changeset 57278:c16ac7a2eba4 jdk-14+21

8226511: Implement JFR Event Streaming Reviewed-by: egahlin, mseledtsov, mgronlun Contributed-by: erik.gahlin@oracle.com, mikhailo.seledtsov@oracle.com, markus.gronlund@oracle.com
author mgronlun
date Wed, 30 Oct 2019 19:43:52 +0100
parents 2c3cc4b01880
children fba8635290df
files src/hotspot/share/gc/g1/g1Trace.cpp src/hotspot/share/gc/shenandoah/shenandoahJfrSupport.cpp src/hotspot/share/gc/z/zTracer.cpp src/hotspot/share/jfr/dcmd/jfrDcmds.cpp src/hotspot/share/jfr/dcmd/jfrDcmds.hpp src/hotspot/share/jfr/jfr.cpp src/hotspot/share/jfr/jfr.hpp src/hotspot/share/jfr/jni/jfrJavaSupport.cpp src/hotspot/share/jfr/jni/jfrJavaSupport.hpp src/hotspot/share/jfr/jni/jfrJniMethod.cpp src/hotspot/share/jfr/jni/jfrJniMethod.hpp src/hotspot/share/jfr/jni/jfrJniMethodRegistration.cpp src/hotspot/share/jfr/leakprofiler/chains/edgeStore.cpp src/hotspot/share/jfr/leakprofiler/checkpoint/eventEmitter.cpp src/hotspot/share/jfr/leakprofiler/checkpoint/objectSampleCheckpoint.cpp src/hotspot/share/jfr/leakprofiler/checkpoint/objectSampleWriter.cpp src/hotspot/share/jfr/leakprofiler/checkpoint/rootResolver.cpp src/hotspot/share/jfr/leakprofiler/leakProfiler.cpp src/hotspot/share/jfr/leakprofiler/sampling/objectSampler.cpp src/hotspot/share/jfr/metadata/jfrSerializer.hpp src/hotspot/share/jfr/metadata/metadata.xml src/hotspot/share/jfr/periodic/jfrNetworkUtilization.cpp src/hotspot/share/jfr/periodic/jfrPeriodic.cpp src/hotspot/share/jfr/periodic/jfrThreadCPULoadEvent.cpp src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp src/hotspot/share/jfr/recorder/checkpoint/jfrCheckpointManager.cpp src/hotspot/share/jfr/recorder/checkpoint/jfrCheckpointManager.hpp src/hotspot/share/jfr/recorder/checkpoint/jfrCheckpointWriter.cpp src/hotspot/share/jfr/recorder/checkpoint/jfrCheckpointWriter.hpp src/hotspot/share/jfr/recorder/checkpoint/jfrMetadataEvent.cpp src/hotspot/share/jfr/recorder/checkpoint/jfrMetadataEvent.hpp src/hotspot/share/jfr/recorder/checkpoint/types/jfrThreadGroup.cpp src/hotspot/share/jfr/recorder/checkpoint/types/jfrThreadState.cpp src/hotspot/share/jfr/recorder/checkpoint/types/jfrThreadState.hpp src/hotspot/share/jfr/recorder/checkpoint/types/jfrType.cpp src/hotspot/share/jfr/recorder/checkpoint/types/jfrType.hpp src/hotspot/share/jfr/recorder/checkpoint/types/jfrTypeManager.cpp src/hotspot/share/jfr/recorder/checkpoint/types/jfrTypeManager.hpp src/hotspot/share/jfr/recorder/checkpoint/types/jfrTypeSet.cpp src/hotspot/share/jfr/recorder/checkpoint/types/jfrTypeSet.hpp src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceId.cpp src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceId.inline.hpp src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceIdEpoch.cpp src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceIdEpoch.hpp src/hotspot/share/jfr/recorder/repository/jfrChunk.cpp src/hotspot/share/jfr/recorder/repository/jfrChunk.hpp src/hotspot/share/jfr/recorder/repository/jfrChunkState.cpp src/hotspot/share/jfr/recorder/repository/jfrChunkState.hpp src/hotspot/share/jfr/recorder/repository/jfrChunkWriter.cpp src/hotspot/share/jfr/recorder/repository/jfrChunkWriter.hpp src/hotspot/share/jfr/recorder/repository/jfrEmergencyDump.cpp src/hotspot/share/jfr/recorder/repository/jfrRepository.cpp src/hotspot/share/jfr/recorder/repository/jfrRepository.hpp src/hotspot/share/jfr/recorder/service/jfrPostBox.cpp src/hotspot/share/jfr/recorder/service/jfrPostBox.hpp src/hotspot/share/jfr/recorder/service/jfrRecorderService.cpp src/hotspot/share/jfr/recorder/service/jfrRecorderService.hpp src/hotspot/share/jfr/recorder/service/jfrRecorderThread.cpp src/hotspot/share/jfr/recorder/service/jfrRecorderThreadLoop.cpp src/hotspot/share/jfr/recorder/stacktrace/jfrStackTraceRepository.cpp src/hotspot/share/jfr/recorder/stacktrace/jfrStackTraceRepository.hpp src/hotspot/share/jfr/recorder/storage/jfrBuffer.cpp src/hotspot/share/jfr/recorder/storage/jfrBuffer.hpp src/hotspot/share/jfr/recorder/storage/jfrMemorySpace.hpp src/hotspot/share/jfr/recorder/storage/jfrMemorySpace.inline.hpp src/hotspot/share/jfr/recorder/storage/jfrStorage.cpp src/hotspot/share/jfr/recorder/storage/jfrStorage.hpp src/hotspot/share/jfr/recorder/storage/jfrStorageControl.cpp src/hotspot/share/jfr/recorder/storage/jfrStorageUtils.hpp src/hotspot/share/jfr/recorder/storage/jfrStorageUtils.inline.hpp src/hotspot/share/jfr/recorder/storage/jfrVirtualMemory.cpp src/hotspot/share/jfr/recorder/stringpool/jfrStringPool.cpp src/hotspot/share/jfr/recorder/stringpool/jfrStringPool.hpp src/hotspot/share/jfr/support/jfrThreadLocal.cpp src/hotspot/share/jfr/support/jfrThreadLocal.hpp src/hotspot/share/jfr/support/jfrTraceIdExtension.hpp src/hotspot/share/jfr/utilities/jfrAllocation.cpp src/hotspot/share/jfr/utilities/jfrDoublyLinkedList.hpp src/hotspot/share/jfr/utilities/jfrLogTagSets.hpp src/hotspot/share/jfr/utilities/jfrThreadIterator.cpp src/hotspot/share/jfr/utilities/jfrThreadIterator.hpp src/hotspot/share/jfr/utilities/jfrTypes.hpp src/hotspot/share/jfr/writers/jfrJavaEventWriter.hpp src/hotspot/share/jfr/writers/jfrStorageAdapter.hpp src/hotspot/share/jfr/writers/jfrWriterHost.inline.hpp src/hotspot/share/logging/logTag.hpp src/hotspot/share/runtime/mutexLocker.cpp src/jdk.jfr/share/classes/jdk/jfr/Recording.java src/jdk.jfr/share/classes/jdk/jfr/consumer/ChunkParser.java src/jdk.jfr/share/classes/jdk/jfr/consumer/ConstantMap.java src/jdk.jfr/share/classes/jdk/jfr/consumer/EventParser.java src/jdk.jfr/share/classes/jdk/jfr/consumer/EventStream.java src/jdk.jfr/share/classes/jdk/jfr/consumer/LongMap.java src/jdk.jfr/share/classes/jdk/jfr/consumer/ObjectFactory.java src/jdk.jfr/share/classes/jdk/jfr/consumer/Parser.java src/jdk.jfr/share/classes/jdk/jfr/consumer/ParserFactory.java src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedClass.java src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedClassLoader.java src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedEvent.java src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedFrame.java src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedMethod.java src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedObject.java src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedStackTrace.java src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedThread.java src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedThreadGroup.java src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordingFile.java src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordingStream.java src/jdk.jfr/share/classes/jdk/jfr/consumer/TimeConverter.java src/jdk.jfr/share/classes/jdk/jfr/events/ActiveRecordingEvent.java src/jdk.jfr/share/classes/jdk/jfr/events/ActiveSettingEvent.java src/jdk.jfr/share/classes/jdk/jfr/internal/EventControl.java src/jdk.jfr/share/classes/jdk/jfr/internal/EventInstrumentation.java src/jdk.jfr/share/classes/jdk/jfr/internal/EventWriter.java src/jdk.jfr/share/classes/jdk/jfr/internal/FilePurger.java src/jdk.jfr/share/classes/jdk/jfr/internal/JVM.java src/jdk.jfr/share/classes/jdk/jfr/internal/LogTag.java src/jdk.jfr/share/classes/jdk/jfr/internal/LongMap.java src/jdk.jfr/share/classes/jdk/jfr/internal/MetadataDescriptor.java src/jdk.jfr/share/classes/jdk/jfr/internal/MetadataReader.java src/jdk.jfr/share/classes/jdk/jfr/internal/MetadataRepository.java src/jdk.jfr/share/classes/jdk/jfr/internal/MetadataWriter.java src/jdk.jfr/share/classes/jdk/jfr/internal/PlatformEventType.java src/jdk.jfr/share/classes/jdk/jfr/internal/PlatformRecorder.java src/jdk.jfr/share/classes/jdk/jfr/internal/PlatformRecording.java src/jdk.jfr/share/classes/jdk/jfr/internal/Repository.java src/jdk.jfr/share/classes/jdk/jfr/internal/RepositoryChunk.java src/jdk.jfr/share/classes/jdk/jfr/internal/RequestEngine.java src/jdk.jfr/share/classes/jdk/jfr/internal/SecuritySupport.java src/jdk.jfr/share/classes/jdk/jfr/internal/SettingsManager.java src/jdk.jfr/share/classes/jdk/jfr/internal/TypeLibrary.java src/jdk.jfr/share/classes/jdk/jfr/internal/Utils.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/AbstractEventStream.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/ChunkHeader.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/ChunkParser.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/ConstantLookup.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/ConstantMap.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/Dispatcher.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/EventDirectoryStream.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/EventFileStream.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/EventParser.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/FileAccess.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/JdkJfrConsumer.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/ObjectContext.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/ObjectFactory.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/Parser.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/ParserFactory.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/ParserFilter.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/RecordingInput.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/RecordingInternals.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/RepositoryFiles.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/StreamConfiguration.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/StringParser.java src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/TimeConverter.java src/jdk.jfr/share/classes/jdk/jfr/internal/dcmd/DCmdConfigure.java src/jdk.jfr/share/classes/jdk/jfr/internal/dcmd/DCmdStart.java src/jdk.jfr/share/classes/jdk/jfr/internal/tool/Disassemble.java src/jdk.jfr/share/classes/jdk/jfr/internal/tool/EventPrintWriter.java src/jdk.jfr/share/classes/jdk/jfr/internal/tool/Metadata.java src/jdk.jfr/share/classes/jdk/jfr/internal/tool/Summary.java src/jdk.jfr/share/conf/jfr/default.jfc src/jdk.jfr/share/conf/jfr/profile.jfc test/hotspot/gtest/jfr/test_networkUtilization.cpp test/hotspot/gtest/jfr/test_threadCpuLoad.cpp test/jdk/ProblemList.txt test/jdk/jdk/jfr/api/consumer/TestReadTwice.java test/jdk/jdk/jfr/api/consumer/TestRecordingFile.java test/jdk/jdk/jfr/api/consumer/TestRecordingInternals.java test/jdk/jdk/jfr/api/consumer/filestream/TestMultipleChunk.java test/jdk/jdk/jfr/api/consumer/filestream/TestOrdered.java test/jdk/jdk/jfr/api/consumer/filestream/TestReuse.java test/jdk/jdk/jfr/api/consumer/recordingstream/EventProducer.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestAwaitTermination.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestClose.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestConstructor.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestDisable.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestEnable.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestMaxAge.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestOnClose.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestOnErrorAsync.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestOnErrorSync.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestOnEvent.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestOnFlush.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestRecursive.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestRemove.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestSetEndTime.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestSetFlushInterval.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestSetMaxAge.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestSetMaxSize.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestSetSettings.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestSetStartTime.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestStart.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestStartAsync.java test/jdk/jdk/jfr/api/consumer/recordingstream/TestUtils.java test/jdk/jdk/jfr/api/consumer/security/DriverRecordingDumper.java test/jdk/jdk/jfr/api/consumer/security/TestMissingPermission.java test/jdk/jdk/jfr/api/consumer/security/TestRecordingFile.java test/jdk/jdk/jfr/api/consumer/security/TestRecordingStream.java test/jdk/jdk/jfr/api/consumer/security/TestStreamingFile.java test/jdk/jdk/jfr/api/consumer/security/TestStreamingLocal.java test/jdk/jdk/jfr/api/consumer/security/TestStreamingRemote.java test/jdk/jdk/jfr/api/consumer/security/local-streaming.policy test/jdk/jdk/jfr/api/consumer/security/no-permission.policy test/jdk/jdk/jfr/api/consumer/streaming/TestChunkGap.java test/jdk/jdk/jfr/api/consumer/streaming/TestEmptyChunks.java test/jdk/jdk/jfr/api/consumer/streaming/TestEnableEvents.java test/jdk/jdk/jfr/api/consumer/streaming/TestEventRegistration.java test/jdk/jdk/jfr/api/consumer/streaming/TestFilledChunks.java test/jdk/jdk/jfr/api/consumer/streaming/TestFiltering.java test/jdk/jdk/jfr/api/consumer/streaming/TestLatestEvent.java test/jdk/jdk/jfr/api/consumer/streaming/TestRecordingBefore.java test/jdk/jdk/jfr/api/consumer/streaming/TestRemovedChunks.java test/jdk/jdk/jfr/api/consumer/streaming/TestRepositoryMigration.java test/jdk/jdk/jfr/api/consumer/streaming/TestRepositoryProperty.java test/jdk/jdk/jfr/api/consumer/streaming/TestStartMultiChunk.java test/jdk/jdk/jfr/api/consumer/streaming/TestStartSingleChunk.java test/jdk/jdk/jfr/api/consumer/streaming/TestUnstarted.java test/jdk/jdk/jfr/api/event/TestEventDuration.java test/jdk/jdk/jfr/api/recording/time/TestSetFlushInterval.java test/jdk/jdk/jfr/event/metadata/TestLookForUntestedEvents.java test/jdk/jdk/jfr/event/oldobject/TestLargeRootSet.java test/jdk/jdk/jfr/event/runtime/TestFlush.java test/jdk/jdk/jfr/jcmd/TestJcmdStartFlushInterval.java test/jdk/jdk/jfr/jvm/TestThreadExclusion.java test/jdk/jdk/jfr/jvm/TestUnsupportedVM.java test/jdk/jdk/jfr/startupargs/TestFlushInterval.java test/lib/jdk/test/lib/jfr/EventNames.java
diffstat 226 files changed, 13503 insertions(+), 2802 deletions(-) [+]
line wrap: on
line diff
--- a/src/hotspot/share/gc/g1/g1Trace.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/gc/g1/g1Trace.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -59,10 +59,10 @@
 };
 
 static void register_jfr_type_constants() {
-  JfrSerializer::register_serializer(TYPE_G1HEAPREGIONTYPE, false, true,
+  JfrSerializer::register_serializer(TYPE_G1HEAPREGIONTYPE, true,
                                      new G1HeapRegionTypeConstant());
 
-  JfrSerializer::register_serializer(TYPE_G1YCTYPE, false, true,
+  JfrSerializer::register_serializer(TYPE_G1YCTYPE, true,
                                      new G1YCTypeConstant());
 }
 
--- a/src/hotspot/share/gc/shenandoah/shenandoahJfrSupport.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/gc/shenandoah/shenandoahJfrSupport.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -47,7 +47,6 @@
 
 void ShenandoahJFRSupport::register_jfr_type_serializers() {
   JfrSerializer::register_serializer(TYPE_SHENANDOAHHEAPREGIONSTATE,
-                                     false,
                                      true,
                                      new ShenandoahHeapRegionStateConstant());
 }
--- a/src/hotspot/share/gc/z/zTracer.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/gc/z/zTracer.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -59,11 +59,9 @@
 
 static void register_jfr_type_serializers() {
   JfrSerializer::register_serializer(TYPE_ZSTATISTICSCOUNTERTYPE,
-                                     false /* require_safepoint */,
                                      true /* permit_cache */,
                                      new ZStatisticsCounterTypeConstant());
   JfrSerializer::register_serializer(TYPE_ZSTATISTICSSAMPLERTYPE,
-                                     false /* require_safepoint */,
                                      true /* permit_cache */,
                                      new ZStatisticsSamplerTypeConstant());
 }
--- a/src/hotspot/share/jfr/dcmd/jfrDcmds.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/dcmd/jfrDcmds.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -349,6 +349,7 @@
   _filename("filename", "Resulting recording filename, e.g. \\\"" JFR_FILENAME_EXAMPLE "\\\"", "STRING", false),
   _maxage("maxage", "Maximum time to keep recorded data (on disk) in (s)econds, (m)inutes, (h)ours, or (d)ays, e.g. 60m, or 0 for no limit", "NANOTIME", false, "0"),
   _maxsize("maxsize", "Maximum amount of bytes to keep (on disk) in (k)B, (M)B or (G)B, e.g. 500M, or 0 for no limit", "MEMORY SIZE", false, "0"),
+  _flush_interval("flush-interval", "Minimum time before flushing buffers, measured in (s)econds, e.g. 4 s, or 0 for flushing when a recording ends", "NANOTIME", false, "1s"),
   _dump_on_exit("dumponexit", "Dump running recording when JVM shuts down", "BOOLEAN", false),
   _path_to_gc_roots("path-to-gc-roots", "Collect path to GC roots", "BOOLEAN", false, "false") {
   _dcmdparser.add_dcmd_option(&_name);
@@ -359,6 +360,7 @@
   _dcmdparser.add_dcmd_option(&_filename);
   _dcmdparser.add_dcmd_option(&_maxage);
   _dcmdparser.add_dcmd_option(&_maxsize);
+  _dcmdparser.add_dcmd_option(&_flush_interval);
   _dcmdparser.add_dcmd_option(&_dump_on_exit);
   _dcmdparser.add_dcmd_option(&_path_to_gc_roots);
 };
@@ -411,6 +413,10 @@
     maxsize = JfrJavaSupport::new_java_lang_Long(_maxsize.value()._size, CHECK);
   }
 
+  jobject flush_interval = NULL;
+  if (_flush_interval.is_set()) {
+    flush_interval = JfrJavaSupport::new_java_lang_Long(_flush_interval.value()._nanotime, CHECK);
+  }
   jobject duration = NULL;
   if (_duration.is_set()) {
     duration = JfrJavaSupport::new_java_lang_Long(_duration.value()._nanotime, CHECK);
@@ -464,7 +470,7 @@
   static const char method[] = "execute";
   static const char signature[] = "(Ljava/lang/String;[Ljava/lang/String;Ljava/lang/Long;"
     "Ljava/lang/Long;Ljava/lang/Boolean;Ljava/lang/String;"
-    "Ljava/lang/Long;Ljava/lang/Long;Ljava/lang/Boolean;Ljava/lang/Boolean;)Ljava/lang/String;";
+    "Ljava/lang/Long;Ljava/lang/Long;Ljava/lang/Long;Ljava/lang/Boolean;Ljava/lang/Boolean;)Ljava/lang/String;";
 
   JfrJavaArguments execute_args(&result, klass, method, signature, CHECK);
   execute_args.set_receiver(h_dcmd_instance);
@@ -478,6 +484,7 @@
   execute_args.push_jobject(filename);
   execute_args.push_jobject(maxage);
   execute_args.push_jobject(maxsize);
+  execute_args.push_jobject(flush_interval);
   execute_args.push_jobject(dump_on_exit);
   execute_args.push_jobject(path_to_gc_roots);
 
--- a/src/hotspot/share/jfr/dcmd/jfrDcmds.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/dcmd/jfrDcmds.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -90,6 +90,7 @@
   DCmdArgument<char*> _filename;
   DCmdArgument<NanoTimeArgument> _maxage;
   DCmdArgument<MemorySizeArgument> _maxsize;
+  DCmdArgument<NanoTimeArgument> _flush_interval;
   DCmdArgument<bool> _dump_on_exit;
   DCmdArgument<bool> _path_to_gc_roots;
 
--- a/src/hotspot/share/jfr/jfr.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/jfr.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -71,6 +71,18 @@
   JfrThreadLocal::on_exit(t);
 }
 
+void Jfr::exclude_thread(Thread* t) {
+  JfrThreadLocal::exclude(t);
+}
+
+void Jfr::include_thread(Thread* t) {
+  JfrThreadLocal::include(t);
+}
+
+bool Jfr::is_excluded(Thread* t) {
+  return t != NULL && t->jfr_thread_local()->is_excluded();
+}
+
 void Jfr::on_java_thread_dismantle(JavaThread* jt) {
   if (JfrRecorder::is_recording()) {
     JfrCheckpointManager::write_thread_checkpoint(jt);
--- a/src/hotspot/share/jfr/jfr.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/jfr.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -53,6 +53,9 @@
   static bool on_flight_recorder_option(const JavaVMOption** option, char* delimiter);
   static bool on_start_flight_recording_option(const JavaVMOption** option, char* delimiter);
   static void weak_oops_do(BoolObjectClosure* is_alive, OopClosure* f);
+  static void exclude_thread(Thread* thread);
+  static bool is_excluded(Thread* thread);
+  static void include_thread(Thread* thread);
 };
 
 #endif // SHARE_JFR_JFR_HPP
--- a/src/hotspot/share/jfr/jni/jfrJavaSupport.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/jni/jfrJavaSupport.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -23,7 +23,6 @@
  */
 
 #include "precompiled.hpp"
-#include "jni.h"
 #include "classfile/javaClasses.inline.hpp"
 #include "classfile/modules.hpp"
 #include "classfile/symbolTable.hpp"
@@ -42,9 +41,11 @@
 #include "runtime/fieldDescriptor.inline.hpp"
 #include "runtime/java.hpp"
 #include "runtime/jniHandles.inline.hpp"
+#include "runtime/semaphore.inline.hpp"
 #include "runtime/synchronizer.hpp"
 #include "runtime/thread.inline.hpp"
 #include "runtime/threadSMR.hpp"
+#include "utilities/growableArray.hpp"
 
 #ifdef ASSERT
 void JfrJavaSupport::check_java_thread_in_vm(Thread* t) {
@@ -58,6 +59,12 @@
   assert(t->is_Java_thread(), "invariant");
   assert(((JavaThread*)t)->thread_state() == _thread_in_native, "invariant");
 }
+
+static void check_new_unstarted_java_thread(Thread* t) {
+  assert(t != NULL, "invariant");
+  assert(t->is_Java_thread(), "invariant");
+  assert(((JavaThread*)t)->thread_state() == _thread_new, "invariant");
+}
 #endif
 
 /*
@@ -93,6 +100,21 @@
   JNIHandles::destroy_global(handle);
 }
 
+jweak JfrJavaSupport::global_weak_jni_handle(const oop obj, Thread* t) {
+  DEBUG_ONLY(check_java_thread_in_vm(t));
+  HandleMark hm(t);
+  return JNIHandles::make_weak_global(Handle(t, obj));
+}
+
+jweak JfrJavaSupport::global_weak_jni_handle(const jobject handle, Thread* t) {
+  const oop obj = JNIHandles::resolve(handle);
+  return obj == NULL ? NULL : global_weak_jni_handle(obj, t);
+}
+
+void JfrJavaSupport::destroy_global_weak_jni_handle(jweak handle) {
+  JNIHandles::destroy_weak_global(handle);
+}
+
 oop JfrJavaSupport::resolve_non_null(jobject obj) {
   return JNIHandles::resolve_non_null(obj);
 }
@@ -603,9 +625,149 @@
   return true;
 }
 
-jlong JfrJavaSupport::jfr_thread_id(jobject target_thread) {
+class ThreadExclusionListAccess : public StackObj {
+ private:
+  static Semaphore _mutex_semaphore;
+ public:
+  ThreadExclusionListAccess() { _mutex_semaphore.wait(); }
+  ~ThreadExclusionListAccess() { _mutex_semaphore.signal(); }
+};
+
+Semaphore ThreadExclusionListAccess::_mutex_semaphore(1);
+static GrowableArray<jweak>* exclusion_list = NULL;
+
+static bool equals(const jweak excluded_thread, Handle target_thread) {
+  return JfrJavaSupport::resolve_non_null(excluded_thread) == target_thread();
+}
+
+static int find_exclusion_thread_idx(Handle thread) {
+  if (exclusion_list != NULL) {
+    for (int i = 0; i < exclusion_list->length(); ++i) {
+      if (equals(exclusion_list->at(i), thread)) {
+        return i;
+      }
+    }
+  }
+  return -1;
+}
+
+static Handle as_handle(jobject thread) {
+  return Handle(Thread::current(), JfrJavaSupport::resolve_non_null(thread));
+}
+
+static bool thread_is_not_excluded(Handle thread) {
+  return -1 == find_exclusion_thread_idx(thread);
+}
+
+static bool thread_is_not_excluded(jobject thread) {
+  return thread_is_not_excluded(as_handle(thread));
+}
+
+static bool is_thread_excluded(jobject thread) {
+  return !thread_is_not_excluded(thread);
+}
+
+#ifdef ASSERT
+static bool is_thread_excluded(Handle thread) {
+  return !thread_is_not_excluded(thread);
+}
+#endif // ASSERT
+
+static int add_thread_to_exclusion_list(jobject thread) {
+  ThreadExclusionListAccess lock;
+  if (exclusion_list == NULL) {
+    exclusion_list = new (ResourceObj::C_HEAP, mtTracing) GrowableArray<jweak>(10, true, mtTracing);
+  }
+  assert(exclusion_list != NULL, "invariant");
+  assert(thread_is_not_excluded(thread), "invariant");
+  jweak ref = JfrJavaSupport::global_weak_jni_handle(thread, Thread::current());
+  const int idx = exclusion_list->append(ref);
+  assert(is_thread_excluded(thread), "invariant");
+  return idx;
+}
+
+static void remove_thread_from_exclusion_list(Handle thread) {
+  assert(exclusion_list != NULL, "invariant");
+  assert(is_thread_excluded(thread), "invariant");
+  assert(exclusion_list != NULL, "invariant");
+  const int idx = find_exclusion_thread_idx(thread);
+  assert(idx >= 0, "invariant");
+  assert(idx < exclusion_list->length(), "invariant");
+  JfrJavaSupport::destroy_global_weak_jni_handle(exclusion_list->at(idx));
+  exclusion_list->delete_at(idx);
+  assert(thread_is_not_excluded(thread), "invariant");
+  if (0 == exclusion_list->length()) {
+    delete exclusion_list;
+    exclusion_list = NULL;
+  }
+}
+
+static void remove_thread_from_exclusion_list(jobject thread) {
+  ThreadExclusionListAccess lock;
+  remove_thread_from_exclusion_list(as_handle(thread));
+}
+
+// includes removal
+static bool check_exclusion_state_on_thread_start(JavaThread* jt) {
+  Handle h_obj(jt, jt->threadObj());
+  ThreadExclusionListAccess lock;
+  if (thread_is_not_excluded(h_obj)) {
+    return false;
+  }
+  remove_thread_from_exclusion_list(h_obj);
+  return true;
+}
+
+jlong JfrJavaSupport::jfr_thread_id(jobject thread) {
   ThreadsListHandle tlh;
   JavaThread* native_thread = NULL;
-  (void)tlh.cv_internal_thread_to_JavaThread(target_thread, &native_thread, NULL);
+  (void)tlh.cv_internal_thread_to_JavaThread(thread, &native_thread, NULL);
   return native_thread != NULL ? JFR_THREAD_ID(native_thread) : 0;
 }
+
+void JfrJavaSupport::exclude(jobject thread) {
+  HandleMark hm;
+  ThreadsListHandle tlh;
+  JavaThread* native_thread = NULL;
+  (void)tlh.cv_internal_thread_to_JavaThread(thread, &native_thread, NULL);
+  if (native_thread != NULL) {
+    JfrThreadLocal::exclude(native_thread);
+  } else {
+    // not started yet, track the thread oop
+    add_thread_to_exclusion_list(thread);
+  }
+}
+
+void JfrJavaSupport::include(jobject thread) {
+  HandleMark hm;
+  ThreadsListHandle tlh;
+  JavaThread* native_thread = NULL;
+  (void)tlh.cv_internal_thread_to_JavaThread(thread, &native_thread, NULL);
+  if (native_thread != NULL) {
+    JfrThreadLocal::include(native_thread);
+  } else {
+    // not started yet, untrack the thread oop
+    remove_thread_from_exclusion_list(thread);
+  }
+}
+
+bool JfrJavaSupport::is_excluded(jobject thread) {
+  HandleMark hm;
+  ThreadsListHandle tlh;
+  JavaThread* native_thread = NULL;
+  (void)tlh.cv_internal_thread_to_JavaThread(thread, &native_thread, NULL);
+  return native_thread != NULL ? native_thread->jfr_thread_local()->is_excluded() : is_thread_excluded(thread);
+}
+
+void JfrJavaSupport::on_thread_start(Thread* t) {
+  assert(t != NULL, "invariant");
+  assert(Thread::current() == t, "invariant");
+  if (!t->is_Java_thread()) {
+    return;
+  }
+  DEBUG_ONLY(check_new_unstarted_java_thread(t);)
+  HandleMark hm;
+  if (check_exclusion_state_on_thread_start((JavaThread*)t)) {
+    JfrThreadLocal::exclude(t);
+  }
+}
--- a/src/hotspot/share/jfr/jni/jfrJavaSupport.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/jni/jfrJavaSupport.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -29,18 +29,21 @@
 #include "utilities/exceptions.hpp"
 
 class Klass;
-class JavaThread;
 class outputStream;
 
 class JfrJavaSupport : public AllStatic {
  public:
   static jobject local_jni_handle(const oop obj, Thread* t);
   static jobject local_jni_handle(const jobject handle, Thread* t);
-  static void destroy_local_jni_handle(const jobject handle);
+  static void destroy_local_jni_handle(jobject handle);
 
   static jobject global_jni_handle(const oop obj, Thread* t);
   static jobject global_jni_handle(const jobject handle, Thread* t);
-  static void destroy_global_jni_handle(const jobject handle);
+  static void destroy_global_jni_handle(jobject handle);
+
+  static jweak global_weak_jni_handle(const oop obj, Thread* t);
+  static jweak global_weak_jni_handle(const jobject handle, Thread* t);
+  static void destroy_global_weak_jni_handle(jweak handle);
 
   static oop resolve_non_null(jobject obj);
   static void notify_all(jobject obj, TRAPS);
@@ -85,7 +88,11 @@
   static bool is_jdk_jfr_module_available();
   static bool is_jdk_jfr_module_available(outputStream* stream, TRAPS);
 
-  static jlong jfr_thread_id(jobject target_thread);
+  static jlong jfr_thread_id(jobject thread);
+  static void exclude(jobject thread);
+  static void include(jobject thread);
+  static bool is_excluded(jobject thread);
+  static void on_thread_start(Thread* t);
 
   // critical
   static void abort(jstring errorMsg, TRAPS);
--- a/src/hotspot/share/jfr/jni/jfrJniMethod.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/jni/jfrJniMethod.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -284,6 +284,10 @@
   return JfrJavaEventWriter::flush(writer, used_size, requested_size, thread);
 JVM_END
 
