _self;
  uint _added_java;
  uint _added_native;
};

class OSThreadSampler : public os::SuspendedThreadTask {
 public:
  OSThreadSampler(JavaThread* thread,
                  JfrThreadSampleClosure& closure,
                  JfrStackFrame *frames,
                  u4 max_frames) : os::SuspendedThreadTask((Thread*)thread),

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

  virtual void call();
  bool success() { return _success; }
  JfrStackTrace& stacktrace() { return _stacktrace; }

 private:
  JfrThreadSampleClosure& _closure;
  JavaThread* _jt;
  oop _thread_oop;
  JfrStackTrace _stacktrace;
  bool _success;
};

static void write_native_event(JfrThreadSampleClosure& closure, JavaThread* jt, oop thread_oop) {
  EventNativeMethodSample *ev = closure.next_event_native();
  ev->set_starttime(JfrTicks::now());
  ev->set_sampledThread(JFR_THREAD_ID(jt));
  ev->set_state(static_cast<u8>(java_lang_Thread::get_thread_status(thread_oop)));
}

void JfrNativeSamplerCallback::call() {
  // When a thread is only attach it will be native without a last java frame
  if (!_jt->has_last_Java_frame()) {
    return;
  }

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

bool JfrThreadSampleClosure::sample_thread_in_native(JavaThread* thread, JfrStackFrame* frames, u4 max_frames) {
  JfrNativeSamplerCallback cb(*this, thread, frames, max_frames);
  if (JfrOptionSet::sample_protection()) {
    os::ThreadCrashProtection crash_protection;
    if (!crash_protection.call(cb)) {
      log_error(jfr)("Thread method sampler crashed for native");
    }
  } else {
    cb.call();
  }
  if (!cb.success()) {
    return false;
  }
  EventNativeMethodSample *event = &_events_native[_added_native - 1];
  traceid id = JfrStackTraceRepository::add(cb.stacktrace());
  assert(id != 0, "Stacktrace id should not be 0");
  event->set_stackTrace(id);
  return true;
}

static const uint MAX_NR_OF_JAVA_SAMPLES = 5;
static const uint MAX_NR_OF_NATIVE_SAMPLES = 1;

void JfrThreadSampleClosure::commit_events(JfrSampleType type) {
  if (JAVA_SAMPLE == type) {

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

    assert(_added_java > 0 && _added_java <= MAX_NR_OF_JAVA_SAMPLES, "invariant");
    for (uint i = 0; i < _added_java; ++i) {
      _events[i].commit();
    }
  } else {
    assert(NATIVE_SAMPLE == type, "invariant");
    assert(_added_native > 0 && _added_native <= MAX_NR_OF_NATIVE_SAMPLES, "invariant");
    for (uint i = 0; i < _added_native; ++i) {
      _events_native[i].commit();
    }
  }
}

JfrThreadSampleClosure::JfrThreadSampleClosure(EventExecutionSample* events, EventNativeMethodSample* events_native) :
  _events(events),
  _events_native(events_native),
  _self(Thread::current()),
  _added_java(0),
  _added_native(0) {
}

class JfrThreadSampler : public NonJavaThread {
  friend class JfrThreadSampling;
 private:
  Semaphore _sample;

src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp:

void JfrThreadSampler::post_run() {
  this->NonJavaThread::post_run();
  delete this;
}


void JfrThreadSampler::task_stacktrace(JfrSampleType type, JavaThread** last_thread) {
  ResourceMark rm;
  EventExecutionSample samples[MAX_NR_OF_JAVA_SAMPLES];
  EventNativeMethodSample samples_native[MAX_NR_OF_NATIVE_SAMPLES];
  JfrThreadSampleClosure sample_task(samples, samples_native);

  const uint sample_limit = JAVA_SAMPLE == type ? MAX_NR_OF_JAVA_SAMPLES : MAX_NR_OF_NATIVE_SAMPLES;
  uint num_samples = 0;
  JavaThread* start = NULL;

  {
    elapsedTimer sample_time;
    sample_time.start();
    {
      MutexLocker tlock(Threads_lock);

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

JVM_ENTRY_NO_ENV(void, jfr_subscribe_log_level(JNIEnv* env, jobject jvm, jobject log_tag, jint id))
  JfrJavaLog::subscribe_log_level(log_tag, id, thread);
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_set_output(JNIEnv* env, jobject jvm, jstring path))
  JfrRepository::set_chunk_path(path, thread);
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_set_method_sampling_interval(JNIEnv* env, jobject jvm, jlong type, jlong intervalMillis))
  if (intervalMillis < 0) {
    intervalMillis = 0;
  }
  JfrEventId typed_event_id = (JfrEventId)type;
  assert(EventExecutionSample::eventId == typed_event_id || EventNativeMethodSample::eventId == typed_event_id, "invariant");
  if (intervalMillis > 0) {
    JfrEventSetting::set_enabled(typed_event_id, true); // ensure sampling event is enabled
  }
  if (EventExecutionSample::eventId == type) {
    JfrThreadSampling::set_java_sample_interval(intervalMillis);
  } else {
    JfrThreadSampling::set_native_sample_interval(intervalMillis);
  }
JVM_END

JVM_ENTRY_NO_ENV(void, jfr_store_metadata_descriptor(JNIEnv* env, jobject jvm, jbyteArray descriptor))

Configuration enabled period
profiling true 20 ms
default true 20 ms

Field Type Description
sampledThread Thread Thread
stackTrace StackTrace Stack Trace
state ThreadState Thread State

Examples 3
sampledThread Thread
group ThreadGroup
name string
finagle/netty4
parent ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
finagle/netty4-2-8
javaThreadId long
873
osName string
finagle/netty4-2-8
osThreadId long
4061
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(IJII)I
hidden boolean
false
modifiers int
266
name string
epollWait
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
17
name string
io/netty/channel/epoll/Native
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
io/netty/channel/epoll
type FrameType
Native
truncated boolean
false
startTime long: millis
371884239268
state ThreadState
STATE_RUNNABLE
sampledThread Thread
group ThreadGroup
name string
finagle/netty4
parent ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
finagle/netty4-2-8
javaThreadId long
870
osName string
finagle/netty4-2-8
osThreadId long
3382
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(IJII)I
hidden boolean
false
modifiers int
266
name string
epollWait
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
17
name string
io/netty/channel/epoll/Native
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
io/netty/channel/epoll
type FrameType
Native
truncated boolean
false
startTime long: millis
279038828310
state ThreadState
STATE_RUNNABLE
sampledThread Thread
group ThreadGroup
name string
finagle/netty4
parent ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
finagle/netty4-2-2
javaThreadId long
866
osName string
finagle/netty4-2-2
osThreadId long
3408
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(IJII)I
hidden boolean
false
modifiers int
266
name string
epollWait
type Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
17
name string
io/netty/channel/epoll/Native
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
io/netty/channel/epoll
type FrameType
Native
truncated boolean
false
startTime long: millis
375157702072
state ThreadState
STATE_RUNNABLE

JVM: Runtime

BiasedLockRevocation

profiling default startTime duration eventThread stackTrace 11 17 until JDK 18

Category: Java Virtual Machine / Runtime

Revoked bias of object

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/biasedLocking.cpp:

static void post_self_revocation_event(EventBiasedLockSelfRevocation* event, Klass* k) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_lockClass(k);
  event->commit();
}

static void post_revocation_event(EventBiasedLockRevocation* event, Klass* k, RevokeOneBias* op) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(op != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_lockClass(k);
  event->set_safepointId(0);
  event->set_previousOwner(op->biased_locker());
  event->commit();
}

static void post_class_revocation_event(EventBiasedLockClassRevocation* event, Klass* k, VM_BulkRevokeBias* op) {

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

  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(op != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_revokedClass(k);
  event->set_disableBiasing(!op->is_bulk_rebias());
  event->set_safepointId(op->safepoint_id());
  event->commit();
}


BiasedLocking::Condition BiasedLocking::single_revoke_with_handshake(Handle obj, JavaThread *requester, JavaThread *biaser) {

  EventBiasedLockRevocation event;
  if (PrintBiasedLockingStatistics) {
    Atomic::inc(handshakes_count_addr());
  }
  log_info(biasedlocking, handshake)("JavaThread " INTPTR_FORMAT " handshaking JavaThread "
                                     INTPTR_FORMAT " to revoke object " INTPTR_FORMAT, p2i(requester),
                                     p2i(biaser), p2i(obj()));

  RevokeOneBias revoke(obj, requester, biaser);
  Handshake::execute(&revoke, biaser);
  if (revoke.status_code() == NOT_REVOKED) {
    return NOT_REVOKED;

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

Field Type Description
lockClass Class Lock Class Class of object whose biased lock was revoked
safepointId ulong Safepoint Identifier
previousOwner Thread Previous Owner Thread owning the bias before revocation

BiasedLockSelfRevocation

profiling default startTime duration eventThread stackTrace 11 17 until JDK 18

Category: Java Virtual Machine / Runtime

Revoked bias of object biased towards own thread

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/biasedLocking.cpp:

    _status_code = BiasedLocking::NOT_REVOKED;
  }

  BiasedLocking::Condition status_code() const {
    return _status_code;
  }

  traceid biased_locker() const {
    return _biased_locker_id;
  }
};


static void post_self_revocation_event(EventBiasedLockSelfRevocation* event, Klass* k) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_lockClass(k);
  event->commit();
}

static void post_revocation_event(EventBiasedLockRevocation* event, Klass* k, RevokeOneBias* op) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(op != NULL, "invariant");

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

  JavaThread* thread = THREAD->as_Java_thread();

  markWord mark = obj->mark();

  if (!mark.has_bias_pattern()) {
    return;
  }

  Klass *k = obj->klass();
  assert(mark.biased_locker() == thread &&
         k->prototype_header().bias_epoch() == mark.bias_epoch(), "Revoke failed, unhandled biased lock state");
  ResourceMark rm;
  log_info(biasedlocking)("Revoking bias by walking my own stack:");
  EventBiasedLockSelfRevocation event;
  BiasedLocking::walk_stack_and_revoke(obj(), thread);
  thread->set_cached_monitor_info(NULL);
  assert(!obj->mark().has_bias_pattern(), "invariant");
  if (event.should_commit()) {
    post_self_revocation_event(&event, k);
  }
}

void BiasedLocking::revoke(Handle obj, TRAPS) {
  assert(!SafepointSynchronize::is_at_safepoint(), "must not be called while at safepoint");

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

    HeuristicsResult heuristics = update_heuristics(obj());
    if (heuristics == HR_NOT_BIASED) {
      return;
    } else if (heuristics == HR_SINGLE_REVOKE) {
      JavaThread *blt = mark.biased_locker();
      assert(blt != NULL, "invariant");
      if (blt == THREAD) {
        // A thread is trying to revoke the bias of an object biased
        // toward it, again likely due to an identity hash code
        // computation. We can again avoid a safepoint/handshake in this case
        // since we are only going to walk our own stack. There are no
        // races with revocations occurring in other threads because we
        // reach no safepoints in the revocation path.
        EventBiasedLockSelfRevocation event;
        ResourceMark rm;
        walk_stack_and_revoke(obj(), blt);
        blt->set_cached_monitor_info(NULL);
        assert(!obj->mark().has_bias_pattern(), "invariant");
        if (event.should_commit()) {
          post_self_revocation_event(&event, obj->klass());
        }
        return;
      } else {
        BiasedLocking::Condition cond = single_revoke_with_handshake(obj, THREAD->as_Java_thread(), blt);
        if (cond != NOT_REVOKED) {

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

Field Type Description
lockClass Class Lock Class Class of object whose biased lock was revoked

BiasedLockClassRevocation

profiling default startTime duration eventThread stackTrace 11 17 until JDK 18

Category: Java Virtual Machine / Runtime

Revoked biases for all instances of a class

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/biasedLocking.cpp:

static void post_revocation_event(EventBiasedLockRevocation* event, Klass* k, RevokeOneBias* op) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(op != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_lockClass(k);
  event->set_safepointId(0);
  event->set_previousOwner(op->biased_locker());
  event->commit();
}

static void post_class_revocation_event(EventBiasedLockClassRevocation* event, Klass* k, VM_BulkRevokeBias* op) {
  assert(event != NULL, "invariant");
  assert(k != NULL, "invariant");
  assert(op != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_revokedClass(k);
  event->set_disableBiasing(!op->is_bulk_rebias());
  event->set_safepointId(op->safepoint_id());
  event->commit();
}

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

        if (event.should_commit()) {
          post_self_revocation_event(&event, obj->klass());
        }
        return;
      } else {
        BiasedLocking::Condition cond = single_revoke_with_handshake(obj, THREAD->as_Java_thread(), blt);
        if (cond != NOT_REVOKED) {
          return;
        }
      }
    } else {
      assert((heuristics == HR_BULK_REVOKE) ||
         (heuristics == HR_BULK_REBIAS), "?");
      EventBiasedLockClassRevocation event;
      VM_BulkRevokeBias bulk_revoke(&obj, THREAD->as_Java_thread(),
                                    (heuristics == HR_BULK_REBIAS));
      VMThread::execute(&bulk_revoke);
      if (event.should_commit()) {
        post_class_revocation_event(&event, obj->klass(), &bulk_revoke);
      }
      return;
    }
  }
}

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

Field Type Description
revokedClass Class Revoked Class Class whose biased locks were revoked
disableBiasing boolean Disable Further Biasing Whether further biasing for instances of this class will be allowed
safepointId ulong Safepoint Identifier

ReservedStackActivation

profiling default startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime

Activation of Reserved Stack Area caused by stack overflow with ReservedStackAccess annotated method in call stack

Code Context

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

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

        for (ScopeDesc *sd = nm->scope_desc_near(fr.pc()); sd != NULL; sd = sd->sender()) {
          method = sd->method();
          if (method != NULL && method->has_reserved_stack_access()) {
            found = true;
      }
    }
      }
    }
    if (found) {
      activation = fr;
      warning("Potentially dangerous stack overflow in "
              "ReservedStackAccess annotated method %s [%d]",
              method->name_and_sig_as_C_string(), count++);
      EventReservedStackActivation event;
      if (event.should_commit()) {
        event.set_method(method);
        event.commit();
      }
    }
    if (fr.is_first_java_frame()) {
      break;
    } else {
      fr = fr.java_sender();
    }
  }

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
method Method Java Method

SafepointBegin

profiling default startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime / Safepoint

Safepointing begin

Code Context

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

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

static void post_safepoint_begin_event(EventSafepointBegin& event,
                                       uint64_t safepoint_id,
                                       int thread_count,
                                       int critical_thread_count) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.set_totalThreadCount(thread_count);
    event.set_jniCriticalThreadCount(critical_thread_count);
    event.commit();
  }
}

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

  OrderAccess::storestore(); // storestore, global state -> local state
  for (JavaThreadIteratorWithHandle jtiwh; JavaThread *cur = jtiwh.next(); ) {
    // Make sure the threads start polling, it is time to yield.
    SafepointMechanism::arm_local_poll(cur);
  }

  OrderAccess::fence(); // storestore|storeload, global state -> local state
}

// Roll all threads forward to a safepoint and suspend them all
void SafepointSynchronize::begin() {
  assert(Thread::current()->is_VM_thread(), "Only VM thread may execute a safepoint");

  EventSafepointBegin begin_event;
  SafepointTracing::begin(VMThread::vm_op_type());

  Universe::heap()->safepoint_synchronize_begin();

  // By getting the Threads_lock, we assure that no threads are about to start or
  // exit. It is released again in SafepointSynchronize::end().
  Threads_lock->lock();

  assert( _state == _not_synchronized, "trying to safepoint synchronize with wrong state");

  int nof_threads = Threads::number_of_threads();

Configuration enabled threshold
profiling true 0 ms
default true 10 ms

Field Type Description
safepointId ulong Safepoint Identifier
totalThreadCount int Total Threads The total number of threads at the start of safe point
jniCriticalThreadCount int JNI Critical Threads The number of threads in JNI critical sections

Examples 3
jniCriticalThreadCount int
0
safepointId ulong
769
startTime long: millis
447267741269
totalThreadCount int
95
jniCriticalThreadCount int
0
safepointId ulong
1512
startTime long: millis
285820294813
totalThreadCount int
185
jniCriticalThreadCount int
0
safepointId ulong
1228
startTime long: millis
428281370548
totalThreadCount int
191

SafepointStateSynchronization

startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime / Safepoint

Synchronize run state of threads

Code Context

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

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

    event.set_totalThreadCount(thread_count);
    event.set_jniCriticalThreadCount(critical_thread_count);
    event.commit();
  }
}

static void post_safepoint_cleanup_event(EventSafepointCleanup& event, uint64_t safepoint_id) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.commit();
  }
}

static void post_safepoint_synchronize_event(EventSafepointStateSynchronization& event,
                                             uint64_t safepoint_id,
                                             int initial_number_of_threads,
                                             int threads_waiting_to_block,
                                             uint64_t iterations) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.set_initialThreadCount(initial_number_of_threads);
    event.set_runningThreadCount(threads_waiting_to_block);
    event.set_iterations(iterations);
    event.commit();
  }

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

  _current_jni_active_count = 0;

  // Set number of threads to wait for
  _waiting_to_block = nof_threads;

  jlong safepoint_limit_time = 0;
  if (SafepointTimeout) {
    // Set the limit time, so that it can be compared to see if this has taken
    // too long to complete.
    safepoint_limit_time = SafepointTracing::start_of_safepoint() + (jlong)SafepointTimeoutDelay * (NANOUNITS / MILLIUNITS);
    timeout_error_printed = false;
  }

  EventSafepointStateSynchronization sync_event;
  int initial_running = 0;

  // Arms the safepoint, _current_jni_active_count and _waiting_to_block must be set before.
  arm_safepoint();

  // Will spin until all threads are safe.
  int iterations = synchronize_threads(safepoint_limit_time, nof_threads, &initial_running);
  assert(_waiting_to_block == 0, "No thread should be running");

#ifndef PRODUCT
  // Mark all threads

Configuration enabled threshold
profiling false 0 ms
default false 10 ms

Field Type Description
safepointId ulong Safepoint Identifier
initialThreadCount int Initial Threads The number of threads running at the beginning of state check
runningThreadCount int Running Threads The number of threads still running
iterations int Iterations Number of state check iterations

Examples 3
initialThreadCount int
1
iterations int
3
runningThreadCount int
0
safepointId ulong
1185
startTime long: millis
382346754317
initialThreadCount int
2
iterations int
3
runningThreadCount int
0
safepointId ulong
761
startTime long: millis
444484734745
initialThreadCount int
1
iterations int
3
runningThreadCount int
0
safepointId ulong
1565
startTime long: millis
304082589634

SafepointCleanup

startTime duration eventThread 11 17 21 until JDK 23

Category: Java Virtual Machine / Runtime / Safepoint

Safepointing begin running cleanup tasks

Code Context

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

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

static void post_safepoint_begin_event(EventSafepointBegin& event,
                                       uint64_t safepoint_id,
                                       int thread_count,
                                       int critical_thread_count) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.set_totalThreadCount(thread_count);
    event.set_jniCriticalThreadCount(critical_thread_count);
    event.commit();
  }
}

static void post_safepoint_cleanup_event(EventSafepointCleanup& event, uint64_t safepoint_id) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.commit();
  }
}

static void post_safepoint_synchronize_event(EventSafepointStateSynchronization& event,
                                             uint64_t safepoint_id,
                                             int initial_number_of_threads,
                                             int threads_waiting_to_block,
                                             uint64_t iterations) {

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

  // Update the count of active JNI critical regions
  GCLocker::set_jni_lock_count(_current_jni_active_count);

  post_safepoint_synchronize_event(sync_event,
                                   _safepoint_id,
                                   initial_running,
                                   _waiting_to_block, iterations);

  SafepointTracing::synchronized(nof_threads, initial_running, _nof_threads_hit_polling_page);

  // We do the safepoint cleanup first since a GC related safepoint
  // needs cleanup to be completed before running the GC op.
  EventSafepointCleanup cleanup_event;
  do_cleanup_tasks();
  post_safepoint_cleanup_event(cleanup_event, _safepoint_id);

  post_safepoint_begin_event(begin_event, _safepoint_id, nof_threads, _current_jni_active_count);
  SafepointTracing::cleanup();
}

void SafepointSynchronize::disarm_safepoint() {
  uint64_t active_safepoint_counter = _safepoint_counter;
  {
    JavaThreadIteratorWithHandle jtiwh;