+JVM_ENTRY_NO_ENV(void, jfr_flush(JNIEnv* env, jobject jvm))
+  JfrRepository::flush(thread);
+JVM_END
+
 JVM_ENTRY_NO_ENV(void, jfr_set_repository_location(JNIEnv* env, jobject repo, jstring location))
   return JfrRepository::set_path(location, thread);
 JVM_END
@@ -311,3 +315,20 @@
 JVM_ENTRY_NO_ENV(void, jfr_emit_old_object_samples(JNIEnv* env, jobject jvm, jlong cutoff_ticks, jboolean emit_all))
   LeakProfiler::emit_events(cutoff_ticks, emit_all == JNI_TRUE);
 JVM_END
+
+JVM_ENTRY_NO_ENV(void, jfr_exclude_thread(JNIEnv* env, jobject jvm, jobject t))
+  JfrJavaSupport::exclude(t);
+JVM_END
+
+JVM_ENTRY_NO_ENV(void, jfr_include_thread(JNIEnv* env, jobject jvm, jobject t))
+  JfrJavaSupport::include(t);
+JVM_END
+
+JVM_ENTRY_NO_ENV(jboolean, jfr_is_thread_excluded(JNIEnv* env, jobject jvm, jobject t))
+  return JfrJavaSupport::is_excluded(t);
+JVM_END
+
+JVM_ENTRY_NO_ENV(jlong, jfr_chunk_start_nanos(JNIEnv* env, jobject jvm))
+  return JfrRepository::current_chunk_start_nanos();
+JVM_END
+
--- a/src/hotspot/share/jfr/jni/jfrJniMethod.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/jni/jfrJniMethod.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -113,6 +113,7 @@
 
 jboolean JNICALL jfr_event_writer_flush(JNIEnv* env, jclass cls, jobject writer, jint used_size, jint requested_size);
 
+void JNICALL jfr_flush(JNIEnv* env, jobject jvm);
 void JNICALL jfr_abort(JNIEnv* env, jobject jvm, jstring errorMsg);
 
 jlong JNICALL jfr_get_epoch_address(JNIEnv* env, jobject jvm);
@@ -131,6 +132,13 @@
 
 jboolean JNICALL jfr_should_rotate_disk(JNIEnv* env, jobject jvm);
 
+void JNICALL jfr_exclude_thread(JNIEnv* env, jobject jvm, jobject t);
+
+void JNICALL jfr_include_thread(JNIEnv* env, jobject jvm, jobject t);
+
+jboolean JNICALL jfr_is_thread_excluded(JNIEnv* env, jobject jvm, jobject t);
+
+jlong JNICALL jfr_chunk_start_nanos(JNIEnv* env, jobject jvm);
 
 #ifdef __cplusplus
 }
--- a/src/hotspot/share/jfr/jni/jfrJniMethodRegistration.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/jni/jfrJniMethodRegistration.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -70,6 +70,7 @@
       (char*)"getEventWriter", (char*)"()Ljava/lang/Object;", (void*)jfr_get_event_writer,
       (char*)"newEventWriter", (char*)"()Ljdk/jfr/internal/EventWriter;", (void*)jfr_new_event_writer,
       (char*)"flush", (char*)"(Ljdk/jfr/internal/EventWriter;II)Z", (void*)jfr_event_writer_flush,
+      (char*)"flush", (char*)"()V", (void*)jfr_flush,
       (char*)"setRepositoryLocation", (char*)"(Ljava/lang/String;)V", (void*)jfr_set_repository_location,
       (char*)"abort", (char*)"(Ljava/lang/String;)V", (void*)jfr_abort,
       (char*)"getEpochAddress", (char*)"()J",(void*)jfr_get_epoch_address,
@@ -79,7 +80,11 @@
       (char*)"getUnloadedEventClassCount", (char*)"()J", (void*)jfr_get_unloaded_event_classes_count,
       (char*)"setCutoff", (char*)"(JJ)Z", (void*)jfr_set_cutoff,
       (char*)"emitOldObjectSamples", (char*)"(JZ)V", (void*)jfr_emit_old_object_samples,
-      (char*)"shouldRotateDisk", (char*)"()Z", (void*)jfr_should_rotate_disk
+      (char*)"shouldRotateDisk", (char*)"()Z", (void*)jfr_should_rotate_disk,
+      (char*)"exclude", (char*)"(Ljava/lang/Thread;)V", (void*)jfr_exclude_thread,
+      (char*)"include", (char*)"(Ljava/lang/Thread;)V", (void*)jfr_include_thread,
+      (char*)"isExcluded", (char*)"(Ljava/lang/Thread;)Z", (void*)jfr_is_thread_excluded,
+      (char*)"getChunkStartNanos", (char*)"()J", (void*)jfr_chunk_start_nanos
     };
 
     const size_t method_array_length = sizeof(method) / sizeof(JNINativeMethod);
--- a/src/hotspot/share/jfr/leakprofiler/chains/edgeStore.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/leakprofiler/chains/edgeStore.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -259,6 +259,7 @@
   assert(leak_context_edge->parent() == NULL, "invariant");
 
   if (1 == length) {
+    store_gc_root_id_in_leak_context_edge(leak_context_edge, leak_context_edge);
     return;
   }
 
--- a/src/hotspot/share/jfr/leakprofiler/checkpoint/eventEmitter.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/leakprofiler/checkpoint/eventEmitter.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -34,6 +34,7 @@
 #include "memory/resourceArea.hpp"
 #include "oops/markWord.hpp"
 #include "oops/oop.inline.hpp"
+#include "runtime/mutexLocker.hpp"
 #include "runtime/thread.inline.hpp"
 #include "runtime/vmThread.hpp"
 
@@ -51,8 +52,8 @@
 }
 
 void EventEmitter::emit(ObjectSampler* sampler, int64_t cutoff_ticks, bool emit_all) {
+  assert(JfrStream_lock->owned_by_self(), "invariant");
   assert(sampler != NULL, "invariant");
-
   ResourceMark rm;
   EdgeStore edge_store;
   if (cutoff_ticks <= 0) {
@@ -68,6 +69,7 @@
 }
 
 size_t EventEmitter::write_events(ObjectSampler* object_sampler, EdgeStore* edge_store, bool emit_all) {
+  assert_locked_or_safepoint(JfrStream_lock);
   assert(_thread == Thread::current(), "invariant");
   assert(_thread->jfr_thread_local() == _jfr_thread_local, "invariant");
   assert(object_sampler != NULL, "invariant");
--- a/src/hotspot/share/jfr/leakprofiler/checkpoint/objectSampleCheckpoint.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/leakprofiler/checkpoint/objectSampleCheckpoint.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -37,6 +37,7 @@
 #include "jfr/recorder/stacktrace/jfrStackTraceRepository.hpp"
 #include "jfr/utilities/jfrHashtable.hpp"
 #include "jfr/utilities/jfrTypes.hpp"
+#include "runtime/mutexLocker.hpp"
 #include "runtime/safepoint.hpp"
 #include "runtime/thread.hpp"
 #include "utilities/growableArray.hpp"
@@ -271,7 +272,7 @@
   }
   const JfrStackTrace* const stack_trace = resolve(sample);
   DEBUG_ONLY(validate_stack_trace(sample, stack_trace));
-  JfrCheckpointWriter writer(false, true, Thread::current());
+  JfrCheckpointWriter writer;
   writer.write_type(TYPE_STACKTRACE);
   writer.write_count(1);
   ObjectSampleCheckpoint::write_stacktrace(stack_trace, writer);
@@ -291,6 +292,7 @@
 
 // caller needs ResourceMark
 void ObjectSampleCheckpoint::on_rotation(const ObjectSampler* sampler, JfrStackTraceRepository& stack_trace_repo) {
+  assert(JfrStream_lock->owned_by_self(), "invariant");
   assert(sampler != NULL, "invariant");
   assert(LeakProfiler::is_running(), "invariant");
   install_stack_traces(sampler, stack_trace_repo);
@@ -388,7 +390,7 @@
 static void write_sample_blobs(const ObjectSampler* sampler, bool emit_all, Thread* thread) {
   // sample set is predicated on time of last sweep
   const jlong last_sweep = emit_all ? max_jlong : sampler->last_sweep().value();
-  JfrCheckpointWriter writer(false, false, thread);
+  JfrCheckpointWriter writer(thread, false);
   BlobWriter cbw(sampler, writer, last_sweep);
   iterate_samples(cbw, true);
   // reset blob write states
@@ -397,13 +399,14 @@
 }
 
 void ObjectSampleCheckpoint::write(const ObjectSampler* sampler, EdgeStore* edge_store, bool emit_all, Thread* thread) {
+  assert_locked_or_safepoint(JfrStream_lock);
   assert(sampler != NULL, "invariant");
   assert(edge_store != NULL, "invariant");
   assert(thread != NULL, "invariant");
   write_sample_blobs(sampler, emit_all, thread);
   // write reference chains
   if (!edge_store->is_empty()) {
-    JfrCheckpointWriter writer(false, true, thread);
+    JfrCheckpointWriter writer(thread);
     ObjectSampleWriter osw(writer, edge_store);
     edge_store->iterate(osw);
   }
--- a/src/hotspot/share/jfr/leakprofiler/checkpoint/objectSampleWriter.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/leakprofiler/checkpoint/objectSampleWriter.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -355,10 +355,6 @@
 
 static traceid get_gc_root_description_info_id(const Edge& edge, traceid id) {
   assert(edge.is_root(), "invariant");
-  if (EdgeUtils::is_leak_edge(edge)) {
-    return 0;
-  }
-
   if (root_infos == NULL) {
     root_infos = new RootDescriptionInfo();
   }
@@ -606,8 +602,8 @@
 static void register_serializers() {
   static bool is_registered = false;
   if (!is_registered) {
-    JfrSerializer::register_serializer(TYPE_OLDOBJECTROOTSYSTEM, false, true, new RootSystemType());
-    JfrSerializer::register_serializer(TYPE_OLDOBJECTROOTTYPE, false, true, new RootType());
+    JfrSerializer::register_serializer(TYPE_OLDOBJECTROOTSYSTEM, true, new RootSystemType());
+    JfrSerializer::register_serializer(TYPE_OLDOBJECTROOTTYPE, true, new RootType());
     is_registered = true;
   }
 }
--- a/src/hotspot/share/jfr/leakprofiler/checkpoint/rootResolver.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/leakprofiler/checkpoint/rootResolver.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -29,6 +29,7 @@
 #include "gc/shared/strongRootsScope.hpp"
 #include "jfr/leakprofiler/utilities/unifiedOop.hpp"
 #include "jfr/leakprofiler/checkpoint/rootResolver.hpp"
+#include "jfr/utilities/jfrThreadIterator.hpp"
 #include "memory/iterator.hpp"
 #include "memory/universe.hpp"
 #include "oops/klass.hpp"
@@ -36,7 +37,6 @@
 #include "prims/jvmtiThreadState.hpp"
 #include "runtime/frame.inline.hpp"
 #include "runtime/mutexLocker.hpp"
-#include "runtime/threadSMR.inline.hpp"
 #include "runtime/vframe_hp.hpp"
 #include "services/management.hpp"
 #include "utilities/growableArray.hpp"
@@ -256,8 +256,9 @@
  public:
   ReferenceToThreadRootClosure(RootCallback& callback) :_callback(callback), _complete(false) {
     assert_locked_or_safepoint(Threads_lock);
-    for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) {
-      if (do_thread_roots(jt)) {
+    JfrJavaThreadIterator iter;
+    while (iter.has_next()) {
+      if (do_thread_roots(iter.next())) {
         return;
       }
     }
--- a/src/hotspot/share/jfr/leakprofiler/leakProfiler.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/leakprofiler/leakProfiler.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -31,6 +31,7 @@
 #include "jfr/recorder/service/jfrOptionSet.hpp"
 #include "logging/log.hpp"
 #include "memory/iterator.hpp"
+#include "runtime/mutexLocker.hpp"
 #include "runtime/thread.inline.hpp"
 #include "runtime/vmThread.hpp"
 
@@ -92,6 +93,7 @@
   if (!is_running()) {
     return;
   }
+  MutexLocker lock(JfrStream_lock);
   // exclusive access to object sampler instance
   ObjectSampler* const sampler = ObjectSampler::acquire();
   assert(sampler != NULL, "invariant");
--- a/src/hotspot/share/jfr/leakprofiler/sampling/objectSampler.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/leakprofiler/sampling/objectSampler.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -110,6 +110,9 @@
   }
   const JfrThreadLocal* const tl = thread->jfr_thread_local();
   assert(tl != NULL, "invariant");
+  if (tl->is_excluded()) {
+    return 0;
+  }
   if (!tl->has_thread_blob()) {
     JfrCheckpointManager::create_thread_blob(thread);
   }
--- a/src/hotspot/share/jfr/metadata/jfrSerializer.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/metadata/jfrSerializer.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -70,7 +70,8 @@
 class JfrSerializer : public CHeapObj<mtTracing> {
  public:
   virtual ~JfrSerializer() {}
-  static bool register_serializer(JfrTypeId id, bool require_safepoint, bool permit_cache, JfrSerializer* serializer);
+  virtual void on_rotation() {}
+  static bool register_serializer(JfrTypeId id, bool permit_cache, JfrSerializer* serializer);
   virtual void serialize(JfrCheckpointWriter& writer) = 0;
 };
 
--- a/src/hotspot/share/jfr/metadata/metadata.xml	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/metadata/metadata.xml	Wed Oct 30 19:43:52 2019 +0100
@@ -154,7 +154,7 @@
     <Field type="string" name="newValue" label="New Value" />
     <Field type="FlagValueOrigin" name="origin" label="Origin" />
   </Event>
- 
+
   <Type name="VirtualSpace">
     <Field type="ulong" contentType="address" name="start" label="Start Address" description="Start address of the virtual space" />
     <Field type="ulong" contentType="address" name="committedEnd" label="Committed End Address" description="End address of the committed memory for the virtual space" />
@@ -162,27 +162,27 @@
     <Field type="ulong" contentType="address" name="reservedEnd" label="Reserved End Address" description="End address of the reserved memory for the virtual space" />
     <Field type="ulong" contentType="bytes" name="reservedSize" label="Reserved Size" description="Size of the reserved memory for the virtual space" />
   </Type>
-  
+
   <Type name="ObjectSpace">
     <Field type="ulong" contentType="address" name="start" label="Start Address" description="Start address of the space" />
     <Field type="ulong" contentType="address" name="end" label="End Address" description="End address of the space" />
     <Field type="ulong" contentType="bytes" name="used" label="Used" description="Bytes allocated by objects in the space" />
     <Field type="ulong" contentType="bytes" name="size" label="Size" description="Size of the space" />
   </Type>
-  
+
   <Event name="GCHeapSummary" category="Java Virtual Machine, GC, Heap" label="Heap Summary" startTime="false">
     <Field type="uint" name="gcId" label="GC Identifier" relation="GcId" />
     <Field type="GCWhen" name="when" label="When" />
     <Field type="VirtualSpace" struct="true" name="heapSpace" label="Heap Space" />
     <Field type="ulong" contentType="bytes" name="heapUsed" label="Heap Used" description="Bytes allocated by objects in the heap" />
   </Event>
- 
+
   <Type name="MetaspaceSizes">
     <Field type="ulong" contentType="bytes" name="committed" label="Committed" description="Committed memory for this space" />
     <Field type="ulong" contentType="bytes" name="used" label="Used" description="Bytes allocated by objects in the space" />
     <Field type="ulong" contentType="bytes" name="reserved" label="Reserved" description="Reserved memory for this space" />
   </Type>
- 
+
   <Event name="MetaspaceSummary" category="Java Virtual Machine, GC, Heap" label="Metaspace Summary" startTime="false">
     <Field type="uint" name="gcId" label="GC Identifier" relation="GcId" />
     <Field type="GCWhen" name="when" label="When" />
@@ -442,7 +442,7 @@
     <Field type="uint" name="gcWorkerId" label="GC Worker Identifier" />
     <Field type="string" name="name" label="Name" />
   </Event>
-  
+
   <Event name="AllocationRequiringGC" category="Java Virtual Machine, GC, Detailed" label="Allocation Requiring GC" thread="true" stackTrace="true"
     startTime="false">
     <Field type="uint" name="gcId" label="Pending GC Identifier" relation="GcId" />
@@ -484,7 +484,7 @@
     <Field type="string" name="failureMessage" label="Failure Message" />
     <Field type="uint" name="compileId" label="Compilation Identifier" relation="CompileId" />
   </Event>
-  
+
   <Type name="CalleeMethod">
     <Field type="string" name="type" label="Class" />
     <Field type="string" name="name" label="Method Name" />
@@ -585,21 +585,21 @@
     <Field type="OldObjectGcRoot" name="root" label="GC Root" />
   </Event>
 
-  <Event name="DumpReason" category="Flight Recorder" label="Recording Reason" 
-         description="Who requested the recording and why" 
+  <Event name="DumpReason" category="Flight Recorder" label="Recording Reason"
+         description="Who requested the recording and why"
          startTime="false">
     <Field type="string" name="reason" label="Reason" description="Reason for writing recording data to disk" />
     <Field type="int" name="recordingId" label="Recording Id" description="Id of the recording that triggered the dump, or -1 if it was not related to a recording" />
   </Event>
 
-  <Event name="DataLoss" category="Flight Recorder" label="Data Loss" 
+  <Event name="DataLoss" category="Flight Recorder" label="Data Loss"
          description="Data could not be copied out from a buffer, typically because of contention"
          startTime="false">
     <Field type="ulong" contentType="bytes" name="amount" label="Amount" description="Amount lost data" />
     <Field type="ulong" contentType="bytes" name="total" label="Total" description="Total lost amount for thread" />
   </Event>
 
-  <Event name="JVMInformation" category="Java Virtual Machine" label="JVM Information" 
+  <Event name="JVMInformation" category="Java Virtual Machine" label="JVM Information"
          description="Description of JVM and the Java application"
          period="endChunk">
     <Field type="string" name="jvmName" label="JVM Name" />
@@ -1004,6 +1004,42 @@
     <Field type="string" name="state" label="State" />
   </Type>
 
+  <Event name="Flush" category="Flight Recorder" label="Flush" thread="false" experimental="true">
+    <Field type="ulong" name="flushId" label="Flush Identifier" relation="FlushId" />
+    <Field type="ulong" name="elements" label="Elements Written" />
+    <Field type="ulong" contentType="bytes" name="size" label="Size Written" />
+  </Event>
+
+  <Event name="FlushStorage" category="Flight Recorder" label="Flush Storage" thread="false" experimental="true">
+    <Field type="ulong" name="flushId" label="Flush Identifier" relation="FlushId" />
+    <Field type="ulong" name="elements" label="Elements Written" />
+    <Field type="ulong" contentType="bytes" name="size" label="Size Written" />
+  </Event>
+
+  <Event name="FlushStacktrace" category="Flight Recorder" label="Flush Stacktrace" thread="false" experimental="true">
+    <Field type="ulong" name="flushId" label="Flush Identifier" relation="FlushId" />
+    <Field type="ulong" name="elements" label="Elements Written" />
+    <Field type="ulong" contentType="bytes" name="size" label="Size Written" />
+  </Event>
+
+  <Event name="FlushStringPool" category="Flight Recorder" label="Flush String Pool" thread="false" experimental="true">
+    <Field type="ulong" name="flushId" label="Flush Identifier" relation="FlushId" />
+    <Field type="ulong" name="elements" label="Elements Written" />
+    <Field type="ulong" contentType="bytes" name="size" label="Size Written" />
+  </Event>
+
+  <Event name="FlushMetadata" category="Flight Recorder" label="Flush Metadata" thread="false" experimental="true">
+    <Field type="ulong" name="flushId" label="Flush Identifier" relation="FlushId" />
+    <Field type="ulong" name="elements" label="Elements Written" />
+    <Field type="ulong" contentType="bytes" name="size" label="Size Written" />
+  </Event>
+
+  <Event name="FlushTypeSet" category="Flight Recorder" label="Flush Type Set" thread="false" experimental="true">
+    <Field type="ulong" name="flushId" label="Flush Identifier" relation="FlushId" />
+    <Field type="ulong" name="elements" label="Elements Written" />
+    <Field type="ulong" contentType="bytes" name="size" label="Size Written" />
+  </Event>
+
   <Type name="ZStatisticsCounterType" label="Z Statistics Counter">
     <Field type="string" name="counter" label="Counter" />
   </Type>
@@ -1183,35 +1219,40 @@
     <Field type="int" name="bytecodeIndex" label="Bytecode Index" />
     <Field type="FrameType" name="type" label="Frame Type" />
   </Type>
- 
+
+  <Type name="ChunkHeader" label="Chunk Header">
+    <Field type="byte" array="true" name="payload" label="Payload" />
+  </Type>
+
   <Relation name="JavaMonitorAddress"/>
   <Relation name="SafepointId"/>
   <Relation name="GcId"/>
   <Relation name="CompileId" />
   <Relation name="SweepId"/>
- 
-  <XmlType name="Package" parameterType="const PackageEntry*" fieldType="const PackageEntry*"/> 
-  <XmlType name="Class" javaType="java.lang.Class" parameterType="const Klass*" fieldType="const Klass*"/> 
-  <XmlType name="Module"  parameterType="const ModuleEntry*" fieldType="const ModuleEntry*"/> 
-  <XmlType name="ClassLoader" parameterType="const ClassLoaderData*" fieldType="const ClassLoaderData*"/> 
-  <XmlType name="Method" parameterType="const Method*" fieldType="const Method*"/> 
-  <XmlType name="Thread" javaType="java.lang.Thread" parameterType="u8" fieldType="u8"/> 
-  <XmlType name="Tickspan" contentType="tickspan" javaType="long" parameterType="const Tickspan&amp;" fieldType="Tickspan"/> 
-  <XmlType name="Ticks" contentType="tickstamp" javaType="long" parameterType="const Ticks&amp;" fieldType="Ticks"/> 
-  <XmlType name="ulong" javaType="long" unsigned="true" parameterType="u8" fieldType="u8"/> 
-  <XmlType name="uint" javaType="int" unsigned="true" parameterType="unsigned" fieldType="unsigned"/> 
-  <XmlType name="ushort" javaType="short" unsigned="true" parameterType="u2" fieldType="u2"/> 
-  <XmlType name="ubyte" javaType="byte" unsigned="true" parameterType="u1" fieldType="u1"/> 
-  <XmlType name="long" javaType="long" parameterType="s8" fieldType="s8"/> 
-  <XmlType name="int" javaType="int" parameterType="s4" fieldType="s4"/> 
-  <XmlType name="short" javaType="short" parameterType="s2" fieldType="s2"/> 
-  <XmlType name="byte" javaType="byte"  parameterType="s1" fieldType="s1"/> 
-  <XmlType name="double" javaType="double" parameterType="double" fieldType="double"/> 
-  <XmlType name="float" javaType="float"  parameterType="float" fieldType="float"/> 
-  <XmlType name="boolean" javaType="boolean" parameterType="bool" fieldType="bool"/> 
-  <XmlType name="char" javaType="char" parameterType="char" fieldType="char"/> 
-  <XmlType name="string" javaType="java.lang.String" parameterType="const char*" fieldType="const char*"/> 
- 
+  <Relation name="FlushId"/>
+
+  <XmlType name="Package" parameterType="const PackageEntry*" fieldType="const PackageEntry*"/>
+  <XmlType name="Class" javaType="java.lang.Class" parameterType="const Klass*" fieldType="const Klass*"/>
+  <XmlType name="Module"  parameterType="const ModuleEntry*" fieldType="const ModuleEntry*"/>
+  <XmlType name="ClassLoader" parameterType="const ClassLoaderData*" fieldType="const ClassLoaderData*"/>
+  <XmlType name="Method" parameterType="const Method*" fieldType="const Method*"/>
+  <XmlType name="Thread" javaType="java.lang.Thread" parameterType="u8" fieldType="u8"/>
+  <XmlType name="Tickspan" contentType="tickspan" javaType="long" parameterType="const Tickspan&amp;" fieldType="Tickspan"/>
+  <XmlType name="Ticks" contentType="tickstamp" javaType="long" parameterType="const Ticks&amp;" fieldType="Ticks"/>
+  <XmlType name="ulong" javaType="long" unsigned="true" parameterType="u8" fieldType="u8"/>
+  <XmlType name="uint" javaType="int" unsigned="true" parameterType="unsigned" fieldType="unsigned"/>
+  <XmlType name="ushort" javaType="short" unsigned="true" parameterType="u2" fieldType="u2"/>
+  <XmlType name="ubyte" javaType="byte" unsigned="true" parameterType="u1" fieldType="u1"/>
+  <XmlType name="long" javaType="long" parameterType="s8" fieldType="s8"/>
+  <XmlType name="int" javaType="int" parameterType="s4" fieldType="s4"/>
+  <XmlType name="short" javaType="short" parameterType="s2" fieldType="s2"/>
+  <XmlType name="byte" javaType="byte"  parameterType="s1" fieldType="s1"/>
+  <XmlType name="double" javaType="double" parameterType="double" fieldType="double"/>
+  <XmlType name="float" javaType="float"  parameterType="float" fieldType="float"/>
+  <XmlType name="boolean" javaType="boolean" parameterType="bool" fieldType="bool"/>
+  <XmlType name="char" javaType="char" parameterType="char" fieldType="char"/>
+  <XmlType name="string" javaType="java.lang.String" parameterType="const char*" fieldType="const char*"/>
+
   <XmlContentType name="bytes" annotation="jdk.jfr.DataAmount(BYTES)" />
   <XmlContentType name="tickstamp" annotation="jdk.jfr.Timestamp(TICKS)" />
   <XmlContentType name="epochmillis" annotation="jdk.jfr.Timestamp(MILLISECONDS_SINCE_EPOCH)" />
@@ -1223,5 +1264,5 @@
   <XmlContentType name="hertz" annotation="jdk.jfr.Frequency" />
   <XmlContentType name="bytes-per-second" annotation="jdk.jfr.DataAmount(BYTES), jdk.jfr.Frequency" />
   <XmlContentType name="bits-per-second" annotation="jdk.jfr.DataAmount(BITS), jdk.jfr.Frequency" />
- 
+
 </Metadata>
--- a/src/hotspot/share/jfr/periodic/jfrNetworkUtilization.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/periodic/jfrNetworkUtilization.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -39,7 +39,7 @@
   traceid id;
   uint64_t bytes_in;
   uint64_t bytes_out;
-  bool in_use;
+  mutable bool written;
 };
 
 static GrowableArray<InterfaceEntry>* _interfaces = NULL;
@@ -71,7 +71,7 @@
   entry.id = ++interface_id;
   entry.bytes_in = iface->get_bytes_in();
   entry.bytes_out = iface->get_bytes_out();
-  entry.in_use = false;
+  entry.written = false;
   return _interfaces->at(_interfaces->append(entry));
 }
 
@@ -108,6 +108,39 @@
   return ((current - old) * NANOSECS_PER_SEC) / interval.nanoseconds();
 }
 
+class JfrNetworkInterfaceName : public JfrSerializer {
+ public:
+   void serialize(JfrCheckpointWriter& writer) {} // we write each constant lazily
+
+   void on_rotation() {
+     for (int i = 0; i < _interfaces->length(); ++i) {
+       const InterfaceEntry& entry = _interfaces->at(i);
+       if (entry.written) {
+         entry.written = false;
+       }
+     }
+   }
+};
+
+static bool register_network_interface_name_serializer() {
+  assert(_interfaces != NULL, "invariant");
+  return JfrSerializer::register_serializer(TYPE_NETWORKINTERFACENAME,
+    false, // disallow caching; we want a callback every rotation
+    new JfrNetworkInterfaceName());
+}
+
+static void write_interface_constant(const InterfaceEntry& entry) {
+  if (entry.written) {
+    return;
+  }
+  JfrCheckpointWriter writer;
+  writer.write_type(TYPE_NETWORKINTERFACENAME);
+  writer.write_count(1);
+  writer.write_key(entry.id);
+  writer.write(entry.name);
+  entry.written = true;
+}
+
 static bool get_interfaces(NetworkInterface** network_interfaces) {
   const int ret_val = JfrOSInterface::network_utilization(network_interfaces);
   if (ret_val == OS_ERR) {
@@ -117,39 +150,6 @@
   return ret_val != FUNCTIONALITY_NOT_IMPLEMENTED;
 }
 
-class JfrNetworkInterfaceName : public JfrSerializer {
- public:
-  void serialize(JfrCheckpointWriter& writer) {
-    assert(_interfaces != NULL, "invariant");
-    const JfrCheckpointContext ctx = writer.context();
-    const intptr_t count_offset = writer.reserve(sizeof(u4)); // Don't know how many yet
-    int active_interfaces = 0;
-    for (int i = 0; i < _interfaces->length(); ++i) {
-      InterfaceEntry& entry = _interfaces->at(i);
-      if (entry.in_use) {
-        entry.in_use = false;
-        writer.write_key(entry.id);
-        writer.write(entry.name);
-        ++active_interfaces;
-      }
-    }
-    if (active_interfaces == 0) {
-      // nothing to write, restore context
-      writer.set_context(ctx);
-      return;
-    }
-    writer.write_count(active_interfaces, count_offset);
-  }
-};
-
-static bool register_network_interface_name_serializer() {
-  assert(_interfaces != NULL, "invariant");
-  return JfrSerializer::register_serializer(TYPE_NETWORKINTERFACENAME,
-                                            false, // require safepoint
-                                            false, // disallow caching; we want a callback every rotation
-                                            new JfrNetworkInterfaceName());
-}
-
 void JfrNetworkUtilization::send_events() {
   ResourceMark rm;
   NetworkInterface* network_interfaces;
@@ -169,7 +169,7 @@
       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) {
-        entry.in_use = true;
+        write_interface_constant(entry);
         EventNetworkUtilization event(UNTIMED);
         event.set_starttime(cur_time);
         event.set_endtime(cur_time);
--- a/src/hotspot/share/jfr/periodic/jfrPeriodic.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/periodic/jfrPeriodic.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -44,6 +44,7 @@
 #include "jfr/periodic/jfrNetworkUtilization.hpp"
 #include "jfr/recorder/jfrRecorder.hpp"
 #include "jfr/support/jfrThreadId.hpp"
+#include "jfr/utilities/jfrThreadIterator.hpp"
 #include "jfr/utilities/jfrTime.hpp"
 #include "jfrfiles/jfrPeriodic.hpp"
 #include "logging/log.hpp"
@@ -56,7 +57,6 @@
 #include "runtime/os.hpp"
 #include "runtime/os_perf.hpp"
 #include "runtime/thread.inline.hpp"
-#include "runtime/threadSMR.hpp"
 #include "runtime/sweeper.hpp"
 #include "runtime/vmThread.hpp"
 #include "services/classLoadingService.hpp"
@@ -410,13 +410,12 @@
   GrowableArray<jlong> allocated(initial_size);
   GrowableArray<traceid> thread_ids(initial_size);
   JfrTicks time_stamp = JfrTicks::now();
-  {
-    // Collect allocation statistics while holding threads lock
-    MutexLocker ml(Threads_lock);
-    for (JavaThreadIteratorWithHandle jtiwh; JavaThread *jt = jtiwh.next(); ) {
-      allocated.append(jt->cooked_allocated_bytes());
-      thread_ids.append(JFR_THREAD_ID(jt));
-    }
+  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.
--- a/src/hotspot/share/jfr/periodic/jfrThreadCPULoadEvent.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/periodic/jfrThreadCPULoadEvent.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -28,11 +28,10 @@
 #include "jfr/periodic/jfrThreadCPULoadEvent.hpp"
 #include "jfr/support/jfrThreadId.hpp"
 #include "jfr/support/jfrThreadLocal.hpp"
+#include "jfr/utilities/jfrThreadIterator.hpp"
 #include "jfr/utilities/jfrTime.hpp"
 #include "utilities/globalDefinitions.hpp"
 #include "runtime/os.hpp"
-#include "runtime/thread.inline.hpp"
-#include "runtime/threadSMR.inline.hpp"
 
 jlong JfrThreadCPULoadEvent::get_wallclock_time() {
   return os::javaTimeNanos();
@@ -115,8 +114,12 @@
   JfrTicks event_time = JfrTicks::now();
   jlong cur_wallclock_time = JfrThreadCPULoadEvent::get_wallclock_time();
 
-  JavaThreadIteratorWithHandle jtiwh;
-  while (JavaThread* jt = jtiwh.next()) {
+  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);
@@ -129,7 +132,7 @@
       event.commit();
     }
   }
-  log_trace(jfr)("Measured CPU usage for %d threads in %.3f milliseconds", jtiwh.length(),
+  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);
--- a/src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -30,6 +30,7 @@
 #include "jfr/recorder/service/jfrOptionSet.hpp"
 #include "jfr/recorder/stacktrace/jfrStackTraceRepository.hpp"
 #include "jfr/support/jfrThreadId.hpp"
+#include "jfr/support/jfrThreadLocal.hpp"
 #include "jfr/utilities/jfrTime.hpp"
 #include "logging/log.hpp"
 #include "runtime/frame.inline.hpp"
@@ -352,9 +353,14 @@
   }
 }
 
+static bool is_excluded(JavaThread* thread) {
+  assert(thread != NULL, "invariant");
+  return thread->is_hidden_from_external_view() || thread->in_deopt_handler() || thread->jfr_thread_local()->is_excluded();
+}
+
 bool JfrThreadSampleClosure::do_sample_thread(JavaThread* thread, JfrStackFrame* frames, u4 max_frames, JfrSampleType type) {
   assert(Threads_lock->owned_by_self(), "Holding the thread table lock.");
-  if (thread->is_hidden_from_external_view() || thread->in_deopt_handler()) {
+  if (is_excluded(thread)) {
     return false;
   }
 
--- a/src/hotspot/share/jfr/recorder/checkpoint/jfrCheckpointManager.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/jfrCheckpointManager.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -37,11 +37,14 @@
 #include "jfr/recorder/storage/jfrMemorySpace.inline.hpp"
 #include "jfr/recorder/storage/jfrStorageUtils.inline.hpp"
 #include "jfr/utilities/jfrBigEndian.hpp"
+#include "jfr/utilities/jfrIterator.hpp"
+#include "jfr/utilities/jfrThreadIterator.hpp"
 #include "jfr/utilities/jfrTypes.hpp"
+#include "jfr/writers/jfrJavaEventWriter.hpp"
 #include "logging/log.hpp"
 #include "memory/resourceArea.hpp"
 #include "runtime/handles.inline.hpp"
-#include "runtime/mutexLocker.hpp"
+#include "runtime/mutex.hpp"
 #include "runtime/orderAccess.hpp"
 #include "runtime/os.inline.hpp"
 #include "runtime/safepoint.hpp"
@@ -168,7 +171,7 @@
 }
 
 bool JfrCheckpointManager::use_epoch_transition_mspace(const Thread* thread) const {
-  return _service_thread != thread && OrderAccess::load_acquire(&_checkpoint_epoch_state) != JfrTraceIdEpoch::epoch();
+  return _service_thread != thread && _checkpoint_epoch_state != JfrTraceIdEpoch::epoch();
 }
 
 static const size_t lease_retry = 10;
@@ -181,12 +184,24 @@
   return lease_free(size, manager._free_list_mspace, lease_retry, thread);
 }
 
+JfrCheckpointMspace* JfrCheckpointManager::lookup(BufferPtr old) const {
+  assert(old != NULL, "invariant");
+  return _free_list_mspace->in_free_list(old) ? _free_list_mspace : _epoch_transition_mspace;
+}
+
+BufferPtr JfrCheckpointManager::lease_buffer(BufferPtr old, Thread* thread, size_t size /* 0 */) {
+  assert(old != NULL, "invariant");
+  JfrCheckpointMspace* mspace = instance().lookup(old);
+  assert(mspace != NULL, "invariant");
+  return lease_free(size, mspace, lease_retry, thread);
+}
+
 /*
-* If the buffer was a "lease" from the free list, release back.
-*
-* The buffer is effectively invalidated for the thread post-return,
-* and the caller should take means to ensure that it is not referenced.
-*/
+ * If the buffer was a lease, release back.
+ *
+ * The buffer is effectively invalidated for the thread post-return,
+ * and the caller should take means to ensure that it is not referenced.
+ */
 static void release(BufferPtr const buffer, Thread* thread) {
   DEBUG_ONLY(assert_release(buffer);)
   buffer->clear_lease();
@@ -202,7 +217,7 @@
     return NULL;
   }
   // migration of in-flight information
-  BufferPtr const new_buffer = lease_buffer(thread, used + requested);
+  BufferPtr const new_buffer = lease_buffer(old, thread, used + requested);
   if (new_buffer != NULL) {
     migrate_outstanding_writes(old, new_buffer, used, requested);
   }
@@ -213,8 +228,8 @@
 // offsets into the JfrCheckpointEntry
 static const juint starttime_offset = sizeof(jlong);
 static const juint duration_offset = starttime_offset + sizeof(jlong);
-static const juint flushpoint_offset = duration_offset + sizeof(jlong);
-static const juint types_offset = flushpoint_offset + sizeof(juint);
+static const juint checkpoint_type_offset = duration_offset + sizeof(jlong);
+static const juint types_offset = checkpoint_type_offset + sizeof(juint);
 static const juint payload_offset = types_offset + sizeof(juint);
 
 template <typename Return>
@@ -234,21 +249,21 @@
   return read_data<jlong>(data + duration_offset);
 }
 
-static bool is_flushpoint(const u1* data) {
-  return read_data<juint>(data + flushpoint_offset) == (juint)1;
+static u1 checkpoint_type(const u1* data) {
+  return read_data<u1>(data + checkpoint_type_offset);
 }
 
 static juint number_of_types(const u1* data) {
   return read_data<juint>(data + types_offset);
 }
 
-static void write_checkpoint_header(JfrChunkWriter& cw, int64_t offset_prev_cp_event, const u1* data) {
+static void write_checkpoint_header(JfrChunkWriter& cw, int64_t delta_to_last_checkpoint, const u1* data) {
   cw.reserve(sizeof(u4));
   cw.write<u8>(EVENT_CHECKPOINT);
   cw.write(starttime(data));
   cw.write(duration(data));
-  cw.write(offset_prev_cp_event);
-  cw.write(is_flushpoint(data));
+  cw.write(delta_to_last_checkpoint);
+  cw.write(checkpoint_type(data));
   cw.write(number_of_types(data));
 }
 
@@ -261,9 +276,9 @@
   assert(data != NULL, "invariant");
   const int64_t event_begin = cw.current_offset();
   const int64_t last_checkpoint_event = cw.last_checkpoint_offset();
-  const int64_t delta = last_checkpoint_event == 0 ? 0 : last_checkpoint_event - event_begin;
+  const int64_t delta_to_last_checkpoint = last_checkpoint_event == 0 ? 0 : last_checkpoint_event - event_begin;
   const int64_t checkpoint_size = total_size(data);
-  write_checkpoint_header(cw, delta, data);
+  write_checkpoint_header(cw, delta_to_last_checkpoint, data);
   write_checkpoint_content(cw, data, checkpoint_size);
   const int64_t event_size = cw.current_offset() - event_begin;
   cw.write_padded_at_offset<u4>(event_size, event_begin);
@@ -305,13 +320,13 @@
 typedef CheckpointWriteOp<JfrCheckpointMspace::Type> WriteOperation;
 typedef ReleaseOp<JfrCheckpointMspace> CheckpointReleaseOperation;
 
-template <template <typename> class WriterHost, template <typename, typename> class CompositeOperation>
+template <template <typename> class WriterHost, template <typename, typename, typename> class CompositeOperation>
 static size_t write_mspace(JfrCheckpointMspace* mspace, JfrChunkWriter& chunkwriter) {
   assert(mspace != NULL, "invariant");
   WriteOperation wo(chunkwriter);
   WriterHost<WriteOperation> wh(wo);
   CheckpointReleaseOperation cro(mspace, Thread::current(), false);
-  CompositeOperation<WriterHost<WriteOperation>, CheckpointReleaseOperation> co(&wh, &cro);
+  CompositeOperation<WriterHost<WriteOperation>, CheckpointReleaseOperation, CompositeOperationAnd> co(&wh, &cro);
   assert(mspace->is_full_empty(), "invariant");
   process_free_list(co, mspace);
   return wo.processed();
@@ -333,6 +348,16 @@
   return write_mspace<ExclusiveOp, CompositeOperation>(_epoch_transition_mspace, _chunkwriter);
 }
 
+typedef MutexedWriteOp<WriteOperation> FlushOperation;
+
+size_t JfrCheckpointManager::flush() {
+  WriteOperation wo(_chunkwriter);
+  FlushOperation fo(wo);
+  assert(_free_list_mspace->is_full_empty(), "invariant");
+  process_free_list(fo, _free_list_mspace);
+  return wo.processed();
+}
+
 typedef DiscardOp<DefaultDiscarder<JfrBuffer> > DiscardOperation;
 size_t JfrCheckpointManager::clear() {
   JfrTypeSet::clear();
@@ -340,44 +365,88 @@
   process_free_list(discarder, _free_list_mspace);
   process_free_list(discarder, _epoch_transition_mspace);
   synchronize_epoch();
-  return discarder.processed();
+  return discarder.elements();
 }
 
-size_t JfrCheckpointManager::write_types() {
-  JfrCheckpointWriter writer(false, true, Thread::current());
-  JfrTypeManager::write_types(writer);
+// Optimization for write_static_type_set() and write_threads() is to write
+// directly into the epoch transition mspace because we will immediately
+// serialize and reset this mspace post-write.
+static JfrBuffer* get_epoch_transition_buffer(JfrCheckpointMspace* mspace, Thread* t) {
+  assert(mspace != NULL, "invariant");
+  JfrBuffer* const buffer = mspace->free_head();
+  assert(buffer != NULL, "invariant");
+  buffer->acquire(t);
+  buffer->set_lease();
+  DEBUG_ONLY(assert_free_lease(buffer);)
+  return buffer;
+}
+
+bool JfrCheckpointManager::is_static_type_set_required() {
+  return JfrTypeManager::has_new_static_type();
+}
+
+size_t JfrCheckpointManager::write_static_type_set() {
+  Thread* const t = Thread::current();
+  ResourceMark rm(t);
+  HandleMark hm(t);
+  JfrCheckpointWriter writer(t, get_epoch_transition_buffer(_epoch_transition_mspace, t), STATICS);
+  JfrTypeManager::write_static_types(writer);
   return writer.used_size();
 }
 
-size_t JfrCheckpointManager::write_safepoint_types() {
-  // this is also a "flushpoint"
-  JfrCheckpointWriter writer(true, true, Thread::current());
-  JfrTypeManager::write_safepoint_types(writer);
+size_t JfrCheckpointManager::write_threads() {
+  Thread* const t = Thread::current();
+  ResourceMark rm(t);
+  HandleMark hm(t);
+  JfrCheckpointWriter writer(t, get_epoch_transition_buffer(_epoch_transition_mspace, t), THREADS);
+  JfrTypeManager::write_threads(writer);
   return writer.used_size();
 }
 
+size_t JfrCheckpointManager::write_static_type_set_and_threads() {
+  write_static_type_set();
+  write_threads();
+  return write_epoch_transition_mspace();
+}
+
+void JfrCheckpointManager::shift_epoch() {
+  debug_only(const u1 current_epoch = JfrTraceIdEpoch::current();)
+  JfrTraceIdEpoch::shift_epoch();
+  assert(current_epoch != JfrTraceIdEpoch::current(), "invariant");
+}
+
+void JfrCheckpointManager::on_rotation() {
+  assert(SafepointSynchronize::is_at_safepoint(), "invariant");
+  JfrTypeManager::on_rotation();
+  notify_threads();
+}
+
 void JfrCheckpointManager::write_type_set() {
   assert(!SafepointSynchronize::is_at_safepoint(), "invariant");
-  // can safepoint here
-  MutexLocker cld_lock(ClassLoaderDataGraph_lock);
-  MutexLocker module_lock(Module_lock);
-  if (!LeakProfiler::is_running()) {
-    JfrCheckpointWriter writer(true, true, Thread::current());
-    JfrTypeSet::serialize(&writer, NULL, false);
+  if (LeakProfiler::is_running()) {
+    Thread* const t = Thread::current();
+    // can safepoint here
+    MutexLocker cld_lock(ClassLoaderDataGraph_lock);
+    MutexLocker module_lock(Module_lock);
+    JfrCheckpointWriter leakp_writer(t);
+    JfrCheckpointWriter writer(t);
+    JfrTypeSet::serialize(&writer, &leakp_writer, false, false);
+    ObjectSampleCheckpoint::on_type_set(leakp_writer);
   } else {
-    Thread* const t = Thread::current();
-    JfrCheckpointWriter leakp_writer(false, true, t);
-    JfrCheckpointWriter writer(false, true, t);
-    JfrTypeSet::serialize(&writer, &leakp_writer, false);
-    ObjectSampleCheckpoint::on_type_set(leakp_writer);
+    // can safepoint here
+    MutexLocker cld_lock(ClassLoaderDataGraph_lock);
+    MutexLocker module_lock(Module_lock);
+    JfrCheckpointWriter writer(Thread::current());
+    JfrTypeSet::serialize(&writer, NULL, false, false);
   }
+  write();
 }
 
 void JfrCheckpointManager::write_type_set_for_unloaded_classes() {
   assert_locked_or_safepoint(ClassLoaderDataGraph_lock);
-  JfrCheckpointWriter writer(false, true, Thread::current());
+  JfrCheckpointWriter writer(Thread::current());
   const JfrCheckpointContext ctx = writer.context();
-  JfrTypeSet::serialize(&writer, NULL, true);
+  JfrTypeSet::serialize(&writer, NULL, true, false);
   if (LeakProfiler::is_running()) {
     ObjectSampleCheckpoint::on_type_set_unload(writer);
   }
@@ -387,16 +456,51 @@
   }
 }
 
-void JfrCheckpointManager::create_thread_blob(JavaThread* jt) {
-  JfrTypeManager::create_thread_blob(jt);
+bool JfrCheckpointManager::is_type_set_required() {
+  return JfrTraceIdEpoch::has_changed_tag_state();
 }
 
-void JfrCheckpointManager::write_thread_checkpoint(JavaThread* jt) {
-  JfrTypeManager::write_thread_checkpoint(jt);
+size_t JfrCheckpointManager::flush_type_set() {
+  assert(!SafepointSynchronize::is_at_safepoint(), "invariant");
+  size_t elements = 0;
+  {
+    JfrCheckpointWriter writer(Thread::current());
+    // can safepoint here
+    MutexLocker cld_lock(ClassLoaderDataGraph_lock);
+    MutexLocker module_lock(Module_lock);
+    elements = JfrTypeSet::serialize(&writer, NULL, false, true);
+  }
+  flush();
+  return elements;
 }
 
-void JfrCheckpointManager::shift_epoch() {
-  debug_only(const u1 current_epoch = JfrTraceIdEpoch::current();)
-  JfrTraceIdEpoch::shift_epoch();
-  assert(current_epoch != JfrTraceIdEpoch::current(), "invariant");
+void JfrCheckpointManager::flush_static_type_set() {
+  flush();
 }
+
+void JfrCheckpointManager::create_thread_blob(Thread* t) {
+  JfrTypeManager::create_thread_blob(t);
+}
+
+void JfrCheckpointManager::write_thread_checkpoint(Thread* t) {
+  JfrTypeManager::write_thread_checkpoint(t);
+}
+
+class JfrNotifyClosure : public ThreadClosure {
+ public:
+  void do_thread(Thread* t) {
+    assert(t != NULL, "invariant");
+    assert(t->is_Java_thread(), "invariant");
+    assert_locked_or_safepoint(Threads_lock);
+    JfrJavaEventWriter::notify((JavaThread*)t);
+  }
+};
+
+void JfrCheckpointManager::notify_threads() {
+  assert(SafepointSynchronize::is_at_safepoint(), "invariant");
+  JfrNotifyClosure tc;
+  JfrJavaThreadIterator iter;
+  while (iter.has_next()) {
+    tc.do_thread(iter.next());
+  }
+}
--- a/src/hotspot/share/jfr/recorder/checkpoint/jfrCheckpointManager.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/jfrCheckpointManager.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -68,18 +68,29 @@
   void unlock();
   DEBUG_ONLY(bool is_locked() const;)
 
+  JfrCheckpointMspace* lookup(Buffer* old) const;
+  bool use_epoch_transition_mspace(const Thread* t) const;
+  size_t write_epoch_transition_mspace();
+
   static Buffer* lease_buffer(Thread* t, size_t size = 0);
+  static Buffer* lease_buffer(Buffer* old, Thread* t, size_t size = 0);
   static Buffer* flush(Buffer* old, size_t used, size_t requested, Thread* t);
 
   size_t clear();
   size_t write();
-  size_t write_epoch_transition_mspace();
-  size_t write_types();
-  size_t write_safepoint_types();
+  size_t flush();
+
+  bool is_static_type_set_required();
+  size_t write_static_type_set();
+  size_t write_threads();
+  size_t write_static_type_set_and_threads();
+  bool is_type_set_required();
   void write_type_set();
+  static void write_type_set_for_unloaded_classes();
+
   void shift_epoch();
   void synchronize_epoch();
-  bool use_epoch_transition_mspace(const Thread* t) const;
+  void notify_threads();
 
   JfrCheckpointManager(JfrChunkWriter& cw);
   ~JfrCheckpointManager();
@@ -87,14 +98,17 @@
   static JfrCheckpointManager& instance();
   static JfrCheckpointManager* create(JfrChunkWriter& cw);
   bool initialize();
+  void on_rotation();
   static void destroy();
 
  public:
+  size_t flush_type_set();
+  void flush_static_type_set();
+  static void create_thread_blob(Thread* t);
+  static void write_thread_checkpoint(Thread* t);
   void register_service_thread(const Thread* t);
-  static void write_type_set_for_unloaded_classes();
-  static void create_thread_blob(JavaThread* jt);
-  static void write_thread_checkpoint(JavaThread* jt);
 
+  friend class Jfr;
   friend class JfrRecorder;
   friend class JfrRecorderService;
   friend class JfrCheckpointFlush;
--- a/src/hotspot/share/jfr/recorder/checkpoint/jfrCheckpointWriter.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/jfrCheckpointWriter.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -31,12 +31,26 @@
 JfrCheckpointFlush::JfrCheckpointFlush(Type* old, size_t used, size_t requested, Thread* t) :
   _result(JfrCheckpointManager::flush(old, used, requested, t)) {}
 
-JfrCheckpointWriter::JfrCheckpointWriter(bool flushpoint, bool header, Thread* thread) :
-  JfrCheckpointWriterBase(JfrCheckpointManager::lease_buffer(thread), thread),
+JfrCheckpointWriter::JfrCheckpointWriter(JfrCheckpointType type /* GENERIC */) :
+  JfrCheckpointWriterBase(JfrCheckpointManager::lease_buffer(Thread::current()), Thread::current()),
   _time(JfrTicks::now()),
   _offset(0),
   _count(0),
-  _flushpoint(flushpoint),
+  _type(type),
+  _header(true) {
+  assert(this->is_acquired(), "invariant");
+  assert(0 == this->current_offset(), "invariant");
+  if (_header) {
+    reserve(sizeof(JfrCheckpointEntry));
+  }
+}
+
+JfrCheckpointWriter::JfrCheckpointWriter(Thread* t, bool header /* true */, JfrCheckpointType type /* GENERIC */) :
+  JfrCheckpointWriterBase(JfrCheckpointManager::lease_buffer(t), t),
+  _time(JfrTicks::now()),
+  _offset(0),
+  _count(0),
+  _type(type),
   _header(header) {
   assert(this->is_acquired(), "invariant");
   assert(0 == this->current_offset(), "invariant");
@@ -45,13 +59,27 @@
   }
 }
 
-static void write_checkpoint_header(u1* pos, int64_t size, jlong time, bool flushpoint, u4 type_count) {
+JfrCheckpointWriter::JfrCheckpointWriter(Thread* t, JfrBuffer* buffer, JfrCheckpointType type /* GENERIC */) :
+  JfrCheckpointWriterBase(buffer, t),
+  _time(JfrTicks::now()),
+  _offset(0),
+  _count(0),
+  _type(type),
+  _header(true) {
+  assert(this->is_acquired(), "invariant");
+  assert(0 == this->current_offset(), "invariant");
+  if (_header) {
+    reserve(sizeof(JfrCheckpointEntry));
+  }
+}
+
+static void write_checkpoint_header(u1* pos, int64_t size, jlong time, u4 checkpoint_type, u4 type_count) {
   assert(pos != NULL, "invariant");
   JfrBigEndianWriter be_writer(pos, sizeof(JfrCheckpointEntry));
   be_writer.write(size);
   be_writer.write(time);
   be_writer.write(JfrTicks::now().value() - time);
-  be_writer.write(flushpoint ? (u4)1 : (u4)0);
+  be_writer.write(checkpoint_type);
   be_writer.write(type_count);
   assert(be_writer.is_valid(), "invariant");
 }
@@ -74,18 +102,10 @@
   assert(this->used_size() > sizeof(JfrCheckpointEntry), "invariant");
   const int64_t size = this->current_offset();
   assert(size + this->start_pos() == this->current_pos(), "invariant");
-  write_checkpoint_header(const_cast<u1*>(this->start_pos()), size, _time, is_flushpoint(), count());
+  write_checkpoint_header(const_cast<u1*>(this->start_pos()), size, _time, (u4)_type, count());
   release();
 }
 
-void JfrCheckpointWriter::set_flushpoint(bool flushpoint) {
-  _flushpoint = flushpoint;
-}
-
-bool JfrCheckpointWriter::is_flushpoint() const {
-  return _flushpoint;
-}
-
 u4 JfrCheckpointWriter::count() const {
   return _count;
 }
@@ -140,7 +160,7 @@
   }
   *size = this->used_size();
   assert(this->start_pos() + *size == this->current_pos(), "invariant");
-  write_checkpoint_header(const_cast<u1*>(this->start_pos()), this->used_offset(), _time, is_flushpoint(), count());
+  write_checkpoint_header(const_cast<u1*>(this->start_pos()), this->used_offset(), _time, (u4)_type, count());
   _header = false; // the header was just written
   if (move) {
     this->seek(_offset);
--- a/src/hotspot/share/jfr/recorder/checkpoint/jfrCheckpointWriter.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/jfrCheckpointWriter.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -54,23 +54,24 @@
 };
 
 class JfrCheckpointWriter : public JfrCheckpointWriterBase {
+  friend class JfrCheckpointManager;
   friend class JfrSerializerRegistration;
  private:
   JfrTicks _time;
   int64_t _offset;
   u4 _count;
-  bool _flushpoint;
+  JfrCheckpointType _type;
   bool _header;
 
   u4 count() const;
   void set_count(u4 count);
   void increment();
-  void set_flushpoint(bool flushpoint);
-  bool is_flushpoint() const;
   const u1* session_data(size_t* size, bool move = false, const JfrCheckpointContext* ctx = NULL);
   void release();
+  JfrCheckpointWriter(Thread* t, JfrBuffer* buffer, JfrCheckpointType type = GENERIC);
  public:
-  JfrCheckpointWriter(bool flushpoint, bool header, Thread* thread);
+  JfrCheckpointWriter(JfrCheckpointType type = GENERIC);
+  JfrCheckpointWriter(Thread* t, bool header = true, JfrCheckpointType mode = GENERIC);
   ~JfrCheckpointWriter();
   void write_type(JfrTypeId type_id);
   void write_count(u4 nof_entries);
--- a/src/hotspot/share/jfr/recorder/checkpoint/jfrMetadataEvent.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/jfrMetadataEvent.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -29,61 +29,53 @@
 #include "oops/klass.inline.hpp"
 #include "oops/oop.inline.hpp"
 #include "oops/typeArrayOop.inline.hpp"
-#include "runtime/semaphore.hpp"
 #include "runtime/thread.inline.hpp"
 
-static jbyteArray _metadata_blob = NULL;
-static Semaphore metadata_mutex_semaphore(1);
+static jbyteArray metadata_blob = NULL;
+static u8 metadata_id = 0;
+static u8 last_metadata_id = 0;
 
-void JfrMetadataEvent::lock() {
-  metadata_mutex_semaphore.wait();
+static void write_metadata_blob(JfrChunkWriter& chunkwriter) {
+  assert(metadata_blob != NULL, "invariant");
+  const typeArrayOop arr = (typeArrayOop)JfrJavaSupport::resolve_non_null(metadata_blob);
+  assert(arr != NULL, "invariant");
+  const int length = arr->length();
+  const Klass* const k = arr->klass();
+  assert(k != NULL && k->is_array_klass(), "invariant");
+  const TypeArrayKlass* const byte_arr_klass = TypeArrayKlass::cast(k);
+  const jbyte* const data_address = arr->byte_at_addr(0);
+  chunkwriter.write_unbuffered(data_address, length);
 }
 
-void JfrMetadataEvent::unlock() {
-  metadata_mutex_semaphore.signal();
-}
-
-static void write_metadata_blob(JfrChunkWriter& chunkwriter, jbyteArray metadata_blob) {
-  if (metadata_blob != NULL) {
-    const typeArrayOop arr = (typeArrayOop)JfrJavaSupport::resolve_non_null(metadata_blob);
-    assert(arr != NULL, "invariant");
-    const int length = arr->length();
-    const Klass* const k = arr->klass();
-    assert(k != NULL && k->is_array_klass(), "invariant");
-    const TypeArrayKlass* const byte_arr_klass = TypeArrayKlass::cast(k);
-    const jbyte* const data_address = arr->byte_at_addr(0);
-    chunkwriter.write_unbuffered(data_address, length);
+void JfrMetadataEvent::write(JfrChunkWriter& chunkwriter) {
+  assert(chunkwriter.is_valid(), "invariant");
+  if (last_metadata_id == metadata_id && chunkwriter.has_metadata()) {
+    return;
   }
-}
-
-// the semaphore is assumed to be locked  (was locked previous safepoint)
-size_t JfrMetadataEvent::write(JfrChunkWriter& chunkwriter, jlong metadata_offset) {
-  assert(chunkwriter.is_valid(), "invariant");
-  assert(chunkwriter.current_offset() == metadata_offset, "invariant");
   // header
-  chunkwriter.reserve(sizeof(u4));
+  const int64_t metadata_offset = chunkwriter.reserve(sizeof(u4));
   chunkwriter.write<u8>(EVENT_METADATA); // ID 0
   // time data
   chunkwriter.write(JfrTicks::now());
   chunkwriter.write((u8)0); // duration
-  chunkwriter.write((u8)0); // metadata id
-  write_metadata_blob(chunkwriter, _metadata_blob); // payload
-  unlock(); // open up for java to provide updated metadata
+  chunkwriter.write(metadata_id); // metadata id
+  write_metadata_blob(chunkwriter); // payload
   // fill in size of metadata descriptor event
-  const jlong size_written = chunkwriter.current_offset() - metadata_offset;
+  const int64_t size_written = chunkwriter.current_offset() - metadata_offset;
   chunkwriter.write_padded_at_offset((u4)size_written, metadata_offset);
-  return size_written;
+  chunkwriter.set_last_metadata_offset(metadata_offset);
+  last_metadata_id = metadata_id;
 }
 
 void JfrMetadataEvent::update(jbyteArray metadata) {
   JavaThread* thread = (JavaThread*)Thread::current();
   assert(thread->is_Java_thread(), "invariant");
   DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(thread));
-  lock();
-  if (_metadata_blob != NULL) {
-    JfrJavaSupport::destroy_global_jni_handle(_metadata_blob);
+  if (metadata_blob != NULL) {
+    JfrJavaSupport::destroy_global_jni_handle(metadata_blob);
   }
   const oop new_desc_oop = JfrJavaSupport::resolve_non_null(metadata);
-  _metadata_blob = new_desc_oop != NULL ? (jbyteArray)JfrJavaSupport::global_jni_handle(new_desc_oop, thread) : NULL;
-  unlock();
+  assert(new_desc_oop != NULL, "invariant");
+  metadata_blob = (jbyteArray)JfrJavaSupport::global_jni_handle(new_desc_oop, thread);
+  ++metadata_id;
 }
--- a/src/hotspot/share/jfr/recorder/checkpoint/jfrMetadataEvent.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/jfrMetadataEvent.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -33,13 +33,10 @@
 //
 // Metadata is continuously updated in Java as event classes are loaded / unloaded.
 // Using update(), Java stores a binary representation back to native.
-// This is for easy access on chunk finalization as well as having it readily available in the case of fatal error.
 //
 class JfrMetadataEvent : AllStatic {
  public:
-  static void lock();
-  static void unlock();
-  static size_t write(JfrChunkWriter& writer, jlong metadata_offset);
+  static void write(JfrChunkWriter& writer);
   static void update(jbyteArray metadata);
 };
 
--- a/src/hotspot/share/jfr/recorder/checkpoint/types/jfrThreadGroup.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/types/jfrThreadGroup.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -25,7 +25,6 @@
 #include "precompiled.hpp"
 #include "jfr/recorder/checkpoint/jfrCheckpointWriter.hpp"
 #include "jfr/recorder/checkpoint/types/jfrThreadGroup.hpp"
-#include "jfr/utilities/jfrResourceManager.hpp"
 #include "jfr/utilities/jfrTypes.hpp"
 #include "runtime/handles.inline.hpp"
 #include "runtime/jniHandles.inline.hpp"
@@ -33,6 +32,8 @@
 #include "runtime/semaphore.hpp"
 #include "utilities/growableArray.hpp"
 
+static const int initial_array_size = 30;
+
 class ThreadGroupExclusiveAccess : public StackObj {
  private:
   static Semaphore _mutex_semaphore;
@@ -257,12 +258,10 @@
   }
 }
 
-JfrThreadGroup::JfrThreadGroup() : _list(NULL) {
-  _list = new (ResourceObj::C_HEAP, mtTracing) GrowableArray<JfrThreadGroupEntry*>(30, true);
-}
+JfrThreadGroup::JfrThreadGroup() :
+  _list(new (ResourceObj::C_HEAP, mtTracing) GrowableArray<JfrThreadGroupEntry*>(initial_array_size, true, mtTracing)) {}
 
 JfrThreadGroup::~JfrThreadGroup() {
-  assert(SafepointSynchronize::is_at_safepoint(), "invariant");
   if (_list != NULL) {
     for (int i = 0; i < _list->length(); i++) {
       JfrThreadGroupEntry* e = _list->at(i);
@@ -281,14 +280,11 @@
 }
 
 traceid JfrThreadGroup::thread_group_id(const JavaThread* jt, Thread* current) {
-  ResourceMark rm(current);
-  HandleMark hm(current);
   JfrThreadGroupsHelper helper(jt, current);
   return helper.is_valid() ? thread_group_id_internal(helper) : 0;
 }
 
 traceid JfrThreadGroup::thread_group_id(JavaThread* const jt) {
-  assert(!JfrStream_lock->owned_by_self(), "holding stream lock but should not hold it here");
   return thread_group_id(jt, jt);
 }
 
@@ -396,9 +392,7 @@
   ThreadGroupExclusiveAccess lock;
   JfrThreadGroup* tg_instance = instance();
   assert(tg_instance != NULL, "invariant");
-  ResourceManager<JfrThreadGroup> tg_handle(tg_instance);
-  set_instance(NULL);
-  tg_handle->write_thread_group_entries(writer);
+  tg_instance->write_thread_group_entries(writer);
 }
 
 // for writing a particular thread group
--- a/src/hotspot/share/jfr/recorder/checkpoint/types/jfrThreadState.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/types/jfrThreadState.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+* Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
@@ -23,9 +23,13 @@
 */
 