Configuration enabled threshold
profiling false 0 ms
default false 10 ms

Field Type Description
safepointId ulong Safepoint Identifier

Examples 3
safepointId ulong
1536
startTime long: millis
291081477143
safepointId ulong
1236
startTime long: millis
433240326624
safepointId ulong
769
startTime long: millis
447267825155

SafepointCleanupTask

startTime duration eventThread 11 17 21 until JDK 23

Category: Java Virtual Machine / Runtime / Safepoint

Safepointing begin running cleanup tasks

Code Context

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

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

                                             uint64_t safepoint_id,
                                             int initial_number_of_threads,
                                             int threads_waiting_to_block,
                                             uint64_t iterations) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.set_initialThreadCount(initial_number_of_threads);
    event.set_runningThreadCount(threads_waiting_to_block);
    event.set_iterations(iterations);
    event.commit();
  }
}

static void post_safepoint_cleanup_task_event(EventSafepointCleanupTask& event,
                                              uint64_t safepoint_id,
                                              const char* name) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.set_name(name);
    event.commit();
  }
}

static void post_safepoint_end_event(EventSafepointEnd& event, uint64_t safepoint_id) {
  if (event.should_commit()) {

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

class ParallelSPCleanupTask : public AbstractGangTask {
private:
  SubTasksDone _subtasks;
  uint _num_workers;
  bool _do_lazy_roots;

  class Tracer {
  private:
    const char*               _name;
    EventSafepointCleanupTask _event;
    TraceTime                 _timer;

  public:
    Tracer(const char* name) :
        _name(name),
        _event(),
        _timer(name, TRACETIME_LOG(Info, safepoint, cleanup)) {}
    ~Tracer() {
      post_safepoint_cleanup_task_event(_event, SafepointSynchronize::safepoint_id(), _name);
    }
  };

Configuration enabled threshold
profiling false 0 ms
default false 10 ms

Field Type Description
safepointId ulong Safepoint Identifier
name string Task Name The task name

Examples 3
name string
updating inline caches
safepointId ulong
1278
startTime long: millis
449828795394
name string
updating inline caches
safepointId ulong
680
startTime long: millis
381790414756
name string
updating inline caches
safepointId ulong
1526
startTime long: millis
288058005618

SafepointEnd

startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime / Safepoint

Safepointing end

Code Context

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

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

static void post_safepoint_cleanup_task_event(EventSafepointCleanupTask& event,
                                              uint64_t safepoint_id,
                                              const char* name) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.set_name(name);
    event.commit();
  }
}

static void post_safepoint_end_event(EventSafepointEnd& event, uint64_t safepoint_id) {
  if (event.should_commit()) {
    event.set_safepointId(safepoint_id);
    event.commit();
  }
}

// SafepointCheck
SafepointStateTracker::SafepointStateTracker(uint64_t safepoint_id, bool at_safepoint)
  : _safepoint_id(safepoint_id), _at_safepoint(at_safepoint) {}

bool SafepointStateTracker::safepoint_state_changed() {

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

  } // ~JavaThreadIteratorWithHandle

  // Release threads lock, so threads can be created/destroyed again.
  Threads_lock->unlock();

  // Wake threads after local state is correctly set.
  _wait_barrier->disarm();
}

// Wake up all threads, so they are ready to resume execution after the safepoint
// operation has been carried out
void SafepointSynchronize::end() {
  assert(Threads_lock->owned_by_self(), "must hold Threads_lock");
  EventSafepointEnd event;
  assert(Thread::current()->is_VM_thread(), "Only VM thread can execute a safepoint");

  disarm_safepoint();

  Universe::heap()->safepoint_synchronize_end();

  SafepointTracing::end();

  post_safepoint_end_event(event, safepoint_id());
}

Configuration enabled threshold
profiling false 0 ms
default false 10 ms

Field Type Description
safepointId ulong Safepoint Identifier

Examples 3
safepointId ulong
1528
startTime long: millis
289278734488
safepointId ulong
1262
startTime long: millis
441752847671
safepointId ulong
734
startTime long: millis
429266498237

ExecuteVMOperation

profiling default startTime duration eventThread 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime

Execution of a VM Operation

Code Context

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

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

  // Wait until VM thread is terminated
  // Note: it should be OK to use Terminator_lock here. But this is called
  // at a very delicate time (VM shutdown) and we are operating in non- VM
  // thread at Safepoint. It's safer to not share lock with other threads.
  {
    MonitorLocker ml(_terminate_lock, Mutex::_no_safepoint_check_flag);
    while (!VMThread::is_terminated()) {
      ml.wait();
    }
  }
}

static void post_vm_operation_event(EventExecuteVMOperation* event, VM_Operation* op) {
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  assert(op != NULL, "invariant");
  const bool evaluate_at_safepoint = op->evaluate_at_safepoint();
  event->set_operation(op->type());
  event->set_safepoint(evaluate_at_safepoint);
  event->set_blocking(true);
  event->set_caller(JFR_THREAD_ID(op->calling_thread()));
  event->set_safepointId(evaluate_at_safepoint ? SafepointSynchronize::safepoint_id() : 0);
  event->commit();
}

void VMThread::evaluate_operation(VM_Operation* op) {
  ResourceMark rm;

  {
    PerfTraceTime vm_op_timer(perf_accumulated_vm_operation_time());
    HOTSPOT_VMOPS_BEGIN(
                     (char *) op->name(), strlen(op->name()),
                     op->evaluate_at_safepoint() ? 0 : 1);

    EventExecuteVMOperation event;
    op->evaluate();
    if (event.should_commit()) {
      post_vm_operation_event(&event, op);
    }

    HOTSPOT_VMOPS_END(
                     (char *) op->name(), strlen(op->name()),
                     op->evaluate_at_safepoint() ? 0 : 1);
  }

}

Configuration enabled threshold
profiling true 0 ms
default true 10 ms

Field Type Description
operation VMOperationType Operation
safepoint boolean At Safepoint If the operation occured at a safepoint
blocking boolean Caller Blocked If the calling thread was blocked until the operation was complete
caller Thread Caller Thread requesting operation. If non-blocking, will be set to 0 indicating thread is unknown
safepointId ulong Safepoint Identifier The safepoint (if any) under which this operation was completed

Examples 3
blocking boolean
true
caller Thread
group ThreadGroup
null
javaName string
null
javaThreadId long
0
osName string
G1 Main Marker
osThreadId long
2292
virtual boolean
false
operation VMOperationType
G1PauseCleanup
safepoint boolean
true
safepointId ulong
1488
startTime long: millis
279089689991
blocking boolean
true
caller Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
main
javaThreadId long
1
osName string
main
osThreadId long
2255
virtual boolean
false
operation VMOperationType
ICBufferFull
safepoint boolean
true
safepointId ulong
1232
startTime long: millis
431711628841
blocking boolean
true
caller Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
JFR Periodic Tasks
javaThreadId long
15
osName string
JFR Periodic Tasks
osThreadId long
2940
virtual boolean
false
operation VMOperationType
ClassLoaderStatsOperation
safepoint boolean
true
safepointId ulong
694
startTime long: millis
387687120634

Shutdown

profiling default startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime

JVM shutting down

Code Context

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

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

  JavaThread* thread = JavaThread::current();

#ifdef ASSERT
  _vm_complete = false;
#endif
  // Wait until we are the last non-daemon thread to execute
  { MonitorLocker nu(Threads_lock);
    while (Threads::number_of_non_daemon_threads() > 1)
      // This wait should make safepoint checks, wait without a timeout,
      // and wait as a suspend-equivalent condition.
      nu.wait(0, Mutex::_as_suspend_equivalent_flag);
  }

  EventShutdown e;
  if (e.should_commit()) {
    e.set_reason("No remaining non-daemon Java threads");
    e.commit();
  }

  // Hang forever on exit if we are reporting an error.
  if (ShowMessageBoxOnError && VMError::is_error_reported()) {
    os::infinite_sleep();
  }
  os::wait_for_keypress_at_exit();

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

// java.lang.Runtime /////////////////////////////////////////////////////////////////////////

extern volatile jint vm_created;

JVM_ENTRY_NO_ENV(void, JVM_BeforeHalt())
  JVMWrapper("JVM_BeforeHalt");
  // Link all classes for dynamic CDS dumping before vm exit.
  if (DynamicDumpSharedSpaces) {
    MetaspaceShared::link_and_cleanup_shared_classes(THREAD);
  }
  EventShutdown event;
  if (event.should_commit()) {
    event.set_reason("Shutdown requested from Java");
    event.commit();
  }
JVM_END


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

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

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

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();
}

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
reason string Reason Reason for JVM shutdown

Examples 3
reason string
No remaining non-daemon Java threads
stackTrace StackTrace
null
startTime long: millis
367335947087
reason string
No remaining non-daemon Java threads
stackTrace StackTrace
null
startTime long: millis
482443717902
reason string
No remaining non-daemon Java threads
stackTrace StackTrace
null
startTime long: millis
493401214751

SymbolTableStatistics

profiling default startTime duration every chunk 13 17 21 25 26 27

Category: Java Virtual Machine / Runtime / Tables

Code Context

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

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

  event.set_entryCount(statistics._number_of_entries);
  event.set_totalFootprint(statistics._total_footprint);
  event.set_bucketCountMaximum(statistics._maximum_bucket_size);
  event.set_bucketCountAverage(statistics._average_bucket_size);
  event.set_bucketCountVariance(statistics._variance_of_bucket_size);
  event.set_bucketCountStandardDeviation(statistics._stddev_of_bucket_size);
  event.set_insertionRate(statistics._add_rate);
  event.set_removalRate(statistics._remove_rate);
  event.commit();
}

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

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

TRACE_REQUEST_FUNC(PlaceholderTableStatistics) {
  TableStatistics statistics = SystemDictionary::placeholders_statistics();
  emit_table_statistics<EventPlaceholderTableStatistics>(statistics);
}

Configuration enabled period
profiling true 10 s
default true 10 s

Field Type Description
bucketCount ulong Bucket Count Number of buckets
entryCount ulong Entry Count Number of all entries
totalFootprint ulong: bytes Total Footprint Total memory footprint (the table itself plus all of the entries)
bucketCountMaximum ulong Maximum Bucket Count The maximum bucket length (entries in a single bucket)
bucketCountAverage float Average Bucket Count The average bucket length
bucketCountVariance float Bucket Count Variance How far bucket lengths are spread out from their average value
bucketCountStandardDeviation float Bucket Count Standard Deviation How far bucket lengths are spread out from their mean (expected) value
insertionRate float Insertion Rate How many items were added since last event (per second)
removalRate float Removal Rate How many items were removed since last event (per second)

Examples 3
bucketCount ulong
131072
bucketCountAverage float
4.2176666
bucketCountMaximum ulong
18
bucketCountStandardDeviation float
2.0538146
bucketCountVariance float
4.218155
entryCount ulong
552818
insertionRate float
4666.9175
removalRate float
51.000275
startTime long: millis
455787342415
totalFootprint ulong: bytes
62915176
bucketCount ulong
131072
bucketCountAverage float
4.3553925
bucketCountMaximum ulong
17
bucketCountStandardDeviation float
2.088268
bucketCountVariance float
4.3608637
entryCount ulong
570870
insertionRate float
454.71884
removalRate float
4614.919
startTime long: millis
363644732907
totalFootprint ulong: bytes
64516584
bucketCount ulong
65536
bucketCountAverage float
7.8194885
bucketCountMaximum ulong
21
bucketCountStandardDeviation float
2.806837
bucketCountVariance float
7.878335
entryCount ulong
512458
insertionRate float
697.4281
removalRate float
194.95113
startTime long: millis
449986484396
totalFootprint ulong: bytes
55223752

StringTableStatistics

profiling default startTime duration every chunk 13 17 21 25 26 27

Category: Java Virtual Machine / Runtime / Tables

Code Context

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

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

  event.set_bucketCountStandardDeviation(statistics._stddev_of_bucket_size);
  event.set_insertionRate(statistics._add_rate);
  event.set_removalRate(statistics._remove_rate);
  event.commit();
}

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

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

TRACE_REQUEST_FUNC(PlaceholderTableStatistics) {
  TableStatistics statistics = SystemDictionary::placeholders_statistics();
  emit_table_statistics<EventPlaceholderTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(LoaderConstraintsTableStatistics) {
  TableStatistics statistics = SystemDictionary::loader_constraints_statistics();
  emit_table_statistics<EventLoaderConstraintsTableStatistics>(statistics);
}

Configuration enabled period
profiling true 10 s
default true 10 s

Field Type Description
bucketCount ulong Bucket Count Number of buckets
entryCount ulong Entry Count Number of all entries
totalFootprint ulong: bytes Total Footprint Total memory footprint (the table itself plus all of the entries)
bucketCountMaximum ulong Maximum Bucket Count The maximum bucket length (entries in a single bucket)
bucketCountAverage float Average Bucket Count The average bucket length
bucketCountVariance float Bucket Count Variance How far bucket lengths are spread out from their average value
bucketCountStandardDeviation float Bucket Count Standard Deviation How far bucket lengths are spread out from their mean (expected) value
insertionRate float Insertion Rate How many items were added since last event (per second)
removalRate float Removal Rate How many items were removed since last event (per second)

Examples 3
bucketCount ulong
65536
bucketCountAverage float
1.8048859
bucketCountMaximum ulong
10
bucketCountStandardDeviation float
1.3388131
bucketCountVariance float
1.7924206
entryCount ulong
118285
insertionRate float
419.1846
removalRate float
12.165391
startTime long: millis
483701102080
totalFootprint ulong: bytes
12129992
bucketCount ulong
65536
bucketCountAverage float
1.7816162
bucketCountMaximum ulong
10
bucketCountStandardDeviation float
1.3207544
bucketCountVariance float
1.7443923
entryCount ulong
116760
insertionRate float
434.7887
removalRate float
36.967827
startTime long: millis
476128955040
totalFootprint ulong: bytes
11956552
bucketCount ulong
65536
bucketCountAverage float
1.4456177
bucketCountMaximum ulong
10
bucketCountStandardDeviation float
1.2022887
bucketCountVariance float
1.4454983
entryCount ulong
94740
insertionRate float
50.173584
removalRate float
11.928523
startTime long: millis
321651390839
totalFootprint ulong: bytes
10633656

PlaceholderTableStatistics

profiling default startTime duration every chunk 17 until JDK 20

Category: Java Virtual Machine / Runtime / Tables

Code Context

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

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

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(PlaceholderTableStatistics) {
  TableStatistics statistics = SystemDictionary::placeholders_statistics();
  emit_table_statistics<EventPlaceholderTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(LoaderConstraintsTableStatistics) {
  TableStatistics statistics = SystemDictionary::loader_constraints_statistics();
  emit_table_statistics<EventLoaderConstraintsTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(ProtectionDomainCacheTableStatistics) {
  TableStatistics statistics = SystemDictionary::protection_domain_cache_statistics();
  emit_table_statistics<EventProtectionDomainCacheTableStatistics>(statistics);
}

Configuration enabled period
profiling true 10 s
default true 10 s

Field Type Description
bucketCount ulong Bucket Count Number of buckets
entryCount ulong Entry Count Number of all entries
totalFootprint ulong: bytes Total Footprint Total memory footprint (the table itself plus all of the entries)
bucketCountMaximum ulong Maximum Bucket Count The maximum bucket length (entries in a single bucket)
bucketCountAverage float Average Bucket Count The average bucket length
bucketCountVariance float Bucket Count Variance How far bucket lengths are spread out from their average value
bucketCountStandardDeviation float Bucket Count Standard Deviation How far bucket lengths are spread out from their mean (expected) value
insertionRate float Insertion Rate How many items were added since last event (per second)
removalRate float Removal Rate How many items were removed since last event (per second)

LoaderConstraintsTableStatistics

profiling default startTime duration every chunk 17 until JDK 20

Category: Java Virtual Machine / Runtime / Tables

Code Context

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

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

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

TRACE_REQUEST_FUNC(PlaceholderTableStatistics) {
  TableStatistics statistics = SystemDictionary::placeholders_statistics();
  emit_table_statistics<EventPlaceholderTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(LoaderConstraintsTableStatistics) {
  TableStatistics statistics = SystemDictionary::loader_constraints_statistics();
  emit_table_statistics<EventLoaderConstraintsTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(ProtectionDomainCacheTableStatistics) {
  TableStatistics statistics = SystemDictionary::protection_domain_cache_statistics();
  emit_table_statistics<EventProtectionDomainCacheTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(CompilerStatistics) {
  EventCompilerStatistics event;
  event.set_compileCount(CompileBroker::get_total_compile_count());
  event.set_bailoutCount(CompileBroker::get_total_bailout_count());

Configuration enabled period
profiling true 10 s
default true 10 s

Field Type Description
bucketCount ulong Bucket Count
entryCount ulong Entry Count Number of all entries
totalFootprint ulong: bytes Total Footprint Total memory footprint (the table itself plus all of the entries)
bucketCountMaximum ulong Maximum Bucket Count The maximum bucket length (entries in a single bucket)
bucketCountAverage float Average Bucket Count The average bucket length
bucketCountVariance float Bucket Count Variance How far bucket lengths are spread out from their average value
bucketCountStandardDeviation float Bucket Count Standard Deviation How far bucket lengths are spread out from their mean (expected) value
insertionRate float Insertion Rate How many items were added since last event (per second)
removalRate float Removal Rate How many items were removed since last event (per second)

ProtectionDomainCacheTableStatistics

profiling default startTime duration every chunk 17 until JDK 20

Category: Java Virtual Machine / Runtime / Tables

Code Context

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

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

TRACE_REQUEST_FUNC(PlaceholderTableStatistics) {
  TableStatistics statistics = SystemDictionary::placeholders_statistics();
  emit_table_statistics<EventPlaceholderTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(LoaderConstraintsTableStatistics) {
  TableStatistics statistics = SystemDictionary::loader_constraints_statistics();
  emit_table_statistics<EventLoaderConstraintsTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(ProtectionDomainCacheTableStatistics) {
  TableStatistics statistics = SystemDictionary::protection_domain_cache_statistics();
  emit_table_statistics<EventProtectionDomainCacheTableStatistics>(statistics);
}

TRACE_REQUEST_FUNC(CompilerStatistics) {
  EventCompilerStatistics event;
  event.set_compileCount(CompileBroker::get_total_compile_count());
  event.set_bailoutCount(CompileBroker::get_total_bailout_count());
  event.set_invalidatedCount(CompileBroker::get_total_invalidated_count());
  event.set_osrCompileCount(CompileBroker::get_total_osr_compile_count());
  event.set_standardCompileCount(CompileBroker::get_total_standard_compile_count());
  event.set_osrBytesCompiled(CompileBroker::get_sum_osr_bytes_compiled());
  event.set_standardBytesCompiled(CompileBroker::get_sum_standard_bytes_compiled());

Configuration enabled period
profiling true 10 s
default true 10 s

Field Type Description
bucketCount ulong Bucket Count Number of buckets
entryCount ulong Entry Count Number of all entries
totalFootprint ulong: bytes Total Footprint Total memory footprint (the table itself plus all of the entries)
bucketCountMaximum ulong Maximum Bucket Count The maximum bucket length (entries in a single bucket)
bucketCountAverage float Average Bucket Count The average bucket length
bucketCountVariance float Bucket Count Variance How far bucket lengths are spread out from their average value
bucketCountStandardDeviation float Bucket Count Standard Deviation How far bucket lengths are spread out from their mean (expected) value
insertionRate float Insertion Rate How many items were added since last event (per second)
removalRate float Removal Rate How many items were removed since last event (per second)

ThreadDump

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

Category: Java Virtual Machine / Runtime

Code Context

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

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

  Thread* THREAD = Thread::current();
  assert(!HAS_PENDING_EXCEPTION, "dcmd does not expect pending exceptions on entry!");
  // delegate to DCmd execution
  DCmd::parse_and_execute(DCmd_Source_Internal, &st, cmd, ' ', THREAD);
  if (HAS_PENDING_EXCEPTION) {
    log_debug(jfr, system)("unable to create jfr event for DCMD %s", cmd);
    log_debug(jfr, system)("exception type: %s", PENDING_EXCEPTION->klass()->external_name());
    // don't unwind this exception
    CLEAR_PENDING_EXCEPTION;
    // if exception occurred,
    // reset stream.
    st.reset();
    return false;
  }
  return true;
}