 #include "precompiled.hpp"
+#include "classfile/javaClasses.inline.hpp"
 #include "jfr/recorder/checkpoint/types/jfrThreadState.hpp"
 #include "jfr/recorder/checkpoint/jfrCheckpointWriter.hpp"
+#include "jfr/support/jfrThreadLocal.hpp"
 #include "jvmtifiles/jvmti.h"
+#include "runtime/osThread.hpp"
+#include "runtime/thread.hpp"
 
 struct jvmti_thread_state {
   u8 id;
@@ -80,3 +84,47 @@
   }
 }
 
+traceid JfrThreadId::id(const Thread* t) {
+  assert(t != NULL, "invariant");
+  if (!t->is_Java_thread()) {
+    return os_id(t);
+  }
+  const JavaThread* const jt = (JavaThread*)t;
+  const oop thread_obj = jt->threadObj();
+  return thread_obj != NULL ? java_lang_Thread::thread_id(thread_obj) : 0;
+}
+
+traceid JfrThreadId::os_id(const Thread* t) {
+  assert(t != NULL, "invariant");
+  const OSThread* const os_thread = t->osthread();
+  return os_thread != NULL ? os_thread->thread_id() : 0;
+}
+
+traceid JfrThreadId::jfr_id(const Thread* t) {
+  assert(t != NULL, "invariant");
+  return t->jfr_thread_local()->thread_id();
+}
+
+// caller needs ResourceMark
+const char* get_java_thread_name(const Thread* t) {
+  assert(t != NULL, "invariant");
+  assert(t->is_Java_thread(), "invariant");
+  const JavaThread* const jt = ((JavaThread*)t);
+  const char* name_str = "<no-name - thread name unresolved>";
+  const oop thread_obj = jt->threadObj();
+  if (thread_obj != NULL) {
+    const oop name = java_lang_Thread::name(thread_obj);
+    if (name != NULL) {
+      name_str = java_lang_String::as_utf8_string(name);
+    }
+  } else if (jt->is_attaching_via_jni()) {
+    name_str = "<no-name - thread is attaching>";
+  }
+  assert(name_str != NULL, "unexpected NULL thread name");
+  return name_str;
+}
+
+const char* JfrThreadName::name(const Thread* t) {
+  assert(t != NULL, "invariant");
+  return t->is_Java_thread() ? get_java_thread_name(t) : t->name();
+}
--- a/src/hotspot/share/jfr/recorder/checkpoint/types/jfrThreadState.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/types/jfrThreadState.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -28,10 +28,24 @@
 #include "memory/allocation.hpp"
 
 class JfrCheckpointWriter;
+class Thread;
 
 class JfrThreadState : public AllStatic {
  public:
   static void serialize(JfrCheckpointWriter& writer);
 };
 
+class JfrThreadId : public AllStatic {
+public:
+  static traceid id(const Thread* t);
+  static traceid os_id(const Thread* t);
+  static traceid jfr_id(const Thread* t);
+};
+
+class JfrThreadName : public AllStatic {
+ public:
+  // Requires a ResourceMark for get_thread_name/as_utf8
+  static const char* name(const Thread* t);
+};
+
 #endif // SHARE_JFR_RECORDER_CHECKPOINT_TYPES_JFRTHREADSTATE_HPP
--- a/src/hotspot/share/jfr/recorder/checkpoint/types/jfrType.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/types/jfrType.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -31,13 +31,14 @@
 #include "gc/shared/gcTrace.hpp"
 #include "gc/shared/gcWhen.hpp"
 #include "jfr/leakprofiler/leakProfiler.hpp"
-#include "jfr/recorder/checkpoint/jfrCheckpointManager.hpp"
+#include "jfr/recorder/checkpoint/jfrCheckpointWriter.hpp"
 #include "jfr/recorder/checkpoint/types/jfrType.hpp"
 #include "jfr/recorder/jfrRecorder.hpp"
 #include "jfr/recorder/checkpoint/types/jfrThreadGroup.hpp"
 #include "jfr/recorder/checkpoint/types/jfrThreadState.hpp"
 #include "jfr/support/jfrThreadLocal.hpp"
 #include "jfr/writers/jfrJavaEventWriter.hpp"
+#include "jfr/utilities/jfrThreadIterator.hpp"
 #include "memory/metaspaceGCThresholdUpdater.hpp"
 #include "memory/referenceType.hpp"
 #include "memory/universe.hpp"
@@ -84,27 +85,18 @@
   void do_thread(Thread* t);
 };
 
-// Requires a ResourceMark for get_thread_name/as_utf8
 void JfrCheckpointThreadClosure::do_thread(Thread* t) {
   assert(t != NULL, "invariant");
-  assert_locked_or_safepoint(Threads_lock);
-  const JfrThreadLocal* const tl = t->jfr_thread_local();
-  assert(tl != NULL, "invariant");
-  if (tl->is_dead()) {
-    return;
-  }
   ++_count;
-  _writer.write_key(tl->thread_id());
-  _writer.write(t->name());
-  const OSThread* const os_thread = t->osthread();
-  _writer.write<traceid>(os_thread != NULL ? os_thread->thread_id() : 0);
+  _writer.write_key(JfrThreadId::jfr_id(t));
+  const char* const name = JfrThreadName::name(t);
+  assert(name != NULL, "invariant");
+  _writer.write(name);
+  _writer.write<traceid>(JfrThreadId::os_id(t));
   if (t->is_Java_thread()) {
-    JavaThread* const jt = (JavaThread*)t;
-    _writer.write(jt->name());
-    _writer.write(java_lang_Thread::thread_id(jt->threadObj()));
-    _writer.write(JfrThreadGroup::thread_group_id(jt, _curthread));
-    // since we are iterating threads during a safepoint, also issue notification
-    JfrJavaEventWriter::notify(jt);
+    _writer.write(name);
+    _writer.write(JfrThreadId::id(t));
+    _writer.write(JfrThreadGroup::thread_group_id((JavaThread*)t, _curthread));
     return;
   }
   _writer.write((const char*)NULL); // java name
@@ -113,13 +105,18 @@
 }
 
 void JfrThreadConstantSet::serialize(JfrCheckpointWriter& writer) {
-  assert(SafepointSynchronize::is_at_safepoint(), "invariant");
   JfrCheckpointThreadClosure tc(writer);
-  Threads::threads_do(&tc);
+  JfrJavaThreadIterator javathreads;
+  while (javathreads.has_next()) {
+    tc.do_thread(javathreads.next());
+  }
+  JfrNonJavaThreadIterator nonjavathreads;
+  while (nonjavathreads.has_next()) {
+    tc.do_thread(nonjavathreads.next());
+  }
 }
 
 void JfrThreadGroupConstant::serialize(JfrCheckpointWriter& writer) {
-  assert(SafepointSynchronize::is_at_safepoint(), "invariant");
   JfrThreadGroup::serialize(writer);
 }
 
@@ -278,19 +275,21 @@
 void JfrThreadConstant::serialize(JfrCheckpointWriter& writer) {
   assert(_thread != NULL, "invariant");
   assert(_thread == Thread::current(), "invariant");
-  assert(_thread->is_Java_thread(), "invariant");
-  ResourceMark rm(_thread);
-  const oop threadObj = _thread->threadObj();
-  assert(threadObj != NULL, "invariant");
-  const u8 java_lang_thread_id = java_lang_Thread::thread_id(threadObj);
-  const char* const thread_name = _thread->name();
-  const traceid thread_group_id = JfrThreadGroup::thread_group_id(_thread);
   writer.write_count(1);
-  writer.write_key(_thread->jfr_thread_local()->thread_id());
-  writer.write(thread_name);
-  writer.write((traceid)_thread->osthread()->thread_id());
-  writer.write(thread_name);
-  writer.write(java_lang_thread_id);
-  writer.write(thread_group_id);
-  JfrThreadGroup::serialize(&writer, thread_group_id);
+  writer.write_key(JfrThreadId::jfr_id(_thread));
+  const char* const name = JfrThreadName::name(_thread);
+  writer.write(name);
+  writer.write(JfrThreadId::os_id(_thread));
+  if (_thread->is_Java_thread()) {
+    writer.write(name);
+    writer.write(JfrThreadId::id(_thread));
+    JavaThread* const jt = (JavaThread*)_thread;
+    const traceid thread_group_id = JfrThreadGroup::thread_group_id(jt, jt);
+    writer.write(thread_group_id);
+    JfrThreadGroup::serialize(&writer, thread_group_id);
+    return;
+  }
+  writer.write((const char*)NULL); // java name
+  writer.write((traceid)0); // java thread id
+  writer.write((traceid)0); // java thread group
 }
--- a/src/hotspot/share/jfr/recorder/checkpoint/types/jfrType.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/types/jfrType.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -27,16 +27,6 @@
 
 #include "jfr/metadata/jfrSerializer.hpp"
 
-class JfrThreadConstantSet : public JfrSerializer {
- public:
-  void serialize(JfrCheckpointWriter& writer);
-};
-
-class JfrThreadGroupConstant : public JfrSerializer {
- public:
-  void serialize(JfrCheckpointWriter& writer);
-};
-
 class FlagValueOriginConstant : public JfrSerializer {
  public:
   void serialize(JfrCheckpointWriter& writer);
@@ -102,6 +92,16 @@
   void serialize(JfrCheckpointWriter& writer);
 };
 
+class JfrThreadConstantSet : public JfrSerializer {
+ public:
+  void serialize(JfrCheckpointWriter& writer);
+};
+
+class JfrThreadGroupConstant : public JfrSerializer {
+ public:
+  void serialize(JfrCheckpointWriter& writer);
+};
+
 class ThreadStateConstant : public JfrSerializer {
  public:
   void serialize(JfrCheckpointWriter& writer);
@@ -109,9 +109,9 @@
 
 class JfrThreadConstant : public JfrSerializer {
  private:
-  JavaThread* _thread;
+  Thread* _thread;
  public:
-  JfrThreadConstant(JavaThread* jt) : _thread(jt) {}
+  JfrThreadConstant(Thread* t) : _thread(t) {}
   void serialize(JfrCheckpointWriter& writer);
 };
 
--- a/src/hotspot/share/jfr/recorder/checkpoint/types/jfrTypeManager.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/types/jfrTypeManager.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -27,6 +27,7 @@
 #include "jfr/recorder/checkpoint/jfrCheckpointWriter.hpp"
 #include "jfr/recorder/checkpoint/types/jfrType.hpp"
 #include "jfr/recorder/checkpoint/types/jfrTypeManager.hpp"
+#include "jfr/recorder/jfrRecorder.hpp"
 #include "jfr/utilities/jfrDoublyLinkedList.hpp"
 #include "jfr/utilities/jfrIterator.hpp"
 #include "memory/resourceArea.hpp"
@@ -73,29 +74,71 @@
     return _id;
   }
 
-  void invoke(JfrCheckpointWriter& writer) const;
+  void on_rotation() const {
+    _serializer->on_rotation();
+  }
+
+  void invoke(JfrCheckpointWriter& writer) const {
+    if (_cache.valid()) {
+      writer.increment();
+      _cache->write(writer);
+      return;
+    }
+    const JfrCheckpointContext ctx = writer.context();
+    // serialize the type id before invoking callback
+    writer.write_type(_id);
+    const intptr_t start = writer.current_offset();
+    // invoke the serializer routine
+    _serializer->serialize(writer);
+    if (start == writer.current_offset()) {
+      // the serializer implementation did nothing, rewind to restore
+      writer.set_context(ctx);
+      return;
+    }
+    if (_permit_cache) {
+      _cache = writer.copy(&ctx);
+    }
+  }
 };
 
-void JfrSerializerRegistration::invoke(JfrCheckpointWriter& writer) const {
-  if (_cache.valid()) {
-    writer.increment();
-    _cache->write(writer);
-    return;
-  }
-  const JfrCheckpointContext ctx = writer.context();
-  // serialize the type id before invoking callback
-  writer.write_type(_id);
-  const intptr_t start = writer.current_offset();
-  // invoke the serializer routine
-  _serializer->serialize(writer);
-  if (start == writer.current_offset() ) {
-    // the serializer implementation did nothing, rewind to restore
-    writer.set_context(ctx);
-    return;
-  }
-  if (_permit_cache) {
-    _cache = writer.copy(&ctx);
-  }
+static void serialize_threads(JfrCheckpointWriter& writer) {
+  JfrThreadConstantSet thread_set;
+  writer.write_type(TYPE_THREAD);
+  thread_set.serialize(writer);
+}
+
+static void serialize_thread_groups(JfrCheckpointWriter& writer) {
+  JfrThreadGroupConstant thread_group_set;
+  writer.write_type(TYPE_THREADGROUP);
+  thread_group_set.serialize(writer);
+}
+
+void JfrTypeManager::write_threads(JfrCheckpointWriter& writer) {
+  serialize_threads(writer);
+  serialize_thread_groups(writer);
+}
+
+void JfrTypeManager::create_thread_blob(Thread* t) {
+  assert(t != NULL, "invariant");
+  ResourceMark rm(t);
+  HandleMark hm(t);
+  JfrThreadConstant type_thread(t);
+  JfrCheckpointWriter writer(t, true, THREADS);
+  writer.write_type(TYPE_THREAD);
+  type_thread.serialize(writer);
+  // create and install a checkpoint blob
+  t->jfr_thread_local()->set_thread_blob(writer.move());
+  assert(t->jfr_thread_local()->has_thread_blob(), "invariant");
+}
+
+void JfrTypeManager::write_thread_checkpoint(Thread* t) {
+  assert(t != NULL, "invariant");
+  ResourceMark rm(t);
+  HandleMark hm(t);
+  JfrThreadConstant type_thread(t);
+  JfrCheckpointWriter writer(t, true, THREADS);
+  writer.write_type(TYPE_THREAD);
+  type_thread.serialize(writer);
 }
 
 class SerializerRegistrationGuard : public StackObj {
@@ -115,7 +158,6 @@
 typedef JfrDoublyLinkedList<JfrSerializerRegistration> List;
 typedef StopOnNullIterator<const List> Iterator;
 static List types;
-static List safepoint_types;
 
 void JfrTypeManager::destroy() {
   SerializerRegistrationGuard guard;
@@ -126,52 +168,15 @@
     assert(registration != NULL, "invariant");
     delete registration;
   }
-  Iterator sp_type_iter(safepoint_types);
-  while (sp_type_iter.has_next()) {
-    registration = safepoint_types.remove(sp_type_iter.next());
-    assert(registration != NULL, "invariant");
-    delete registration;
-  }
 }
 
-void JfrTypeManager::write_types(JfrCheckpointWriter& writer) {
+void JfrTypeManager::on_rotation() {
   const Iterator iter(types);
   while (iter.has_next()) {
-    iter.next()->invoke(writer);
+    iter.next()->on_rotation();
   }
 }
 
-void JfrTypeManager::write_safepoint_types(JfrCheckpointWriter& writer) {
-  assert(SafepointSynchronize::is_at_safepoint(), "invariant");
-  const Iterator iter(safepoint_types);
-  while (iter.has_next()) {
-    iter.next()->invoke(writer);
-  }
-}
-
-void JfrTypeManager::create_thread_blob(JavaThread* jt) {
-  assert(jt != NULL, "invariant");
-  ResourceMark rm(jt);
-  HandleMark hm(jt);
-  JfrThreadConstant type_thread(jt);
-  JfrCheckpointWriter writer(false, true, jt);
-  writer.write_type(TYPE_THREAD);
-  type_thread.serialize(writer);
-  // create and install a checkpoint blob
-  jt->jfr_thread_local()->set_thread_blob(writer.move());
-  assert(jt->jfr_thread_local()->has_thread_blob(), "invariant");
-}
-
-void JfrTypeManager::write_thread_checkpoint(JavaThread* jt) {
-  assert(jt != NULL, "JavaThread is NULL!");
-  ResourceMark rm(jt);
-  HandleMark hm(jt);
-  JfrThreadConstant type_thread(jt);
-  JfrCheckpointWriter writer(false, true, jt);
-  writer.write_type(TYPE_THREAD);
-  type_thread.serialize(writer);
-}
-
 #ifdef ASSERT
 static void assert_not_registered_twice(JfrTypeId id, List& list) {
   const Iterator iter(list);
@@ -181,52 +186,65 @@
 }
 #endif
 
-static bool register_type(JfrTypeId id, bool require_safepoint, bool permit_cache, JfrSerializer* serializer) {
+static bool new_registration = false;
+
+static bool register_static_type(JfrTypeId id, bool permit_cache, JfrSerializer* serializer) {
   assert(serializer != NULL, "invariant");
   JfrSerializerRegistration* const registration = new JfrSerializerRegistration(id, permit_cache, serializer);
   if (registration == NULL) {
     delete serializer;
     return false;
   }
-  if (require_safepoint) {
-    assert(!safepoint_types.in_list(registration), "invariant");
-    DEBUG_ONLY(assert_not_registered_twice(id, safepoint_types);)
-    safepoint_types.prepend(registration);
-  } else {
-    assert(!types.in_list(registration), "invariant");
-    DEBUG_ONLY(assert_not_registered_twice(id, types);)
-    types.prepend(registration);
+  assert(!types.in_list(registration), "invariant");
+  DEBUG_ONLY(assert_not_registered_twice(id, types);)
+  if (JfrRecorder::is_recording()) {
+    JfrCheckpointWriter writer(STATICS);
+    registration->invoke(writer);
+    new_registration = true;
   }
+  types.prepend(registration);
   return true;
 }
 
 bool JfrTypeManager::initialize() {
   SerializerRegistrationGuard guard;
-
-  // register non-safepointing type serialization
-  register_type(TYPE_FLAGVALUEORIGIN, false, true, new FlagValueOriginConstant());
-  register_type(TYPE_INFLATECAUSE, false, true, new MonitorInflateCauseConstant());
-  register_type(TYPE_GCCAUSE, false, true, new GCCauseConstant());
-  register_type(TYPE_GCNAME, false, true, new GCNameConstant());
-  register_type(TYPE_GCWHEN, false, true, new GCWhenConstant());
-  register_type(TYPE_GCTHRESHOLDUPDATER, false, true, new GCThresholdUpdaterConstant());
-  register_type(TYPE_METADATATYPE, false, true, new MetadataTypeConstant());
-  register_type(TYPE_METASPACEOBJECTTYPE, false, true, new MetaspaceObjectTypeConstant());
-  register_type(TYPE_REFERENCETYPE, false, true, new ReferenceTypeConstant());
-  register_type(TYPE_NARROWOOPMODE, false, true, new NarrowOopModeConstant());
-  register_type(TYPE_COMPILERPHASETYPE, false, true, new CompilerPhaseTypeConstant());
-  register_type(TYPE_CODEBLOBTYPE, false, true, new CodeBlobTypeConstant());
-  register_type(TYPE_VMOPERATIONTYPE, false, true, new VMOperationTypeConstant());
-  register_type(TYPE_THREADSTATE, false, true, new ThreadStateConstant());
-
-  // register safepointing type serialization
-  register_type(TYPE_THREADGROUP, true, false, new JfrThreadGroupConstant());
-  register_type(TYPE_THREAD, true, false, new JfrThreadConstantSet());
+  register_static_type(TYPE_FLAGVALUEORIGIN, true, new FlagValueOriginConstant());
+  register_static_type(TYPE_INFLATECAUSE, true, new MonitorInflateCauseConstant());
+  register_static_type(TYPE_GCCAUSE, true, new GCCauseConstant());
+  register_static_type(TYPE_GCNAME, true, new GCNameConstant());
+  register_static_type(TYPE_GCWHEN, true, new GCWhenConstant());
+  register_static_type(TYPE_GCTHRESHOLDUPDATER, true, new GCThresholdUpdaterConstant());
+  register_static_type(TYPE_METADATATYPE, true, new MetadataTypeConstant());
+  register_static_type(TYPE_METASPACEOBJECTTYPE, true, new MetaspaceObjectTypeConstant());
+  register_static_type(TYPE_REFERENCETYPE, true, new ReferenceTypeConstant());
+  register_static_type(TYPE_NARROWOOPMODE, true, new NarrowOopModeConstant());
+  register_static_type(TYPE_COMPILERPHASETYPE, true, new CompilerPhaseTypeConstant());
+  register_static_type(TYPE_CODEBLOBTYPE, true, new CodeBlobTypeConstant());
+  register_static_type(TYPE_VMOPERATIONTYPE, true, new VMOperationTypeConstant());
+  register_static_type(TYPE_THREADSTATE, true, new ThreadStateConstant());
   return true;
 }
 
 // implementation for the static registration function exposed in the JfrSerializer api
-bool JfrSerializer::register_serializer(JfrTypeId id, bool require_safepoint, bool permit_cache, JfrSerializer* serializer) {
+bool JfrSerializer::register_serializer(JfrTypeId id, bool permit_cache, JfrSerializer* serializer) {
   SerializerRegistrationGuard guard;
-  return register_type(id, require_safepoint, permit_cache, serializer);
+  return register_static_type(id, permit_cache, serializer);
 }
+
+bool JfrTypeManager::has_new_static_type() {
+  if (new_registration) {
+    SerializerRegistrationGuard guard;
+    new_registration = false;
+    return true;
+  }
+  return false;
+}
+
+void JfrTypeManager::write_static_types(JfrCheckpointWriter& writer) {
+  SerializerRegistrationGuard guard;
+  const Iterator iter(types);
+  while (iter.has_next()) {
+    iter.next()->invoke(writer);
+  }
+  new_registration = false;
+}
--- a/src/hotspot/share/jfr/recorder/checkpoint/types/jfrTypeManager.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/types/jfrTypeManager.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -33,10 +33,12 @@
  public:
   static bool initialize();
   static void destroy();
-  static void write_types(JfrCheckpointWriter& writer);
-  static void write_safepoint_types(JfrCheckpointWriter& writer);
-  static void create_thread_blob(JavaThread* jt);
-  static void write_thread_checkpoint(JavaThread* jt);
+  static void on_rotation();
+  static void write_threads(JfrCheckpointWriter& writer);
+  static void create_thread_blob(Thread* t);
+  static void write_thread_checkpoint(Thread* t);
+  static bool has_new_static_type();
+  static void write_static_types(JfrCheckpointWriter& writer);
 };
 
 #endif // SHARE_JFR_RECORDER_CHECKPOINT_TYPES_JFRTYPEMANAGER_HPP
--- a/src/hotspot/share/jfr/recorder/checkpoint/types/jfrTypeSet.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/types/jfrTypeSet.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -73,7 +73,7 @@
 }
 
 static bool current_epoch() {
-  return _class_unload;
+  return _class_unload || _flushpoint;
 }
 
 static bool previous_epoch() {
@@ -246,7 +246,7 @@
 static void do_klass(Klass* klass) {
   assert(klass != NULL, "invariant");
   assert(_subsystem_callback != NULL, "invariant");
-  if (current_epoch()) {
+  if (_flushpoint) {
     if (USED_THIS_EPOCH(klass)) {
       _subsystem_callback->do_artifact(klass);
       return;
@@ -911,10 +911,11 @@
   return total_count;
 }
 
-static void setup(JfrCheckpointWriter* writer, JfrCheckpointWriter* leakp_writer, bool class_unload) {
+static void setup(JfrCheckpointWriter* writer, JfrCheckpointWriter* leakp_writer, bool class_unload, bool flushpoint) {
   _writer = writer;
   _leakp_writer = leakp_writer;
   _class_unload = class_unload;
+  _flushpoint = flushpoint;
   if (_artifacts == NULL) {
     _artifacts = new JfrArtifactSet(class_unload);
   } else {
@@ -928,10 +929,10 @@
 /**
  * Write all "tagged" (in-use) constant artifacts and their dependencies.
  */
-size_t JfrTypeSet::serialize(JfrCheckpointWriter* writer, JfrCheckpointWriter* leakp_writer, bool class_unload) {
+size_t JfrTypeSet::serialize(JfrCheckpointWriter* writer, JfrCheckpointWriter* leakp_writer, bool class_unload, bool flushpoint) {
   assert(writer != NULL, "invariant");
   ResourceMark rm;
-  setup(writer, leakp_writer, class_unload);
+  setup(writer, leakp_writer, class_unload, flushpoint);
   // write order is important because an individual write step
   // might tag an artifact to be written in a subsequent step
   if (!write_klasses()) {
--- a/src/hotspot/share/jfr/recorder/checkpoint/types/jfrTypeSet.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/types/jfrTypeSet.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -32,7 +32,7 @@
 class JfrTypeSet : AllStatic {
  public:
   static void clear();
-  static size_t serialize(JfrCheckpointWriter* writer, JfrCheckpointWriter* leakp_writer, bool class_unload);
+  static size_t serialize(JfrCheckpointWriter* writer, JfrCheckpointWriter* leakp_writer, bool class_unload, bool flushpoint);
 };
 
 #endif // SHARE_JFR_RECORDER_CHECKPOINT_TYPES_JFRTYPESET_HPP
--- a/src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceId.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceId.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -33,7 +33,6 @@
 #include "oops/method.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/atomic.hpp"
-#include "runtime/orderAccess.hpp"
 #include "runtime/vm_version.hpp"
 #include "runtime/jniHandles.inline.hpp"
 #include "runtime/thread.inline.hpp"
@@ -45,7 +44,7 @@
   traceid compare_value;
   traceid exchange_value;
   do {
-    compare_value = OrderAccess::load_acquire(dest);
+    compare_value = *dest;
     exchange_value = compare_value + 1;
   } while (Atomic::cmpxchg(exchange_value, dest, compare_value) != compare_value);
   return exchange_value;
--- a/src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceId.inline.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceId.inline.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -31,7 +31,6 @@
 #include "jfr/recorder/checkpoint/types/traceid/jfrTraceId.hpp"
 #include "jfr/recorder/checkpoint/types/traceid/jfrTraceIdBits.inline.hpp"
 #include "jfr/recorder/checkpoint/types/traceid/jfrTraceIdEpoch.hpp"
-#include "jfr/recorder/checkpoint/types/traceid/jfrTraceIdMacros.hpp"
 #include "jfr/support/jfrKlassExtension.hpp"
 #include "oops/arrayKlass.hpp"
 #include "oops/klass.hpp"
@@ -60,7 +59,14 @@
 
 inline traceid JfrTraceId::use(const Klass* klass) {
   assert(klass != NULL, "invariant");
-  return set_used_and_get(klass);
+  if (SHOULD_TAG(klass)) {
+    SET_USED_THIS_EPOCH(klass);
+    assert(USED_THIS_EPOCH(klass), "invariant");
+    JfrTraceIdEpoch::set_changed_tag_state();
+    return get(klass);
+  }
+  assert(USED_THIS_EPOCH(klass), "invariant");
+  return TRACE_ID(klass);
 }
 
 inline traceid JfrTraceId::use(const Method* method) {
@@ -71,10 +77,16 @@
 inline traceid JfrTraceId::use(const Klass* klass, const Method* method) {
   assert(klass != NULL, "invariant");
   assert(method != NULL, "invariant");
-  SET_METHOD_FLAG_USED_THIS_EPOCH(method);
-
-  SET_METHOD_AND_CLASS_USED_THIS_EPOCH(klass);
+  if (SHOULD_TAG_KLASS_METHOD(klass)) {
+    SET_METHOD_AND_CLASS_USED_THIS_EPOCH(klass);
+  }
   assert(METHOD_AND_CLASS_USED_THIS_EPOCH(klass), "invariant");
+  if (METHOD_FLAG_NOT_USED_THIS_EPOCH(method)) {
+    assert(USED_THIS_EPOCH(klass), "invariant");
+    SET_METHOD_FLAG_USED_THIS_EPOCH(method);
+    JfrTraceIdEpoch::set_changed_tag_state();
+  }
+  assert(METHOD_FLAG_USED_THIS_EPOCH(method), "invariant");
   return (METHOD_ID(klass, method));
 }
 
--- a/src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceIdEpoch.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceIdEpoch.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,15 +25,13 @@
 #include "precompiled.hpp"
 #include "jfr/recorder/checkpoint/types/traceid/jfrTraceIdEpoch.hpp"
 #include "runtime/safepoint.hpp"
-#include "runtime/orderAccess.hpp"
 
 // Alternating epochs on each rotation allow for concurrent tagging.
-// The regular epoch shift happens only during a safepoint.
-// The fence is there only for the emergency dump case which happens outside of safepoint.
+// The epoch shift happens only during a safepoint.
 bool JfrTraceIdEpoch::_epoch_state = false;
+bool volatile JfrTraceIdEpoch::_tag_state = false;
+
 void JfrTraceIdEpoch::shift_epoch() {
+  assert(SafepointSynchronize::is_at_safepoint(), "invariant");
   _epoch_state = !_epoch_state;
-  if (!SafepointSynchronize::is_at_safepoint()) {
-    OrderAccess::fence();
-  }
 }
--- a/src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceIdEpoch.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/checkpoint/types/traceid/jfrTraceIdEpoch.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -25,18 +25,19 @@
 #ifndef SHARE_JFR_RECORDER_CHECKPOINT_TYPES_TRACEID_JFRTRACEIDEPOCH_HPP
 #define SHARE_JFR_RECORDER_CHECKPOINT_TYPES_TRACEID_JFRTRACEIDEPOCH_HPP
 
+#include "jfr/utilities/jfrTypes.hpp"
 #include "memory/allocation.hpp"
-#include "jfr/utilities/jfrTypes.hpp"
+#include "runtime/orderAccess.hpp"
 
-#define USED_BIT 1
-#define METHOD_USED_BIT (USED_BIT << 2)
-#define EPOCH_1_SHIFT 0
-#define EPOCH_2_SHIFT 1
-#define USED_EPOCH_1_BIT (USED_BIT << EPOCH_1_SHIFT)
-#define USED_EPOCH_2_BIT (USED_BIT << EPOCH_2_SHIFT)
-#define METHOD_USED_EPOCH_1_BIT (METHOD_USED_BIT << EPOCH_1_SHIFT)
-#define METHOD_USED_EPOCH_2_BIT (METHOD_USED_BIT << EPOCH_2_SHIFT)
-#define METHOD_AND_CLASS_IN_USE_BITS (METHOD_USED_BIT | USED_BIT)
+#define USED_BIT                             1
+#define METHOD_USED_BIT                      (USED_BIT << 2)
+#define EPOCH_1_SHIFT                        0
+#define EPOCH_2_SHIFT                        1
+#define USED_EPOCH_1_BIT                     (USED_BIT << EPOCH_1_SHIFT)
+#define USED_EPOCH_2_BIT                     (USED_BIT << EPOCH_2_SHIFT)
+#define METHOD_USED_EPOCH_1_BIT              (METHOD_USED_BIT << EPOCH_1_SHIFT)
+#define METHOD_USED_EPOCH_2_BIT              (METHOD_USED_BIT << EPOCH_2_SHIFT)
+#define METHOD_AND_CLASS_IN_USE_BITS         (METHOD_USED_BIT | USED_BIT)
 #define METHOD_AND_CLASS_IN_USE_EPOCH_1_BITS (METHOD_AND_CLASS_IN_USE_BITS << EPOCH_1_SHIFT)
 #define METHOD_AND_CLASS_IN_USE_EPOCH_2_BITS (METHOD_AND_CLASS_IN_USE_BITS << EPOCH_2_SHIFT)
 
@@ -44,6 +45,8 @@
   friend class JfrCheckpointManager;
  private:
   static bool _epoch_state;
+  static bool volatile _tag_state;
+
   static void shift_epoch();
 
  public:
@@ -86,6 +89,20 @@
   static traceid method_and_class_in_use_prev_epoch_bits() {
     return _epoch_state ? METHOD_AND_CLASS_IN_USE_EPOCH_1_BITS :  METHOD_AND_CLASS_IN_USE_EPOCH_2_BITS;
   }
+
+  static bool has_changed_tag_state() {
+    if (OrderAccess::load_acquire(&_tag_state)) {
+      OrderAccess::release_store(&_tag_state, false);
+      return true;
+    }
+    return false;
+  }
+
+  static void set_changed_tag_state() {
+    if (!OrderAccess::load_acquire(&_tag_state)) {
+      OrderAccess::release_store(&_tag_state, true);
+    }
+  }
 };
 