// caller needs ResourceMark
const char* JfrDcmdEvent::thread_dump() {
  assert(EventThreadDump::is_enabled(), "invariant");
  bufferedStream st;
  execute_dcmd(st, "Thread.print");
  return st.as_string();
}

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

/*
 * This is left empty on purpose, having ExecutionSample as a requestable
 * is a way of getting the period. The period is passed to ThreadSampling::update_period.
 * Implementation in jfrSamples.cpp
 */
TRACE_REQUEST_FUNC(ExecutionSample) {
}
TRACE_REQUEST_FUNC(NativeMethodSample) {
}

TRACE_REQUEST_FUNC(ThreadDump) {
  ResourceMark rm;
  EventThreadDump event;
  event.set_result(JfrDcmdEvent::thread_dump());
  event.commit();
}

static int _native_library_callback(const char* name, address base, address top, void *param) {
  EventNativeLibrary event(UNTIMED);
  event.set_name(name);
  event.set_baseAddress((u8)base);
  event.set_topAddress((u8)top);
  event.set_endtime(*(JfrTicks*) param);
  event.commit();

Configuration enabled period
profiling true 60 s
default true everyChunk

Field Type Description
result string Thread Dump

Examples 3
result string
2026-01-04 00:46:43 Full thread dump OpenJDK 64-Bit Server VM (21.0.9+10-LTS mixed mode, sharing): Threads class SMR info: _java_thread_list=0x00007f303c3b0e00, length=45, elements={ 0x00007f30d4057c80, 0x00007f30d41320c0, 0x00007f30d41335f0, 0x00007f30d4134d40, 0x00007f30d4136340, 0x00007f30d41378
startTime long: millis
435465753170
result string
2026-01-04 00:44:59 Full thread dump OpenJDK 64-Bit Server VM (21.0.9+10-LTS mixed mode, sharing): Threads class SMR info: _java_thread_list=0x00007f58c0689570, length=68, elements={ 0x00007f594c057cc0, 0x00007f594c196b80, 0x00007f594c1980e0, 0x00007f594c199860, 0x00007f594c19ae90, 0x00007f594c19c4
startTime long: millis
332347553041
result string
2026-01-04 00:47:08 Full thread dump OpenJDK 64-Bit Server VM (21.0.9+10-LTS mixed mode, sharing): Threads class SMR info: _java_thread_list=0x00007fb93401c0d0, length=51, elements={ 0x00007fb9b4057c60, 0x00007fb9b40ac860, 0x00007fb9b40add90, 0x00007fb9b40af4e0, 0x00007fb9b40b0ae0, 0x00007fb9b40b20
startTime long: millis
472193057213

NativeLibrary

profiling default startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime

Code Context

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

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

TRACE_REQUEST_FUNC(ExecutionSample) {
}
TRACE_REQUEST_FUNC(NativeMethodSample) {
}

TRACE_REQUEST_FUNC(ThreadDump) {
  ResourceMark rm;
  EventThreadDump event;
  event.set_result(JfrDcmdEvent::thread_dump());
  event.commit();
}

static int _native_library_callback(const char* name, address base, address top, void *param) {
  EventNativeLibrary event(UNTIMED);
  event.set_name(name);
  event.set_baseAddress((u8)base);
  event.set_topAddress((u8)top);
  event.set_endtime(*(JfrTicks*) param);
  event.commit();
  return 0;
}

TRACE_REQUEST_FUNC(NativeLibrary) {
  JfrTicks ts= JfrTicks::now();
  os::get_loaded_modules_info(&_native_library_callback, (void *)&ts);

Configuration enabled period
profiling true everyChunk
default true everyChunk

Field Type Description
name string Name
baseAddress ulong: address Base Address Starting address of the module
topAddress ulong: address Top Address Ending address of the module

Examples 3
baseAddress ulong: address
140021642895360
name string
/opt/hostedtoolcache/Java_SapMachine_jdk/21.0.9/x64/lib/libjimage.so
startTime long: millis
278185459316
topAddress ulong: address
140021643018240
baseAddress ulong: address
139847774683136
name string
/opt/hostedtoolcache/Java_SapMachine_jdk/21.0.9/x64/lib/libjaas.so
startTime long: millis
381802683142
topAddress ulong: address
139847774695424
baseAddress ulong: address
140435675877376
name string
/opt/hostedtoolcache/Java_SapMachine_jdk/21.0.9/x64/lib/libnio.so
startTime long: millis
388177860361
topAddress ulong: address
140435675967488

ModuleRequire

profiling default startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime / Modules

A directed edge representing a dependency

Code Context

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

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

   ModuleDependencyClosure(const ModuleEntry* module, EventFunc ef) : ModuleEventCallbackClosure(ef), _module(module) {}
   void do_module(ModuleEntry* entry);
};

class ModuleExportClosure : public ModuleEventCallbackClosure {
 private:
  const PackageEntry* const _package;
 public:
  ModuleExportClosure(const PackageEntry* pkg, EventFunc ef) : ModuleEventCallbackClosure(ef), _package(pkg) {}
  void do_module(ModuleEntry* entry);
};

static void write_module_dependency_event(const void* from_module, const ModuleEntry* to_module) {
  EventModuleRequire event(UNTIMED);
  event.set_endtime(invocation_time);
  event.set_source((const ModuleEntry* const)from_module);
  event.set_requiredModule(to_module);
  event.commit();
}

static void write_module_export_event(const void* package, const ModuleEntry* qualified_export) {
  EventModuleExport event(UNTIMED);
  event.set_endtime(invocation_time);
  event.set_exportedPackage((const PackageEntry*)package);
  event.set_targetModule(qualified_export);

Configuration enabled period
profiling true endChunk
default true endChunk

Field Type Description
source Module Source Module
requiredModule Module Required Module

Examples 3
requiredModule Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
source Module
classLoader ClassLoader
name string
platform
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
10
name string
jdk/internal/loader/ClassLoaders$PlatformClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
jdk/internal/loader
location string
jrt:/jdk.dynalink
name string
jdk.dynalink
version string
21.0.9
startTime long: millis
374646122291
requiredModule Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
source Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
jdk.proxy9
version string
null
startTime long: millis
382361859327
requiredModule Module
classLoader ClassLoader
name string
app
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
10
name string
jdk/internal/loader/ClassLoaders$AppClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
jdk/internal/loader
location string
jrt:/jdk.jdeps
name string
jdk.jdeps
version string
21.0.9
source Module
classLoader ClassLoader
name string
app
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
10
name string
jdk/internal/loader/ClassLoaders$AppClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
jdk/internal/loader
location string
jrt:/jdk.jlink
name string
jdk.jlink
version string
21.0.9
startTime long: millis
279631473390

ModuleExport

profiling default startTime every chunk 11 17 21 25 26 27

Category: Java Virtual Machine / Runtime / Modules

Code Context

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

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

  ModuleExportClosure(const PackageEntry* pkg, EventFunc ef) : ModuleEventCallbackClosure(ef), _package(pkg) {}
  void do_module(ModuleEntry* entry);
};

static void write_module_dependency_event(const void* from_module, const ModuleEntry* to_module) {
  EventModuleRequire event(UNTIMED);
  event.set_endtime(invocation_time);
  event.set_source((const ModuleEntry* const)from_module);
  event.set_requiredModule(to_module);
  event.commit();
}

static void write_module_export_event(const void* package, const ModuleEntry* qualified_export) {
  EventModuleExport event(UNTIMED);
  event.set_endtime(invocation_time);
  event.set_exportedPackage((const PackageEntry*)package);
  event.set_targetModule(qualified_export);
  event.commit();
}

void ModuleDependencyClosure::do_module(ModuleEntry* to_module) {
  assert_locked_or_safepoint(Module_lock);
  assert(to_module != NULL, "invariant");
  assert(_module != NULL, "invariant");
  assert(_event_func != NULL, "invariant");

Configuration enabled period
profiling true endChunk
default true endChunk

Field Type Description
exportedPackage Package Exported Package
targetModule Module Target Module Module to which the package is qualifiedly exported. If null or N/A, the package is unqualifiedly exported

Examples 3
exportedPackage Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/apache/spark/sql/execution
startTime long: millis
279631749684
targetModule Module
null
exportedPackage Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/jdk.net
name string
jdk.net
version string
21.0.9
name string
jdk/nio
startTime long: millis
382362306931
targetModule Module
null
exportedPackage Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
org/antlr/v4/runtime/tree
startTime long: millis
374646561997
targetModule Module
null

Java Application

ThreadStart

profiling default startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Application

Code Context

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

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

void JfrThreadLocal::set_thread_blob(const JfrBlobHandle& ref) {
  assert(!_thread.valid(), "invariant");
  _thread = ref;
}

const JfrBlobHandle& JfrThreadLocal::thread_blob() const {
  return _thread;
}

static void send_java_thread_start_event(JavaThread* jt) {
  EventThreadStart event;
  event.set_thread(jt->jfr_thread_local()->thread_id());
  event.set_parentThread(jt->jfr_thread_local()->parent_thread_id());
  event.commit();
}

void JfrThreadLocal::on_start(Thread* t) {
  assert(t != NULL, "invariant");
  assert(Thread::current() == t, "invariant");
  JfrJavaSupport::on_thread_start(t);
  if (JfrRecorder::is_recording()) {
    JfrCheckpointManager::write_thread_checkpoint(t);

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

  if (native_thread->osthread() == NULL) {
    // No one should hold a reference to the 'native_thread'.
    native_thread->smr_delete();
    if (JvmtiExport::should_post_resource_exhausted()) {
      JvmtiExport::post_resource_exhausted(
        JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR | JVMTI_RESOURCE_EXHAUSTED_THREADS,
        os::native_thread_creation_failed_msg());
    }
    THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(),
              os::native_thread_creation_failed_msg());
  }

#if INCLUDE_JFR
  if (Jfr::is_recording() && EventThreadStart::is_enabled() &&
      EventThreadStart::is_stacktrace_enabled()) {
    JfrThreadLocal* tl = native_thread->jfr_thread_local();
    // skip Thread.start() and Thread.start0()
    tl->set_cached_stack_trace_id(JfrStackTraceRepository::record(thread, 2));
  }
#endif

  Thread::start(native_thread);

JVM_END

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

#if INCLUDE_JNI_CHECK
  if (CheckJNICalls) return jni_functions_check();
#endif // INCLUDE_JNI_CHECK
  return &jni_NativeInterface;
}

// Returns the function structure
struct JNINativeInterface_* jni_functions_nocheck() {
  return &jni_NativeInterface;
}

static void post_thread_start_event(const JavaThread* jt) {
  assert(jt != NULL, "invariant");
  EventThreadStart event;
  if (event.should_commit()) {
    event.set_thread(JFR_THREAD_ID(jt));
    event.set_parentThread((traceid)0);
#if INCLUDE_JFR
    if (EventThreadStart::is_stacktrace_enabled()) {
      jt->jfr_thread_local()->set_cached_stack_trace_id((traceid)0);
      event.commit();
      jt->jfr_thread_local()->clear_cached_stack_trace();
    } else
#endif
    {
      event.commit();
    }
  }
}

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
thread Thread New Java Thread
parentThread Thread Parent Java Thread

Examples 3
parentThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
dispatcher-BlockManagerEndpoint1
javaThreadId long
1133
osName string
dispatcher-BlockManagerEndpoint1
osThreadId long
3720
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
2
lineNumber int
2577
method Method
descriptor string
(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden boolean
false
modifiers int
1
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/lang/System$2
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Inlined
truncated boolean
false
startTime long: millis
390308258130
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-48
javaThreadId long
1256
osName string
block-manager-storage-async-thread-pool-48
osThreadId long
3869
virtual boolean
false
parentThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-69
javaThreadId long
1306
osName string
block-manager-storage-async-thread-pool-69
osThreadId long
4563
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
2
lineNumber int
2577
method Method
descriptor string
(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden boolean
false
modifiers int
1
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/lang/System$2
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Inlined
truncated boolean
false
startTime long: millis
400780334899
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-70
javaThreadId long
1307
osName string
block-manager-storage-async-thread-pool-70
osThreadId long
4564
virtual boolean
false
parentThread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-ask-thread-pool-46
javaThreadId long
1312
osName string
block-manager-ask-thread-pool-46
osThreadId long
3914
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
2
lineNumber int
2577
method Method
descriptor string
(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden boolean
false
modifiers int
1
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/lang/System$2
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Inlined
truncated boolean
false
startTime long: millis
296343465174
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-ask-thread-pool-47
javaThreadId long
1313
osName string
block-manager-ask-thread-pool-47
osThreadId long
3915
virtual boolean
false

ThreadEnd

profiling default startTime eventThread 11 17 21 25 26 27

Category: Java Application

Code Context

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

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

  if (t->jfr_thread_local()->has_cached_stack_trace()) {
    t->jfr_thread_local()->clear_cached_stack_trace();
  }
}

static void send_java_thread_end_events(traceid id, JavaThread* jt) {
  assert(jt != NULL, "invariant");
  assert(Thread::current() == jt, "invariant");
  assert(jt->jfr_thread_local()->trace_id() == id, "invariant");
  if (JfrRecorder::is_recording()) {
    EventThreadEnd event;
    event.set_thread(id);
    event.commit();
    JfrThreadCPULoadEvent::send_event_for_thread(jt);
  }
}

void JfrThreadLocal::release(Thread* t) {
  if (has_java_event_writer()) {
    assert(t->is_Java_thread(), "invariant");
    JfrJavaSupport::destroy_global_jni_handle(java_event_writer());
    _java_event_writer = NULL;

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

#if INCLUDE_JVMCI
  if (EnableJVMCI) {
    JVMCI::shutdown();
  }
#endif

  // Hang forever on exit if we're reporting an error.
  if (ShowMessageBoxOnError && VMError::is_error_reported()) {
    os::infinite_sleep();
  }

  EventThreadEnd event;
  if (event.should_commit()) {
    event.set_thread(JFR_THREAD_ID(thread));
    event.commit();
  }

  JFR_ONLY(Jfr::on_vm_shutdown();)

  // Stop the WatcherThread. We do this before disenrolling various
  // PeriodicTasks to reduce the likelihood of races.
  if (PeriodicTask::num_tasks() > 0) {
    WatcherThread::stop();

Configuration enabled
profiling true
default true

Field Type Description
thread Thread Java Thread

Examples 3
startTime long: millis
417462258569
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-23
javaThreadId long
1213
osName string
block-manager-storage-async-thread-pool-23
osThreadId long
3818
virtual boolean
false
startTime long: millis
310949493125
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
SparkUI-1156
javaThreadId long
1156
osName string
SparkUI-1156
osThreadId long
3710
virtual boolean
false
startTime long: millis
421426184863
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-ask-thread-pool-22
javaThreadId long
1248
osName string
block-manager-ask-thread-pool-22
osThreadId long
4494
virtual boolean
false

ThreadSleep

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

Category: Java Application

Code Context

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

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

  // Implied else: If the JavaThread hasn't started yet, then the
  // priority set in the java.lang.Thread object above will be pushed
  // down when it does start.
JVM_END


JVM_ENTRY(void, JVM_Yield(JNIEnv *env, jclass threadClass))
  JVMWrapper("JVM_Yield");
  if (os::dont_yield()) return;
  HOTSPOT_THREAD_YIELD();
  os::naked_yield();
JVM_END

static void post_thread_sleep_event(EventThreadSleep* event, jlong millis) {
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_time(millis);
  event->commit();
}

JVM_ENTRY(void, JVM_Sleep(JNIEnv* env, jclass threadClass, jlong millis))
  JVMWrapper("JVM_Sleep");

  if (millis < 0) {
    THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), "timeout value is negative");
  }

  if (thread->is_interrupted(true) && !HAS_PENDING_EXCEPTION) {
    THROW_MSG(vmSymbols::java_lang_InterruptedException(), "sleep interrupted");
  }

  // Save current thread state and restore it at the end of this block.
  // And set new thread state to SLEEPING.
  JavaThreadSleepState jtss(thread);

  HOTSPOT_THREAD_SLEEP_BEGIN(millis);
  EventThreadSleep event;

  if (millis == 0) {
    os::naked_yield();
  } else {
    ThreadState old_state = thread->osthread()->get_state();
    thread->osthread()->set_state(SLEEPING);
    if (!thread->sleep(millis)) { // interrupted
      // An asynchronous exception (e.g., ThreadDeathException) could have been thrown on
      // us while we were sleeping. We do not overwrite those.
      if (!HAS_PENDING_EXCEPTION) {
        if (event.should_commit()) {

Configuration enabled stackTrace threshold
profiling true true 10 ms
default true true 20 ms

Field Type Description
time long: millis Sleep Time

Examples 3
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
5
lineNumber int
474
method Method
descriptor string
(Ljdk/internal/event/ThreadSleepEvent;)V
hidden boolean
false
modifiers int
10
name string
afterSleep
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Thread
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Inlined
truncated boolean
false
startTime long: millis
367054624603
time long: millis
10000000
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
5
lineNumber int
474
method Method
descriptor string
(Ljdk/internal/event/ThreadSleepEvent;)V
hidden boolean
false
modifiers int
10
name string
afterSleep
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Thread
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Inlined
truncated boolean
false
startTime long: millis
374293788745
time long: millis
10000000
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
5
lineNumber int
474
method Method
descriptor string
(Ljdk/internal/event/ThreadSleepEvent;)V
hidden boolean
false
modifiers int
10
name string
afterSleep
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Thread
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Inlined
truncated boolean
false
startTime long: millis
278678244290
time long: millis
200000000

ThreadPark

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

Category: Java Application

Code Context

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

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

} UNSAFE_END

UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
  oop p = JNIHandles::resolve(obj);
  if (p == NULL) {
    volatile jlong* addr = (volatile jlong*)index_oop_from_field_offset_long(p, offset);
    return RawAccess<>::atomic_cmpxchg(addr, e, x) == e;
  } else {
    assert_field_offset_sane(p, offset);
    return HeapAccess<>::atomic_cmpxchg_at(p, (ptrdiff_t)offset, e, x) == e;
  }
} UNSAFE_END

static void post_thread_park_event(EventThreadPark* event, const oop obj, jlong timeout_nanos, jlong until_epoch_millis) {
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_parkedClass((obj != NULL) ? obj->klass() : NULL);
  event->set_timeout(timeout_nanos);
  event->set_until(until_epoch_millis);
  event->set_address((obj != NULL) ? (u8)cast_from_oop<uintptr_t>(obj) : 0);
  event->commit();
}

UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time)) {
  HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time);
  EventThreadPark event;

  JavaThreadParkedState jtps(thread, time != 0);
  thread->parker()->park(isAbsolute != 0, time);
  if (event.should_commit()) {
    const oop obj = thread->current_park_blocker();
    if (time == 0) {
      post_thread_park_event(&event, obj, min_jlong, min_jlong);
    } else {
      if (isAbsolute != 0) {
        post_thread_park_event(&event, obj, min_jlong, time);
      } else {

Configuration enabled stackTrace threshold
profiling true true 10 ms
default true true 20 ms

Field Type Description
parkedClass Class Class Parked On
timeout long: nanos Park Timeout
until long: epochmillis Park Until
address ulong: address Address of Object Parked

Examples 3
address ulong: address
30347316376
parkedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionObject
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent/locks
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(ZJ)V
hidden boolean
false
modifiers int
257
name string
park
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
jdk/internal/misc/Unsafe
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
jdk/internal/misc
type FrameType
Native
truncated boolean
false
startTime long: millis
366275063726
timeout long: nanos
119998263947
until long: epochmillis
-9223372036854775808
address ulong: address
30322497120
parkedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionObject
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent/locks
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(ZJ)V
hidden boolean
false
modifiers int
257
name string
park
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
jdk/internal/misc/Unsafe
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
jdk/internal/misc
type FrameType
Native
truncated boolean
false
startTime long: millis
279354424526
timeout long: nanos
-9223372036854775808
until long: epochmillis
-9223372036854775808
address ulong: address
31748228400
parkedClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
24
name string
java/util/concurrent/SynchronousQueue$Transferer
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
-1
method Method
descriptor string
(ZJ)V
hidden boolean
false
modifiers int
257
name string
park
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
jdk/internal/misc/Unsafe
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
jdk/internal/misc
type FrameType
Native
truncated boolean
false
startTime long: millis
375038046201
timeout long: nanos
59999999910
until long: epochmillis
-9223372036854775808

JavaMonitorEnter

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

Category: Java Application

Code Context

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

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

    // above lost the race to async deflation. Undo the work and
    // force the caller to retry.
    const oop l_object = object();
    if (l_object != NULL) {
      // Attempt to restore the header/dmw to the object's header so that
      // we only retry once if the deflater thread happens to be slow.
      install_displaced_markword_in_object(l_object);
    }
    Self->_Stalled = 0;
    add_to_contentions(-1);
    return false;
  }

  JFR_ONLY(JfrConditionalFlushWithStacktrace<EventJavaMonitorEnter> flush(jt);)
  EventJavaMonitorEnter event;
  if (event.is_started()) {
    event.set_monitorClass(object()->klass());
    // Set an address that is 'unique enough', such that events close in
    // time and with the same address are likely (but not guaranteed) to
    // belong to the same object.
    event.set_address((uintptr_t)this);
  }

  { // Change java thread status to indicate blocked on monitor enter.
    JavaThreadBlockedOnMonitorEnterState jtbmes(jt, this);

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

  if (_recursions != 0) {
    _recursions--;        // this is simple recursive enter
    return;
  }

  // Invariant: after setting Responsible=null an thread must execute
  // a MEMBAR or other serializing instruction before fetching EntryList|cxq.
  _Responsible = NULL;

#if INCLUDE_JFR
  // get the owner's thread id for the MonitorEnter event
  // if it is enabled and the thread isn't suspended
  if (not_suspended && EventJavaMonitorEnter::is_enabled()) {
    _previous_owner_tid = JFR_THREAD_ID(Self);
  }
#endif

  for (;;) {
    assert(THREAD == owner_raw(), "invariant");

    // Drop the lock.
    // release semantics: prior loads and stores from within the critical section
    // must not float (reorder) past the following store that drops the lock.
    // Uses a storeload to separate release_store(owner) from the

Configuration enabled stackTrace threshold
profiling true true 10 ms
default true true 20 ms

Field Type Description
monitorClass Class Monitor Class
previousOwner Thread Previous Monitor Owner
address ulong: address Monitor Address

Examples 3
address ulong: address
139845144791808
monitorClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Object
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
previousOwner Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
rpc-boss-3-1
javaThreadId long
1133
osName string
rpc-boss-3-1
osThreadId long
4364
virtual boolean
false
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
7
lineNumber int
573
method Method
descriptor string
(Ljava/lang/String;Z)Ljava/lang/Class;
hidden boolean
false
modifiers int
4
name string
loadClass
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1025
name string
java/lang/ClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
435414149746
address ulong: address
140018462046608
monitorClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Object
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
previousOwner Thread
group ThreadGroup
name string
finagle/netty4
parent ThreadGroup
name string
main
parent ThreadGroup
name string
system
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JavaMonitorWait

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

Category: Java Application

Waiting on a Java monitor

Code Context

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

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

  void* cur = owner_raw();
  if (cur == THREAD) {
    return true;
  }
  if (THREAD->is_lock_owned((address)cur)) {
    set_owner_from_BasicLock(cur, THREAD);  // Convert from BasicLock* to Thread*.
    _recursions = 0;
    return true;
  }
  THROW_MSG_(vmSymbols::java_lang_IllegalMonitorStateException(),
             "current thread is not owner", false);
}

static void post_monitor_wait_event(EventJavaMonitorWait* event,
                                    ObjectMonitor* monitor,
                                    jlong notifier_tid,
                                    jlong timeout,
                                    bool timedout) {
  assert(event != NULL, "invariant");
  assert(monitor != NULL, "invariant");
  event->set_monitorClass(monitor->object()->klass());
  event->set_timeout(timeout);
  // Set an address that is 'unique enough', such that events close in
  // time and with the same address are likely (but not guaranteed) to
  // belong to the same object.

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

// -----------------------------------------------------------------------------
// Wait/Notify/NotifyAll
//
// Note: a subset of changes to ObjectMonitor::wait()
// will need to be replicated in complete_exit
void ObjectMonitor::wait(jlong millis, bool interruptible, TRAPS) {
  Thread * const Self = THREAD;
  JavaThread * jt = Self->as_Java_thread();

  assert(InitDone, "Unexpectedly not initialized");

  CHECK_OWNER();  // Throws IMSE if not owner.

  EventJavaMonitorWait event;

  // check for a pending interrupt
  if (interruptible && jt->is_interrupted(true) && !HAS_PENDING_EXCEPTION) {
    // post monitor waited event.  Note that this is past-tense, we are done waiting.
    if (JvmtiExport::should_post_monitor_waited()) {
      // Note: 'false' parameter is passed here because the
      // wait was not timed out due to thread interrupt.
      JvmtiExport::post_monitor_waited(jt, this, false);

      // In this short circuit of the monitor wait protocol, the
      // current thread never drops ownership of the monitor and

Configuration enabled stackTrace threshold
profiling true true 10 ms
default true true 20 ms

Field Type Description
monitorClass Class Monitor Class Class of object waited on
notifier Thread Notifier Thread Notifying Thread
timeout long: millis Timeout Maximum wait time
timedOut boolean Timed Out Wait has been timed out
address ulong: address Monitor Address Address of object waited on

Examples 3
address ulong: address
140017437052192
monitorClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
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name string
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hidden boolean
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modifiers int
9
name string
org/renaissance/scala/stm/RealityShowPhilosophers$PhilosopherThread
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classLoader ClassLoader
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classLoader ClassLoader
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bootstrap
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location string
jrt:/java.base
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java.base
version string
21.0.9
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location string
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name string
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version string
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name string
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notifier Thread
group ThreadGroup
name string
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parent ThreadGroup
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javaThreadId long
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osName string
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JavaMonitorInflate

profiling startTime duration eventThread stackTrace 11 17 21 25 26 27

Category: Java Application

Code Context

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

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

  if (!ret_code) {
    log_info(monitorinflation)("Async Deflation DID NOT happen after %d checks.", N_CHECKS);
  }

  return ret_code;
}

jlong ObjectSynchronizer::time_since_last_async_deflation_ms() {
  return (os::javaTimeNanos() - last_async_deflation_time_ns()) / (NANOUNITS / MILLIUNITS);
}

static void post_monitor_inflate_event(EventJavaMonitorInflate* event,
                                       const oop obj,
                                       ObjectSynchronizer::InflateCause cause) {
  assert(event != NULL, "invariant");
  assert(event->should_commit(), "invariant");
  event->set_monitorClass(obj->klass());
  event->set_address((uintptr_t)(void*)obj);
  event->set_cause((u1)cause);
  event->commit();
}

// Fast path code shared by multiple functions

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

void ObjectSynchronizer::inflate_helper(oop obj) {
  markWord mark = obj->mark();
  if (mark.has_monitor()) {
    ObjectMonitor* monitor = mark.monitor();
    markWord dmw = monitor->header();
    assert(dmw.is_neutral(), "sanity check: header=" INTPTR_FORMAT, dmw.value());
    return;
  }
  (void)inflate(Thread::current(), obj, inflate_cause_vm_internal);
}

ObjectMonitor* ObjectSynchronizer::inflate(Thread* self, oop object,
                                           const InflateCause cause) {
  EventJavaMonitorInflate event;

  for (;;) {
    const markWord mark = object->mark();
    assert(!mark.has_bias_pattern(), "invariant");

    // The mark can be in one of the following states:
    // *  Inflated     - just return
    // *  Stack-locked - coerce it to inflated
    // *  INFLATING    - busy wait for conversion to complete
    // *  Neutral      - aggressively inflate the object.
    // *  BIASED       - Illegal.  We should never see this

Configuration enabled stackTrace threshold
profiling true true 10 ms
default false true 20 ms

Field Type Description
monitorClass Class Monitor Class
address ulong: address Monitor Address
cause InflateCause Monitor Inflation Cause Cause of inflation

ObjectAllocationInNewTLAB

startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Application

Allocation in new Thread Local Allocation Buffer

Code Context

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

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

void AllocTracer::send_allocation_outside_tlab(Klass* klass, HeapWord* obj, size_t alloc_size, Thread* thread) {
  JFR_ONLY(JfrAllocationTracer tracer(klass, obj, alloc_size, true, thread);)
  EventObjectAllocationOutsideTLAB event;
  if (event.should_commit()) {
    event.set_objectClass(klass);
    event.set_allocationSize(alloc_size);
    event.commit();
  }
}

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

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

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
objectClass Class Object Class Class of allocated object
allocationSize ulong: bytes Allocation Size
tlabSize ulong: bytes TLAB Size

Examples 3
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48
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java/util/concurrent/ThreadPoolExecutor
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374291133182
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startTime long: millis
371521752044
tlabSize ulong: bytes
2664
allocationSize ulong: bytes
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275184639659
tlabSize ulong: bytes
574648

ObjectAllocationOutsideTLAB

startTime eventThread stackTrace 11 17 21 25 26 27

Category: Java Application

Allocation outside Thread Local Allocation Buffers

Code Context

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

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

#if INCLUDE_JFR
#include "jfr/support/jfrAllocationTracer.hpp"
#endif

void AllocTracer::send_allocation_outside_tlab(Klass* klass, HeapWord* obj, size_t alloc_size, Thread* thread) {
  JFR_ONLY(JfrAllocationTracer tracer(klass, obj, alloc_size, true, thread);)
  EventObjectAllocationOutsideTLAB event;
  if (event.should_commit()) {
    event.set_objectClass(klass);
    event.set_allocationSize(alloc_size);
    event.commit();
  }
}

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

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
objectClass Class Object Class Class of allocated object
allocationSize ulong: bytes Allocation Size

Examples 3
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16400
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type FrameType
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truncated boolean
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startTime long: millis
374999972354

ObjectAllocationSample

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

Category: Java Application

Code Context

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

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

static THREAD_LOCAL int64_t _last_allocated_bytes = 0;

inline void send_allocation_sample(const Klass* klass, int64_t allocated_bytes) {
  assert(allocated_bytes > 0, "invariant");
  EventObjectAllocationSample event;
  if (event.should_commit()) {
    const size_t weight = allocated_bytes - _last_allocated_bytes;
    assert(weight > 0, "invariant");
    event.set_objectClass(klass);
    event.set_weight(weight);
    event.commit();
    _last_allocated_bytes = allocated_bytes;
  }
}

inline bool send_allocation_sample_with_result(const Klass* klass, int64_t allocated_bytes) {
  assert(allocated_bytes > 0, "invariant");
  EventObjectAllocationSample event;
  if (event.should_commit()) {
    const size_t weight = allocated_bytes - _last_allocated_bytes;
    assert(weight > 0, "invariant");
    event.set_objectClass(klass);
    event.set_weight(weight);
    event.commit();
    _last_allocated_bytes = allocated_bytes;
    return true;
  }
  return false;
}

Configuration enabled stackTrace throttle
profiling true true 300/s
default true true 150/s

Field Type Description
objectClass Class Object Class Class of allocated object
weight long: bytes Sample Weight The relative weight of the sample. Aggregating the weights for a large number of samples, for a particular class, thread or stack trace, gives a statistically accurate representation of the allocation pressure

Examples 3
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java/net/URLClassLoader
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classLoader ClassLoader
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bootstrap
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location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
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name string
scala/runtime/ObjectRef
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
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modifiers int
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java/net/URLClassLoader
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module Module
classLoader ClassLoader
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location string
jrt:/java.base
name string
java.base
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name string
java/net
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null
version string
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stackTrace StackTrace
frames StackFrame
bytecodeIndex int
0
lineNumber int
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method Method
descriptor string
(Ljava/lang/Object;)Lscala/runtime/ObjectRef;
hidden boolean
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modifiers int
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create
type Class
classLoader ClassLoader
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classLoader ClassLoader
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startTime long: millis
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module Module
classLoader ClassLoader
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module Module
classLoader ClassLoader
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FileForce

profiling default startTime duration stackTrace 11 17 21 25 26 27

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

Category: Java Application

Force updates to be written to file

Code Context

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

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

public final class JDKEvents {

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class,
        ProcessStartEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,

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

package jdk.jfr.events;
import jdk.jfr.internal.handlers.EventHandler;
import jdk.jfr.internal.Utils;

public final class Handlers {
    public final static EventHandler SOCKET_READ = Utils.getHandler(SocketReadEvent.class);
    public final static EventHandler SOCKET_WRITE = Utils.getHandler(SocketWriteEvent.class);
    public final static EventHandler FILE_READ = Utils.getHandler(FileReadEvent.class);
    public final static EventHandler FILE_WRITE = Utils.getHandler(FileWriteEvent.class);
    public final static EventHandler FILE_FORCE = Utils.getHandler(FileForceEvent.class);
    public final static EventHandler ERROR_THROWN = Utils.getHandler(ErrorThrownEvent.class);
    public final static EventHandler EXCEPTION_THROWN = Utils.getHandler(ExceptionThrownEvent.class);
}

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

package jdk.jfr.events;

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

@Name(Type.EVENT_NAME_PREFIX + "FileForce")
@Label("File Force")
@Category("Java Application")
@Description("Force updates to be written to file")
public final class FileForceEvent extends AbstractJDKEvent {

    // The order of these fields must be the same as the parameters in
    // EventHandler::write(..., String, boolean)

    @Label("Path")
    @Description("Full path of the file")
    public String path;

    @Label("Update Metadata")
    @Description("Whether the file metadata is updated")
    public boolean metaData;

src/jdk.jfr/share/classes/jdk/jfr/internal/handlers/EventHandler.java:

    public boolean setRegistered(boolean registered) {
       return platformEventType.setRegistered(registered);
    }

    public void write(long start, long duration, String host, String address, int port, long timeout, long bytesRead, boolean endOfSTream) {
        throwError("SocketReadEvent");
    }

    public void write(long start, long duration, String host, String address, int port, long bytesWritten) {
        throwError("SocketWriteEvent");
    }

    public void write(long start, long duration, String path, boolean metadata) {
        throwError("FileForceEvent");
    }

    public void write(long start, long duration, String path, long bytesRead, boolean endOfFile) {
        throwError("FileReadEvent");
    }

    public void write(long start, long duration, String path, long bytesWritten) {
        throwError("FileWriteEvent");
    }

    public void write(long start, long duration, String path, Class<?> exceptionClass)  {

Configuration enabled stackTrace threshold
profiling true true 10 ms
default true true 20 ms

Field Type Description
path string Path Full path of the file
metaData boolean Update Metadata Whether the file metadata is updated

SocketRead

profiling default startTime duration stackTrace 11 17 21 25 26 27

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

Category: Java Application

Reading data from a socket

Code Context

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

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

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class,
        ProcessStartEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class,
        jdk.internal.event.ProcessStartEvent.class,

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

package jdk.jfr.events;
import jdk.jfr.internal.handlers.EventHandler;
import jdk.jfr.internal.Utils;

public final class Handlers {
    public final static EventHandler SOCKET_READ = Utils.getHandler(SocketReadEvent.class);
    public final static EventHandler SOCKET_WRITE = Utils.getHandler(SocketWriteEvent.class);
    public final static EventHandler FILE_READ = Utils.getHandler(FileReadEvent.class);
    public final static EventHandler FILE_WRITE = Utils.getHandler(FileWriteEvent.class);
    public final static EventHandler FILE_FORCE = Utils.getHandler(FileForceEvent.class);
    public final static EventHandler ERROR_THROWN = Utils.getHandler(ErrorThrownEvent.class);
    public final static EventHandler EXCEPTION_THROWN = Utils.getHandler(ExceptionThrownEvent.class);
}

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

@Name(Type.EVENT_NAME_PREFIX + "SocketRead")
@Label("Socket Read")
@Category("Java Application")
@Description("Reading data from a socket")
public final class SocketReadEvent extends AbstractJDKEvent {

    // The order of these fields must be the same as the parameters in
    // EventHandler::write(..., String, String, int, long, long, boolean)

    @Label("Remote Host")
    public String host;

    @Label("Remote Address")
    public String address;

    @Label("Remote Port")

src/jdk.jfr/share/classes/jdk/jfr/internal/handlers/EventHandler.java:

    private final void readObject(ObjectInputStream in) throws IOException {
        throw new IOException("Class cannot be deserialized");
    }

    public boolean isRegistered() {
        return platformEventType.isRegistered();
    }

    public boolean setRegistered(boolean registered) {
       return platformEventType.setRegistered(registered);
    }

    public void write(long start, long duration, String host, String address, int port, long timeout, long bytesRead, boolean endOfSTream) {
        throwError("SocketReadEvent");
    }

    public void write(long start, long duration, String host, String address, int port, long bytesWritten) {
        throwError("SocketWriteEvent");
    }

    public void write(long start, long duration, String path, boolean metadata) {
        throwError("FileForceEvent");
    }

    public void write(long start, long duration, String path, long bytesRead, boolean endOfFile) {

Configuration enabled stackTrace threshold
profiling true true 10 ms
default true true 20 ms

Field Type Description
host string Remote Host
address string Remote Address
port int Remote Port
timeout long: millis Timeout Value
bytesRead long: bytes Bytes Read Number of bytes read from the socket
endOfStream boolean End of Stream If end of stream was reached

JavaErrorThrow

profiling default startTime duration stackTrace 11 17 21 25 26 27

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

Category: Java Application

An object derived from java.lang.Error has been created. OutOfMemoryErrors are ignored

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
message string Message
thrownClass Class Class

Examples 3
message string
static Lorg/apache/spark/sql/catalyst/expressions/ExprId;.<clinit>()V
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
7
lineNumber int
68
method Method
descriptor string
(Ljava/lang/String;)V
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name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Error
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Inlined
truncated boolean
true
startTime long: millis
442881681021
thrownClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/NoSuchMethodError
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
message string
static Lorg/apache/spark/sql/catalyst/encoders/ExpressionEncoder;.<clinit>()V
stackTrace StackTrace
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bytecodeIndex int
7
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68
method Method
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startTime long: millis
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no hadoop in java.library.path: /usr/java/packages/lib:/usr/lib64:/lib64:/lib:/usr/lib
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FileRead

profiling default startTime duration stackTrace 11 17 21 25 26 27

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

Category: Java Application

Appearing in: SerialGC, ZGC

Missing in: G1GC, ParallelGC, ShenandoahGC

Reading data from a file

Code Context

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

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

public final class JDKEvents {

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class,
        ProcessStartEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.X509CertificateEvent.class,

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

package jdk.jfr.events;
import jdk.jfr.internal.handlers.EventHandler;
import jdk.jfr.internal.Utils;

public final class Handlers {
    public final static EventHandler SOCKET_READ = Utils.getHandler(SocketReadEvent.class);
    public final static EventHandler SOCKET_WRITE = Utils.getHandler(SocketWriteEvent.class);
    public final static EventHandler FILE_READ = Utils.getHandler(FileReadEvent.class);
    public final static EventHandler FILE_WRITE = Utils.getHandler(FileWriteEvent.class);
    public final static EventHandler FILE_FORCE = Utils.getHandler(FileForceEvent.class);
    public final static EventHandler ERROR_THROWN = Utils.getHandler(ErrorThrownEvent.class);
    public final static EventHandler EXCEPTION_THROWN = Utils.getHandler(ExceptionThrownEvent.class);
}

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

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.DataAmount;
import jdk.jfr.Name;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "FileRead")
@Label("File Read")
@Category("Java Application")
@Description("Reading data from a file")
public final class FileReadEvent extends AbstractJDKEvent {

    // The order of these fields must be the same as the parameters in
    // EventHandler::write(..., String, long, boolean)

    @Label("Path")
    @Description("Full path of the file")
    public String path;