 #endif // SHARE_JFR_RECORDER_CHECKPOINT_TYPES_TRACEID_JFRTRACEIDEPOCH_HPP
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/jfr/recorder/repository/jfrChunk.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -0,0 +1,226 @@
+/*
+ * Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "jfr/recorder/repository/jfrChunk.hpp"
+#include "jfr/recorder/service/jfrOptionSet.hpp"
+#include "jfr/utilities/jfrTime.hpp"
+#include "jfr/utilities/jfrTimeConverter.hpp"
+#include "jfr/utilities/jfrTypes.hpp"
+#include "runtime/os.inline.hpp"
+
+static const char* const MAGIC = "FLR";
+static const u2 JFR_VERSION_MAJOR = 2;
+static const u2 JFR_VERSION_MINOR = 1;
+
+// strictly monotone
+static jlong nanos_now() {
+  static jlong last = 0;
+  const jlong now = os::javaTimeMillis() * JfrTimeConverter::NANOS_PER_MILLISEC;
+  if (now > last) {
+    last = now;
+  } else {
+    ++last;
+  }
+  return last;
+}
+
+static jlong ticks_now() {
+  return JfrTicks::now();
+}
+
+JfrChunk::JfrChunk() :
+  _path(NULL),
+  _start_ticks(0),
+  _previous_start_ticks(invalid_time),
+  _start_nanos(0),
+  _previous_start_nanos(invalid_time),
+  _last_update_nanos(0),
+  _last_checkpoint_offset(0),
+  _last_metadata_offset(0),
+  _generation(1) {}
+
+JfrChunk::~JfrChunk() {
+  reset();
+}
+
+void JfrChunk::reset() {
+  if (_path != NULL) {
+    JfrCHeapObj::free(_path, strlen(_path) + 1);
+    _path = NULL;
+  }
+  _last_checkpoint_offset = _last_metadata_offset = 0;
+  _generation = 1;
+}
+
+const char* JfrChunk::magic() const {
+  return MAGIC;
+}
+
+u2 JfrChunk::major_version() const {
+  return JFR_VERSION_MAJOR;
+}
+
+u2 JfrChunk::minor_version() const {
+  return JFR_VERSION_MINOR;
+}
+
+u2 JfrChunk::capabilities() const {
+  // chunk capabilities, CompressedIntegers etc
+  static bool compressed_integers = JfrOptionSet::compressed_integers();
+  return compressed_integers;
+}
+
+int64_t JfrChunk::cpu_frequency() const {
+  static const jlong frequency = JfrTime::frequency();
+  return frequency;
+}
+
+void JfrChunk::set_last_checkpoint_offset(int64_t offset) {
+  _last_checkpoint_offset = offset;
+}
+
+int64_t JfrChunk::last_checkpoint_offset() const {
+  return _last_checkpoint_offset;
+}
+
+int64_t JfrChunk::start_ticks() const {
+  assert(_start_ticks != 0, "invariant");
+  return _start_ticks;
+}
+
+int64_t JfrChunk::start_nanos() const {
+  assert(_start_nanos != 0, "invariant");
+  return _start_nanos;
+}
+
+int64_t JfrChunk::previous_start_ticks() const {
+  assert(_previous_start_ticks != invalid_time, "invariant");
+  return _previous_start_ticks;
+}
+
+int64_t JfrChunk::previous_start_nanos() const {
+  assert(_previous_start_nanos != invalid_time, "invariant");
+  return _previous_start_nanos;
+}
+
+void JfrChunk::update_start_ticks() {
+  _start_ticks = ticks_now();
+}
+
+void JfrChunk::update_start_nanos() {
+  const jlong now = nanos_now();
+  assert(now > _start_nanos, "invariant");
+  assert(now > _last_update_nanos, "invariant");
+  _start_nanos = _last_update_nanos = now;
+}
+
+void JfrChunk::update_current_nanos() {
+  const jlong now = nanos_now();
+  assert(now > _last_update_nanos, "invariant");
+  _last_update_nanos = now;
+}
+
+void JfrChunk::save_current_and_update_start_ticks() {
+  _previous_start_ticks = _start_ticks;
+  update_start_ticks();
+}
+
+void JfrChunk::save_current_and_update_start_nanos() {
+  _previous_start_nanos = _start_nanos;
+  update_start_nanos();
+}
+
+void JfrChunk::set_time_stamp() {
+  save_current_and_update_start_nanos();
+  save_current_and_update_start_ticks();
+}
+
+int64_t JfrChunk::last_chunk_duration() const {
+  assert(_previous_start_nanos != invalid_time, "invariant");
+  return _start_nanos - _previous_start_nanos;
+}
+
+static char* copy_path(const char* path) {
+  assert(path != NULL, "invariant");
+  const size_t path_len = strlen(path);
+  char* new_path = JfrCHeapObj::new_array<char>(path_len + 1);
+  strncpy(new_path, path, path_len + 1);
+  return new_path;
+}
+
+void JfrChunk::set_path(const char* path) {
+  if (_path != NULL) {
+    JfrCHeapObj::free(_path, strlen(_path) + 1);
+    _path = NULL;
+  }
+  if (path != NULL) {
+    _path = copy_path(path);
+  }
+}
+
+const char* JfrChunk::path() const {
+  return _path;
+}
+
+bool JfrChunk::is_started() const {
+  return _start_nanos != 0;
+}
+
+bool JfrChunk::is_finished() const {
+  return 0 == _generation;
+}
+
+int64_t JfrChunk::duration() const {
+  assert(_last_update_nanos >= _start_nanos, "invariant");
+  return _last_update_nanos - _start_nanos;
+}
+
+int64_t JfrChunk::last_metadata_offset() const {
+  return _last_metadata_offset;
+}
+
+void JfrChunk::set_last_metadata_offset(int64_t offset) {
+  assert(offset > _last_metadata_offset, "invariant");
+  _last_metadata_offset = offset;
+}
+
+bool JfrChunk::has_metadata() const {
+  return 0 != _last_metadata_offset;
+}
+
+u1 JfrChunk::generation() const {
+  assert(_generation > 0, "invariant");
+  const u1 this_generation = _generation++;
+  if (GUARD == _generation) {
+    _generation = 1;
+  }
+  return this_generation;
+}
+
+u1 JfrChunk::next_generation() const {
+  assert(_generation > 0, "invariant");
+  const u1 next_gen = _generation;
+  return GUARD == next_gen ? 1 : next_gen;
+}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/jfr/recorder/repository/jfrChunk.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_JFR_RECORDER_REPOSITORY_JFRRCHUNK_HPP
+#define SHARE_VM_JFR_RECORDER_REPOSITORY_JFRRCHUNK_HPP
+
+#include "jfr/utilities/jfrAllocation.hpp"
+
+const u1 COMPLETE = 0;
+const u1 GUARD = 0xff;
+const u1 PAD = 0;
+
+class JfrChunk : public JfrCHeapObj {
+  friend class JfrChunkWriter;
+  friend class JfrChunkHeadWriter;
+ private:
+  char* _path;
+  int64_t _start_ticks;
+  int64_t _previous_start_ticks;
+  int64_t _start_nanos;
+  int64_t _previous_start_nanos;
+  int64_t _last_update_nanos;
+  int64_t _last_checkpoint_offset;
+  int64_t _last_metadata_offset;
+  mutable u1 _generation;
+
+  JfrChunk();
+  ~JfrChunk();
+  void reset();
+
+  const char* magic() const;
+  u2 major_version() const;
+  u2 minor_version() const;
+  int64_t cpu_frequency() const;
+  u2 capabilities() const;
+
+  void update_start_ticks();
+  void update_start_nanos();
+  void save_current_and_update_start_ticks();
+  void save_current_and_update_start_nanos();
+
+  int64_t last_checkpoint_offset() const;
+  void set_last_checkpoint_offset(int64_t offset);
+
+  int64_t last_metadata_offset() const;
+  void set_last_metadata_offset(int64_t offset);
+  bool has_metadata() const;
+
+  int64_t start_ticks() const;
+  int64_t start_nanos() const;
+
+  int64_t previous_start_ticks() const;
+  int64_t previous_start_nanos() const;
+  int64_t last_chunk_duration() const;
+
+  void set_time_stamp();
+  void update_current_nanos();
+
+  void set_path(const char* path);
+  const char* path() const;
+
+  bool is_started() const;
+  bool is_finished() const;
+
+  int64_t duration() const;
+  u1 generation() const;
+  u1 next_generation() const;
+};
+
+#endif // SHARE_VM_JFR_RECORDER_REPOSITORY_JFRRCHUNK_HPP
--- a/src/hotspot/share/jfr/recorder/repository/jfrChunkState.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,120 +0,0 @@
-/*
- * Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-
-#include "precompiled.hpp"
-#include "jfr/dcmd/jfrDcmds.hpp"
-#include "jfr/recorder/jfrRecorder.hpp"
-#include "jfr/recorder/repository/jfrChunkState.hpp"
-#include "jfr/recorder/repository/jfrChunkWriter.hpp"
-#include "jfr/utilities/jfrTime.hpp"
-#include "jfr/utilities/jfrTimeConverter.hpp"
-#include "logging/log.hpp"
-#include "runtime/os.inline.hpp"
-#include "runtime/thread.inline.hpp"
-
-JfrChunkState::JfrChunkState() :
-  _path(NULL),
-  _start_ticks(0),
-  _start_nanos(0),
-  _previous_start_ticks(0),
-  _previous_start_nanos(0),
-  _last_checkpoint_offset(0) {}
-
-JfrChunkState::~JfrChunkState() {
-  reset();
-}
-
-void JfrChunkState::reset() {
-  if (_path != NULL) {
-    JfrCHeapObj::free(_path, strlen(_path) + 1);
-    _path = NULL;
-  }
-  set_last_checkpoint_offset(0);
-}
-
-void JfrChunkState::set_last_checkpoint_offset(int64_t offset) {
-  _last_checkpoint_offset = offset;
-}
-
-int64_t JfrChunkState::last_checkpoint_offset() const {
-  return _last_checkpoint_offset;
-}
-
-int64_t JfrChunkState::previous_start_ticks() const {
-  return _previous_start_ticks;
-}
-
-int64_t JfrChunkState::previous_start_nanos() const {
-  return _previous_start_nanos;
-}
-
-void JfrChunkState::update_start_ticks() {
-  _start_ticks = JfrTicks::now();
-}
-
-void JfrChunkState::update_start_nanos() {
-  _start_nanos = os::javaTimeMillis() * JfrTimeConverter::NANOS_PER_MILLISEC;
-}
-
-void JfrChunkState::save_current_and_update_start_ticks() {
-  _previous_start_ticks = _start_ticks;
-  update_start_ticks();
-}
-
-void JfrChunkState::save_current_and_update_start_nanos() {
-  _previous_start_nanos = _start_nanos;
-  update_start_nanos();
-}
-
-void JfrChunkState::update_time_to_now() {
-  save_current_and_update_start_nanos();
-  save_current_and_update_start_ticks();
-}
-
-int64_t JfrChunkState::last_chunk_duration() const {
-  return _start_nanos - _previous_start_nanos;
-}
-
-static char* copy_path(const char* path) {
-  assert(path != NULL, "invariant");
-  const size_t path_len = strlen(path);
-  char* new_path = JfrCHeapObj::new_array<char>(path_len + 1);
-  strncpy(new_path, path, path_len + 1);
-  return new_path;
-}
-
-void JfrChunkState::set_path(const char* path) {
-  assert(JfrStream_lock->owned_by_self(), "invariant");
-  if (_path != NULL) {
-    JfrCHeapObj::free(_path, strlen(_path) + 1);
-    _path = NULL;
-  }
-  if (path != NULL) {
-    _path = copy_path(path);
-  }
-}
-
-const char* JfrChunkState::path() const {
-  return _path;
-}
--- a/src/hotspot/share/jfr/recorder/repository/jfrChunkState.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,59 +0,0 @@
-/*
- * Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-
-#ifndef SHARE_JFR_RECORDER_REPOSITORY_JFRCHUNKSTATE_HPP
-#define SHARE_JFR_RECORDER_REPOSITORY_JFRCHUNKSTATE_HPP
-
-#include "jfr/utilities/jfrAllocation.hpp"
-#include "jfr/utilities/jfrTypes.hpp"
-
-class JfrChunkState : public JfrCHeapObj {
-  friend class JfrChunkWriter;
- private:
-  char* _path;
-  int64_t _start_ticks;
-  int64_t _start_nanos;
-  int64_t _previous_start_ticks;
-  int64_t _previous_start_nanos;
-  int64_t _last_checkpoint_offset;
-
-  void update_start_ticks();
-  void update_start_nanos();
-  void save_current_and_update_start_ticks();
-  void save_current_and_update_start_nanos();
-
-  JfrChunkState();
-  ~JfrChunkState();
-  void reset();
-  int64_t last_checkpoint_offset() const;
-  void set_last_checkpoint_offset(int64_t offset);
-  int64_t previous_start_ticks() const;
-  int64_t previous_start_nanos() const;
-  int64_t last_chunk_duration() const;
-  void update_time_to_now();
-  void set_path(const char* path);
-  const char* path() const;
-};
-
-#endif // SHARE_JFR_RECORDER_REPOSITORY_JFRCHUNKSTATE_HPP
--- a/src/hotspot/share/jfr/recorder/repository/jfrChunkWriter.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/repository/jfrChunkWriter.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -23,82 +23,218 @@
  */
 
 #include "precompiled.hpp"
-#include "jfr/recorder/repository/jfrChunkState.hpp"
+#include "jfr/recorder/repository/jfrChunk.hpp"
 #include "jfr/recorder/repository/jfrChunkWriter.hpp"
-#include "jfr/recorder/service/jfrOptionSet.hpp"
 #include "jfr/utilities/jfrTime.hpp"
-#include "jfr/utilities/jfrTypes.hpp"
 #include "runtime/mutexLocker.hpp"
-#include "runtime/os.hpp"
 #include "runtime/os.inline.hpp"
 
-static const u2 JFR_VERSION_MAJOR = 2;
-static const u2 JFR_VERSION_MINOR = 0;
-static const size_t MAGIC_LEN = 4;
-static const size_t FILEHEADER_SLOT_SIZE = 8;
-static const size_t CHUNK_SIZE_OFFSET = 8;
-
-JfrChunkWriter::JfrChunkWriter() : JfrChunkWriterBase(NULL), _chunkstate(NULL) {}
-
-bool JfrChunkWriter::initialize() {
-  assert(_chunkstate == NULL, "invariant");
-  _chunkstate = new JfrChunkState();
-  return _chunkstate != NULL;
-}
+static const int64_t MAGIC_OFFSET = 0;
+static const int64_t MAGIC_LEN = 4;
+static const int64_t VERSION_OFFSET = MAGIC_LEN;
+static const int64_t SIZE_OFFSET = 8;
+static const int64_t SLOT_SIZE = 8;
+static const int64_t CHECKPOINT_OFFSET = SIZE_OFFSET + SLOT_SIZE;
+static const int64_t METADATA_OFFSET = CHECKPOINT_OFFSET + SLOT_SIZE;
+static const int64_t START_NANOS_OFFSET = METADATA_OFFSET + SLOT_SIZE;
+static const int64_t DURATION_NANOS_OFFSET = START_NANOS_OFFSET + SLOT_SIZE;
+static const int64_t START_TICKS_OFFSET = DURATION_NANOS_OFFSET + SLOT_SIZE;
+static const int64_t CPU_FREQUENCY_OFFSET = START_TICKS_OFFSET + SLOT_SIZE;
+static const int64_t GENERATION_OFFSET = CPU_FREQUENCY_OFFSET + SLOT_SIZE;
+static const int64_t CAPABILITY_OFFSET = GENERATION_OFFSET + 2;
+static const int64_t HEADER_SIZE = CAPABILITY_OFFSET + 2;
 
 static fio_fd open_chunk(const char* path) {
-  assert(JfrStream_lock->owned_by_self(), "invariant");
   return path != NULL ? os::open(path, O_CREAT | O_RDWR, S_IREAD | S_IWRITE) : invalid_fd;
 }
 
-bool JfrChunkWriter::open() {
-  assert(_chunkstate != NULL, "invariant");
-  JfrChunkWriterBase::reset(open_chunk(_chunkstate->path()));
-  const bool is_open = this->has_valid_fd();
-  if (is_open) {
-    this->bytes("FLR", MAGIC_LEN);
-    this->be_write((u2)JFR_VERSION_MAJOR);
-    this->be_write((u2)JFR_VERSION_MINOR);
-    this->reserve(6 * FILEHEADER_SLOT_SIZE);
-    // u8 chunk_size
-    // u8 initial checkpoint offset
-    // u8 metadata section offset
-    // u8 chunk start nanos
-    // u8 chunk duration nanos
-    // u8 chunk start ticks
-    this->be_write(JfrTime::frequency());
-    // chunk capabilities, CompressedIntegers etc
-    this->be_write((u4)JfrOptionSet::compressed_integers() ? 1 : 0);
-    _chunkstate->reset();
+#ifdef ASSERT
+static void assert_writer_position(JfrChunkWriter* writer, int64_t offset) {
+  assert(writer != NULL, "invariant");
+  assert(offset == writer->current_offset(), "invariant");
+}
+#endif
+
+class JfrChunkHeadWriter : public StackObj {
+ private:
+  JfrChunkWriter* _writer;
+  JfrChunk* _chunk;
+ public:
+  void write_magic() {
+    _writer->bytes(_chunk->magic(), MAGIC_LEN);
   }
-  return is_open;
+
+  void write_version() {
+    _writer->be_write(_chunk->major_version());
+    _writer->be_write(_chunk->minor_version());
+  }
+
+  void write_size(int64_t size) {
+    _writer->be_write(size);
+  }
+
+  void write_checkpoint() {
+    _writer->be_write(_chunk->last_checkpoint_offset());
+  }
+
+  void write_metadata() {
+    _writer->be_write(_chunk->last_metadata_offset());
+  }
+
+  void write_time(bool finalize) {
+    if (finalize) {
+      _writer->be_write(_chunk->previous_start_nanos());
+      _writer->be_write(_chunk->last_chunk_duration());
+      _writer->be_write(_chunk->previous_start_ticks());
+      return;
+    }
+    _writer->be_write(_chunk->start_nanos());
+    _writer->be_write(_chunk->duration());
+    _writer->be_write(_chunk->start_ticks());
+  }
+
+  void write_cpu_frequency() {
+    _writer->be_write(_chunk->cpu_frequency());
+  }
+
+  void write_generation(bool finalize) {
+    _writer->be_write(finalize ? COMPLETE : _chunk->generation());
+    _writer->be_write(PAD);
+  }
+
+  void write_next_generation() {
+    _writer->be_write(_chunk->next_generation());
+    _writer->be_write(PAD);
+  }
+
+  void write_guard() {
+    _writer->be_write(GUARD);
+    _writer->be_write(PAD);
+  }
+
+  void write_guard_flush() {
+    write_guard();
+    _writer->flush();
+  }
+
+  void write_capabilities() {
+    _writer->be_write(_chunk->capabilities());
+  }
+
+  void write_size_to_generation(int64_t size, bool finalize) {
+    write_size(size);
+    write_checkpoint();
+    write_metadata();
+    write_time(finalize);
+    write_cpu_frequency();
+    write_generation(finalize);
+  }
+
+  void flush(int64_t size, bool finalize) {
+    assert(_writer->is_valid(), "invariant");
+    assert(_chunk != NULL, "invariant");
+    DEBUG_ONLY(assert_writer_position(_writer, SIZE_OFFSET);)
+    write_size_to_generation(size, finalize);
+    // no need to write capabilities
+    _writer->seek(size); // implicit flush
+  }
+
+  void initialize() {
+    assert(_writer->is_valid(), "invariant");
+    assert(_chunk != NULL, "invariant");
+    DEBUG_ONLY(assert_writer_position(_writer, 0);)
+    write_magic();
+    write_version();
+    write_size_to_generation(HEADER_SIZE, false);
+    write_capabilities();
+    DEBUG_ONLY(assert_writer_position(_writer, HEADER_SIZE);)
+    _writer->flush();
+  }
+
+  JfrChunkHeadWriter(JfrChunkWriter* writer, int64_t offset, bool guard = true) : _writer(writer), _chunk(writer->_chunk) {
+    assert(_writer != NULL, "invariant");
+    assert(_writer->is_valid(), "invariant");
+    assert(_chunk != NULL, "invariant");
+    if (0 == _writer->current_offset()) {
+      assert(HEADER_SIZE == offset, "invariant");
+      initialize();
+    } else {
+      if (guard) {
+        _writer->seek(GENERATION_OFFSET);
+        write_guard();
+        _writer->seek(offset);
+      } else {
+        _chunk->update_current_nanos();
+      }
+    }
+    DEBUG_ONLY(assert_writer_position(_writer, offset);)
+  }
+};
+
+static int64_t prepare_chunk_header_constant_pool(JfrChunkWriter& cw, int64_t event_offset, bool flushpoint) {
+  const int64_t delta = cw.last_checkpoint_offset() == 0 ? 0 : cw.last_checkpoint_offset() - event_offset;
+  const u4 checkpoint_type = flushpoint ? (u4)(FLUSH | HEADER) : (u4)HEADER;
+  cw.reserve(sizeof(u4));
+  cw.write<u8>(EVENT_CHECKPOINT);
+  cw.write<u8>(JfrTicks::now().value());
+  cw.write<u8>(0); // duration
+  cw.write<u8>(delta); // to previous checkpoint
+  cw.write<u4>(checkpoint_type);
+  cw.write<u4>(1); // pool count
+  cw.write<u8>(TYPE_CHUNKHEADER);
+  cw.write<u4>(1); // count
+  cw.write<u8>(1); // key
+  cw.write<u4>(HEADER_SIZE); // length of byte array
+  return cw.current_offset();
 }
 
-size_t JfrChunkWriter::close(int64_t metadata_offset) {
-  write_header(metadata_offset);
-  this->flush();
-  this->close_fd();
-  return (size_t)size_written();
+int64_t JfrChunkWriter::write_chunk_header_checkpoint(bool flushpoint) {
+  assert(this->has_valid_fd(), "invariant");
+  const int64_t event_size_offset = current_offset();
+  const int64_t header_content_pos = prepare_chunk_header_constant_pool(*this, event_size_offset, flushpoint);
+  JfrChunkHeadWriter head(this, header_content_pos, false);
+  head.write_magic();
+  head.write_version();
+  const int64_t chunk_size_offset = reserve(sizeof(int64_t)); // size to be decided when we are done
+  be_write(event_size_offset); // last checkpoint offset will be this checkpoint
+  head.write_metadata();
+  head.write_time(false);
+  head.write_cpu_frequency();
+  head.write_next_generation();
+  head.write_capabilities();
+  assert(current_offset() - header_content_pos == HEADER_SIZE, "invariant");
+  const u4 checkpoint_size = current_offset() - event_size_offset;
+  write_padded_at_offset<u4>(checkpoint_size, event_size_offset);
+  set_last_checkpoint_offset(event_size_offset);
+  const size_t sz_written = size_written();
+  write_be_at_offset(sz_written, chunk_size_offset);
+  return sz_written;
 }
 
-void JfrChunkWriter::write_header(int64_t metadata_offset) {
-  assert(this->is_valid(), "invariant");
-  // Chunk size
-  this->write_be_at_offset(size_written(), CHUNK_SIZE_OFFSET);
-  // initial checkpoint event offset
-  this->write_be_at_offset(_chunkstate->last_checkpoint_offset(), CHUNK_SIZE_OFFSET + (1 * FILEHEADER_SLOT_SIZE));
-  // metadata event offset
-  this->write_be_at_offset(metadata_offset, CHUNK_SIZE_OFFSET + (2 * FILEHEADER_SLOT_SIZE));
-  // start of chunk in nanos since epoch
-  this->write_be_at_offset(_chunkstate->previous_start_nanos(), CHUNK_SIZE_OFFSET + (3 * FILEHEADER_SLOT_SIZE));
-  // duration of chunk in nanos
-  this->write_be_at_offset(_chunkstate->last_chunk_duration(), CHUNK_SIZE_OFFSET + (4 * FILEHEADER_SLOT_SIZE));
-  // start of chunk in ticks
-  this->write_be_at_offset(_chunkstate->previous_start_ticks(), CHUNK_SIZE_OFFSET + (5 * FILEHEADER_SLOT_SIZE));
+int64_t JfrChunkWriter::flush_chunk(bool flushpoint) {
+  assert(_chunk != NULL, "invariant");
+  const int64_t sz_written = write_chunk_header_checkpoint(flushpoint);
+  assert(size_written() == sz_written, "invariant");
+  JfrChunkHeadWriter head(this, SIZE_OFFSET);
+  head.flush(sz_written, !flushpoint);
+  return sz_written;
 }
 
-void JfrChunkWriter::set_chunk_path(const char* chunk_path) {
-  _chunkstate->set_path(chunk_path);
+JfrChunkWriter::JfrChunkWriter() : JfrChunkWriterBase(NULL), _chunk(new JfrChunk()) {}
+
+JfrChunkWriter::~JfrChunkWriter() {
+  assert(_chunk != NULL, "invariant");
+  delete _chunk;
+}
+
+void JfrChunkWriter::set_path(const char* path) {
+  assert(_chunk != NULL, "invariant");
+  _chunk->set_path(path);
+}
+
+void JfrChunkWriter::set_time_stamp() {
+  assert(_chunk != NULL, "invariant");
+  _chunk->set_time_stamp();
 }
 
 int64_t JfrChunkWriter::size_written() const {
@@ -106,13 +242,46 @@
 }
 
 int64_t JfrChunkWriter::last_checkpoint_offset() const {
-  return _chunkstate->last_checkpoint_offset();
+  assert(_chunk != NULL, "invariant");
+  return _chunk->last_checkpoint_offset();
+}
+
+int64_t JfrChunkWriter::current_chunk_start_nanos() const {
+  assert(_chunk != NULL, "invariant");
+  return this->is_valid() ? _chunk->start_nanos() : invalid_time;
 }
 
 void JfrChunkWriter::set_last_checkpoint_offset(int64_t offset) {
-  _chunkstate->set_last_checkpoint_offset(offset);
+  assert(_chunk != NULL, "invariant");
+  _chunk->set_last_checkpoint_offset(offset);
 }
 
-void JfrChunkWriter::time_stamp_chunk_now() {
-  _chunkstate->update_time_to_now();
+void JfrChunkWriter::set_last_metadata_offset(int64_t offset) {
+  assert(_chunk != NULL, "invariant");
+  _chunk->set_last_metadata_offset(offset);
 }
+
+bool JfrChunkWriter::has_metadata() const {
+  assert(_chunk != NULL, "invariant");
+  return _chunk->has_metadata();
+}
+
+bool JfrChunkWriter::open() {
+  assert(_chunk != NULL, "invariant");
+  JfrChunkWriterBase::reset(open_chunk(_chunk->path()));
+  const bool is_open = this->has_valid_fd();
+  if (is_open) {
+    assert(0 == this->current_offset(), "invariant");
+    _chunk->reset();
+    JfrChunkHeadWriter head(this, HEADER_SIZE);
+  }
+  return is_open;
+}
+
+int64_t JfrChunkWriter::close() {
+  assert(this->has_valid_fd(), "invariant");
+  const int64_t size_written = flush_chunk(false);
+  this->close_fd();
+  assert(!this->is_valid(), "invariant");
+  return size_written;
+}
--- a/src/hotspot/share/jfr/recorder/repository/jfrChunkWriter.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/repository/jfrChunkWriter.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -29,29 +29,36 @@
 #include "jfr/writers/jfrStreamWriterHost.inline.hpp"
 #include "jfr/writers/jfrWriterHost.inline.hpp"
 
-typedef MallocAdapter<M> JfrStreamBuffer; // 1 mb buffered writes
-typedef StreamWriterHost<JfrStreamBuffer, JfrCHeapObj> JfrBufferedStreamWriter;
-typedef WriterHost<BigEndianEncoder, CompressedIntegerEncoder, JfrBufferedStreamWriter> JfrChunkWriterBase;
+typedef MallocAdapter<M> JfrChunkBuffer; // 1 mb buffered writes
+typedef StreamWriterHost<JfrChunkBuffer, JfrCHeapObj> JfrBufferedChunkWriter;
+typedef WriterHost<BigEndianEncoder, CompressedIntegerEncoder, JfrBufferedChunkWriter> JfrChunkWriterBase;
 
-class JfrChunkState;
+class JfrChunk;
+class JfrChunkHeadWriter;
 
 class JfrChunkWriter : public JfrChunkWriterBase {
+  friend class JfrChunkHeadWriter;
   friend class JfrRepository;
  private:
-  JfrChunkState* _chunkstate;
-
+  JfrChunk* _chunk;
+  void set_path(const char* path);
+  int64_t flush_chunk(bool flushpoint);
   bool open();
-  size_t close(int64_t metadata_offset);
-  void write_header(int64_t metadata_offset);
-  void set_chunk_path(const char* chunk_path);
+  int64_t close();
+  int64_t current_chunk_start_nanos() const;
+  int64_t write_chunk_header_checkpoint(bool flushpoint);
 
  public:
   JfrChunkWriter();
-  bool initialize();
+  ~JfrChunkWriter();
+
   int64_t size_written() const;
   int64_t last_checkpoint_offset() const;
   void set_last_checkpoint_offset(int64_t offset);
-  void time_stamp_chunk_now();
+  void set_last_metadata_offset(int64_t offset);
+
+  bool has_metadata() const;
+  void set_time_stamp();
 };
 
 #endif // SHARE_JFR_RECORDER_REPOSITORY_JFRCHUNKWRITER_HPP
--- a/src/hotspot/share/jfr/recorder/repository/jfrEmergencyDump.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/repository/jfrEmergencyDump.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -248,7 +248,6 @@
 }
 
 static const char* create_emergency_dump_path() {
-  assert(JfrStream_lock->owned_by_self(), "invariant");
   char* buffer = NEW_RESOURCE_ARRAY_RETURN_NULL(char, JVM_MAXPATHLEN);
   if (NULL == buffer) {
     return NULL;
@@ -291,7 +290,6 @@
 // Caller needs ResourceMark
 static const char* create_emergency_chunk_path(const char* repository_path) {
   assert(repository_path != NULL, "invariant");
-  assert(JfrStream_lock->owned_by_self(), "invariant");
   const size_t repository_path_len = strlen(repository_path);
   // date time
   char date_time_buffer[32] = { 0 };
@@ -307,12 +305,11 @@
     return NULL;
   }
   // append the individual substrings
-  jio_snprintf(chunk_path, chunkname_max_len, "%s%s%s%s", repository_path_len, os::file_separator(), date_time_buffer, chunk_file_jfr_ext);
+  jio_snprintf(chunk_path, chunkname_max_len, "%s%s%s%s", repository_path, os::file_separator(), date_time_buffer, chunk_file_jfr_ext);
   return chunk_path;
 }
 
 static fio_fd emergency_dump_file_descriptor() {
-  assert(JfrStream_lock->owned_by_self(), "invariant");
   ResourceMark rm;
   const char* const emergency_dump_path = create_emergency_dump_path();
   return emergency_dump_path != NULL ? open_exclusivly(emergency_dump_path) : invalid_fd;
@@ -325,7 +322,6 @@
 void JfrEmergencyDump::on_vm_error(const char* repository_path) {
   assert(repository_path != NULL, "invariant");
   ResourceMark rm;
-  MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
   const fio_fd emergency_fd = emergency_dump_file_descriptor();
   if (emergency_fd != invalid_fd) {
     RepositoryIterator iterator(repository_path, strlen(repository_path));
@@ -340,17 +336,25 @@
 *
 * 1. if the thread state is not "_thread_in_vm", we will quick transition
 *    it to "_thread_in_vm".
-* 2. the nesting state for both resource and handle areas are unknown,
-*    so we allocate new fresh arenas, discarding the old ones.
-* 3. if the thread is the owner of some critical lock(s), unlock them.
+* 2. if the thread is the owner of some critical lock(s), unlock them.
 *
 * If we end up deadlocking in the attempt of dumping out jfr data,
 * we rely on the WatcherThread task "is_error_reported()",
-* to exit the VM after a hard-coded timeout.
+* to exit the VM after a hard-coded timeout (disallow WatcherThread to emergency dump).
 * This "safety net" somewhat explains the aggressiveness in this attempt.
 *
 */
-static void prepare_for_emergency_dump(Thread* thread) {
+static bool prepare_for_emergency_dump() {
+  if (JfrStream_lock->owned_by_self()) {
+    // crashed during jfr rotation, disallow recursion
+    return false;
+  }
+  Thread* const thread = Thread::current();
+  if (thread->is_Watcher_thread()) {
+    // need WatcherThread as a safeguard against potential deadlocks
+    return false;
+  }
+
   if (thread->is_Java_thread()) {
     ((JavaThread*)thread)->set_thread_state(_thread_in_vm);
   }
@@ -388,7 +392,6 @@
     VMOperationRequest_lock->unlock();
   }
 