    @Label("Bytes Read")
    @Description("Number of bytes read from the file (possibly 0)")
    @DataAmount

src/jdk.jfr/share/classes/jdk/jfr/internal/handlers/EventHandler.java:

    public void write(long start, long duration, String host, String address, int port, long timeout, long bytesRead, boolean endOfSTream) {
        throwError("SocketReadEvent");
    }

    public void write(long start, long duration, String host, String address, int port, long bytesWritten) {
        throwError("SocketWriteEvent");
    }

    public void write(long start, long duration, String path, boolean metadata) {
        throwError("FileForceEvent");
    }

    public void write(long start, long duration, String path, long bytesRead, boolean endOfFile) {
        throwError("FileReadEvent");
    }

    public void write(long start, long duration, String path, long bytesWritten) {
        throwError("FileWriteEvent");
    }

    public void write(long start, long duration, String path, Class<?> exceptionClass)  {
        throwError("ExceptionThrownEvent or ErrorThrownEvent");
    }

    private void throwError(String classes) {

Configuration enabled stackTrace threshold
profiling true true 10 ms
default true true 20 ms

Field Type Description
path string Path Full path of the file
bytesRead long: bytes Bytes Read Number of bytes read from the file (possibly 0)
endOfFile boolean End of File If end of file was reached

Examples 2
bytesRead long: bytes
27935
endOfFile boolean
false
path string
/home/runner/work/jfrevents/jfrevents/harness-003916-17833306698725904421/apache-spark/als/blockmgr-f7fac2eb-c7cf-4f2a-9591-0f39ec4a6b4a/16/shuffle_12_137_0.data
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
162
lineNumber int
113
method Method
descriptor string
([BII)I
hidden boolean
false
modifiers int
1
name string
read
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/io/FileInputStream
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/io
type FrameType
Inlined
truncated boolean
true
startTime long: millis
389966578659
bytesRead long: bytes
1
endOfFile boolean
false
path string
harness-003931-5537147875304790524/scala-dotty/dotty/out/scala/tools/scalap/scalax/rules/scalasig/AnnotatedWithSelfType.tasty
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
137
lineNumber int
66
method Method
descriptor string
()I
hidden boolean
false
modifiers int
1
name string
read
type Class
classLoader ClassLoader
name string
bootstrap
type Class
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hidden boolean
false
modifiers int
1
name string
java/io/FileInputStream
package Package
exported boolean
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module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
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type FrameType
Interpreted
truncated boolean
false
startTime long: millis
491828405582

FileWrite

profiling default startTime duration stackTrace 11 17 21 25 26 27

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

Category: Java Application

Appearing in: G1GC, ParallelGC

Missing in: SerialGC, ShenandoahGC, ZGC

Writing data to a file

Code Context

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

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

public final class JDKEvents {

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class,
        ProcessStartEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class,

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

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.DataAmount;
import jdk.jfr.Name;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "FileWrite")
@Label("File Write")
@Category("Java Application")
@Description("Writing data to a file")
public final class FileWriteEvent extends AbstractJDKEvent {

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

    @Label("Path")
    @Description("Full path of the file")
    public String path;

    @Label("Bytes Written")
    @Description("Number of bytes written to the file")
    @DataAmount

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

package jdk.jfr.events;
import jdk.jfr.internal.handlers.EventHandler;
import jdk.jfr.internal.Utils;

public final class Handlers {
    public final static EventHandler SOCKET_READ = Utils.getHandler(SocketReadEvent.class);
    public final static EventHandler SOCKET_WRITE = Utils.getHandler(SocketWriteEvent.class);
    public final static EventHandler FILE_READ = Utils.getHandler(FileReadEvent.class);
    public final static EventHandler FILE_WRITE = Utils.getHandler(FileWriteEvent.class);
    public final static EventHandler FILE_FORCE = Utils.getHandler(FileForceEvent.class);
    public final static EventHandler ERROR_THROWN = Utils.getHandler(ErrorThrownEvent.class);
    public final static EventHandler EXCEPTION_THROWN = Utils.getHandler(ExceptionThrownEvent.class);
}

src/jdk.jfr/share/classes/jdk/jfr/internal/handlers/EventHandler.java:

    public void write(long start, long duration, String host, String address, int port, long bytesWritten) {
        throwError("SocketWriteEvent");
    }

    public void write(long start, long duration, String path, boolean metadata) {
        throwError("FileForceEvent");
    }

    public void write(long start, long duration, String path, long bytesRead, boolean endOfFile) {
        throwError("FileReadEvent");
    }

    public void write(long start, long duration, String path, long bytesWritten) {
        throwError("FileWriteEvent");
    }

    public void write(long start, long duration, String path, Class<?> exceptionClass)  {
        throwError("ExceptionThrownEvent or ErrorThrownEvent");
    }

    private void throwError(String classes) {
        throw new InternalError("Method parameters don't match fields in class " + classes);
    }
}

Configuration enabled stackTrace threshold
profiling true true 10 ms
default true true 20 ms

Field Type Description
path string Path Full path of the file
bytesWritten long: bytes Bytes Written Number of bytes written to the file

Examples 2
bytesWritten long: bytes
85805
path string
/home/runner/work/jfrevents/jfrevents/harness-003928-7951762178349451551/apache-spark/als/blockmgr-2bb2e5d4-fda1-4c72-8c69-c810458aa118/3e/shuffle_6_202_0.data.aecc1fe2-0c0f-4b5c-b06a-c169419e5048
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
678
lineNumber int
154
method Method
descriptor string
(Ljava/nio/ByteBuffer;)I
hidden boolean
false
modifiers int
1
name string
write
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
sun/nio/ch/FileChannelImpl
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
sun/nio/ch
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
398117182764
bytesWritten long: bytes
28112
path string
/home/runner/work/jfrevents/jfrevents/harness-003927-11018005009666797249/apache-spark/als/blockmgr-8e66d520-4bed-4a10-a35a-3b794a9b4dcb/33/temp_shuffle_d4341960-d619-437f-9c2b-0dfb3ad1ef14
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
171
lineNumber int
103
method Method
descriptor string
([BII)V
hidden boolean
false
modifiers int
1
name string
write
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/io/FileOutputStream
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/io
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
302040747617

SocketWrite

profiling default startTime duration stackTrace 11 17 21 25 26 27

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

Category: Java Application

Writing data to a socket

Code Context

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

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

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class,
        ProcessStartEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class,
        jdk.internal.event.ProcessStartEvent.class,
        DirectBufferStatisticsEvent.class

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

package jdk.jfr.events;
import jdk.jfr.internal.handlers.EventHandler;
import jdk.jfr.internal.Utils;

public final class Handlers {
    public final static EventHandler SOCKET_READ = Utils.getHandler(SocketReadEvent.class);
    public final static EventHandler SOCKET_WRITE = Utils.getHandler(SocketWriteEvent.class);
    public final static EventHandler FILE_READ = Utils.getHandler(FileReadEvent.class);
    public final static EventHandler FILE_WRITE = Utils.getHandler(FileWriteEvent.class);
    public final static EventHandler FILE_FORCE = Utils.getHandler(FileForceEvent.class);
    public final static EventHandler ERROR_THROWN = Utils.getHandler(ErrorThrownEvent.class);
    public final static EventHandler EXCEPTION_THROWN = Utils.getHandler(ExceptionThrownEvent.class);
}

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

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.DataAmount;
import jdk.jfr.Name;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "SocketWrite")
@Label("Socket Write")
@Category("Java Application")
@Description("Writing data to a socket")
public final class SocketWriteEvent extends AbstractJDKEvent {

    // The order of these fields must be the same as the parameters in
    // EventHandler::write(..., String, String, int, long)

    @Label("Remote Host")
    public String host;

    @Label("Remote Address")
    public String address;

    @Label("Remote Port")

src/jdk.jfr/share/classes/jdk/jfr/internal/handlers/EventHandler.java:

    public boolean isRegistered() {
        return platformEventType.isRegistered();
    }

    public boolean setRegistered(boolean registered) {
       return platformEventType.setRegistered(registered);
    }

    public void write(long start, long duration, String host, String address, int port, long timeout, long bytesRead, boolean endOfSTream) {
        throwError("SocketReadEvent");
    }

    public void write(long start, long duration, String host, String address, int port, long bytesWritten) {
        throwError("SocketWriteEvent");
    }

    public void write(long start, long duration, String path, boolean metadata) {
        throwError("FileForceEvent");
    }

    public void write(long start, long duration, String path, long bytesRead, boolean endOfFile) {
        throwError("FileReadEvent");
    }

    public void write(long start, long duration, String path, long bytesWritten) {

Configuration enabled stackTrace threshold
profiling true true 10 ms
default true true 20 ms

Field Type Description
host string Remote Host
address string Remote Address
port int Remote Port
bytesWritten long: bytes Bytes Written Number of bytes written to the socket

JavaExceptionThrow

startTime duration stackTrace 11 17 21 25 26 27

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

Category: Java Application

An object derived from java.lang.Exception has been created

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
message string Message
thrownClass Class Class

Examples 3
message string
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
30
lineNumber int
259
method Method
descriptor string
()V
hidden boolean
false
modifiers int
1
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Throwable
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Inlined
truncated boolean
true
startTime long: millis
366352320630
thrownClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/io/EOFException
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/io
message string
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
30
lineNumber int
259
method Method
descriptor string
()V
hidden boolean
false
modifiers int
1
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Throwable
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
JIT compiled
truncated boolean
true
startTime long: millis
381987656707
thrownClass Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/io/EOFException
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/io
message string
null
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
62
lineNumber int
375
method Method
descriptor string
(Ljava/lang/String;Ljava/lang/Throwable;ZZ)V
hidden boolean
false
modifiers int
4
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Throwable
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
JIT compiled
truncated boolean
false
startTime long: millis
279258612422
thrownClass Class
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
hidden boolean
false
modifiers int
1
name string
scala/runtime/NonLocalReturnControl
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/runtime

Java Application Statistics

JavaThreadStatistics

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

Category: Java Application / Statistics

Code Context

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

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

 *
 *  If running inside a guest OS on top of a hypervisor in a virtualized environment,
 *  the total memory reported is the amount of memory configured for the guest OS by the hypervisor.
 */
TRACE_REQUEST_FUNC(PhysicalMemory) {
  u8 totalPhysicalMemory = os::physical_memory();
  EventPhysicalMemory event;
  event.set_totalSize(totalPhysicalMemory);
  event.set_usedSize(totalPhysicalMemory - os::available_memory());
  event.commit();
}

TRACE_REQUEST_FUNC(JavaThreadStatistics) {
  EventJavaThreadStatistics event;
  event.set_activeCount(ThreadService::get_live_thread_count());
  event.set_daemonCount(ThreadService::get_daemon_thread_count());
  event.set_accumulatedCount(ThreadService::get_total_thread_count());
  event.set_peakCount(ThreadService::get_peak_thread_count());
  event.commit();
}

TRACE_REQUEST_FUNC(ClassLoadingStatistics) {
  EventClassLoadingStatistics event;
  event.set_loadedClassCount(ClassLoadingService::loaded_class_count());
  event.set_unloadedClassCount(ClassLoadingService::unloaded_class_count());

Configuration enabled period
profiling true 1000 ms
default true 1000 ms

Field Type Description
activeCount long Active Threads Number of live active threads including both daemon and non-daemon threads
daemonCount long Daemon Threads Number of live daemon threads
accumulatedCount long Accumulated Threads Number of threads created and also started since JVM start
peakCount long Peak Threads Peak live thread count since JVM start or when peak count was reset

Examples 3
accumulatedCount long
1905
activeCount long
72
daemonCount long
67
peakCount long
293
startTime long: millis
489749202138
accumulatedCount long
1348
activeCount long
45
daemonCount long
39
peakCount long
273
startTime long: millis
319600817738
accumulatedCount long
1852
activeCount long
46
daemonCount long
45
peakCount long
278
startTime long: millis
464834832883

ClassLoadingStatistics

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

Category: Java Application / Statistics

Code Context

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

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

  event.commit();
}

TRACE_REQUEST_FUNC(JavaThreadStatistics) {
  EventJavaThreadStatistics event;
  event.set_activeCount(ThreadService::get_live_thread_count());
  event.set_daemonCount(ThreadService::get_daemon_thread_count());
  event.set_accumulatedCount(ThreadService::get_total_thread_count());
  event.set_peakCount(ThreadService::get_peak_thread_count());
  event.commit();
}

TRACE_REQUEST_FUNC(ClassLoadingStatistics) {
  EventClassLoadingStatistics event;
  event.set_loadedClassCount(ClassLoadingService::loaded_class_count());
  event.set_unloadedClassCount(ClassLoadingService::unloaded_class_count());
  event.commit();
}

class JfrClassLoaderStatsClosure : public ClassLoaderStatsClosure {
public:
  JfrClassLoaderStatsClosure() : ClassLoaderStatsClosure(NULL) {}

  bool do_entry(oop const& key, ClassLoaderStats const& cls) {
    const ClassLoaderData* this_cld = cls._class_loader != NULL ?

Configuration enabled period
profiling true 1000 ms
default true 1000 ms

Field Type Description
loadedClassCount long Loaded Class Count Number of classes loaded since JVM start
unloadedClassCount long Unloaded Class Count Number of classes unloaded since JVM start

Examples 3
loadedClassCount long
95100
startTime long: millis
404961172989
unloadedClassCount long
2376
loadedClassCount long
117795
startTime long: millis
451722524243
unloadedClassCount long
4641
loadedClassCount long
128903
startTime long: millis
355519568903
unloadedClassCount long
3227

ClassLoaderStatistics

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

Category: Java Application / Statistics

Code Context

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

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

  event.set_unloadedClassCount(ClassLoadingService::unloaded_class_count());
  event.commit();
}

class JfrClassLoaderStatsClosure : public ClassLoaderStatsClosure {
public:
  JfrClassLoaderStatsClosure() : ClassLoaderStatsClosure(NULL) {}

  bool do_entry(oop const& key, ClassLoaderStats const& cls) {
    const ClassLoaderData* this_cld = cls._class_loader != NULL ?
      java_lang_ClassLoader::loader_data_acquire(cls._class_loader) : NULL;
    const ClassLoaderData* parent_cld = cls._parent != NULL ?
      java_lang_ClassLoader::loader_data_acquire(cls._parent) : NULL;
    EventClassLoaderStatistics event;
    event.set_classLoader(this_cld);
    event.set_parentClassLoader(parent_cld);
    event.set_classLoaderData((intptr_t)cls._cld);
    event.set_classCount(cls._classes_count);
    event.set_chunkSize(cls._chunk_sz);
    event.set_blockSize(cls._block_sz);
    event.set_hiddenClassCount(cls._hidden_classes_count);
    event.set_hiddenChunkSize(cls._hidden_chunk_sz);
    event.set_hiddenBlockSize(cls._hidden_block_sz);
    event.commit();
    return true;

Configuration enabled period
profiling true everyChunk
default true everyChunk

Field Type Description
classLoader ClassLoader Class Loader
parentClassLoader ClassLoader Parent Class Loader
classLoaderData ulong: address ClassLoaderData Pointer Pointer to the ClassLoaderData structure in the JVM
classCount long Classes Number of loaded classes
chunkSize ulong: bytes Total Chunk Size Total size of all allocated metaspace chunks (each chunk has several blocks)
blockSize ulong: bytes Total Block Size Total size of all allocated metaspace blocks (each chunk has several blocks)
hiddenClassCount long 15+ Hidden Classes Number of hidden classes
hiddenChunkSize ulong: bytes 15+ Total Hidden Classes Chunk Size Total size of all allocated metaspace chunks for hidden classes (each chunk has several blocks)
hiddenBlockSize ulong: bytes 15+ Total Hidden Classes Block Size Total size of all allocated metaspace blocks for hidden classes (each chunk has several blocks)

Examples 3
blockSize ulong: bytes
3488
chunkSize ulong: bytes
4096
classCount long
1
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
jdk/internal/reflect/DelegatingClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
jdk/internal/reflect
classLoaderData ulong: address
139847744023472
hiddenBlockSize ulong: bytes
0
hiddenChunkSize ulong: bytes
0
hiddenClassCount long
0
parentClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
startTime long: millis
371359377756
blockSize ulong: bytes
3176
chunkSize ulong: bytes
4096
classCount long
1
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
jdk/internal/reflect/DelegatingClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
jdk/internal/reflect
classLoaderData ulong: address
140016911884544
hiddenBlockSize ulong: bytes
0
hiddenChunkSize ulong: bytes
0
hiddenClassCount long
0
parentClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
startTime long: millis
278182165201
blockSize ulong: bytes
3440
chunkSize ulong: bytes
4096
classCount long
1
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
jdk/internal/reflect/DelegatingClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
jdk/internal/reflect
classLoaderData ulong: address
140431230966960
hiddenBlockSize ulong: bytes
0
hiddenChunkSize ulong: bytes
0
hiddenClassCount long
0
parentClassLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
startTime long: millis
378912610528

ThreadAllocationStatistics

profiling default startTime every chunk 11 17 21 25 26 27

Category: Java Application / Statistics

Code Context

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

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

  GrowableArray<jlong> allocated(initial_size);
  GrowableArray<traceid> thread_ids(initial_size);
  JfrTicks time_stamp = JfrTicks::now();
  JfrJavaThreadIterator iter;
  while (iter.has_next()) {
    JavaThread* const jt = iter.next();
    assert(jt != NULL, "invariant");
    allocated.append(jt->cooked_allocated_bytes());
    thread_ids.append(JFR_THREAD_ID(jt));
  }

  // Write allocation statistics to buffer.
  for(int i = 0; i < thread_ids.length(); i++) {
    EventThreadAllocationStatistics event(UNTIMED);
    event.set_allocated(allocated.at(i));
    event.set_thread(thread_ids.at(i));
    event.set_endtime(time_stamp);
    event.commit();
  }
}

/**
 *  PhysicalMemory event represents:
 *
 *  @totalSize == The amount of physical memory (hw) installed and reported by the OS, in bytes.

Configuration enabled period
profiling true everyChunk
default true everyChunk

Field Type Description
allocated ulong: bytes Allocated Approximate number of bytes allocated since thread start
thread Thread Thread

Examples 3
allocated ulong: bytes
65176
startTime long: millis
371363060942
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
QueryStageCreator-0
javaThreadId long
1110
osName string
QueryStageCreator-0
osThreadId long
4332
virtual boolean
false
allocated ulong: bytes
96
startTime long: millis
278185390348
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
org.apache.hadoop.fs.FileSystem$Statistics$StatisticsDataReferenceCleaner
javaThreadId long
767
osName string
org.apache.hadoop.fs.FileSystem$Statistics$StatisticsDataReferenceCleaner
osThreadId long
3250
virtual boolean
false
allocated ulong: bytes
80
startTime long: millis
378913010243
thread Thread
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
QueryStageCreator-1
javaThreadId long
1093
osName string
QueryStageCreator-1
osThreadId long
3675
virtual boolean
false

ExceptionStatistics

profiling default startTime duration stackTrace 11 17 21 25 26 27

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

Category: Java Application / Statistics

Number of objects derived from java.lang.Throwable that have been created

Code Context

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

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

        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class,
        ProcessStartEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class,
        jdk.internal.event.ProcessStartEvent.class,
        DirectBufferStatisticsEvent.class
    };

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

    private static boolean initializationTriggered;

    @SuppressWarnings("unchecked")
    public synchronized static void initialize() {
        try {
            if (initializationTriggered == false) {
                for (Class<?> mirrorEventClass : mirrorEventClasses) {
                    SecuritySupport.registerMirror(((Class<? extends Event>)mirrorEventClass));
                }
                for (Class<?> eventClass : eventClasses) {
                    SecuritySupport.registerEvent((Class<? extends Event>) eventClass);
                }
                initializationTriggered = true;
                RequestEngine.addTrustedJDKHook(ExceptionStatisticsEvent.class, emitExceptionStatistics);
                RequestEngine.addTrustedJDKHook(DirectBufferStatisticsEvent.class, emitDirectBufferStatistics);
            }
        } catch (Exception e) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.WARN, "Could not initialize JDK events. " + e.getMessage());
        }
    }

    public static void addInstrumentation() {
        try {
            List<Class<?>> list = new ArrayList<>();
            for (int i = 0; i < instrumentationClasses.length; i++) {

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

            list.add(java.lang.Throwable.class);
            list.add(java.lang.Error.class);
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.INFO, "Retransformed JDK classes");
            jvm.retransformClasses(list.toArray(new Class<?>[list.size()]));
        } catch (IllegalStateException ise) {
            throw ise;
        } catch (Exception e) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.WARN, "Could not add instrumentation for JDK events. " + e.getMessage());
        }
    }

    private static void emitExceptionStatistics() {
        ExceptionStatisticsEvent t = new ExceptionStatisticsEvent();
        t.throwables = ThrowableTracer.numThrowables();
        t.commit();
    }

    @SuppressWarnings("deprecation")
    public static byte[] retransformCallback(Class<?> klass, byte[] oldBytes) throws Throwable {
        if (java.lang.Throwable.class == klass) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.TRACE, "Instrumenting java.lang.Throwable");
            return ConstructorTracerWriter.generateBytes(java.lang.Throwable.class, oldBytes);
        }

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

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.StackTrace;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "ExceptionStatistics")
@Label("Exception Statistics")
@Category({ "Java Application", "Statistics" })
@Description("Number of objects derived from java.lang.Throwable that have been created")
@StackTrace(false)
public final class ExceptionStatisticsEvent extends AbstractJDKEvent {

    @Label("Exceptions Created")
    public long throwables;
}

Configuration enabled period
profiling true 1000 ms
default true 1000 ms

Field Type Description
throwables long Exceptions Created

Examples 3
stackTrace StackTrace
null
startTime long: millis
392663382710
throwables long
2201473
stackTrace StackTrace
null
startTime long: millis
339434618922
throwables long
2230501
stackTrace StackTrace
null
startTime long: millis
438479368219
throwables long
2206162

DirectBufferStatistics

profiling default startTime duration stackTrace 15 17 21 25 26 27

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

Category: Java Application / Statistics

Statistics of direct buffer

Code Context

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

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

        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,
        ActiveSettingEvent.class,
        ActiveRecordingEvent.class,
        jdk.internal.event.SecurityPropertyModificationEvent.class,
        jdk.internal.event.TLSHandshakeEvent.class,
        jdk.internal.event.X509CertificateEvent.class,
        jdk.internal.event.X509ValidationEvent.class,
        jdk.internal.event.ProcessStartEvent.class,
        DirectBufferStatisticsEvent.class
    };

    // This is a list of the classes with instrumentation code that should be applied.
    private static final Class<?>[] instrumentationClasses = new Class<?>[] {
        FileInputStreamInstrumentor.class,
        FileOutputStreamInstrumentor.class,
        RandomAccessFileInstrumentor.class,
        FileChannelImplInstrumentor.class,
        SocketInputStreamInstrumentor.class,
        SocketOutputStreamInstrumentor.class,
        SocketChannelImplInstrumentor.class

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

    @SuppressWarnings("unchecked")
    public synchronized static void initialize() {
        try {
            if (initializationTriggered == false) {
                for (Class<?> mirrorEventClass : mirrorEventClasses) {
                    SecuritySupport.registerMirror(((Class<? extends Event>)mirrorEventClass));
                }
                for (Class<?> eventClass : eventClasses) {
                    SecuritySupport.registerEvent((Class<? extends Event>) eventClass);
                }
                initializationTriggered = true;
                RequestEngine.addTrustedJDKHook(ExceptionStatisticsEvent.class, emitExceptionStatistics);
                RequestEngine.addTrustedJDKHook(DirectBufferStatisticsEvent.class, emitDirectBufferStatistics);
            }
        } catch (Exception e) {
            Logger.log(LogTag.JFR_SYSTEM, LogLevel.WARN, "Could not initialize JDK events. " + e.getMessage());
        }
    }

    public static void addInstrumentation() {
        try {
            List<Class<?>> list = new ArrayList<>();
            for (int i = 0; i < instrumentationClasses.length; i++) {
                JIInstrumentationTarget tgt = instrumentationClasses[i].getAnnotation(JIInstrumentationTarget.class);

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

        for (int i = 0; i < targetClasses.length; i++) {
            if (targetClasses[i].equals(klass)) {
                Class<?> c = instrumentationClasses[i];
                if (Logger.shouldLog(LogTag.JFR_SYSTEM, LogLevel.TRACE)) {
                    Logger.log(LogTag.JFR_SYSTEM, LogLevel.TRACE, "Processing instrumentation class: " + c);
                }
                return new JIClassInstrumentation(instrumentationClasses[i], klass, oldBytes).getNewBytes();
            }
        }
        return oldBytes;
    }

    public static void remove() {
        RequestEngine.removeHook(JDKEvents::emitExceptionStatistics);
        RequestEngine.removeHook(emitDirectBufferStatistics);
    }

    private static void emitDirectBufferStatistics() {
        DirectBufferStatisticsEvent e = new DirectBufferStatisticsEvent();
        e.commit();
    }
}

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

package jdk.jfr.events;

import jdk.internal.misc.VM;
import jdk.internal.misc.VM.BufferPool;

import jdk.jfr.*;
import jdk.jfr.internal.Type;

@Name(Type.EVENT_NAME_PREFIX + "DirectBufferStatistics")
@Label("Direct Buffer Statistics")
@Description("Statistics of direct buffer")
public final class DirectBufferStatisticsEvent extends AbstractBufferStatisticsEvent {

    private static final BufferPool DIRECT_BUFFER_POOL = findPoolByName("direct");

    public DirectBufferStatisticsEvent() {
        super(DIRECT_BUFFER_POOL);
        this.maxCapacity = VM.maxDirectMemory();
    }

    @Label("Maximum Capacity")
    @Description("Maximum direct buffer capacity the process can use")
    @DataAmount
    final long maxCapacity;
}

Configuration enabled period
profiling true 5 s
default true 5 s

Examples 3
stackTrace StackTrace
null
startTime long: millis
472108629965
stackTrace StackTrace
null
startTime long: millis
321605670953
stackTrace StackTrace
null
startTime long: millis
450722945228

Java Development Kit

X509Validation

startTime duration stackTrace 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/X509ValidationEvent.java

Category: Java Development Kit / Security

Serial numbers from X.509 Certificates forming chain of trust

Code Context

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

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

public final class JDKEvents {

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class,
        ProcessStartEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,

src/jdk.jfr/share/classes/jdk/jfr/events/X509ValidationEvent.java:

package jdk.jfr.events;

import jdk.jfr.*;
import jdk.jfr.internal.MirrorEvent;

@Category({"Java Development Kit", "Security"})
@Label("X509 Validation")
@Name("jdk.X509Validation")
@Description("Serial numbers from X.509 Certificates forming chain of trust")
@MirrorEvent(className = "jdk.internal.event.X509ValidationEvent")
public final class X509ValidationEvent extends AbstractJDKEvent {
    @CertificateId
    @Label("Certificate Id")
    public long certificateId;

    @Label("Certificate Position")
    @Description("Certificate position in chain of trust, 1 = trust anchor")
    public int certificatePosition;

    @Label("Validation Counter")
    public long validationCounter;
}

src/java.base/share/classes/jdk/internal/event/X509ValidationEvent.java:

package jdk.internal.event;

/**
 * Event recording details of X.509 Certificate serial numbers
 * used in X509 cert path validation.
 */

public final class X509ValidationEvent extends Event {
    public long certificateId;
    public int certificatePosition;
    public long validationCounter;
}

src/java.base/share/classes/sun/security/provider/certpath/PKIXCertPathValidator.java:

        // only add a RevocationChecker if revocation is enabled and
        // a PKIXRevocationChecker has not already been added
        if (params.revocationEnabled() && !revCheckerAdded) {
            certPathCheckers.add(new RevocationChecker(anchor, params));
        }
        // add user-specified checkers
        certPathCheckers.addAll(checkers);

        PKIXMasterCertPathValidator.validate(params.certPath(),
                                             params.certificates(),
                                             certPathCheckers);

        X509ValidationEvent xve = new X509ValidationEvent();
        if (xve.shouldCommit() || EventHelper.isLoggingSecurity()) {
            int[] certIds = params.certificates().stream()
                    .mapToInt(x -> x.hashCode())
                    .toArray();
            int anchorCertId =
                    anchor.getTrustedCert().hashCode();
            if (xve.shouldCommit()) {
                xve.certificateId = anchorCertId;
                int certificatePos = 1; //anchor cert
                xve.certificatePosition = certificatePos;
                xve.validationCounter = validationCounter.incrementAndGet();

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
certificateId long: certificateId Certificate Id
certificatePosition int Certificate Position Certificate position in chain of trust, 1 = trust anchor
validationCounter long Validation Counter

X509Certificate

startTime duration stackTrace 11 17 21 25 26 27

Source src/jdk.jfr/share/classes/jdk/jfr/events/X509CertificateEvent.java

Category: Java Development Kit / Security

Details of X.509 Certificate parsed by JDK

Code Context

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

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

public final class JDKEvents {

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class,
        ProcessStartEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,

src/jdk.jfr/share/classes/jdk/jfr/events/X509CertificateEvent.java:

package jdk.jfr.events;

import jdk.jfr.*;
import jdk.jfr.internal.MirrorEvent;

@Category({"Java Development Kit", "Security"})
@Label("X509 Certificate")
@Name("jdk.X509Certificate")
@Description("Details of X.509 Certificate parsed by JDK")
@MirrorEvent(className = "jdk.internal.event.X509CertificateEvent")
public final class X509CertificateEvent extends AbstractJDKEvent {
    @Label("Signature Algorithm")
    public String algorithm;

    @Label("Serial Number")
    public String serialNumber;

    @Label("Subject")
    public String subject;

    @Label("Issuer")
    public String issuer;

    @Label("Key Type")

src/java.base/share/classes/jdk/internal/event/X509CertificateEvent.java:

package jdk.internal.event;


/**
 * Event recording details of X.509 Certificate.
 */

public final class X509CertificateEvent extends Event {
    public String algorithm;
    public String serialNumber;
    public String subject;
    public String issuer;
    public String keyType;
    public int keyLength;
    public long certificateId;
    public long validFrom;
    public long validUntil;
}

src/java.base/share/classes/sun/security/provider/X509Factory.java:

                length = (highByte << 24 ) | (nextByte << 16) |
                        (midByte << 8) | lowByte;
            } else { // ignore longer length forms
                throw new IOException("Invalid BER/DER data (too huge?)");
            }
            if (readFully(is, bout, length) != length) {
                throw new IOException("Incomplete BER/DER data");
            }
        }
        return tag;
    }

    private void commitEvent(X509CertImpl info) {
        X509CertificateEvent xce = new X509CertificateEvent();
        if (xce.shouldCommit() || EventHelper.isLoggingSecurity()) {
            PublicKey pKey = info.getPublicKey();
            String algId = info.getSigAlgName();
            String serNum = info.getSerialNumber().toString(16);
            String subject = info.getSubjectDN().getName();
            String issuer = info.getIssuerDN().getName();
            String keyType = pKey.getAlgorithm();
            int length = KeyUtil.getKeySize(pKey);
            int hashCode = info.hashCode();
            long beginDate = info.getNotBefore().getTime();
            long endDate = info.getNotAfter().getTime();

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
algorithm string Signature Algorithm
serialNumber string Serial Number
subject string Subject
issuer string Issuer
keyType string Key Type
keyLength int Key Length
certificateId long: certificateId Certificate Id
validFrom long: epochmillis Valid From
validUntil long: epochmillis Valid Until

Examples 3
algorithm string
SHA1withDSA
certificateId long: certificateId
3045411335
issuer string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
keyLength int
1024
keyType string
DSA
serialNumber string
46:10:1f:71
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
185
lineNumber int
128
method Method
descriptor string
(Ljava/security/cert/Certificate;)V
hidden boolean
false
modifiers int
9
name string
tryCommitCertEvent
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
sun/security/jca/JCAUtil
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
sun/security/jca
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
441957310824
subject string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
validFrom long: epochmillis
1175461745000
validUntil long: epochmillis
4329061745000
algorithm string
SHA1withDSA
certificateId long: certificateId
3045411335
issuer string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
keyLength int
1024
keyType string
DSA
serialNumber string
46:10:1f:71
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
185
lineNumber int
128
method Method
descriptor string
(Ljava/security/cert/Certificate;)V
hidden boolean
false
modifiers int
9
name string
tryCommitCertEvent
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
sun/security/jca/JCAUtil
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
sun/security/jca
type FrameType
Interpreted
truncated boolean
true
startTime long: millis
449306982013
subject string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
validFrom long: epochmillis
1175461745000
validUntil long: epochmillis
4329061745000
algorithm string
SHA1withDSA
certificateId long: certificateId
3045411335
issuer string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
keyLength int
1024
keyType string
DSA
serialNumber string
46:10:1f:71
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
185
lineNumber int
128
method Method
descriptor string
(Ljava/security/cert/Certificate;)V
hidden boolean
false
modifiers int
9
name string
tryCommitCertEvent
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
sun/security/jca/JCAUtil
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
sun/security/jca
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
323674348680
subject string
CN=Unknown, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown
validFrom long: epochmillis
1175461745000
validUntil long: epochmillis
4329061745000

TLSHandshake

startTime duration stackTrace 11 17 21 25 26 27

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

Category: Java Development Kit / Security

Parameters used in TLS Handshake

Code Context

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

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

public final class JDKEvents {

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class,
        ProcessStartEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,

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

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.internal.MirrorEvent;

@Category({"Java Development Kit", "Security"})
@Label("TLS Handshake")
@Name("jdk.TLSHandshake")
@Description("Parameters used in TLS Handshake")
@MirrorEvent(className = "jdk.internal.event.TLSHandshakeEvent")
public final class TLSHandshakeEvent extends AbstractJDKEvent {
    @Label("Peer Host")
    public String peerHost;

    @Label("Peer Port")
    public int peerPort;

    @Label("Protocol Version")
    public String protocolVersion;

    @Label("Cipher Suite")
    public String cipherSuite;

src/java.base/share/classes/jdk/internal/event/TLSHandshakeEvent.java:

package jdk.internal.event;

/**
 * Event recording details of successful TLS handshakes.
 */

public final class TLSHandshakeEvent extends Event {
    public String peerHost;
    public int peerPort;
    public String protocolVersion;
    public String cipherSuite;
    public long certificateId;
}

src/java.base/share/classes/sun/security/ssl/Finished.java:

            // May need to retransmit the last flight for DTLS.
            if (!shc.sslContext.isDTLS()) {
                shc.conContext.finishHandshake();
            }
            recordEvent(shc.conContext.conSession);

            //
            // produce
            NewSessionTicket.t13PosthandshakeProducer.produce(shc);
        }
    }

    private static void recordEvent(SSLSessionImpl session) {
        TLSHandshakeEvent event = new TLSHandshakeEvent();
        if (event.shouldCommit() || EventHelper.isLoggingSecurity()) {
            int peerCertificateId = 0;
            try {
                // use hash code for Id
                peerCertificateId = session
                        .getCertificateChain()[0]
                        .hashCode();
            } catch (SSLPeerUnverifiedException e) {
                 // not verified msg
            }
            if (event.shouldCommit()) {

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
peerHost string Peer Host
peerPort int Peer Port
protocolVersion string Protocol Version
cipherSuite string Cipher Suite
certificateId long: certificateId Certificate Id Peer Certificate Id

SecurityPropertyModification

startTime duration stackTrace 11 17 21 25 26 27

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

Category: Java Development Kit / Security

Modification of Security property

Code Context

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

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

public final class JDKEvents {

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class,
        ProcessStartEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,

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

package jdk.jfr.events;

import jdk.jfr.*;
import jdk.jfr.internal.MirrorEvent;

@Category({"Java Development Kit", "Security"})
@Label("Security Property Modification")
@Name("jdk.SecurityPropertyModification")
@Description("Modification of Security property")
@MirrorEvent(className = "jdk.internal.event.SecurityPropertyModificationEvent")
public final class SecurityPropertyModificationEvent extends AbstractJDKEvent {
    @Label("Key")
    public String key;

    @Label("Value")
    public String value;
}

src/java.base/share/classes/jdk/internal/event/SecurityPropertyModificationEvent.java:

package jdk.internal.event;

/**
 * Event details relating to the modification of a Security property.
 */

public final class SecurityPropertyModificationEvent extends Event {
    public String key;
    public String value;
}

src/java.base/share/classes/java/security/Security.java:

     *          if a security manager exists and its {@link
     *          java.lang.SecurityManager#checkPermission} method
     *          denies access to set the specified security property value
     * @throws  NullPointerException if key or datum is null
     *
     * @see #getProperty
     * @see java.security.SecurityPermission
     */
    public static void setProperty(String key, String datum) {
        check("setProperty." + key);
        props.put(key, datum);
        invalidateSMCache(key);  /* See below. */

        SecurityPropertyModificationEvent spe = new SecurityPropertyModificationEvent();
        // following is a no-op if event is disabled
        spe.key = key;
        spe.value = datum;
        spe.commit();

        if (EventHelper.isLoggingSecurity()) {
            EventHelper.logSecurityPropertyEvent(key, datum);
        }
    }

    /*

Configuration enabled stackTrace
profiling false true
default false true

Field Type Description
key string Key
value string Value

Operating System

OSInformation

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

Category: Operating System

Code Context

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

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

  event.set_jvmVersion(VM_Version::internal_vm_info_string());
  event.set_javaArguments(Arguments::java_command());
  event.set_jvmArguments(Arguments::jvm_args());
  event.set_jvmFlags(Arguments::jvm_flags());
  event.set_jvmStartTime(Management::vm_init_done_time());
  event.set_pid(os::current_process_id());
  event.commit();
 }

TRACE_REQUEST_FUNC(OSInformation) {
  ResourceMark rm;
  char* os_name = NEW_RESOURCE_ARRAY(char, 2048);
  JfrOSInterface::os_version(&os_name);
  EventOSInformation event;
  event.set_osVersion(os_name);
  event.commit();
}

TRACE_REQUEST_FUNC(VirtualizationInformation) {
  EventVirtualizationInformation event;
  event.set_name(JfrOSInterface::virtualization_name());
  event.commit();
}

TRACE_REQUEST_FUNC(ModuleRequire) {

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
osVersion string OS Version

Examples 3
osVersion string
DISTRIB_ID=Ubuntu DISTRIB_RELEASE=24.04 DISTRIB_CODENAME=noble DISTRIB_DESCRIPTION="Ubuntu 24.04.3 LTS" uname: Linux 6.11.0-1018-azure #18~24.04.1-Ubuntu SMP Sat Jun 28 04:46:03 UTC 2025 x86_64 libc: glibc 2.39 NPTL 2.39
startTime long: millis
398096344797
osVersion string
DISTRIB_ID=Ubuntu DISTRIB_RELEASE=24.04 DISTRIB_CODENAME=noble DISTRIB_DESCRIPTION="Ubuntu 24.04.3 LTS" uname: Linux 6.11.0-1018-azure #18~24.04.1-Ubuntu SMP Sat Jun 28 04:46:03 UTC 2025 x86_64 libc: glibc 2.39 NPTL 2.39
startTime long: millis
428281290409
osVersion string
DISTRIB_ID=Ubuntu DISTRIB_RELEASE=24.04 DISTRIB_CODENAME=noble DISTRIB_DESCRIPTION="Ubuntu 24.04.3 LTS" uname: Linux 6.11.0-1018-azure #18~24.04.1-Ubuntu SMP Sat Jun 28 04:46:03 UTC 2025 x86_64 libc: glibc 2.39 NPTL 2.39
startTime long: millis
345534183972

VirtualizationInformation

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

Category: Operating System

Code Context

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

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

  event.commit();
 }

TRACE_REQUEST_FUNC(OSInformation) {
  ResourceMark rm;
  char* os_name = NEW_RESOURCE_ARRAY(char, 2048);
  JfrOSInterface::os_version(&os_name);
  EventOSInformation event;
  event.set_osVersion(os_name);
  event.commit();
}

TRACE_REQUEST_FUNC(VirtualizationInformation) {
  EventVirtualizationInformation event;
  event.set_name(JfrOSInterface::virtualization_name());
  event.commit();
}

TRACE_REQUEST_FUNC(ModuleRequire) {
  JfrModuleEvent::generate_module_dependency_events();
}

TRACE_REQUEST_FUNC(ModuleExport) {
  JfrModuleEvent::generate_module_export_events();
}

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
name string Name

Examples 3
name string
Hyper-V virtualization
startTime long: millis
450857919685
name string
Hyper-V virtualization
startTime long: millis
398096346159
name string
Hyper-V virtualization
startTime long: millis
352191106254