-
   if (Service_lock->owned_by_self()) {
     Service_lock->unlock();
   }
@@ -413,13 +416,10 @@
     JfrBuffer_lock->unlock();
   }
 
-  if (JfrStream_lock->owned_by_self()) {
-    JfrStream_lock->unlock();
-  }
-
   if (JfrStacktrace_lock->owned_by_self()) {
     JfrStacktrace_lock->unlock();
   }
+  return true;
 }
 
 static volatile int jfr_shutdown_lock = 0;
@@ -429,24 +429,9 @@
 }
 
 void JfrEmergencyDump::on_vm_shutdown(bool exception_handler) {
-  if (!guard_reentrancy()) {
+  if (!(guard_reentrancy() && prepare_for_emergency_dump())) {
     return;
   }
-  // function made non-reentrant
-  Thread* thread = Thread::current();
-  if (exception_handler) {
-    // we are crashing
-    if (thread->is_Watcher_thread()) {
-      // The Watcher thread runs the periodic thread sampling task.
-      // If it has crashed, it is likely that another thread is
-      // left in a suspended state. This would mean the system
-      // will not be able to ever move to a safepoint. We try
-      // to avoid issuing safepoint operations when attempting
-      // an emergency dump, but a safepoint might be already pending.
-      return;
-    }
-    prepare_for_emergency_dump(thread);
-  }
   EventDumpReason event;
   if (event.should_commit()) {
     event.set_reason(exception_handler ? "Crash" : "Out of Memory");
@@ -458,8 +443,6 @@
     LeakProfiler::emit_events(max_jlong, false);
   }
   const int messages = MSGBIT(MSG_VM_ERROR);
-  ResourceMark rm(thread);
-  HandleMark hm(thread);
   JfrRecorderService service;
   service.rotate(messages);
 }
--- a/src/hotspot/share/jfr/recorder/repository/jfrRepository.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/repository/jfrRepository.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -26,13 +26,14 @@
 #include "jfr/jfr.hpp"
 #include "jfr/jni/jfrJavaSupport.hpp"
 #include "jfr/recorder/jfrRecorder.hpp"
-#include "jfr/recorder/repository/jfrChunkState.hpp"
 #include "jfr/recorder/repository/jfrChunkWriter.hpp"
 #include "jfr/recorder/repository/jfrEmergencyDump.hpp"
 #include "jfr/recorder/repository/jfrRepository.hpp"
 #include "jfr/recorder/service/jfrPostBox.hpp"
+#include "logging/log.hpp"
 #include "memory/resourceArea.hpp"
 #include "runtime/mutex.hpp"
+#include "runtime/os.hpp"
 #include "runtime/thread.inline.hpp"
 
 static JfrRepository* _instance = NULL;
@@ -43,11 +44,6 @@
 
 static JfrChunkWriter* _chunkwriter = NULL;
 
-static bool initialize_chunkwriter() {
-  assert(_chunkwriter == NULL, "invariant");
-  _chunkwriter = new JfrChunkWriter();
-  return _chunkwriter != NULL && _chunkwriter->initialize();
-}
 
 JfrChunkWriter& JfrRepository::chunkwriter() {
   return *_chunkwriter;
@@ -56,7 +52,9 @@
 JfrRepository::JfrRepository(JfrPostBox& post_box) : _path(NULL), _post_box(post_box) {}
 
 bool JfrRepository::initialize() {
-  return initialize_chunkwriter();
+  assert(_chunkwriter == NULL, "invariant");
+  _chunkwriter = new JfrChunkWriter();
+  return _chunkwriter != NULL;
 }
 
 JfrRepository::~JfrRepository() {
@@ -84,7 +82,6 @@
 }
 
 void JfrRepository::on_vm_error() {
-  assert(!JfrStream_lock->owned_by_self(), "invariant");
   if (_path == NULL) {
     // completed already
     return;
@@ -107,15 +104,19 @@
   return true;
 }
 
-void JfrRepository::set_chunk_path(const char* path) {
-  assert(JfrStream_lock->owned_by_self(), "invariant");
-  chunkwriter().set_chunk_path(path);
+void JfrRepository::notify_on_new_chunk_path() {
+  if (Jfr::is_recording()) {
+    // rotations are synchronous, block until rotation completes
+    instance()._post_box.post(MSG_ROTATE);
+  }
 }
 
-void JfrRepository::notify_on_new_chunk_path() {
-  if (Jfr::is_recording()) {
-    instance()._post_box.post(MSG_ROTATE);
-  }
+void JfrRepository::set_chunk_path(const char* path) {
+  chunkwriter().set_path(path);
+}
+
+jlong JfrRepository::current_chunk_start_nanos() {
+  return chunkwriter().current_chunk_start_nanos();
 }
 
 /**
@@ -134,14 +135,11 @@
   DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(jt));
   ResourceMark rm(jt);
   const char* const canonical_chunk_path = JfrJavaSupport::c_str(path, jt);
-  {
-    MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
-    if (NULL == canonical_chunk_path && !_chunkwriter->is_valid()) {
-      // new output is NULL and current output is NULL
-      return;
-    }
-    instance().set_chunk_path(canonical_chunk_path);
+  if (NULL == canonical_chunk_path && !_chunkwriter->is_valid()) {
+    // new output is NULL and current output is NULL
+    return;
   }
+  instance().set_chunk_path(canonical_chunk_path);
   notify_on_new_chunk_path();
 }
 
@@ -155,14 +153,28 @@
 }
 
 bool JfrRepository::open_chunk(bool vm_error /* false */) {
-  assert(JfrStream_lock->owned_by_self(), "invariant");
   if (vm_error) {
     ResourceMark rm;
-    _chunkwriter->set_chunk_path(JfrEmergencyDump::build_dump_path(_path));
+    _chunkwriter->set_path(JfrEmergencyDump::build_dump_path(_path));
   }
   return _chunkwriter->open();
 }
 
-size_t JfrRepository::close_chunk(int64_t metadata_offset) {
-  return _chunkwriter->close(metadata_offset);
+size_t JfrRepository::close_chunk() {
+  return _chunkwriter->close();
 }
+
+void JfrRepository::flush(JavaThread* jt) {
+  DEBUG_ONLY(JfrJavaSupport::check_java_thread_in_vm(jt));
+  if (!Jfr::is_recording()) {
+    return;
+  }
+  if (!_chunkwriter->is_valid()) {
+    return;
+  }
+  instance()._post_box.post(MSG_FLUSHPOINT);
+}
+
+size_t JfrRepository::flush_chunk() {
+  return _chunkwriter->flush_chunk(true);
+}
--- a/src/hotspot/share/jfr/recorder/repository/jfrRepository.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/repository/jfrRepository.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -55,8 +55,10 @@
   bool set_path(const char* path);
   void set_chunk_path(const char* path);
   bool open_chunk(bool vm_error = false);
-  size_t close_chunk(int64_t metadata_offset);
+  size_t close_chunk();
+  size_t flush_chunk();
   void on_vm_error();
+
   static void notify_on_new_chunk_path();
   static JfrChunkWriter& chunkwriter();
 
@@ -68,6 +70,8 @@
  public:
   static void set_path(jstring location, JavaThread* jt);
   static void set_chunk_path(jstring path, JavaThread* jt);
+  static void flush(JavaThread* jt);
+  static jlong current_chunk_start_nanos();
 };
 
 #endif // SHARE_JFR_RECORDER_REPOSITORY_JFRREPOSITORY_HPP
--- a/src/hotspot/share/jfr/recorder/service/jfrPostBox.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/service/jfrPostBox.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -26,14 +26,14 @@
 #include "jfr/recorder/service/jfrPostBox.hpp"
 #include "jfr/utilities/jfrTryLock.hpp"
 #include "runtime/atomic.hpp"
-#include "runtime/orderAccess.hpp"
 #include "runtime/thread.inline.hpp"
 
 #define MSG_IS_SYNCHRONOUS ( (MSGBIT(MSG_ROTATE)) |          \
                              (MSGBIT(MSG_STOP))   |          \
                              (MSGBIT(MSG_START))  |          \
                              (MSGBIT(MSG_CLONE_IN_MEMORY)) | \
-                             (MSGBIT(MSG_VM_ERROR))          \
+                             (MSGBIT(MSG_VM_ERROR))        | \
+                             (MSGBIT(MSG_FLUSHPOINT))        \
                            )
 
 static JfrPostBox* _instance = NULL;
@@ -84,7 +84,7 @@
 
 void JfrPostBox::deposit(int new_messages) {
   while (true) {
-    const int current_msgs = OrderAccess::load_acquire(&_messages);
+    const int current_msgs = Atomic::load(&_messages);
     // OR the new message
     const int exchange_value = current_msgs | new_messages;
     const int result = Atomic::cmpxchg(exchange_value, &_messages, current_msgs);
@@ -114,7 +114,7 @@
   deposit(msg);
   // serial_id is used to check when what we send in has been processed.
   // _msg_read_serial is read under JfrMsg_lock protection.
-  const uintptr_t serial_id = OrderAccess::load_acquire(&_msg_read_serial) + 1;
+  const uintptr_t serial_id = Atomic::load(&_msg_read_serial) + 1;
   msg_lock.notify_all();
   while (!is_message_processed(serial_id)) {
     msg_lock.wait();
@@ -129,12 +129,12 @@
  */
 bool JfrPostBox::is_message_processed(uintptr_t serial_id) const {
   assert(JfrMsg_lock->owned_by_self(), "_msg_handled_serial must be read under JfrMsg_lock protection");
-  return serial_id <= OrderAccess::load_acquire(&_msg_handled_serial);
+  return serial_id <= Atomic::load(&_msg_handled_serial);
 }
 
 bool JfrPostBox::is_empty() const {
   assert(JfrMsg_lock->owned_by_self(), "not holding JfrMsg_lock!");
-  return OrderAccess::load_acquire(&_messages) == 0;
+  return Atomic::load(&_messages) == 0;
 }
 
 int JfrPostBox::collect() {
--- a/src/hotspot/share/jfr/recorder/service/jfrPostBox.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/service/jfrPostBox.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -41,6 +41,7 @@
   MSG_SHUTDOWN,
   MSG_VM_ERROR,
   MSG_DEADBUFFER,
+  MSG_FLUSHPOINT,
   MSG_NO_OF_MSGS
 };
 
@@ -53,15 +54,16 @@
  *  MSG_START(1)            ; MSGBIT(MSG_START) == (1 << 0x1) == 0x2
  *  MSG_STOP (2)            ; MSGBIT(MSG_STOP) == (1 << 0x2) == 0x4
  *  MSG_ROTATE (3)          ; MSGBIT(MSG_ROTATE) == (1 << 0x3) == 0x8
- *  MSG_VM_ERROR (8)        ; MSGBIT(MSG_VM_ERROR) == (1 << 8) == 0x100
+ *  MSG_VM_ERROR (8)        ; MSGBIT(MSG_VM_ERROR) == (1 << 0x8) == 0x100
+ *  MSG_FLUSHPOINT (10)     ; MSGBIT(MSG_FLUSHPOINT) == (1 << 0xa) == 0x400
  *
  *  Asynchronous messages (posting thread returns immediately upon deposit):
  *
  *  MSG_FULLBUFFER (4)      ; MSGBIT(MSG_FULLBUFFER) == (1 << 0x4) == 0x10
- *  MSG_CHECKPOINT (5)      ; MSGBIT(CHECKPOINT) == (1 << 5) == 0x20
- *  MSG_WAKEUP (6)          ; MSGBIT(WAKEUP) == (1 << 6) == 0x40
- *  MSG_SHUTDOWN (7)        ; MSGBIT(MSG_SHUTDOWN) == (1 << 7) == 0x80
- *  MSG_DEADBUFFER (9)      ; MSGBIT(MSG_DEADBUFFER) == (1 << 9) == 0x200
+ *  MSG_CHECKPOINT (5)      ; MSGBIT(CHECKPOINT) == (1 << 0x5) == 0x20
+ *  MSG_WAKEUP (6)          ; MSGBIT(WAKEUP) == (1 << 0x6) == 0x40
+ *  MSG_SHUTDOWN (7)        ; MSGBIT(MSG_SHUTDOWN) == (1 << 0x7) == 0x80
+ *  MSG_DEADBUFFER (9)      ; MSGBIT(MSG_DEADBUFFER) == (1 << 0x9) == 0x200
  */
 
 class JfrPostBox : public JfrCHeapObj {
--- a/src/hotspot/share/jfr/recorder/service/jfrRecorderService.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/service/jfrRecorderService.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -23,6 +23,7 @@
  */
 
 #include "precompiled.hpp"
+#include "jfrfiles/jfrEventClasses.hpp"
 #include "jfr/jni/jfrJavaSupport.hpp"
 #include "jfr/leakprofiler/leakProfiler.hpp"
 #include "jfr/leakprofiler/checkpoint/objectSampleCheckpoint.hpp"
@@ -55,81 +56,102 @@
 #include "runtime/vmOperations.hpp"
 #include "runtime/vmThread.hpp"
 
-// set data iff *dest == NULL
-static bool try_set(void* const data, void** dest, bool clear) {
-  assert(data != NULL, "invariant");
-  const void* const current = OrderAccess::load_acquire(dest);
-  if (current != NULL) {
-    if (current != data) {
-      // already set
-      return false;
-    }
-    assert(current == data, "invariant");
-    if (!clear) {
-      // recursion disallowed
-      return false;
-    }
+// incremented on each flushpoint
+static u8 flushpoint_id = 0;
+
+template <typename E, typename Instance, size_t(Instance::*func)()>
+class Content {
+ private:
+  Instance& _instance;
+  u4 _elements;
+ public:
+  typedef E EventType;
+  Content(Instance& instance) : _instance(instance), _elements(0) {}
+  bool process() {
+    _elements = (u4)(_instance.*func)();
+    return true;
   }
-  return Atomic::cmpxchg(clear ? NULL : data, dest, current) == current;
-}
+  u4 elements() const { return _elements; }
+};
 
-static void* rotation_thread = NULL;
-static const int rotation_try_limit = 1000;
-static const int rotation_retry_sleep_millis = 10;
+template <typename Content>
+class WriteContent : public StackObj {
+ protected:
+  const JfrTicks _start_time;
+  JfrTicks _end_time;
+  JfrChunkWriter& _cw;
+  Content& _content;
+  const int64_t _start_offset;
+ public:
+  typedef typename Content::EventType EventType;
 
-class RotationLock : public StackObj {
- private:
-  Thread* const _thread;
-  bool _acquired;
-
-  void log(bool recursion) {
-    assert(!_acquired, "invariant");
-    const char* error_msg = NULL;
-    if (recursion) {
-      error_msg = "Unable to issue rotation due to recursive calls.";
-    }
-    else {
-      error_msg = "Unable to issue rotation due to wait timeout.";
-    }
-    log_info(jfr)( // For user, should not be "jfr, system"
-      "%s", error_msg);
-  }
- public:
-  RotationLock(Thread* thread) : _thread(thread), _acquired(false) {
-    assert(_thread != NULL, "invariant");
-    if (_thread == rotation_thread) {
-      // recursion not supported
-      log(true);
-      return;
-    }
-
-    // limited to not spin indefinitely
-    for (int i = 0; i < rotation_try_limit; ++i) {
-      if (try_set(_thread, &rotation_thread, false)) {
-        _acquired = true;
-        assert(_thread == rotation_thread, "invariant");
-        return;
-      }
-      if (_thread->is_Java_thread()) {
-        // in order to allow the system to move to a safepoint
-        MutexLocker msg_lock(JfrMsg_lock);
-        JfrMsg_lock->wait(rotation_retry_sleep_millis);
-      }
-      else {
-        os::naked_short_sleep(rotation_retry_sleep_millis);
-      }
-    }
-    log(false);
+  WriteContent(JfrChunkWriter& cw, Content& content) :
+    _start_time(JfrTicks::now()),
+    _end_time(),
+    _cw(cw),
+    _content(content),
+    _start_offset(_cw.current_offset()) {
+    assert(_cw.is_valid(), "invariant");
   }
 
-  ~RotationLock() {
-    assert(_thread != NULL, "invariant");
-    if (_acquired) {
-      assert(_thread == rotation_thread, "invariant");
-      while (!try_set(_thread, &rotation_thread, true));
-    }
+  bool process() {
+    // invocation
+    _content.process();
+    _end_time = JfrTicks::now();
+    return 0 != _content.elements();
   }
-  bool not_acquired() const { return !_acquired; }
+
+  const JfrTicks& start_time() const {
+    return _start_time;
+  }
+
+  const JfrTicks& end_time() const {
+    return _end_time;
+  }
+
+  int64_t start_offset() const {
+    return _start_offset;
+  }
+
+  int64_t end_offset() const {
+    return current_offset();
+  }
+
+  int64_t current_offset() const {
+    return _cw.current_offset();
+  }
+
+  u4 elements() const {
+    return (u4) _content.elements();
+  }
+
+  u4 size() const {
+    return (u4)(end_offset() - start_offset());
+  }
+
+  static bool is_event_enabled() {
+    return EventType::is_enabled();
+  }
+
+  static u8 event_id() {
+    return EventType::eventId;
+  }
+
+  void write_elements(int64_t offset) {
+    _cw.write_padded_at_offset<u4>(elements(), offset);
+  }
+
+  void write_size() {
+    _cw.write_padded_at_offset<u4>(size(), start_offset());
+  }
+
+  void set_last_checkpoint() {
+    _cw.set_last_checkpoint_offset(start_offset());
+  }
+
+  void rewind() {
+    _cw.seek(start_offset());
+  }
 };
 
 static int64_t write_checkpoint_event_prologue(JfrChunkWriter& cw, u8 type_id) {
@@ -138,65 +160,176 @@
   cw.reserve(sizeof(u4));
   cw.write<u8>(EVENT_CHECKPOINT);
   cw.write(JfrTicks::now());
-  cw.write((int64_t)0); // duration
+  cw.write<u8>(0); // duration
   cw.write(delta_to_last_checkpoint);
-  cw.write<bool>(false); // flushpoint
-  cw.write((u4)1); // nof types in this checkpoint
+  cw.write<u4>(GENERIC); // checkpoint type
+  cw.write<u4>(1); // nof types in this checkpoint
   cw.write(type_id);
-  const int64_t number_of_elements_offset = cw.current_offset();
-  cw.reserve(sizeof(u4));
-  return number_of_elements_offset;
+  return cw.reserve(sizeof(u4));
 }
 
-template <typename ContentFunctor>
-class WriteCheckpointEvent : public StackObj {
+template <typename Content>
+class WriteCheckpointEvent : public WriteContent<Content> {
  private:
-  JfrChunkWriter& _cw;
-  u8 _type_id;
-  ContentFunctor& _content_functor;
+  const u8 _type_id;
  public:
-  WriteCheckpointEvent(JfrChunkWriter& cw, u8 type_id, ContentFunctor& functor) :
-    _cw(cw),
-    _type_id(type_id),
-    _content_functor(functor) {
-    assert(_cw.is_valid(), "invariant");
-  }
+  WriteCheckpointEvent(JfrChunkWriter& cw, Content& content, u8 type_id) :
+    WriteContent<Content>(cw, content), _type_id(type_id) {}
+
   bool process() {
-    // current_cp_offset is also offset for the event size header field
-    const int64_t current_cp_offset = _cw.current_offset();
-    const int64_t num_elements_offset = write_checkpoint_event_prologue(_cw, _type_id);
-    // invocation
-    _content_functor.process();
-    const u4 number_of_elements = (u4)_content_functor.processed();
-    if (number_of_elements == 0) {
+    const int64_t num_elements_offset = write_checkpoint_event_prologue(this->_cw, _type_id);
+    if (!WriteContent<Content>::process()) {
       // nothing to do, rewind writer to start
-      _cw.seek(current_cp_offset);
-      return true;
+      this->rewind();
+      assert(this->current_offset() == this->start_offset(), "invariant");
+      return false;
     }
-    assert(number_of_elements > 0, "invariant");
-    assert(_cw.current_offset() > num_elements_offset, "invariant");
-    _cw.write_padded_at_offset<u4>(number_of_elements, num_elements_offset);
-    _cw.write_padded_at_offset<u4>((u4)_cw.current_offset() - current_cp_offset, current_cp_offset);
-    // update writer with last checkpoint position
-    _cw.set_last_checkpoint_offset(current_cp_offset);
+    assert(this->elements() > 0, "invariant");
+    assert(this->current_offset() > num_elements_offset, "invariant");
+    this->write_elements(num_elements_offset);
+    this->write_size();
+    this->set_last_checkpoint();
     return true;
   }
 };
 
-template <typename Instance, size_t(Instance::*func)()>
-class ServiceFunctor {
+template <typename Functor>
+static u4 invoke(Functor& f) {
+  f.process();
+  return f.elements();
+}
+
+template <typename Functor>
+static void write_flush_event(Functor& f) {
+  if (Functor::is_event_enabled()) {
+    typename Functor::EventType 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();
+  }
+}
+
+template <typename Functor>
+static u4 invoke_with_flush_event(Functor& f) {
+  const u4 elements = invoke(f);
+  write_flush_event(f);
+  return elements;
+}
+
+class StackTraceRepository : public StackObj {
  private:
-  Instance& _instance;
-  size_t _processed;
+  JfrStackTraceRepository& _repo;
+  JfrChunkWriter& _cw;
+  size_t _elements;
+  bool _clear;
+
  public:
-  ServiceFunctor(Instance& instance) : _instance(instance), _processed(0) {}
+  typedef EventFlushStacktrace EventType;
+  StackTraceRepository(JfrStackTraceRepository& repo, JfrChunkWriter& cw, bool clear) :
+    _repo(repo), _cw(cw), _elements(0), _clear(clear) {}
   bool process() {
-    _processed = (_instance.*func)();
+    _elements = _repo.write(_cw, _clear);
     return true;
   }
-  size_t processed() const { return _processed; }
+  size_t elements() const { return _elements; }
+  void reset() { _elements = 0; }
 };
 
+typedef WriteCheckpointEvent<StackTraceRepository> WriteStackTrace;
+
+static u4 flush_stacktrace(JfrStackTraceRepository& stack_trace_repo, JfrChunkWriter& chunkwriter) {
+  StackTraceRepository str(stack_trace_repo, chunkwriter, false);
+  WriteStackTrace wst(chunkwriter, str, TYPE_STACKTRACE);
+  return invoke_with_flush_event(wst);
+}
+
+static u4 write_stacktrace(JfrStackTraceRepository& stack_trace_repo, JfrChunkWriter& chunkwriter, bool clear) {
+  StackTraceRepository str(stack_trace_repo, chunkwriter, clear);
+  WriteStackTrace wst(chunkwriter, str, TYPE_STACKTRACE);
+  return invoke(wst);
+}
+
+typedef Content<EventFlushStorage, JfrStorage, &JfrStorage::write> Storage;
+typedef WriteContent<Storage> WriteStorage;
+
+static size_t flush_storage(JfrStorage& storage, JfrChunkWriter& chunkwriter) {
+  assert(chunkwriter.is_valid(), "invariant");
+  Storage fsf(storage);
+  WriteStorage fs(chunkwriter, fsf);
+  return invoke_with_flush_event(fs);
+}
+
+static size_t write_storage(JfrStorage& storage, JfrChunkWriter& chunkwriter) {
+  assert(chunkwriter.is_valid(), "invariant");
+  Storage fsf(storage);
+  WriteStorage fs(chunkwriter, fsf);
+  return invoke(fs);
+}
+
+typedef Content<EventFlushStringPool, JfrStringPool, &JfrStringPool::write> StringPool;
+typedef Content<EventFlushStringPool, JfrStringPool, &JfrStringPool::write_at_safepoint> StringPoolSafepoint;
+typedef WriteCheckpointEvent<StringPool> WriteStringPool;
+typedef WriteCheckpointEvent<StringPoolSafepoint> WriteStringPoolSafepoint;
+
+static u4 flush_stringpool(JfrStringPool& string_pool, JfrChunkWriter& chunkwriter) {
+  StringPool sp(string_pool);
+  WriteStringPool wsp(chunkwriter, sp, TYPE_STRING);
+  return invoke_with_flush_event(wsp);
+}
+
+static u4 write_stringpool(JfrStringPool& string_pool, JfrChunkWriter& chunkwriter) {
+  StringPool sp(string_pool);
+  WriteStringPool wsp(chunkwriter, sp, TYPE_STRING);
+  return invoke(wsp);
+}
+
+static u4 write_stringpool_safepoint(JfrStringPool& string_pool, JfrChunkWriter& chunkwriter) {
+  StringPoolSafepoint sps(string_pool);
+  WriteStringPoolSafepoint wsps(chunkwriter, sps, TYPE_STRING);
+  return invoke(wsps);
+}
+
+typedef Content<EventFlushTypeSet, JfrCheckpointManager, &JfrCheckpointManager::flush_type_set> FlushTypeSetFunctor;
+typedef WriteContent<FlushTypeSetFunctor> FlushTypeSet;
+
+static u4 flush_typeset(JfrCheckpointManager& checkpoint_manager, JfrChunkWriter& chunkwriter) {
+  FlushTypeSetFunctor flush_type_set(checkpoint_manager);
+  FlushTypeSet fts(chunkwriter, flush_type_set);
+  return invoke_with_flush_event(fts);
+}
+
+class MetadataEvent : public StackObj {
+ private:
+  JfrChunkWriter& _cw;
+ public:
+  typedef EventFlushMetadata EventType;
+  MetadataEvent(JfrChunkWriter& cw) : _cw(cw) {}
+  bool process() {
+    JfrMetadataEvent::write(_cw);
+    return true;
+  }
+  size_t elements() const { return 1; }
+};
+
+typedef WriteContent<MetadataEvent> WriteMetadata;
+
+static u4 flush_metadata(JfrChunkWriter& chunkwriter) {
+  assert(chunkwriter.is_valid(), "invariant");
+  MetadataEvent me(chunkwriter);
+  WriteMetadata wm(chunkwriter, me);
+  return invoke_with_flush_event(wm);
+}
+
+static u4 write_metadata(JfrChunkWriter& chunkwriter) {
+  assert(chunkwriter.is_valid(), "invariant");
+  MetadataEvent me(chunkwriter);
+  WriteMetadata wm(chunkwriter, me);
+  return invoke(wm);
+}
+
 template <typename Instance, void(Instance::*func)()>
 class JfrVMOperation : public VM_Operation {
  private:
@@ -208,23 +341,13 @@
   Mode evaluation_mode() const { return _safepoint; } // default
 };
 
-class WriteStackTraceRepository : public StackObj {
- private:
-  JfrStackTraceRepository& _repo;
-  JfrChunkWriter& _cw;
-  size_t _elements_processed;
-  bool _clear;
-
- public:
-  WriteStackTraceRepository(JfrStackTraceRepository& repo, JfrChunkWriter& cw, bool clear) :
-    _repo(repo), _cw(cw), _elements_processed(0), _clear(clear) {}
-  bool process() {
-    _elements_processed = _repo.write(_cw, _clear);
-    return true;
-  }
-  size_t processed() const { return _elements_processed; }
-  void reset() { _elements_processed = 0; }
-};
+JfrRecorderService::JfrRecorderService() :
+  _checkpoint_manager(JfrCheckpointManager::instance()),
+  _chunkwriter(JfrRepository::chunkwriter()),
+  _repository(JfrRepository::instance()),
+  _stack_trace_repository(JfrStackTraceRepository::instance()),
+  _storage(JfrStorage::instance()),
+  _string_pool(JfrStringPool::instance()) {}
 
 static bool recording = false;
 
@@ -237,19 +360,8 @@
   return recording;
 }
 
-JfrRecorderService::JfrRecorderService() :
-  _checkpoint_manager(JfrCheckpointManager::instance()),
-  _chunkwriter(JfrRepository::chunkwriter()),
-  _repository(JfrRepository::instance()),
-  _stack_trace_repository(JfrStackTraceRepository::instance()),
-  _storage(JfrStorage::instance()),
-  _string_pool(JfrStringPool::instance()) {}
-
 void JfrRecorderService::start() {
-  RotationLock rl(Thread::current());
-  if (rl.not_acquired()) {
-    return;
-  }
+  MutexLocker lock(JfrStream_lock);
   log_debug(jfr, system)("Request to START recording");
   assert(!is_recording(), "invariant");
   clear();
@@ -268,9 +380,9 @@
 }
 
 void JfrRecorderService::pre_safepoint_clear() {
-  _stack_trace_repository.clear();
   _string_pool.clear();
   _storage.clear();
+  _stack_trace_repository.clear();
 }
 
 void JfrRecorderService::invoke_safepoint_clear() {
@@ -278,28 +390,28 @@
   VMThread::execute(&safepoint_task);
 }
 
-//
-// safepoint clear sequence
-//
-//  clear stacktrace repository ->
-//    clear string pool ->
-//      clear storage ->
-//        shift epoch ->
-//          update time
-//
 void JfrRecorderService::safepoint_clear() {
   assert(SafepointSynchronize::is_at_safepoint(), "invariant");
-  _stack_trace_repository.clear();
   _string_pool.clear();
   _storage.clear();
   _checkpoint_manager.shift_epoch();
-  _chunkwriter.time_stamp_chunk_now();
+  _chunkwriter.set_time_stamp();
+  _stack_trace_repository.clear();
 }
 
 void JfrRecorderService::post_safepoint_clear() {
   _checkpoint_manager.clear();
 }
 
+void JfrRecorderService::open_new_chunk(bool vm_error) {
+  JfrChunkRotation::on_rotation();
+  const bool valid_chunk = _repository.open_chunk(vm_error);
+  _storage.control().set_to_disk(valid_chunk);
+  if (valid_chunk) {
+    _checkpoint_manager.write_static_type_set_and_threads();
+  }
+}
+
 static void stop() {
   assert(JfrRecorderService::is_recording(), "invariant");
   log_debug(jfr, system)("Recording STOPPED");
@@ -307,11 +419,30 @@
   assert(!JfrRecorderService::is_recording(), "invariant");
 }
 
+void JfrRecorderService::prepare_for_vm_error_rotation() {
+  assert(JfrStream_lock->owned_by_self(), "invariant");
+  if (!_chunkwriter.is_valid()) {
+    open_new_chunk(true);
+  }
+  _checkpoint_manager.register_service_thread(Thread::current());
+}
+
+void JfrRecorderService::vm_error_rotation() {
+  assert(JfrStream_lock->owned_by_self(), "invariant");
+  if (_chunkwriter.is_valid()) {
+    Thread* const t = Thread::current();
+    _storage.flush_regular_buffer(t->jfr_thread_local()->native_buffer(), t);
+    invoke_flush();
+    _chunkwriter.set_time_stamp();
+    _repository.close_chunk();
+    assert(!_chunkwriter.is_valid(), "invariant");
+    _repository.on_vm_error();
+  }
+}
+
 void JfrRecorderService::rotate(int msgs) {
-  RotationLock rl(Thread::current());
-  if (rl.not_acquired()) {
-    return;
-  }
+  assert(!JfrStream_lock->owned_by_self(), "invariant");
+  MutexLocker lock(JfrStream_lock);
   static bool vm_error = false;
   if (msgs & MSGBIT(MSG_VM_ERROR)) {
     vm_error = true;
@@ -329,45 +460,19 @@
   }
 }
 
-void JfrRecorderService::prepare_for_vm_error_rotation() {
-  if (!_chunkwriter.is_valid()) {
-    open_new_chunk(true);
-  }
-  _checkpoint_manager.register_service_thread(Thread::current());
-  JfrMetadataEvent::lock();
-}
-
-void JfrRecorderService::open_new_chunk(bool vm_error) {
-  assert(!_chunkwriter.is_valid(), "invariant");
-  assert(!JfrStream_lock->owned_by_self(), "invariant");
-  JfrChunkRotation::on_rotation();
-  MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
-  if (!_repository.open_chunk(vm_error)) {
-    assert(!_chunkwriter.is_valid(), "invariant");
-    _storage.control().set_to_disk(false);
-    return;
-  }
-  assert(_chunkwriter.is_valid(), "invariant");
-  _storage.control().set_to_disk(true);
-}
-
 void JfrRecorderService::in_memory_rotation() {
-  assert(!_chunkwriter.is_valid(), "invariant");
+  assert(JfrStream_lock->owned_by_self(), "invariant");
   // currently running an in-memory recording
+  assert(!_storage.control().to_disk(), "invariant");
   open_new_chunk();
   if (_chunkwriter.is_valid()) {
     // dump all in-memory buffer data to the newly created chunk
-    serialize_storage_from_in_memory_recording();
+    write_storage(_storage, _chunkwriter);
   }
 }
 