InitialEnvironmentVariable

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

Category: Operating System

Code Context

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

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

  } else if (vrt == PowerFullPartitionMode) {
    return "Power full partition";
  }

  return "No virtualization detected";
}

int JfrOSInterface::generate_initial_environment_variable_events() {
  if (environ == NULL) {
    return OS_ERR;
  }

  if (EventInitialEnvironmentVariable::is_enabled()) {
    // One time stamp for all events, so they can be grouped together
    JfrTicks time_stamp = JfrTicks::now();
    for (char** p = environ; *p != NULL; p++) {
      char* variable = *p;
      char* equal_sign = strchr(variable, '=');
      if (equal_sign != NULL) {
        // Extract key/value
        ResourceMark rm;
        ptrdiff_t key_length = equal_sign - variable;
        char* key = NEW_RESOURCE_ARRAY(char, key_length + 1);
        char* value = equal_sign + 1;
        strncpy(key, variable, key_length);
        key[key_length] = '\0';
        EventInitialEnvironmentVariable event(UNTIMED);
        event.set_endtime(time_stamp);
        event.set_key(key);
        event.set_value(value);
        event.commit();
      }
    }
  }
  return OS_OK;
}

int JfrOSInterface::system_processes(SystemProcess** sys_processes, int* no_of_sys_processes) {

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
key string Key
value string Value

Examples 3
key string
GITHUB_REF
startTime long: millis
378900894646
value string
refs/heads/main
key string
GITHUB_WORKFLOW_SHA
startTime long: millis
278169438967
value string
87e835ef437fb7b5077cbaa98b8b5252b8c098a5
key string
AZURE_EXTENSION_DIR
startTime long: millis
371346718444
value string
/opt/az/azcliextensions

SystemProcess

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

Category: Operating System

Code Context

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

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

    while (processes != NULL) {
      SystemProcess* tmp = processes;
      const char* info = processes->command_line();
      if (info == NULL) {
         info = processes->path();
      }
      if (info == NULL) {
         info = processes->name();
      }
      if (info == NULL) {
         info = "?";
      }
      jio_snprintf(pid_buf, sizeof(pid_buf), "%d", processes->pid());
      EventSystemProcess event(UNTIMED);
      event.set_pid(pid_buf);
      event.set_commandLine(info);
      event.set_starttime(start_time);
      event.set_endtime(end_time);
      event.commit();
      processes = processes->next();
      delete tmp;
    }
  }
}

Configuration enabled period
profiling true endChunk
default true endChunk

Field Type Description
pid string Process Identifier
commandLine string Command Line

CPUInformation

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

Category: Operating System / Processor

Code Context

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

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

TRACE_REQUEST_FUNC(CPUInformation) {
  CPUInformation cpu_info;
  int ret_val = JfrOSInterface::cpu_information(cpu_info);
  if (ret_val == OS_ERR) {
    log_debug(jfr, system)( "Unable to generate requestable event CPUInformation");
    return;
  }
  if (ret_val == FUNCTIONALITY_NOT_IMPLEMENTED) {
     return;
  }
  if (ret_val == OS_OK) {
    EventCPUInformation event;
    event.set_cpu(cpu_info.cpu_name());
    event.set_description(cpu_info.cpu_description());
    event.set_sockets(cpu_info.number_of_sockets());
    event.set_cores(cpu_info.number_of_cores());
    event.set_hwThreads(cpu_info.number_of_hardware_threads());
    event.commit();
  }
}

TRACE_REQUEST_FUNC(CPULoad) {
  double u = 0; // user time

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
cpu string Type
description string Description
sockets uint Sockets
cores uint Cores
hwThreads uint Hardware Threads

Examples 3
cores uint
16
cpu string
AMD Unknown x86 (HT) SSE SSE2 SSE3 SSSE3 SSE4.1 SSE4.2 SSE4A AMD64
description string
Brand: AMD EPYC 7763 64-Core Processor , Vendor: AuthenticAMD Family: Unknown x86 (0x19), Model: <unknown> (0x1), Stepping: 0x1 Ext. family: 0xa, Ext. model: 0x0, Type: 0x0, Signature: 0x00a00f11 Features: ebx: 0x01100800, ecx: 0xfeda3203, edx: 0x178bfbff Ext. features: eax: 0x00a00f1
hwThreads uint
4
sockets uint
1
startTime long: millis
285179579076
cores uint
16
cpu string
AMD Unknown x86 (HT) SSE SSE2 SSE3 SSSE3 SSE4.1 SSE4.2 SSE4A AMD64
description string
Brand: AMD EPYC 7763 64-Core Processor , Vendor: AuthenticAMD Family: Unknown x86 (0x19), Model: <unknown> (0x1), Stepping: 0x1 Ext. family: 0xa, Ext. model: 0x0, Type: 0x0, Signature: 0x00a00f11 Features: ebx: 0x02100800, ecx: 0xfeda3203, edx: 0x178bfbff Ext. features: eax: 0x00a00f1
hwThreads uint
4
sockets uint
1
startTime long: millis
433004637338
cores uint
16
cpu string
AMD Unknown x86 (HT) SSE SSE2 SSE3 SSSE3 SSE4.1 SSE4.2 SSE4A AMD64
description string
Brand: AMD EPYC 7763 64-Core Processor , Vendor: AuthenticAMD Family: Unknown x86 (0x19), Model: <unknown> (0x1), Stepping: 0x1 Ext. family: 0xa, Ext. model: 0x0, Type: 0x0, Signature: 0x00a00f11 Features: ebx: 0x03100800, ecx: 0xfeda3203, edx: 0x178bfbff Ext. features: eax: 0x00a00f1
hwThreads uint
4
sockets uint
1
startTime long: millis
404623103408

CPUTimeStampCounter

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

Category: Operating System / Processor

Code Context

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

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

    event.commit();
  }
}

TRACE_REQUEST_FUNC(ThreadCPULoad) {
  JfrThreadCPULoadEvent::send_events();
}

TRACE_REQUEST_FUNC(NetworkUtilization) {
  JfrNetworkUtilization::send_events();
}

TRACE_REQUEST_FUNC(CPUTimeStampCounter) {
  EventCPUTimeStampCounter event;
  event.set_fastTimeEnabled(JfrTime::is_ft_enabled());
  event.set_fastTimeAutoEnabled(JfrTime::is_ft_supported());
  event.set_osFrequency(os::elapsed_frequency());
  event.set_fastTimeFrequency(JfrTime::frequency());
  event.commit();
}

TRACE_REQUEST_FUNC(SystemProcess) {
  char pid_buf[16];
  SystemProcess* processes = NULL;
  int num_of_processes = 0;

Configuration enabled period
profiling true beginChunk
default true beginChunk

Field Type Description
fastTimeEnabled boolean Fast Time
fastTimeAutoEnabled boolean Trusted Platform
osFrequency long: hertz OS Frequency
fastTimeFrequency long: hertz Fast Time Frequency

Examples 3
fastTimeAutoEnabled boolean
true
fastTimeEnabled boolean
false
fastTimeFrequency long: hertz
1000000000
osFrequency long: hertz
1000000000
startTime long: millis
422012644610
fastTimeAutoEnabled boolean
true
fastTimeEnabled boolean
false
fastTimeFrequency long: hertz
1000000000
osFrequency long: hertz
1000000000
startTime long: millis
303912207031
fastTimeAutoEnabled boolean
true
fastTimeEnabled boolean
false
fastTimeFrequency long: hertz
1000000000
osFrequency long: hertz
1000000000
startTime long: millis
406979884245

CPULoad

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

Category: Operating System / Processor

OS CPU Load

Code Context

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

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

  double t = 0; // total time
  int ret_val = OS_ERR;
  {
    // Can take some time on certain platforms, especially under heavy load.
    // Transition to native to avoid unnecessary stalls for pending safepoint synchronizations.
    ThreadToNativeFromVM transition(JavaThread::current());
    ret_val = JfrOSInterface::cpu_loads_process(&u, &s, &t);
  }
  if (ret_val == OS_ERR) {
    log_debug(jfr, system)( "Unable to generate requestable event CPULoad");
    return;
  }
  if (ret_val == OS_OK) {
    EventCPULoad event;
    event.set_jvmUser((float)u);
    event.set_jvmSystem((float)s);
    event.set_machineTotal((float)t);
    event.commit();
  }
}

TRACE_REQUEST_FUNC(ThreadCPULoad) {
  JfrThreadCPULoadEvent::send_events();
}

Configuration enabled period
profiling true 1000 ms
default true 1000 ms

Field Type Description
jvmUser float: percentage JVM User
jvmSystem float: percentage JVM System
machineTotal float: percentage Machine Total

Examples 3
jvmSystem float: percentage
0.0042868275
jvmUser float: percentage
0.37607172
machineTotal float: percentage
0.38035855
startTime long: millis
433189860881
jvmSystem float: percentage
0.009603841
jvmUser float: percentage
0.52340937
machineTotal float: percentage
0.53421366
startTime long: millis
392663345921
jvmSystem float: percentage
0.0049751243
jvmUser float: percentage
0.41791046
machineTotal float: percentage
0.42288557
startTime long: millis
315013982427

ThreadCPULoad

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

Category: Operating System / Processor

Code Context

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

src/hotspot/share/jfr/periodic/jfrThreadCPULoadEvent.hpp:

#ifndef SHARE_JFR_PERIODIC_JFRTHREADCPULOADEVENT_HPP
#define SHARE_JFR_PERIODIC_JFRTHREADCPULOADEVENT_HPP

#include "jni.h"
#include "memory/allocation.hpp"

class JavaThread;
class EventThreadCPULoad;

class JfrThreadCPULoadEvent : public AllStatic {
  static int _last_active_processor_count;
 public:
  static jlong get_wallclock_time();
  static int get_processor_count();
  static bool update_event(EventThreadCPULoad& event, JavaThread* thread, jlong cur_wallclock_time, int processor_count);
  static void send_events();
  static void send_event_for_thread(JavaThread* jt);
};

#endif // SHARE_JFR_PERIODIC_JFRTHREADCPULOADEVENT_HPP

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

int JfrThreadCPULoadEvent::get_processor_count() {
  int cur_processor_count = os::active_processor_count();
  int last_processor_count = _last_active_processor_count;
  _last_active_processor_count = cur_processor_count;

  // If the number of processors decreases, we don't know at what point during
  // the sample interval this happened, so use the largest number to try
  // to avoid percentages above 100%
  return MAX2(cur_processor_count, last_processor_count);
}

// Returns false if the thread has not been scheduled since the last call to updateEvent
// (i.e. the delta for both system and user time is 0 milliseconds)
bool JfrThreadCPULoadEvent::update_event(EventThreadCPULoad& event, JavaThread* thread, jlong cur_wallclock_time, int processor_count) {
  JfrThreadLocal* const tl = thread->jfr_thread_local();

  jlong cur_cpu_time = os::thread_cpu_time(thread, true);
  jlong prev_cpu_time = tl->get_cpu_time();

  jlong prev_wallclock_time = tl->get_wallclock_time();
  tl->set_wallclock_time(cur_wallclock_time);

  // Threshold of 1 ms
  if (cur_cpu_time - prev_cpu_time < 1 * NANOSECS_PER_MILLISEC) {
    return false;

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

  Thread* periodic_thread = Thread::current();
  JfrThreadLocal* const periodic_thread_tl = periodic_thread->jfr_thread_local();
  traceid periodic_thread_id = periodic_thread_tl->thread_id();
  const int processor_count = JfrThreadCPULoadEvent::get_processor_count();
  JfrTicks event_time = JfrTicks::now();
  jlong cur_wallclock_time = JfrThreadCPULoadEvent::get_wallclock_time();

  JfrJavaThreadIterator iter;
  int number_of_threads = 0;
  while (iter.has_next()) {
    JavaThread* const jt = iter.next();
    assert(jt != NULL, "invariant");
    ++number_of_threads;
    EventThreadCPULoad event(UNTIMED);
    if (JfrThreadCPULoadEvent::update_event(event, jt, cur_wallclock_time, processor_count)) {
      event.set_starttime(event_time);
      if (jt != periodic_thread) {
        // Commit reads the thread id from this thread's trace data, so put it there temporarily
        periodic_thread_tl->set_thread_id(JFR_THREAD_ID(jt));
      } else {
        periodic_thread_tl->set_thread_id(periodic_thread_id);
      }
      event.commit();
    }
  }
  log_trace(jfr)("Measured CPU usage for %d threads in %.3f milliseconds", number_of_threads,
    (double)(JfrTicks::now() - event_time).milliseconds());
  // Restore this thread's thread id
  periodic_thread_tl->set_thread_id(periodic_thread_id);
}

void JfrThreadCPULoadEvent::send_event_for_thread(JavaThread* jt) {
  EventThreadCPULoad event;
  if (event.should_commit()) {
    if (update_event(event, jt, get_wallclock_time(), get_processor_count())) {
      event.commit();
    }
  }
}

Configuration enabled period
profiling true 10 s
default true 10 s

Field Type Description
user float: percentage User Mode CPU Load User mode thread CPU load
system float: percentage System Mode CPU Load System mode thread CPU load

Examples 3
startTime long: millis
311008751966
system float: percentage
0.0
user float: percentage
8.78532E-4
startTime long: millis
443290830613
system float: percentage
0.0024994593
user float: percentage
0.011008594
startTime long: millis
380959998366
system float: percentage
1.8468874E-5
user float: percentage
0.0

ThreadContextSwitchRate

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

Category: Operating System / Processor

Code Context

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

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

    // Can take some time on certain platforms, especially under heavy load.
    // Transition to native to avoid unnecessary stalls for pending safepoint synchronizations.
    ThreadToNativeFromVM transition(JavaThread::current());
    ret_val = JfrOSInterface::context_switch_rate(&rate);
  }
  if (ret_val == OS_ERR) {
    log_debug(jfr, system)( "Unable to generate requestable event ThreadContextSwitchRate");
    return;
  }
  if (ret_val == FUNCTIONALITY_NOT_IMPLEMENTED) {
    return;
  }
  if (ret_val == OS_OK) {
    EventThreadContextSwitchRate event;
    event.set_switchRate((float)rate + 0.0f);
    event.commit();
  }
}

#define SEND_FLAGS_OF_TYPE(eventType, flagType)                   \
  do {                                                            \
    JVMFlag *flag = JVMFlag::flags;                               \
    while (flag->name() != NULL) {                                \
      if (flag->is_ ## flagType()) {                              \
        if (flag->is_unlocked()) {                                \

Configuration enabled period
profiling true 10 s
default true 10 s

Field Type Description
switchRate float: hertz Switch Rate Number of context switches per second

Examples 3
startTime long: millis
483527417888
switchRate float: hertz
2819.583
startTime long: millis
353439904639
switchRate float: hertz
4041.2117
startTime long: millis
465841394888
switchRate float: hertz
3215.0718

NetworkUtilization

profiling default startTime every chunk 11 17 21 25 26 27

Category: Operating System / Network

Code Context

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

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

  static JfrTicks last_sample_instant;
  const JfrTicks cur_time = JfrTicks::now();
  const JfrTickspan interval = last_sample_instant == 0 ? cur_time - cur_time : cur_time - last_sample_instant;
  last_sample_instant = cur_time;
  for (NetworkInterface *cur = network_interfaces; cur != NULL; cur = cur->next()) {
    InterfaceEntry& entry = get_entry(cur);
    if (interval.value() > 0) {
      const uint64_t current_bytes_in = cur->get_bytes_in();
      const uint64_t current_bytes_out = cur->get_bytes_out();
      const uint64_t read_rate = rate_per_second(current_bytes_in, entry.bytes_in, interval);
      const uint64_t write_rate = rate_per_second(current_bytes_out, entry.bytes_out, interval);
      if (read_rate > 0 || write_rate > 0) {
        write_interface_constant(entry);
        EventNetworkUtilization event(UNTIMED);
        event.set_starttime(cur_time);
        event.set_endtime(cur_time);
        event.set_networkInterface(entry.id);
        event.set_readRate(8 * read_rate);
        event.set_writeRate(8 * write_rate);
        event.commit();
      }
      // update existing entry with new values
      entry.bytes_in = current_bytes_in;
      entry.bytes_out = current_bytes_out;
    }

Configuration enabled period
profiling true 5 s
default true 5 s

Field Type Description
networkInterface NetworkInterfaceName Network Interface Network Interface Name
readRate long: bits-per-second Read Rate Number of incoming bits per second
writeRate long: bits-per-second Write Rate Number of outgoing bits per second

Examples 3
networkInterface NetworkInterfaceName
lo
readRate long: bits-per-second
5356984
startTime long: millis
488745197288
writeRate long: bits-per-second
5357064
networkInterface NetworkInterfaceName
eth0
readRate long: bits-per-second
5240
startTime long: millis
305317423130
writeRate long: bits-per-second
18648
networkInterface NetworkInterfaceName
eth0
readRate long: bits-per-second
7472
startTime long: millis
380959981926
writeRate long: bits-per-second
19016

PhysicalMemory

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

Category: Operating System / Memory

OS Physical Memory

Code Context

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

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

 *  PhysicalMemory event represents:
 *
 *  @totalSize == The amount of physical memory (hw) installed and reported by the OS, in bytes.
 *  @usedSize  == The amount of physical memory currently in use in the system (reserved/committed), in bytes.
 *
 *  Both fields are systemwide, i.e. represents the entire OS/HW environment.
 *  These fields do not include virtual memory.
 *
 *  If running inside a guest OS on top of a hypervisor in a virtualized environment,
 *  the total memory reported is the amount of memory configured for the guest OS by the hypervisor.
 */
TRACE_REQUEST_FUNC(PhysicalMemory) {
  u8 totalPhysicalMemory = os::physical_memory();
  EventPhysicalMemory event;
  event.set_totalSize(totalPhysicalMemory);
  event.set_usedSize(totalPhysicalMemory - os::available_memory());
  event.commit();
}

TRACE_REQUEST_FUNC(JavaThreadStatistics) {
  EventJavaThreadStatistics event;
  event.set_activeCount(ThreadService::get_live_thread_count());
  event.set_daemonCount(ThreadService::get_daemon_thread_count());
  event.set_accumulatedCount(ThreadService::get_total_thread_count());
  event.set_peakCount(ThreadService::get_peak_thread_count());

Configuration enabled period
profiling true everyChunk
default true everyChunk

Field Type Description
totalSize ulong: bytes Total Size Total amount of physical memory available to OS
usedSize ulong: bytes Used Size Total amount of physical memory in use

Examples 3
startTime long: millis
491687050707
totalSize ulong: bytes
16772575232
usedSize ulong: bytes
4259500032
startTime long: millis
306655758784
totalSize ulong: bytes
16772579328
usedSize ulong: bytes
3744083968
startTime long: millis
451356334595
totalSize ulong: bytes
16772579328
usedSize ulong: bytes
6201458688

ProcessStart

profiling default startTime duration stackTrace 15 17 21 25 26 27

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

Category: Operating System

Operating system process started

Code Context

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

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

public final class JDKEvents {

    private static final Class<?>[] mirrorEventClasses = {
        SecurityPropertyModificationEvent.class,
        TLSHandshakeEvent.class,
        X509CertificateEvent.class,
        X509ValidationEvent.class,
        ProcessStartEvent.class
    };

    private static final Class<?>[] eventClasses = {
        FileForceEvent.class,
        FileReadEvent.class,
        FileWriteEvent.class,
        SocketReadEvent.class,
        SocketWriteEvent.class,
        ExceptionThrownEvent.class,
        ExceptionStatisticsEvent.class,
        ErrorThrownEvent.class,

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

package jdk.jfr.events;

import jdk.jfr.Category;
import jdk.jfr.Description;
import jdk.jfr.Label;
import jdk.jfr.Name;
import jdk.jfr.internal.MirrorEvent;

@Category({"Operating System"})
@Label("Process Start")
@Name("jdk.ProcessStart")
@Description("Operating system process started")
@MirrorEvent(className = "jdk.internal.event.ProcessStartEvent")
public final class ProcessStartEvent extends AbstractJDKEvent {
    @Label("Process Id")
    public long pid;

    @Label("Directory")
    public String directory;

    @Label("Command")
    public String command;
}

src/java.base/share/classes/java/lang/ProcessBuilder.java:

        for (int i = 1; i < cmdarray.length; i++) {
            if (cmdarray[i].indexOf('\u0000') >= 0) {
                throw new IOException("invalid null character in command");
            }
        }

        try {
            Process process = ProcessImpl.start(cmdarray,
                                     environment,
                                     dir,
                                     redirects,
                                     redirectErrorStream);
            ProcessStartEvent event = new ProcessStartEvent();
            if (event.isEnabled()) {
                StringJoiner command = new StringJoiner(" ");
                for (String s: cmdarray) {
                    command.add(s);
                }
                event.directory = dir;
                event.command = command.toString();
                event.pid = process.pid();
                event.commit();
            }
            return process;

src/java.base/share/classes/jdk/internal/event/ProcessStartEvent.java:

package jdk.internal.event;

/**
 * Event for the start of an OS procsss
 */

public final class ProcessStartEvent extends Event {
    public long pid;
    public String directory;
    public String command;
}

Configuration enabled stackTrace
profiling true true
default true true

Field Type Description
pid long Process Id
directory string Directory
command string Command

Examples 3
command string
rm -rf /home/runner/work/jfrevents/jfrevents/harness-003928-7951762178349451551/apache-spark/als/blockmgr-2bb2e5d4-fda1-4c72-8c69-c810458aa118
directory string
null
pid long
4641
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
232
lineNumber int
1154
method Method
descriptor string
([Ljava/lang/ProcessBuilder$Redirect;)Ljava/lang/Process;
hidden boolean
false
modifiers int
2
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/ProcessBuilder
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
433362799838
command string
rm -rf /home/runner/work/jfrevents/jfrevents/harness-003927-11018005009666797249/apache-spark/movie-lens/spark-f0f85a40-8ea7-4165-9eb7-024a947081cd
directory string
null
pid long
4604
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
232
lineNumber int
1154
method Method
descriptor string
([Ljava/lang/ProcessBuilder$Redirect;)Ljava/lang/Process;
hidden boolean
false
modifiers int
2
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/ProcessBuilder
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
367580608709
command string
setsid bash -c echo $$
directory string
null
pid long
4003
stackTrace StackTrace
frames StackFrame
bytecodeIndex int
232
lineNumber int
1154
method Method
descriptor string
([Ljava/lang/ProcessBuilder$Redirect;)Ljava/lang/Process;
hidden boolean
false
modifiers int
2
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
17
name string
java/lang/ProcessBuilder
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Interpreted
truncated boolean
false
startTime long: millis
446257092926

Types

Bytecode

14+

Bytecode Instruction

Field Type Description
bytecode string Instruction

Examples 3
invokevirtual
checkcast
getstatic

CalleeMethod

Field Type Description
type string Class
name string Method Name
descriptor string Method Descriptor

Examples 3
descriptor string
(Ljava/lang/String;)Ljava/lang/StringBuilder;
name string
append
type string
java/lang/StringBuilder
descriptor string
(ILjava/lang/Object;)Ljava/util/HashMap$TreeNode;
name string
getTreeNode
type string
java/util/HashMap$TreeNode
descriptor string
(Lscala/Function1;)V
name string
foreach$mVc$sp
type string
scala/collection/immutable/Range

ChunkHeader

14+

Chunk Header

Field Type Description
payload array byte Payload

Class

Java Class

Field Type Description
classLoader ClassLoader Class Loader
name Symbol Name
package Package Package
modifiers int Access Modifiers
hidden boolean 15+ Hidden

ClassLoader

Java Class Loader

Field Type Description
type Class Type
name Symbol Name

CodeBlobType

Code Blob Type

Field Type Description
type string Type

Examples 3
CodeHeap 'profiled nmethods'
CodeHeap 'non-profiled nmethods'
CodeHeap 'non-profiled nmethods'

CompilerPhaseType

Compiler Phase Type

Field Type Description
phase string Phase

CompilerType

14+

Compiler Type

Field Type Description
compiler string Compiler

Examples 3

CopyFailed

Field Type Description
objectCount ulong Object Count
firstSize ulong: bytes First Failed Object Size
smallestSize ulong: bytes Smallest Failed Object Size
totalSize ulong: bytes Total Object Size

DeoptimizationAction

14+

Deoptimization Action

Field Type Description
action string Action

Examples 3
maybe_recompile
maybe_recompile
maybe_recompile

DeoptimizationReason

14+

Deoptimization Reason

Field Type Description
reason string Reason

Examples 3
class_check
class_check
predicate

FlagValueOrigin

Flag Value Origin

Field Type Description
origin string Origin

Examples 3
Default
Default
Default

FrameType

Frame type

Field Type Description
description string Description

Examples 3
JIT compiled
Inlined
Inlined

G1EvacuationStatistics

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Field Type Description
gcId uint GC Identifier
allocated ulong: bytes Allocated Total memory allocated by PLABs
wasted ulong: bytes Wasted Total memory wasted within PLABs due to alignment or refill
used ulong: bytes Used Total memory occupied by objects within PLABs
undoWaste ulong: bytes Undo Wasted Total memory wasted due to allocation undo within PLABs
regionEndWaste ulong: bytes Region End Wasted Total memory wasted at the end of regions due to refill
regionsRefilled uint: bytes Region Refills Total memory wasted at the end of regions due to refill
directAllocated ulong: bytes Allocated (direct) Total memory allocated using direct allocation outside of PLABs
failureUsed ulong: bytes Used (failure) Total memory occupied by objects in regions where evacuation failed
failureWaste ulong: bytes Wasted (failure) Total memory left unused in regions where evacuation failed

Examples 2
allocated ulong: bytes
332304
directAllocated ulong: bytes
824
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
1099
regionEndWaste ulong: bytes
0
regionsRefilled uint: bytes
1
undoWaste ulong: bytes
0
used ulong: bytes
315744
wasted ulong: bytes
4728
allocated ulong: bytes
3948224
directAllocated ulong: bytes
8016
failureUsed ulong: bytes
0
failureWaste ulong: bytes
0
gcId uint
1001
regionEndWaste ulong: bytes
0
regionsRefilled uint: bytes
2
undoWaste ulong: bytes
0
used ulong: bytes
3664208
wasted ulong: bytes
1808

G1HeapRegionType

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

G1 Heap Region Type

Field Type Description
type string Type

Examples 2
Eden
Free

G1YCType

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

G1 YC Type

Field Type Description
type string Type

Examples 1
Prepare Mixed

GCCause

GC Cause

Field Type Description
cause string Cause

Examples 3
Allocation Failure
Heap Inspection Initiated GC
G1 Evacuation Pause

GCName

GC Name

Field Type Description
name string Name

Examples 3
G1New
ParallelScavenge
G1Old

GCThresholdUpdater

GC Threshold Updater

Field Type Description
updater string Updater

Examples 3
compute_new_size
compute_new_size
compute_new_size

GCWhen

GC When

Field Type Description
when string When

Examples 3
After GC
After GC
Before GC

InflateCause

Inflation Cause

Field Type Description
cause string Cause

MetadataType

Metadata Type

Field Type Description
type string Type

Examples 3
Metadata
Class
Metadata

MetaspaceObjectType

Metaspace Object Type

Field Type Description
type string Type

MetaspaceSizes

Field Type Description
committed ulong: bytes Committed Committed memory for this space
used ulong: bytes Used Bytes allocated by objects in the space
reserved ulong: bytes Reserved Reserved memory for this space

Examples 3
committed ulong: bytes
571080704
reserved ulong: bytes
603979776
used ulong: bytes
569170248
committed ulong: bytes
88080384
reserved ulong: bytes
1073741824
used ulong: bytes
86220768
committed ulong: bytes
659161088
reserved ulong: bytes
1677721600
used ulong: bytes
655391016

Method

Java Method

Field Type Description
type Class Type
name Symbol Name
descriptor Symbol Descriptor
modifiers int Access Modifiers
hidden boolean Hidden

Module

Module

Field Type Description
name Symbol Name
version Symbol Version
location Symbol Location
classLoader ClassLoader Class Loader

NarrowOopMode

Narrow Oop Mode

Field Type Description
mode string Mode

Examples 3
Zero based
Zero based
Zero based

NetworkInterfaceName

Network Interface

Field Type Description
networkInterface string Network Interface Network Interface Name

Examples 3
lo
eth0
eth0

ObjectSpace

Appearing in: ParallelGC

Missing in: G1GC, SerialGC, ShenandoahGC, ZGC

Field Type Description
start ulong: address Start Address Start address of the space
end ulong: address End Address End address of the space
used ulong: bytes Used Bytes allocated by objects in the space
size ulong: bytes Size Size of the space

Examples 3
end ulong: address
34230239232
size ulong: bytes
1268252672
start ulong: address
32961986560
used ulong: bytes
0
end ulong: address
34326708224
size ulong: bytes
46137344
start ulong: address
34280570880
used ulong: bytes
0
end ulong: address
31729909760
size ulong: bytes
1564475392
start ulong: address
30165434368
used ulong: bytes
262506928

OldObject

Appearing in: G1GC, ParallelGC, SerialGC, ZGC

Missing in: ShenandoahGC

Old Object

Field Type Description
address ulong: address Memory Address
type Class Java Class
description string Object Description Object description
referrer Reference Referrer Object Object referencing this object

Examples 3
address ulong: address
30381608600
description string
Size: 1
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/ArrayList
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util
address ulong: address
31620103680
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1040
name string
[Ljava/util/concurrent/ConcurrentHashMap$Node;
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent
address ulong: address
30325390632
description string
null
referrer Reference
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1041
name string
[C
package Package
null

OldObjectArray

Old Object Array

Field Type Description
size int Array Size Size of array
index int Index Index in the array

OldObjectField

Old Object Field

Field Type Description
name string Field Name of field
modifiers short Field Modifiers Field modifiers

OldObjectGcRoot

Appearing in: G1GC, ParallelGC, SerialGC, ZGC

Missing in: ShenandoahGC

GC Root

Field Type Description
description string Root Description Root information
system OldObjectRootSystem System The subsystem of origin for the root
type OldObjectRootType Type The root type

Examples 3
null
null
null

OldObjectRootSystem

GC Root System

Field Type Description
system string System

OldObjectRootType

GC Root Type

Field Type Description
type string Type

Package

Package

Field Type Description
name Symbol Name
module Module Module
exported boolean Exported

Reference

Appearing in: G1GC, ParallelGC, SerialGC, ZGC

Missing in: ShenandoahGC

Reference

Field Type Description
array OldObjectArray Array Information Array or null if it is not an array
field OldObjectField Field Information Field or null if it is an array
object OldObject Object Object holder for this reference
skip int Skip Value The object is this many hops away

Examples 3
null
null
null

ReferenceType

Reference Type

Field Type Description
type string Type

Examples 3
Phantom reference
Phantom reference
Weak reference

ShenandoahHeapRegionState

Appearing in: ShenandoahGC

Missing in: G1GC, ParallelGC, SerialGC, ZGC

Shenandoah Heap Region State

Field Type Description
state string State

Examples 3
Regular
Empty Uncommitted
Empty Committed

StackFrame

Field Type Description
method Method Java Method
lineNumber int Line Number
bytecodeIndex int Bytecode Index
type FrameType Frame Type

Examples 3
bytecodeIndex int
10
lineNumber int
1661
method Method
descriptor string
()Ljava/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionNode;
hidden boolean
false
modifiers int
2
name string
newConditionNode
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionObject
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent/locks
type FrameType
Inlined
bytecodeIndex int
2
lineNumber int
2577
method Method
descriptor string
(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden boolean
false
modifiers int
1
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/lang/System$2
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Inlined
bytecodeIndex int
62
lineNumber int
375
method Method
descriptor string
(Ljava/lang/String;Ljava/lang/Throwable;ZZ)V
hidden boolean
false
modifiers int
4
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Throwable
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
JIT compiled

StackTrace

Stacktrace

Field Type Description
truncated boolean Truncated
frames array StackFrame struct Stack Frames

Symbol

Symbol

Field Type Description
string string String

Thread

Thread

Field Type Description
osName string OS Thread Name
osThreadId long OS Thread Id
javaName string Java Thread Name
javaThreadId long Java Thread Id
group ThreadGroup Java Thread Group

ThreadGroup

Thread Group

Field Type Description
parent ThreadGroup Parent
name string Name

Examples 3
null
name string
system
parent ThreadGroup
null
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null

ThreadState

Java Thread State

Field Type Description
name string Name

Examples 3
STATE_RUNNABLE
STATE_RUNNABLE
STATE_RUNNABLE

VMOperationType

VM Operation Type

Field Type Description
type string Type

Examples 3
ClassLoaderStatsOperation
ICBufferFull
G1PauseCleanup

VirtualSpace

Field Type Description
start ulong: address Start Address Start address of the virtual space
committedEnd ulong: address Committed End Address End address of the committed memory for the virtual space
committedSize ulong: bytes Committed Size Size of the committed memory for the virtual space
reservedEnd ulong: address Reserved End Address End address of the reserved memory for the virtual space
reservedSize ulong: bytes Reserved Size Size of the reserved memory for the virtual space

Examples 3
committedEnd ulong: address
31729909760
committedSize ulong: bytes
1564475392
reservedEnd ulong: address
32961986560
reservedSize ulong: bytes
2796552192
start ulong: address
30165434368
committedEnd ulong: address
33022803968
committedSize ulong: bytes
2857369600
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4194304000
start ulong: address
30165434368
committedEnd ulong: address
31144804352
committedSize ulong: bytes
979369984
reservedEnd ulong: address
34359738368
reservedSize ulong: bytes
4194304000
start ulong: address
30165434368

ZPageTypeType

15+

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Z Page Type

Field Type Description
type string Type

Examples 2
Small
Large

ZStatisticsCounterType

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Z Statistics Counter

Field Type Description
counter string Counter

Examples 1
Page Cache Hit L1

ZStatisticsSamplerType

Appearing in: ZGC

Missing in: G1GC, ParallelGC, SerialGC, ShenandoahGC

Z Statistics Sampler

Field Type Description
sampler string Sampler

Examples 1
Undo Object Allocation Failed

XML Content Types

address

Annotation: jdk.jfr.MemoryAddress

Examples 3
30165434368
30322497120
31117541376

bits-per-second

Annotation: jdk.jfr.DataAmount(BITS), jdk.jfr.Frequency

Examples 3
7472
18648
5240

bytes

Annotation: jdk.jfr.DataAmount(BYTES)

Examples 3
0
32
574648

bytes-per-second

Appearing in: G1GC

Missing in: ParallelGC, SerialGC, ShenandoahGC, ZGC

Annotation: jdk.jfr.DataAmount(BYTES), jdk.jfr.Frequency

Examples 2
2.933858826181162E8
3.4715499403522414E8

certificateId

Annotation: jdk.jfr.events.CertificateId

Examples 3
3045411335
3045411335
3045411335

epochmillis

Annotation: jdk.jfr.Timestamp(MILLISECONDS_SINCE_EPOCH)

Examples 3
1767487166908
1767487167450
-9223372036854775808

hertz

Annotation: jdk.jfr.Frequency

Examples 3
1000000000
1000000000
4041.2117

millis

Annotation: jdk.jfr.Timespan(MILLISECONDS)

Examples 3
279258612422
296343465174
275184639659

nanos

Annotation: jdk.jfr.Timespan(NANOSECONDS)

Examples 3
59999999910
-9223372036854775808
119998263947

percentage

Annotation: jdk.jfr.Percentage

Examples 3
0.42288557
0.0049751243
0.41791046

tickspan

Annotation: jdk.jfr.Timespan(TICKS)

Examples 3
2208901
7469435
23678449692

tickstamp

Annotation: jdk.jfr.Timestamp(TICKS)

XML Types

Class

Parameter Type const Klass*
Field Type const Klass*
Java Type java.lang.Class
Examples 3
null
null
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net

ClassLoader

Parameter Type const ClassLoaderData*
Field Type const ClassLoaderData*
Examples 3
name string
bootstrap
type Class
null
name string
bootstrap
type Class
null
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net

Method

Parameter Type const Method*
Field Type const Method*
Examples 3
descriptor string
()Ljava/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionNode;
hidden boolean
false
modifiers int
2
name string
newConditionNode
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionObject
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent/locks
descriptor string
(Ljava/lang/String;Ljava/lang/Throwable;ZZ)V
hidden boolean
false
modifiers int
4
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Throwable
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
descriptor string
(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden boolean
false
modifiers int
1
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/lang/System$2
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang

Module

Parameter Type const ModuleEntry*
Field Type const ModuleEntry*
Examples 3
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9

Package

Parameter Type const PackageEntry*
Field Type const PackageEntry*
Examples 3
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/io
exported boolean
true
module Module
classLoader ClassLoader
name string
null
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/net/URLClassLoader
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net
location string
null
name string
null
version string
null
name string
scala/runtime
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/net

StackTrace

15+

Parameter Type u8
Field Type u8
Java Type jdk.types.StackTrace
Examples 3
frames StackFrame
bytecodeIndex int
62
lineNumber int
375
method Method
descriptor string
(Ljava/lang/String;Ljava/lang/Throwable;ZZ)V
hidden boolean
false
modifiers int
4
name string
<init>
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/lang/Throwable
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
JIT compiled
truncated boolean
false
frames StackFrame
bytecodeIndex int
2
lineNumber int
2577
method Method
descriptor string
(Ljava/lang/Thread;Ljdk/internal/vm/ThreadContainer;)V
hidden boolean
false
modifiers int
1
name string
start
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
0
name string
java/lang/System$2
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/lang
type FrameType
Inlined
truncated boolean
false
frames StackFrame
bytecodeIndex int
10
lineNumber int
1661
method Method
descriptor string
()Ljava/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionNode;
hidden boolean
false
modifiers int
2
name string
newConditionNode
type Class
classLoader ClassLoader
name string
bootstrap
type Class
null
hidden boolean
false
modifiers int
1
name string
java/util/concurrent/locks/AbstractQueuedSynchronizer$ConditionObject
package Package
exported boolean
true
module Module
classLoader ClassLoader
name string
bootstrap
type Class
null
location string
jrt:/java.base
name string
java.base
version string
21.0.9
name string
java/util/concurrent/locks
type FrameType
Inlined
truncated boolean
false

Thread

Parameter Type u8
Field Type u8
Java Type java.lang.Thread
Examples 3
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-ask-thread-pool-47
javaThreadId long
1313
osName string
block-manager-ask-thread-pool-47
osThreadId long
3915
virtual boolean
false
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-ask-thread-pool-46
javaThreadId long
1312
osName string
block-manager-ask-thread-pool-46
osThreadId long
3914
virtual boolean
false
group ThreadGroup
name string
main
parent ThreadGroup
name string
system
parent ThreadGroup
null
javaName string
block-manager-storage-async-thread-pool-70
javaThreadId long
1307
osName string
block-manager-storage-async-thread-pool-70
osThreadId long
4564
virtual boolean
false

Ticks

unsigned

Appearing in: G1GC, ParallelGC, SerialGC, ZGC

Missing in: ShenandoahGC

Parameter Type const Ticks&
Field Type Ticks
Java Type long
Content Type tickstamp
Examples 3
343658241782
227371834695
309806672172

Tickspan

unsigned

Parameter Type const Tickspan&
Field Type Tickspan
Java Type long
Content Type tickspan

boolean

Parameter Type bool
Field Type bool
Java Type boolean
Examples 3
false
true
true

byte

Parameter Type s1
Field Type s1
Java Type byte

char

Parameter Type char
Field Type char
Java Type char

double

Parameter Type double
Field Type double
Java Type double
Examples 3
10.0
-1.0
50.0

float

Parameter Type float
Field Type float
Java Type float
Examples 3
4.3608637
4.3553925
2.088268

int

Parameter Type s4
Field Type s4
Java Type int
Examples 3

long

Parameter Type s8
Field Type s8
Java Type long
Examples 3
3914
3915
1313

short

Parameter Type s2
Field Type s2
Java Type short

string

Parameter Type const char*
Field Type const char*
Java Type java.lang.String
Examples 3
java/net/URLClassLoader
bootstrap
null

ubyte

unsigned

Parameter Type u1
Field Type u1
Java Type byte
Examples 3
32
7
15

uint

unsigned

Parameter Type unsigned
Field Type unsigned
Java Type int
Examples 3
957
454
968

ulong

unsigned

Parameter Type u8
Field Type u8
Java Type long
Examples 3

ushort

unsigned

Parameter Type u2
Field Type u2
Java Type short
Examples 3