-void JfrRecorderService::serialize_storage_from_in_memory_recording() {
-  assert(!JfrStream_lock->owned_by_self(), "not holding stream lock!");
-  MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
-  _storage.write();
-}
-
 void JfrRecorderService::chunk_rotation() {
+  assert(JfrStream_lock->owned_by_self(), "invariant");
   finalize_current_chunk();
   open_new_chunk();
 }
@@ -375,7 +480,6 @@
 void JfrRecorderService::finalize_current_chunk() {
   assert(_chunkwriter.is_valid(), "invariant");
   write();
-  assert(!_chunkwriter.is_valid(), "invariant");
 }
 
 void JfrRecorderService::write() {
@@ -386,54 +490,20 @@
   post_safepoint_write();
 }
 
-typedef ServiceFunctor<JfrStringPool, &JfrStringPool::write> WriteStringPool;
-typedef ServiceFunctor<JfrStringPool, &JfrStringPool::write_at_safepoint> WriteStringPoolSafepoint;
-typedef WriteCheckpointEvent<WriteStackTraceRepository> WriteStackTraceCheckpoint;
-typedef WriteCheckpointEvent<WriteStringPool> WriteStringPoolCheckpoint;
-typedef WriteCheckpointEvent<WriteStringPoolSafepoint> WriteStringPoolCheckpointSafepoint;
-
-static void write_stacktrace_checkpoint(JfrStackTraceRepository& stack_trace_repo, JfrChunkWriter& chunkwriter, bool clear) {
-  WriteStackTraceRepository write_stacktrace_repo(stack_trace_repo, chunkwriter, clear);
-  WriteStackTraceCheckpoint write_stack_trace_checkpoint(chunkwriter, TYPE_STACKTRACE, write_stacktrace_repo);
-  write_stack_trace_checkpoint.process();
-}
-static void write_stringpool_checkpoint(JfrStringPool& string_pool, JfrChunkWriter& chunkwriter) {
-  WriteStringPool write_string_pool(string_pool);
-  WriteStringPoolCheckpoint write_string_pool_checkpoint(chunkwriter, TYPE_STRING, write_string_pool);
-  write_string_pool_checkpoint.process();
-}
-
-static void write_stringpool_checkpoint_safepoint(JfrStringPool& string_pool, JfrChunkWriter& chunkwriter) {
-  WriteStringPoolSafepoint write_string_pool(string_pool);
-  WriteStringPoolCheckpointSafepoint write_string_pool_checkpoint(chunkwriter, TYPE_STRING, write_string_pool);
-  write_string_pool_checkpoint.process();
-}
-
-//
-// pre-safepoint write sequence
-//
-//  lock stream lock ->
-//    write non-safepoint dependent types ->
-//      write checkpoint epoch transition list->
-//        write stack trace checkpoint ->
-//          write string pool checkpoint ->
-//            write object sample stacktraces ->
-//              write storage ->
-//                release stream lock
-//
 void JfrRecorderService::pre_safepoint_write() {
-  MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
   assert(_chunkwriter.is_valid(), "invariant");
-  _checkpoint_manager.write_types();
-  _checkpoint_manager.write_epoch_transition_mspace();
-  write_stacktrace_checkpoint(_stack_trace_repository, _chunkwriter, false);
-  write_stringpool_checkpoint(_string_pool, _chunkwriter);
   if (LeakProfiler::is_running()) {
     // Exclusive access to the object sampler instance.
     // The sampler is released (unlocked) later in post_safepoint_write.
     ObjectSampleCheckpoint::on_rotation(ObjectSampler::acquire(), _stack_trace_repository);
   }
-  _storage.write();
+  if (_string_pool.is_modified()) {
+    write_stringpool(_string_pool, _chunkwriter);
+  }
+  write_storage(_storage, _chunkwriter);
+  if (_stack_trace_repository.is_modified()) {
+    write_stacktrace(_stack_trace_repository, _chunkwriter, false);
+  }
 }
 
 void JfrRecorderService::invoke_safepoint_write() {
@@ -441,50 +511,18 @@
   VMThread::execute(&safepoint_task);
 }
 
-//
-// safepoint write sequence
-//
-//   lock stream lock ->
-//       write stacktrace repository ->
-//         write string pool ->
-//           write safepoint dependent types ->
-//             write storage ->
-//                 shift_epoch ->
-//                   update time ->
-//                     lock metadata descriptor ->
-//                       release stream lock
-//
 void JfrRecorderService::safepoint_write() {
   assert(SafepointSynchronize::is_at_safepoint(), "invariant");
-  MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
-  write_stacktrace_checkpoint(_stack_trace_repository, _chunkwriter, true);
-  write_stringpool_checkpoint_safepoint(_string_pool, _chunkwriter);
-  _checkpoint_manager.write_safepoint_types();
+  if (_string_pool.is_modified()) {
+    write_stringpool_safepoint(_string_pool, _chunkwriter);
+  }
+  _checkpoint_manager.on_rotation();
   _storage.write_at_safepoint();
   _checkpoint_manager.shift_epoch();
-  _chunkwriter.time_stamp_chunk_now();
-  JfrMetadataEvent::lock();
+  _chunkwriter.set_time_stamp();
+  write_stacktrace(_stack_trace_repository, _chunkwriter, true);
 }
 
-static int64_t write_metadata_event(JfrChunkWriter& chunkwriter) {
-  assert(chunkwriter.is_valid(), "invariant");
-  const int64_t metadata_offset = chunkwriter.current_offset();
-  JfrMetadataEvent::write(chunkwriter, metadata_offset);
-  return metadata_offset;
-}
-
-//
-// post-safepoint write sequence
-//
-//   write type set ->
-//     release object sampler ->
-//       lock stream lock ->
-//         write checkpoints ->
-//           write metadata event ->
-//             write chunk header ->
-//               close chunk fd ->
-//                 release stream lock
-//
 void JfrRecorderService::post_safepoint_write() {
   assert(_chunkwriter.is_valid(), "invariant");
   // During the safepoint tasks just completed, the system transitioned to a new epoch.
@@ -497,38 +535,84 @@
     // Note: There is a dependency on write_type_set() above, ensure the release is subsequent.
     ObjectSampler::release();
   }
-  MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
-  // serialize any outstanding checkpoint memory
-  _checkpoint_manager.write();
   // serialize the metadata descriptor event and close out the chunk
-  _repository.close_chunk(write_metadata_event(_chunkwriter));
-  assert(!_chunkwriter.is_valid(), "invariant");
+  write_metadata(_chunkwriter);
+  _repository.close_chunk();
 }
 
-void JfrRecorderService::vm_error_rotation() {
-  if (_chunkwriter.is_valid()) {
-    finalize_current_chunk_on_vm_error();
-    assert(!_chunkwriter.is_valid(), "invariant");
-    _repository.on_vm_error();
+static JfrBuffer* thread_local_buffer(Thread* t) {
+  assert(t != NULL, "invariant");
+  return t->jfr_thread_local()->native_buffer();
+}
+
+static void reset_buffer(JfrBuffer* buffer, Thread* t) {
+  assert(buffer != NULL, "invariant");
+  assert(t != NULL, "invariant");
+  assert(buffer == thread_local_buffer(t), "invariant");
+  buffer->set_pos(const_cast<u1*>(buffer->top()));
+}
+
+static void reset_thread_local_buffer(Thread* t) {
+  reset_buffer(thread_local_buffer(t), t);
+}
+
+static void write_thread_local_buffer(JfrChunkWriter& chunkwriter, Thread* t) {
+  JfrBuffer * const buffer = thread_local_buffer(t);
+  assert(buffer != NULL, "invariant");
+  if (!buffer->empty()) {
+    chunkwriter.write_unbuffered(buffer->top(), buffer->pos() - buffer->top());
+    reset_buffer(buffer, t);
   }
 }
 
-void JfrRecorderService::finalize_current_chunk_on_vm_error() {
+size_t JfrRecorderService::flush() {
+  assert(JfrStream_lock->owned_by_self(), "invariant");
+  size_t total_elements = flush_metadata(_chunkwriter);
+  const size_t storage_elements = flush_storage(_storage, _chunkwriter);
+  if (0 == storage_elements) {
+    return total_elements;
+  }
+  total_elements += storage_elements;
+  if (_string_pool.is_modified()) {
+    total_elements += flush_stringpool(_string_pool, _chunkwriter);
+  }
+  if (_stack_trace_repository.is_modified()) {
+    total_elements += flush_stacktrace(_stack_trace_repository, _chunkwriter);
+  }
+  if (_checkpoint_manager.is_type_set_required()) {
+    total_elements += flush_typeset(_checkpoint_manager, _chunkwriter);
+  } else if (_checkpoint_manager.is_static_type_set_required()) {
+    // don't tally this, it is only in order to flush the waiting constants
+    _checkpoint_manager.flush_static_type_set();
+  }
+  return total_elements;
+}
+
+typedef Content<EventFlush, JfrRecorderService, &JfrRecorderService::flush> FlushFunctor;
+typedef WriteContent<FlushFunctor> Flush;
+
+void JfrRecorderService::invoke_flush() {
+  assert(JfrStream_lock->owned_by_self(), "invariant");
   assert(_chunkwriter.is_valid(), "invariant");
-  pre_safepoint_write();
-  // Do not attempt safepoint dependent operations during emergency dump.
-  // Optimistically write tagged artifacts.
-  _checkpoint_manager.shift_epoch();
-  // update time
-  _chunkwriter.time_stamp_chunk_now();
-  post_safepoint_write();
-  assert(!_chunkwriter.is_valid(), "invariant");
+  Thread* const t = Thread::current();
+  ResourceMark rm(t);
+  HandleMark hm(t);
+  ++flushpoint_id;
+  reset_thread_local_buffer(t);
+  FlushFunctor flushpoint(*this);
+  Flush fl(_chunkwriter, flushpoint);
+  invoke_with_flush_event(fl);
+  write_thread_local_buffer(_chunkwriter, t);
+  _repository.flush_chunk();
+}
+
+void JfrRecorderService::flushpoint() {
+  MutexLocker lock(JfrStream_lock);
+  invoke_flush();
 }
 
 void JfrRecorderService::process_full_buffers() {
   if (_chunkwriter.is_valid()) {
-    assert(!JfrStream_lock->owned_by_self(), "invariant");
-    MutexLocker stream_lock(JfrStream_lock, Mutex::_no_safepoint_check_flag);
     _storage.write_full();
   }
 }
--- a/src/hotspot/share/jfr/recorder/service/jfrRecorderService.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/service/jfrRecorderService.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -46,11 +46,10 @@
   void open_new_chunk(bool vm_error = false);
   void chunk_rotation();
   void in_memory_rotation();
-  void serialize_storage_from_in_memory_recording();
   void finalize_current_chunk();
-  void finalize_current_chunk_on_vm_error();
   void prepare_for_vm_error_rotation();
   void vm_error_rotation();
+  void invoke_flush();
 
   void clear();
   void pre_safepoint_clear();
@@ -67,7 +66,9 @@
  public:
   JfrRecorderService();
   void start();
+  size_t flush();
   void rotate(int msgs);
+  void flushpoint();
   void process_full_buffers();
   void scavenge();
   void evaluate_chunk_size_for_rotation();
--- a/src/hotspot/share/jfr/recorder/service/jfrRecorderThread.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/service/jfrRecorderThread.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -27,6 +27,7 @@
 #include "classfile/javaClasses.hpp"
 #include "classfile/symbolTable.hpp"
 #include "classfile/systemDictionary.hpp"
+#include "jfr/jfr.hpp"
 #include "jfr/jni/jfrJavaSupport.hpp"
 #include "jfr/recorder/jfrRecorder.hpp"
 #include "jfr/recorder/checkpoint/jfrCheckpointManager.hpp"
@@ -64,7 +65,6 @@
   if (allocation_failed) {
     JfrJavaSupport::throw_out_of_memory_error("Unable to create native recording thread for JFR", CHECK_NULL);
   }
-
   Thread::start(new_thread);
   return new_thread;
 }
@@ -98,8 +98,9 @@
   instanceHandle h_thread_oop(THREAD, (instanceOop)result.get_jobject());
   assert(h_thread_oop.not_null(), "invariant");
   // attempt thread start
-  const Thread* const t = start_thread(h_thread_oop, recorderthread_entry,THREAD);
+  Thread* const t = start_thread(h_thread_oop, recorderthread_entry,THREAD);
   if (!HAS_PENDING_EXCEPTION) {
+    Jfr::exclude_thread(t);
     cp_manager->register_service_thread(t);
     return true;
   }
--- a/src/hotspot/share/jfr/recorder/service/jfrRecorderThreadLoop.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/service/jfrRecorderThreadLoop.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -40,6 +40,7 @@
   #define START (msgs & (MSGBIT(MSG_START)))
   #define SHUTDOWN (msgs & MSGBIT(MSG_SHUTDOWN))
   #define ROTATE (msgs & (MSGBIT(MSG_ROTATE)|MSGBIT(MSG_STOP)))
+  #define FLUSHPOINT (msgs & (MSGBIT(MSG_FLUSHPOINT)))
   #define PROCESS_FULL_BUFFERS (msgs & (MSGBIT(MSG_ROTATE)|MSGBIT(MSG_STOP)|MSGBIT(MSG_FULLBUFFER)))
   #define SCAVENGE (msgs & (MSGBIT(MSG_DEADBUFFER)))
 
@@ -72,6 +73,8 @@
         service.start();
       } else if (ROTATE) {
         service.rotate(msgs);
+      } else if (FLUSHPOINT) {
+        service.flushpoint();
       }
       JfrMsg_lock->lock();
       post_box.notify_waiters();
@@ -90,6 +93,7 @@
   #undef START
   #undef SHUTDOWN
   #undef ROTATE
+  #undef FLUSHPOINT
   #undef PROCESS_FULL_BUFFERS
   #undef SCAVENGE
 }
--- a/src/hotspot/share/jfr/recorder/stacktrace/jfrStackTraceRepository.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/stacktrace/jfrStackTraceRepository.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -62,7 +62,7 @@
 };
 
 bool JfrStackTraceRepository::initialize() {
-  return JfrSerializer::register_serializer(TYPE_FRAMETYPE, false, true, new JfrFrameType());
+  return JfrSerializer::register_serializer(TYPE_FRAMETYPE, true, new JfrFrameType());
 }
 
 void JfrStackTraceRepository::destroy() {
@@ -71,7 +71,16 @@
   _instance = NULL;
 }
 
-size_t JfrStackTraceRepository::write_impl(JfrChunkWriter& sw, bool clear) {
+static traceid last_id = 0;
+
+bool JfrStackTraceRepository::is_modified() const {
+  return last_id != _next_id;
+}
+
+size_t JfrStackTraceRepository::write(JfrChunkWriter& sw, bool clear) {
+  if (_entries == 0) {
+    return 0;
+  }
   MutexLocker lock(JfrStacktrace_lock, Mutex::_no_safepoint_check_flag);
   assert(_entries > 0, "invariant");
   int count = 0;
@@ -93,29 +102,10 @@
     memset(_table, 0, sizeof(_table));
     _entries = 0;
   }
+  last_id = _next_id;
   return count;
 }
 
-size_t JfrStackTraceRepository::write(JfrChunkWriter& sw, bool clear) {
-  return _entries > 0 ? write_impl(sw, clear) : 0;
-}
-
-traceid JfrStackTraceRepository::write(JfrCheckpointWriter& writer, traceid id, unsigned int hash) {
-  assert(JfrStacktrace_lock->owned_by_self(), "invariant");
-  const JfrStackTrace* const trace = lookup(hash, id);
-  assert(trace != NULL, "invariant");
-  assert(trace->hash() == hash, "invariant");
-  assert(trace->id() == id, "invariant");
-  trace->write(writer);
-  return id;
-}
-
-void JfrStackTraceRepository::write_metadata(JfrCheckpointWriter& writer) {
-  JfrFrameType fct;
-  writer.write_type(TYPE_FRAMETYPE);
-  fct.serialize(writer);
-}
-
 size_t JfrStackTraceRepository::clear() {
   MutexLocker lock(JfrStacktrace_lock, Mutex::_no_safepoint_check_flag);
   if (_entries == 0) {
@@ -142,7 +132,7 @@
   if (tl->has_cached_stack_trace()) {
     return tl->cached_stack_trace_id();
   }
-  if (!thread->is_Java_thread() || thread->is_hidden_from_external_view()) {
+  if (!thread->is_Java_thread() || thread->is_hidden_from_external_view() || tl->is_excluded()) {
     return 0;
   }
   JfrStackFrame* frames = tl->stackframes();
--- a/src/hotspot/share/jfr/recorder/stacktrace/jfrStackTraceRepository.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/stacktrace/jfrStackTraceRepository.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -40,7 +40,7 @@
   friend class ObjectSampleCheckpoint;
   friend class ObjectSampler;
   friend class StackTraceBlobInstaller;
-  friend class WriteStackTraceRepository;
+  friend class StackTraceRepository;
 
  private:
   static const u4 TABLE_SIZE = 2053;
@@ -51,19 +51,18 @@
   JfrStackTraceRepository();
   static JfrStackTraceRepository& instance();
   static JfrStackTraceRepository* create();
+  static void destroy();
   bool initialize();
-  static void destroy();
 
-  size_t write_impl(JfrChunkWriter& cw, bool clear);
-  static void write_metadata(JfrCheckpointWriter& cpw);
-  traceid write(JfrCheckpointWriter& cpw, traceid id, unsigned int hash);
+  bool is_modified() const;
   size_t write(JfrChunkWriter& cw, bool clear);
   size_t clear();
 
+  const JfrStackTrace* lookup(unsigned int hash, traceid id) const;
+
   traceid add_trace(const JfrStackTrace& stacktrace);
   static traceid add(const JfrStackTrace& stacktrace);
   traceid record_for(JavaThread* thread, int skip, JfrStackFrame* frames, u4 max_frames);
-  const JfrStackTrace* lookup(unsigned int hash, traceid id) const;
 
  public:
   static traceid record(Thread* thread, int skip = 0);
--- a/src/hotspot/share/jfr/recorder/storage/jfrBuffer.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/storage/jfrBuffer.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -54,10 +54,18 @@
   return true;
 }
 
-void JfrBuffer::reinitialize() {
+void JfrBuffer::reinitialize(bool exclusion /* false */) {
   assert(!lease(), "invariant");
   assert(!transient(), "invariant");
   set_pos(start());
+  if (exclusion != excluded()) {
+    // update
+    if (exclusion) {
+      set_excluded();
+    } else {
+      clear_excluded();
+    }
+  }
   clear_retired();
   set_top(start());
 }
@@ -80,7 +88,7 @@
 const u1* JfrBuffer::stable_top() const {
   const u1* current_top;
   do {
-    current_top = OrderAccess::load_acquire(&_top);
+    current_top = Atomic::load(&_top);
   } while (MUTEX_CLAIM == current_top);
   return current_top;
 }
@@ -107,7 +115,8 @@
   assert(new_top <= end(), "invariant");
   assert(new_top >= start(), "invariant");
   assert(top() == MUTEX_CLAIM, "invariant");
-  OrderAccess::release_store(&_top, new_top);
+  OrderAccess::storestore();
+  _top = new_top;
 }
 
 size_t JfrBuffer::unflushed_size() const {
@@ -118,18 +127,19 @@
   assert(id != NULL, "invariant");
   const void* current_id;
   do {
-    current_id = OrderAccess::load_acquire(&_identity);
+    current_id = Atomic::load(&_identity);
   } while (current_id != NULL || Atomic::cmpxchg(id, &_identity, current_id) != current_id);
 }
 
 bool JfrBuffer::try_acquire(const void* id) {
   assert(id != NULL, "invariant");
-  const void* const current_id = OrderAccess::load_acquire(&_identity);
+  const void* const current_id = Atomic::load(&_identity);
   return current_id == NULL && Atomic::cmpxchg(id, &_identity, current_id) == current_id;
 }
 
 void JfrBuffer::release() {
-  OrderAccess::release_store(&_identity, (const void*)NULL);
+  OrderAccess::storestore();
+  _identity = NULL;
 }
 
 bool JfrBuffer::acquired_by(const void* id) const {
@@ -186,7 +196,8 @@
 enum FLAG {
   RETIRED = 1,
   TRANSIENT = 2,
-  LEASE = 4
+  LEASE = 4,
+  EXCLUDED = 8
 };
 
 bool JfrBuffer::transient() const {
@@ -221,27 +232,35 @@
   assert(!lease(), "invariant");
 }
 
-static u2 load_acquire_flags(const u2* const flags) {
-  return OrderAccess::load_acquire(flags);
+bool JfrBuffer::excluded() const {
+  return (u1)EXCLUDED == (_flags & (u1)EXCLUDED);
 }
 
-static void release_store_flags(u2* const flags, u2 new_flags) {
-  OrderAccess::release_store(flags, new_flags);
+void JfrBuffer::set_excluded() {
+  _flags |= (u1)EXCLUDED;
+  assert(excluded(), "invariant");
+}
+
+void JfrBuffer::clear_excluded() {
+  if (excluded()) {
+    OrderAccess::storestore();
+    _flags ^= (u1)EXCLUDED;
+  }
+  assert(!excluded(), "invariant");
 }
 
 bool JfrBuffer::retired() const {
-  return (u1)RETIRED == (load_acquire_flags(&_flags) & (u1)RETIRED);
+  return (_flags & (u1)RETIRED) == (u1)RETIRED;
 }
 
 void JfrBuffer::set_retired() {
-  const u2 new_flags = load_acquire_flags(&_flags) | (u1)RETIRED;
-  release_store_flags(&_flags, new_flags);
+  OrderAccess::storestore();
+  _flags |= (u1)RETIRED;
 }
 
 void JfrBuffer::clear_retired() {
-  u2 new_flags = load_acquire_flags(&_flags);
-  if ((u1)RETIRED == (new_flags & (u1)RETIRED)) {
-    new_flags ^= (u1)RETIRED;
-    release_store_flags(&_flags, new_flags);
+  if (retired()) {
+    OrderAccess::storestore();
+    _flags ^= (u1)RETIRED;
   }
 }
--- a/src/hotspot/share/jfr/recorder/storage/jfrBuffer.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/storage/jfrBuffer.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -61,7 +61,7 @@
  public:
   JfrBuffer();
   bool initialize(size_t header_size, size_t size, const void* id = NULL);
-  void reinitialize();
+  void reinitialize(bool exclusion = false);
   void concurrent_reinitialization();
   size_t discard();
   JfrBuffer* next() const {
@@ -165,12 +165,15 @@
   bool retired() const;
   void set_retired();
   void clear_retired();
+
+  bool excluded() const;
+  void set_excluded();
+  void clear_excluded();
 };
 
 class JfrAgeNode : public JfrBuffer {
  private:
   JfrBuffer* _retired;
-
  public:
   JfrAgeNode() : _retired(NULL) {}
   void set_retired_buffer(JfrBuffer* retired) {
--- a/src/hotspot/share/jfr/recorder/storage/jfrMemorySpace.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/storage/jfrMemorySpace.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -99,8 +99,8 @@
   template <typename IteratorCallback, typename IteratorType>
   void iterate(IteratorCallback& callback, bool full = true, jfr_iter_direction direction = forward);
 
-  debug_only(bool in_full_list(const Type* t) const { return _full.in_list(t); })
-  debug_only(bool in_free_list(const Type* t) const { return _free.in_list(t); })
+  bool in_full_list(const Type* t) const { return _full.in_list(t); }
+  bool in_free_list(const Type* t) const { return _free.in_list(t); }
 };
 
 #endif // SHARE_JFR_RECORDER_STORAGE_JFRMEMORYSPACE_HPP
--- a/src/hotspot/share/jfr/recorder/storage/jfrMemorySpace.inline.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/storage/jfrMemorySpace.inline.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -141,6 +141,7 @@
   }
   assert(t->empty(), "invariant");
   assert(!t->retired(), "invariant");
+  assert(!t->excluded(), "invariant");
   assert(t->identity() == NULL, "invariant");
   if (!should_populate_cache()) {
     remove_free(t);
--- a/src/hotspot/share/jfr/recorder/storage/jfrStorage.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/storage/jfrStorage.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -26,6 +26,7 @@
 #include "jfr/jfrEvents.hpp"
 #include "jfr/jni/jfrJavaSupport.hpp"
 #include "jfr/recorder/jfrRecorder.hpp"
+#include "jfr/recorder/checkpoint/jfrCheckpointManager.hpp"
 #include "jfr/recorder/repository/jfrChunkWriter.hpp"
 #include "jfr/recorder/service/jfrOptionSet.hpp"
 #include "jfr/recorder/service/jfrPostBox.hpp"
@@ -253,6 +254,18 @@
     assert(buffer->empty(), "invariant");
     return true;
   }
+
+  if (buffer->excluded()) {
+    const bool thread_is_excluded = thread->jfr_thread_local()->is_excluded();
+    buffer->reinitialize(thread_is_excluded);
+    assert(buffer->empty(), "invariant");
+    if (!thread_is_excluded) {
+      // state change from exclusion to inclusion requires a thread checkpoint
+      JfrCheckpointManager::write_thread_checkpoint(thread);
+    }
+    return true;
+  }
+
   BufferPtr const promotion_buffer = get_promotion_buffer(unflushed_size, _global_mspace, *this, promotion_retry, thread);
   if (promotion_buffer == NULL) {
     write_data_loss(buffer, thread);
@@ -301,7 +314,7 @@
   assert(buffer != NULL, "invariant");
   assert(buffer->retired(), "invariant");
   const size_t unflushed_size = buffer->unflushed_size();
-  buffer->reinitialize();
+  buffer->concurrent_reinitialization();
   log_registration_failure(unflushed_size);
 }
 
@@ -470,6 +483,7 @@
   assert(t != NULL, "invariant");
   assert(cur != NULL, "invariant");
   assert(cur->lease(), "invariant");
+  assert(!cur->excluded(), "invariant");
   assert(cur_pos != NULL, "invariant");
   assert(native ? t->jfr_thread_local()->native_buffer() == cur : t->jfr_thread_local()->java_buffer() == cur, "invariant");
   assert(t->jfr_thread_local()->shelved_buffer() != NULL, "invariant");
@@ -496,6 +510,9 @@
   // the case for stable thread local buffers; it is not the case for large buffers.
   if (!cur->empty()) {
     flush_regular_buffer(cur, t);
+    if (cur->excluded()) {
+      return cur;
+    }
   }
   assert(t->jfr_thread_local()->shelved_buffer() == NULL, "invariant");
   if (cur->free_size() >= req) {
@@ -584,28 +601,40 @@
 typedef UnBufferedWriteToChunk<JfrBuffer> WriteOperation;
 typedef MutexedWriteOp<WriteOperation> MutexedWriteOperation;
 typedef ConcurrentWriteOp<WriteOperation> ConcurrentWriteOperation;
-typedef ConcurrentWriteOpExcludeRetired<WriteOperation> ThreadLocalConcurrentWriteOperation;
+
+typedef Retired<JfrBuffer, true> NonRetired;
+typedef Excluded<JfrBuffer, true> NonExcluded;
+typedef CompositeOperation<NonRetired, NonExcluded> BufferPredicate;
+typedef PredicatedMutexedWriteOp<WriteOperation, BufferPredicate> ThreadLocalMutexedWriteOperation;
+typedef PredicatedConcurrentWriteOp<WriteOperation, BufferPredicate> ThreadLocalConcurrentWriteOperation;
 
 size_t JfrStorage::write() {
-  const size_t full_size_processed = write_full();
+  const size_t full_elements = write_full();
   WriteOperation wo(_chunkwriter);
-  ThreadLocalConcurrentWriteOperation tlwo(wo);
+  NonRetired nr;
+  NonExcluded ne;
+  BufferPredicate bp(&nr, &ne);
+  ThreadLocalConcurrentWriteOperation tlwo(wo, bp);
   process_full_list(tlwo, _thread_local_mspace);
   ConcurrentWriteOperation cwo(wo);
   process_free_list(cwo, _global_mspace);
-  return full_size_processed + wo.processed();
+  return full_elements + wo.elements();
 }
 
 size_t JfrStorage::write_at_safepoint() {
   assert(SafepointSynchronize::is_at_safepoint(), "invariant");
   WriteOperation wo(_chunkwriter);
   MutexedWriteOperation writer(wo); // mutexed write mode
-  process_full_list(writer, _thread_local_mspace);
+  NonRetired nr;
+  NonExcluded ne;
+  BufferPredicate bp(&nr, &ne);
+  ThreadLocalMutexedWriteOperation tlmwo(wo, bp);
+  process_full_list(tlmwo, _thread_local_mspace);
   assert(_transient_mspace->is_free_empty(), "invariant");
   process_full_list(writer, _transient_mspace);
   assert(_global_mspace->is_full_empty(), "invariant");
   process_free_list(writer, _global_mspace);
-  return wo.processed();
+  return wo.elements();
 }
 
 typedef DiscardOp<DefaultDiscarder<JfrStorage::Buffer> > DiscardOperation;
@@ -613,14 +642,14 @@
 typedef CompositeOperation<MutexedWriteOperation, ReleaseOperation> FullOperation;
 
 size_t JfrStorage::clear() {
-  const size_t full_size_processed = clear_full();
+  const size_t full_elements = clear_full();
   DiscardOperation discarder(concurrent); // concurrent discard mode
   process_full_list(discarder, _thread_local_mspace);
   assert(_transient_mspace->is_free_empty(), "invariant");
   process_full_list(discarder, _transient_mspace);
   assert(_global_mspace->is_full_empty(), "invariant");
   process_free_list(discarder, _global_mspace);
-  return full_size_processed + discarder.processed();
+  return full_elements + discarder.elements();
 }
 
 static void insert_free_age_nodes(JfrStorageAgeMspace* age_mspace, JfrAgeNode* head, JfrAgeNode* tail, size_t count) {
@@ -711,15 +740,25 @@
   ReleaseOperation ro(_transient_mspace, thread);
   FullOperation cmd(&writer, &ro);
   const size_t count = process_full(cmd, control(), _age_mspace);
-  log(count, writer.processed());
-  return writer.processed();
+  if (0 == count) {
+    assert(0 == writer.elements(), "invariant");
+    return 0;
+  }
+  const size_t size = writer.size();
+  log(count, size);
+  return count;
 }
 
 size_t JfrStorage::clear_full() {
   DiscardOperation discarder(mutexed); // a retired buffer implies mutexed access
   const size_t count = process_full(discarder, control(), _age_mspace);
-  log(count, discarder.processed(), true);
-  return discarder.processed();
+  if (0 == count) {
+    assert(0 == discarder.elements(), "invariant");
+    return 0;
+  }
+  const size_t size = discarder.size();
+  log(count, size, true);
+  return count;
 }
 
 static void scavenge_log(size_t count, size_t amount, size_t current) {
@@ -749,6 +788,10 @@
       assert(!t->lease(), "invariant");
       ++_count;
       _amount += t->total_size();
+      if (t->excluded()) {
+        t->clear_excluded();
+      }
+      assert(!t->excluded(), "invariant");
       t->clear_retired();
       t->release();
       _control.decrement_dead();
@@ -767,6 +810,11 @@
   }
   Scavenger<JfrThreadLocalMspace> scavenger(ctrl, _thread_local_mspace);
   process_full_list(scavenger, _thread_local_mspace);
-  scavenge_log(scavenger.processed(), scavenger.amount(), ctrl.dead_count());
-  return scavenger.processed();
+  const size_t count = scavenger.processed();
+  if (0 == count) {
+    assert(0 == scavenger.amount(), "invariant");
+    return 0;
+  }
+  scavenge_log(count, scavenger.amount(), ctrl.dead_count());
+  return count;
 }
--- a/src/hotspot/share/jfr/recorder/storage/jfrStorage.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/storage/jfrStorage.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -68,7 +68,6 @@
 
   size_t clear();
   size_t clear_full();
-  size_t write();
   size_t write_full();
   size_t write_at_safepoint();
   size_t scavenge();
@@ -89,6 +88,8 @@
   void discard_oldest(Thread* t);
   static JfrStorageControl& control();
 
+  size_t write();
+
   friend class JfrRecorder;
   friend class JfrRecorderService;
   template <typename, template <typename> class, typename>
--- a/src/hotspot/share/jfr/recorder/storage/jfrStorageControl.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/storage/jfrStorageControl.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -26,14 +26,13 @@
 #include "jfr/recorder/storage/jfrStorageControl.hpp"
 #include "runtime/atomic.hpp"
 #include "runtime/mutexLocker.hpp"
-#include "runtime/orderAccess.hpp"
 
 // returns the updated value
 static jlong atomic_add(size_t value, size_t volatile* const dest) {
   size_t compare_value;
   size_t exchange_value;
   do {
-    compare_value = OrderAccess::load_acquire(dest);
+    compare_value = *dest;
     exchange_value = compare_value + value;
   } while (Atomic::cmpxchg(exchange_value, dest, compare_value) != compare_value);
   return exchange_value;
@@ -43,7 +42,7 @@
   size_t compare_value;
   size_t exchange_value;
   do {
-    compare_value = OrderAccess::load_acquire(dest);
+    compare_value = *dest;
     assert(compare_value >= 1, "invariant");
     exchange_value = compare_value - 1;
   } while (Atomic::cmpxchg(exchange_value, dest, compare_value) != compare_value);
@@ -102,7 +101,7 @@
 // concurrent with accuracy requirement
 
 size_t JfrStorageControl::global_lease_count() const {
-  return OrderAccess::load_acquire(&_global_lease_count);
+  return Atomic::load(&_global_lease_count);
 }
 
 size_t JfrStorageControl::increment_leased() {
--- a/src/hotspot/share/jfr/recorder/storage/jfrStorageUtils.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/storage/jfrStorageUtils.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -31,7 +31,21 @@
 #include "jfr/utilities/jfrTypes.hpp"
 #include "runtime/thread.hpp"
 
-template <typename Operation, typename NextOperation>
+class CompositeOperationOr {
+ public:
+  static bool evaluate(bool value) {
+    return !value;
+  }
+};
+
+class CompositeOperationAnd {
+ public:
+  static bool evaluate(bool value) {
+    return value;
+  }
+};
+
+template <typename Operation, typename NextOperation, typename TruthFunction = CompositeOperationAnd>
 class CompositeOperation {
  private:
   Operation* _op;
@@ -41,11 +55,15 @@
     assert(_op != NULL, "invariant");
   }
   typedef typename Operation::Type Type;
-  bool process(Type* t = NULL) {
-    return _next == NULL ? _op->process(t) : _op->process(t) && _next->process(t);
+  bool process(Type* t) {
+    const bool op_result = _op->process(t);
+    return _next == NULL ? op_result : TruthFunction::evaluate(op_result) ? _next->process(t) : op_result;
   }
-  size_t processed() const {
-    return _next == NULL ? _op->processed() : _op->processed() + _next->processed();
+  size_t elements() const {
+    return _next == NULL ? _op->elements() : _op->elements() + _next->elements();
+  }
+  size_t size() const {
+    return _next == NULL ? _op->size() : _op->size() + _next->size();
   }
 };
 
@@ -53,23 +71,71 @@
 class UnBufferedWriteToChunk {
  private:
   JfrChunkWriter& _writer;
-  size_t _processed;
+  size_t _elements;
+  size_t _size;
  public:
   typedef T Type;
-  UnBufferedWriteToChunk(JfrChunkWriter& writer) : _writer(writer), _processed(0) {}
+  UnBufferedWriteToChunk(JfrChunkWriter& writer) : _writer(writer), _elements(0), _size(0) {}
   bool write(Type* t, const u1* data, size_t size);
-  size_t processed() { return _processed; }
+  size_t elements() const { return _elements; }
+  size_t size() const { return _size; }
 };
 
 template <typename T>
 class DefaultDiscarder {
  private:
-  size_t _processed;
+  size_t _elements;
+  size_t _size;
  public:
   typedef T Type;
-  DefaultDiscarder() : _processed() {}
+  DefaultDiscarder() : _elements(0), _size(0) {}
   bool discard(Type* t, const u1* data, size_t size);
-  size_t processed() const { return _processed; }
+  size_t elements() const { return _elements; }
+  size_t size() const { return _size; }
+};
+
+template <typename T, bool negation>
+class Retired {
+ public:
+  typedef T Type;
+  bool process(Type* t) {
+    assert(t != NULL, "invariant");
+    return negation ? !t->retired() : t->retired();
+  }
+};
+
+template <typename T, bool negation>
+class Excluded {
+ public:
+  typedef T Type;
+  bool process(Type* t) {
+    assert(t != NULL, "invariant");
+    return negation ? !t->excluded() : t->excluded();
+  }
+};
+
+template <typename Operation>
+class MutexedWriteOp {
+ private:
+  Operation& _operation;
+ public:
+  typedef typename Operation::Type Type;
+  MutexedWriteOp(Operation& operation) : _operation(operation) {}
+  bool process(Type* t);
+  size_t elements() const { return _operation.elements(); }
+  size_t size() const { return _operation.size(); }
+};
+
+template <typename Operation, typename Predicate>
+class PredicatedMutexedWriteOp : public MutexedWriteOp<Operation> {
+ private:
+  Predicate& _predicate;
+ public:
+  PredicatedMutexedWriteOp(Operation& operation, Predicate& predicate) :
+    MutexedWriteOp<Operation>(operation), _predicate(predicate) {}
+  bool process(typename Operation::Type* t) {
+    return _predicate.process(t) ? MutexedWriteOp<Operation>::process(t) : true;
+  }
 };
 
 template <typename Operation>
@@ -80,27 +146,20 @@
   typedef typename Operation::Type Type;
   ConcurrentWriteOp(Operation& operation) : _operation(operation) {}
   bool process(Type* t);
-  size_t processed() const { return _operation.processed(); }
+  size_t elements() const { return _operation.elements(); }
+  size_t size() const { return _operation.size(); }
 };
 
-template <typename Operation>
-class ConcurrentWriteOpExcludeRetired : private ConcurrentWriteOp<Operation> {
+template <typename Operation, typename Predicate>
+class PredicatedConcurrentWriteOp : public ConcurrentWriteOp<Operation> {
+ private:
+  Predicate& _predicate;
  public:
-  typedef typename Operation::Type Type;
-  ConcurrentWriteOpExcludeRetired(Operation& operation) : ConcurrentWriteOp<Operation>(operation) {}
-  bool process(Type* t);
-  size_t processed() const { return ConcurrentWriteOp<Operation>::processed(); }
-};
-
-template <typename Operation>
-class MutexedWriteOp {
- private:
-  Operation& _operation;
- public:
-  typedef typename Operation::Type Type;
-  MutexedWriteOp(Operation& operation) : _operation(operation) {}
-  bool process(Type* t);
-  size_t processed() const { return _operation.processed(); }
+  PredicatedConcurrentWriteOp(Operation& operation, Predicate& predicate) :
+    ConcurrentWriteOp<Operation>(operation), _predicate(predicate) {}
+  bool process(typename Operation::Type* t) {
+    return _predicate.process(t) ? ConcurrentWriteOp<Operation>::process(t) : true;
+  }
 };
 
 template <typename Operation>
@@ -126,7 +185,8 @@
   typedef typename Operation::Type Type;
   DiscardOp(jfr_operation_mode mode = concurrent) : _operation(), _mode(mode) {}
   bool process(Type* t);
-  size_t processed() const { return _operation.processed(); }
+  size_t elements() const { return _operation.elements(); }
+  size_t size() const { return _operation.size(); }
 };
 
 #endif // SHARE_JFR_RECORDER_STORAGE_JFRSTORAGEUTILS_HPP
--- a/src/hotspot/share/jfr/recorder/storage/jfrStorageUtils.inline.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/storage/jfrStorageUtils.inline.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -31,13 +31,15 @@
 template <typename T>
 inline bool UnBufferedWriteToChunk<T>::write(T* t, const u1* data, size_t size) {
   _writer.write_unbuffered(data, size);
-  _processed += size;
+  ++_elements;
+  _size += size;
   return true;
 }
 
 template <typename T>
 inline bool DefaultDiscarder<T>::discard(T* t, const u1* data, size_t size) {
-  _processed += size;
+  ++_elements;
+  _size += size;
   return true;
 }
 
@@ -55,15 +57,6 @@
 }
 
 template <typename Operation>
-inline bool ConcurrentWriteOpExcludeRetired<Operation>::process(typename Operation::Type* t) {
-  if (t->retired()) {
-    assert(t->empty(), "invariant");
-    return true;
-  }
-  return ConcurrentWriteOp<Operation>::process(t);
-}
-
-template <typename Operation>
 inline bool MutexedWriteOp<Operation>::process(typename Operation::Type* t) {
   assert(t != NULL, "invariant");
   const u1* const current_top = t->top();
--- a/src/hotspot/share/jfr/recorder/storage/jfrVirtualMemory.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/storage/jfrVirtualMemory.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -26,7 +26,6 @@
 #include "jfr/recorder/storage/jfrVirtualMemory.hpp"
 #include "memory/virtualspace.hpp"
 #include "runtime/globals.hpp"
-#include "runtime/orderAccess.hpp"
 #include "runtime/os.hpp"
 #include "services/memTracker.hpp"
 #include "utilities/globalDefinitions.hpp"
--- a/src/hotspot/share/jfr/recorder/stringpool/jfrStringPool.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/stringpool/jfrStringPool.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -33,7 +33,6 @@
 #include "jfr/recorder/stringpool/jfrStringPoolWriter.hpp"
 #include "jfr/utilities/jfrTypes.hpp"
 #include "logging/log.hpp"
-#include "runtime/atomic.hpp"
 #include "runtime/mutexLocker.hpp"
 #include "runtime/orderAccess.hpp"
 #include "runtime/safepoint.hpp"
@@ -42,12 +41,42 @@
 typedef JfrStringPool::Buffer* BufferPtr;
 
 static JfrStringPool* _instance = NULL;
+static uint64_t store_generation = 0;
+static uint64_t serialized_generation = 0;
+
+inline void set_generation(uint64_t value, uint64_t* const dest) {
+  assert(dest != NULL, "invariant");
+  OrderAccess::release_store(dest, value);
+}
+static void increment_store_generation() {
+  const uint64_t current_serialized = OrderAccess::load_acquire(&serialized_generation);
+  const uint64_t current_stored = OrderAccess::load_acquire(&store_generation);
+  if (current_serialized == current_stored) {
+    set_generation(current_serialized + 1, &store_generation);
+  }
+}
+
+static bool increment_serialized_generation() {
+  const uint64_t current_stored = OrderAccess::load_acquire(&store_generation);
+  const uint64_t current_serialized = OrderAccess::load_acquire(&serialized_generation);
+  if (current_stored != current_serialized) {
+    set_generation(current_stored, &serialized_generation);
+    return true;
+  }
+  return false;
+}
+
+bool JfrStringPool::is_modified() {
+  return increment_serialized_generation();
+}
 
 JfrStringPool& JfrStringPool::instance() {
   return *_instance;
 }
 
 JfrStringPool* JfrStringPool::create(JfrChunkWriter& cw) {
+  store_generation = 0;
+  serialized_generation = 0;
   assert(_instance == NULL, "invariant");
   _instance = new JfrStringPool(cw);
   return _instance;
@@ -131,12 +160,16 @@
 bool JfrStringPool::add(bool epoch, jlong id, jstring string, JavaThread* jt) {
   assert(jt != NULL, "invariant");
   const bool current_epoch = JfrTraceIdEpoch::epoch();
-  if (current_epoch == epoch) {
+  if (current_epoch != epoch) {
+    return current_epoch;
+  }
+  {
     JfrStringPoolWriter writer(jt);
     writer.write(id);
     writer.write(string);
     writer.inc_nof_strings();
   }
+  increment_store_generation();
   return current_epoch;
 }
 
@@ -163,9 +196,10 @@
   size_t processed() { return _strings_processed; }
 };
 
-template <typename Type>
+template <typename T>
 class StringPoolDiscarderStub {
  public:
+  typedef T Type;
   bool write(Type* buffer, const u1* data, size_t size) {
     // stub only, discard happens at higher level
     return true;
@@ -197,6 +231,7 @@
 }
 
 size_t JfrStringPool::clear() {
+  increment_serialized_generation();
   DiscardOperation discard_operation;
   ExclusiveDiscardOperation edo(discard_operation);
   StringPoolReleaseOperation spro(_free_list_mspace, Thread::current(), false);
--- a/src/hotspot/share/jfr/recorder/stringpool/jfrStringPool.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/recorder/stringpool/jfrStringPool.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -71,6 +71,7 @@
   static JfrStringPool* create(JfrChunkWriter& cw);
   bool initialize();
   static void destroy();
+  static bool is_modified();
 
   friend class JfrRecorder;
   friend class JfrRecorderService;
--- a/src/hotspot/share/jfr/support/jfrThreadLocal.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/support/jfrThreadLocal.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -55,6 +55,7 @@
   _stack_trace_hash(0),
   _stackdepth(0),
   _entering_suspend_flag(0),
+  _excluded(false),
   _dead(false) {}
 
 u8 JfrThreadLocal::add_data_lost(u8 value) {
@@ -84,9 +85,13 @@
 void JfrThreadLocal::on_start(Thread* t) {
   assert(t != NULL, "invariant");
   assert(Thread::current() == t, "invariant");
+  JfrJavaSupport::on_thread_start(t);
   if (JfrRecorder::is_recording()) {
-    if (t->is_Java_thread()) {
-      send_java_thread_start_event((JavaThread*)t);
+    if (!t->jfr_thread_local()->is_excluded()) {
+      JfrCheckpointManager::write_thread_checkpoint(t);
+      if (t->is_Java_thread()) {
+        send_java_thread_start_event((JavaThread*)t);
+      }
     }
   }
 }
@@ -103,48 +108,68 @@
   }
 }
 
+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;
+  }
+  if (has_native_buffer()) {
+    JfrStorage::release_thread_local(native_buffer(), t);
+    _native_buffer = NULL;
+  }
+  if (has_java_buffer()) {
+    JfrStorage::release_thread_local(java_buffer(), t);
+    _java_buffer = NULL;
+  }
+  if (_stackframes != NULL) {
+    FREE_C_HEAP_ARRAY(JfrStackFrame, _stackframes);
+    _stackframes = NULL;
+  }
+}
+
 void JfrThreadLocal::release(JfrThreadLocal* tl, Thread* t) {
   assert(tl != NULL, "invariant");
   assert(t != NULL, "invariant");
   assert(Thread::current() == t, "invariant");
   assert(!tl->is_dead(), "invariant");
   assert(tl->shelved_buffer() == NULL, "invariant");
-  if (tl->has_native_buffer()) {
-    JfrStorage::release_thread_local(tl->native_buffer(), t);
-  }
-  if (tl->has_java_buffer()) {
-    JfrStorage::release_thread_local(tl->java_buffer(), t);
-  }
-  if (tl->has_java_event_writer()) {
-    assert(t->is_Java_thread(), "invariant");
-    JfrJavaSupport::destroy_global_jni_handle(tl->java_event_writer());
-  }
-  FREE_C_HEAP_ARRAY(JfrStackFrame, tl->_stackframes);
   tl->_dead = true;
+  tl->release(t);
 }
 
 void JfrThreadLocal::on_exit(Thread* t) {
   assert(t != NULL, "invariant");
   JfrThreadLocal * const tl = t->jfr_thread_local();
   assert(!tl->is_dead(), "invariant");
-  if (t->is_Java_thread()) {
-    JavaThread* const jt = (JavaThread*)t;
-    ObjectSampleCheckpoint::on_thread_exit(jt);
-    send_java_thread_end_events(tl->thread_id(), jt);
+  if (JfrRecorder::is_recording()) {
+    if (t->is_Java_thread()) {
+      JavaThread* const jt = (JavaThread*)t;
+      ObjectSampleCheckpoint::on_thread_exit(jt);
+      send_java_thread_end_events(tl->thread_id(), jt);
+    }
   }
   release(tl, Thread::current()); // because it could be that Thread::current() != t
 }
 
+static JfrBuffer* acquire_buffer(bool excluded) {
+  JfrBuffer* const buffer = JfrStorage::acquire_thread_local(Thread::current());
+  if (buffer != NULL && excluded) {
+    buffer->set_excluded();
+  }
+  return buffer;
+}
+
 JfrBuffer* JfrThreadLocal::install_native_buffer() const {
   assert(!has_native_buffer(), "invariant");
-  _native_buffer = JfrStorage::acquire_thread_local(Thread::current());
+  _native_buffer = acquire_buffer(_excluded);
   return _native_buffer;
 }
 
 JfrBuffer* JfrThreadLocal::install_java_buffer() const {
   assert(!has_java_buffer(), "invariant");
   assert(!has_java_event_writer(), "invariant");
-  _java_buffer = JfrStorage::acquire_thread_local(Thread::current());
+  _java_buffer = acquire_buffer(_excluded);
   return _java_buffer;
 }
 
@@ -162,6 +187,18 @@
   return in_ByteSize(offset_of(JfrThreadLocal, _java_event_writer));
 }
 
+void JfrThreadLocal::exclude(Thread* t) {
+  assert(t != NULL, "invariant");
+  t->jfr_thread_local()->_excluded = true;
+  t->jfr_thread_local()->release(t);
+}
+
+void JfrThreadLocal::include(Thread* t) {
+  assert(t != NULL, "invariant");
+  t->jfr_thread_local()->_excluded = false;
+  t->jfr_thread_local()->release(t);
+}
+
 u4 JfrThreadLocal::stackdepth() const {
   return _stackdepth != 0 ? _stackdepth : (u4)JfrOptionSet::stackdepth();
 }
--- a/src/hotspot/share/jfr/support/jfrThreadLocal.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/support/jfrThreadLocal.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -50,12 +50,13 @@
   unsigned int _stack_trace_hash;
   mutable u4 _stackdepth;
   volatile jint _entering_suspend_flag;
+  bool _excluded;
   bool _dead;
 
   JfrBuffer* install_native_buffer() const;
   JfrBuffer* install_java_buffer() const;
   JfrStackFrame* install_stackframes() const;
-
+  void release(Thread* t);
   static void release(JfrThreadLocal* tl, Thread* t);
 
  public:
@@ -203,6 +204,10 @@
     _trace_id = id;
   }
 
+  bool is_excluded() const {
+    return _excluded;
+  }
+
   bool is_dead() const {
     return _dead;
   }
@@ -211,6 +216,9 @@
   void set_thread_blob(const JfrBlobHandle& handle);
   const JfrBlobHandle& thread_blob() const;
 
+  static void exclude(Thread* t);
+  static void include(Thread* t);
+
   static void on_start(Thread* t);
   static void on_exit(Thread* t);
 
--- a/src/hotspot/share/jfr/support/jfrTraceIdExtension.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/support/jfrTraceIdExtension.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -69,7 +69,7 @@
 
   jbyte* meta_addr() const {
 #ifdef VM_LITTLE_ENDIAN
-    return (jbyte*)(&_flags) + 1;
+    return ((jbyte*)&_flags) + 1;
 #else
     return (jbyte*)&_flags;
 #endif
--- a/src/hotspot/share/jfr/utilities/jfrAllocation.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/utilities/jfrAllocation.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -28,7 +28,6 @@
 #include "logging/log.hpp"
 #include "memory/allocation.inline.hpp"
 #include "runtime/atomic.hpp"
-#include "runtime/orderAccess.hpp"
 #include "runtime/vm_version.hpp"
 #include "utilities/debug.hpp"
 #include "utilities/macros.hpp"
@@ -40,7 +39,7 @@
   jlong compare_value;
   jlong exchange_value;
   do {
-    compare_value = OrderAccess::load_acquire(dest);
+    compare_value = *dest;
     exchange_value = compare_value + value;
   } while (Atomic::cmpxchg(exchange_value, dest, compare_value) != compare_value);
   return exchange_value;
--- a/src/hotspot/share/jfr/utilities/jfrDoublyLinkedList.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/utilities/jfrDoublyLinkedList.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -48,8 +48,8 @@
   void prepend(T* const node);
   void append(T* const node);
   void append_list(T* const head_node, T* const tail_node, size_t count);
-  debug_only(bool in_list(const T* const target_node) const;)
-  debug_only(bool locate(const T* start_node, const T* const target_node) const;)
+  bool in_list(const T* const target_node) const;
+  bool locate(const T* start_node, const T* const target_node) const;
 };
 
 template <typename T>
@@ -153,7 +153,6 @@
   return node;
 }
 
-#ifdef ASSERT
 template <typename T>
 bool JfrDoublyLinkedList<T>::locate(const T* node, const T* const target) const {
   assert(target != NULL, "invariant");
@@ -182,7 +181,6 @@
   }
   assert(count_param == count, "invariant");
 }
-#endif // ASSERT
 
 template <typename T>
 void JfrDoublyLinkedList<T>::append_list(T* const head_node, T* const tail_node, size_t count) {
--- a/src/hotspot/share/jfr/utilities/jfrLogTagSets.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/utilities/jfrLogTagSets.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -53,6 +53,7 @@
   JFR_LOG_TAG(jfr, system, bytecode) \
   JFR_LOG_TAG(jfr, system, parser) \
   JFR_LOG_TAG(jfr, system, metadata) \
+  JFR_LOG_TAG(jfr, system, streaming) \
   JFR_LOG_TAG(jfr, metadata) \
   JFR_LOG_TAG(jfr, event) \
   JFR_LOG_TAG(jfr, setting) \
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/jfr/utilities/jfrThreadIterator.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "jfr/support/jfrThreadLocal.hpp"
+#include "jfr/utilities/jfrThreadIterator.hpp"
+#include "runtime/thread.inline.hpp"
+
+static bool thread_inclusion_predicate(Thread* t) {
+  assert(t != NULL, "invariant");
+  return !t->jfr_thread_local()->is_dead();
+}
+
+static bool java_thread_inclusion_predicate(JavaThread* jt) {
+  assert(jt != NULL, "invariant");
+  return thread_inclusion_predicate(jt) && jt->thread_state() != _thread_new;
+}
+
+static JavaThread* next_java_thread(JavaThreadIteratorWithHandle& iter) {
+  JavaThread* next = iter.next();
+  while (next != NULL && !java_thread_inclusion_predicate(next)) {
+    next = iter.next();
+  }
+  return next;
+}
+
+static NonJavaThread* next_non_java_thread(NonJavaThread::Iterator& iter) {
+  NonJavaThread* next = NULL;
+  while (!iter.end()) {
+    next = iter.current();
+    iter.step();
+    assert(next != NULL, "invariant");
+    if (!thread_inclusion_predicate(next)) {
+      continue;
+    }
+  }
+  return next;
+}
+
+JfrJavaThreadIteratorAdapter::JfrJavaThreadIteratorAdapter() : _iter(), _next(next_java_thread(_iter)) {}
+
+JavaThread* JfrJavaThreadIteratorAdapter::next() {
+  assert(has_next(), "invariant");
+  Type* const temp = _next;
+  _next = next_java_thread(_iter);
+  assert(temp != _next, "invariant");
+  return temp;
+}
+
+JfrNonJavaThreadIteratorAdapter::JfrNonJavaThreadIteratorAdapter() : _iter(), _next(next_non_java_thread(_iter)) {}
+
+bool JfrNonJavaThreadIteratorAdapter::has_next() const {
+  return _next != NULL;
+}
+
+NonJavaThread* JfrNonJavaThreadIteratorAdapter::next() {
+  assert(has_next(), "invariant");
+  Type* const temp = _next;
+  _next = next_non_java_thread(_iter);
+  assert(temp != _next, "invariant");
+  return temp;
+}
+
+// explicit instantiations
+template class JfrThreadIterator<JfrJavaThreadIteratorAdapter, StackObj>;
+template class JfrThreadIterator<JfrNonJavaThreadIteratorAdapter, StackObj>;
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/jfr/utilities/jfrThreadIterator.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_JFR_UTILITIES_JFRTHREADITERATOR_HPP
+#define SHARE_VM_JFR_UTILITIES_JFRTHREADITERATOR_HPP
+
+#include "memory/allocation.hpp"
+#include "runtime/thread.hpp"
+#include "runtime/threadSMR.hpp"
+
+template <typename Adapter, typename AP = StackObj>
+class JfrThreadIterator : public AP {
+ private:
+  Adapter _adapter;
+ public:
+  JfrThreadIterator() : _adapter() {}
+  typename Adapter::Type* next() {
+    assert(has_next(), "invariant");
+    return _adapter.next();
+  }
+  bool has_next() const {
+    return _adapter.has_next();
+  }
+};
+
+class JfrJavaThreadIteratorAdapter {
+ private:
+  JavaThreadIteratorWithHandle _iter;
+  JavaThread* _next;
+ public:
+  typedef JavaThread Type;
+  JfrJavaThreadIteratorAdapter();
+  bool has_next() const {
+    return _next != NULL;
+  }
+  Type* next();
+};
+
+class JfrNonJavaThreadIteratorAdapter {
+ private:
+  NonJavaThread::Iterator _iter;
+  NonJavaThread* _next;
+ public:
+  typedef NonJavaThread Type;
+  JfrNonJavaThreadIteratorAdapter();
+  bool has_next() const;
+  Type* next();
+};
+
+typedef JfrThreadIterator<JfrJavaThreadIteratorAdapter, StackObj> JfrJavaThreadIterator;
+typedef JfrThreadIterator<JfrNonJavaThreadIteratorAdapter, StackObj> JfrNonJavaThreadIterator;
+
+#endif // SHARE_VM_JFR_UTILITIES_JFRTHREADITERATOR_HPP
--- a/src/hotspot/share/jfr/utilities/jfrTypes.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/utilities/jfrTypes.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -26,11 +26,14 @@
 #define SHARE_JFR_UTILITIES_JFRTYPES_HPP
 
 #include "jfrfiles/jfrEventIds.hpp"
+#include "utilities/globalDefinitions.hpp"
 
 typedef u8 traceid;
 typedef int fio_fd;
+
 const int invalid_fd = -1;
 const jlong invalid_offset = -1;
+const int64_t invalid_time = -1;
 const u4 STACK_DEPTH_DEFAULT = 64;
 const u4 MIN_STACK_DEPTH = 1;
 const u4 MAX_STACK_DEPTH = 2048;
@@ -48,4 +51,12 @@
   TIMED
 };
 
+enum JfrCheckpointType {
+  GENERIC,
+  FLUSH,
+  HEADER,
+  STATICS = 4,
+  THREADS = 8
+};
+
 #endif // SHARE_JFR_UTILITIES_JFRTYPES_HPP
--- a/src/hotspot/share/jfr/writers/jfrJavaEventWriter.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/writers/jfrJavaEventWriter.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -32,9 +32,9 @@
 class Thread;
 
 class JfrJavaEventWriter : AllStatic {
-  friend class JfrCheckpointThreadClosure;
+  friend class JfrNotifyClosure;
+  friend class JfrJavaEventWriterNotifyOperation;
   friend class JfrJavaEventWriterNotificationClosure;
-  friend class JfrJavaEventWriterNotifyOperation;
   friend class JfrRecorder;
  private:
   static bool initialize();
--- a/src/hotspot/share/jfr/writers/jfrStorageAdapter.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/writers/jfrStorageAdapter.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -82,7 +82,7 @@
     assert(_thread != NULL, "invariant");
     Flush f(_storage, used, requested, _thread);
     _storage = f.result();
-    return _storage != NULL;
+    return _storage != NULL && !_storage->excluded();
   }
 
   void release() {
@@ -236,7 +236,8 @@
   void release() {}
   bool flush(size_t used, size_t requested) {
     // don't flush/expand a buffer that is not our own
-    return false;
+    _pos = _start;
+    return true;
   }
 };
 
--- a/src/hotspot/share/jfr/writers/jfrWriterHost.inline.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/jfr/writers/jfrWriterHost.inline.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -114,10 +114,7 @@
 template <typename BE, typename IE, typename WriterPolicyImpl >
 template <typename T>
 inline void WriterHost<BE, IE, WriterPolicyImpl>::be_write(T value) {
-  u1* const pos = ensure_size(sizeof(T));
-  if (pos) {
-    this->set_current_pos(BE::be_write(&value, 1, pos));
-  }
+  be_write(&value, 1);
 }
 
 template <typename BE, typename IE, typename WriterPolicyImpl >
--- a/src/hotspot/share/logging/logTag.hpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/logging/logTag.hpp	Wed Oct 30 19:43:52 2019 +0100
@@ -148,6 +148,7 @@
   LOG_TAG(startuptime) \
   LOG_TAG(state) \
   LOG_TAG(stats) \
+  LOG_TAG(streaming) \
   LOG_TAG(stringdedup) \
   LOG_TAG(stringtable) \
   LOG_TAG(symboltable) \
--- a/src/hotspot/share/runtime/mutexLocker.cpp	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/hotspot/share/runtime/mutexLocker.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -312,7 +312,7 @@
 #if INCLUDE_JFR
   def(JfrMsg_lock                  , PaddedMonitor, leaf,        true,  _safepoint_check_always);
   def(JfrBuffer_lock               , PaddedMutex  , leaf,        true,  _safepoint_check_never);
-  def(JfrStream_lock               , PaddedMutex  , leaf+1,      true,  _safepoint_check_never);      // ensure to rank lower than 'safepoint'
+  def(JfrStream_lock               , PaddedMutex  , nonleaf + 1, false, _safepoint_check_always);
   def(JfrStacktrace_lock           , PaddedMutex  , special,     true,  _safepoint_check_never);
   def(JfrThreadSampler_lock        , PaddedMonitor, leaf,        true,  _safepoint_check_never);
 #endif
--- a/src/jdk.jfr/share/classes/jdk/jfr/Recording.java	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/jdk.jfr/share/classes/jdk/jfr/Recording.java	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -413,6 +413,36 @@
         internal.setMaxSize(maxSize);
     }
 
+        /**
+         * Determines how often events are made available for streaming.
+         *
+         * @param interval the interval at which events are made available for streaming.
+         *
+         * @throws IllegalArgumentException if {@code interval} is negative
+         *
+         * @throws IllegalStateException if the recording is in the {@code CLOSED} state
+         *
+         * @since 14
+         */
+        public void setFlushInterval(Duration interval) {
+            Objects.nonNull(interval);
+            if (interval.isNegative()) {
+                throw new IllegalArgumentException("Stream interval can't be negative");
+            }
+            internal.setFlushInterval(interval);
+        }
+
+    /**
+     * Returns how often events are made available for streaming purposes.
+     *
+     * @return the flush interval, or {@code null} if no interval has been set
+     *
+     * @since 14
+     */
+    public Duration getFlushInterval() {
+        return internal.getFlushInterval();
+    }
+
     /**
      * Determines how far back data is kept in the disk repository.
      * <p>
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/ChunkParser.java	Wed Oct 30 16:14:56 2019 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,174 +0,0 @@
-/*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.  Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-package jdk.jfr.consumer;
-
-import java.io.IOException;
-import java.util.Collection;
-import java.util.List;
-
-import jdk.jfr.EventType;
-import jdk.jfr.internal.LogLevel;
-import jdk.jfr.internal.LogTag;
-import jdk.jfr.internal.Logger;
-import jdk.jfr.internal.MetadataDescriptor;
-import jdk.jfr.internal.Type;
-import jdk.jfr.internal.consumer.ChunkHeader;
-import jdk.jfr.internal.consumer.RecordingInput;
-
-/**
- * Parses a chunk.
- *
- */
-final class ChunkParser {
-    private static final long CONSTANT_POOL_TYPE_ID = 1;
-    private final RecordingInput input;
-    private final LongMap<Parser> parsers;
-    private final ChunkHeader chunkHeader;
-    private final long absoluteChunkEnd;
-    private final MetadataDescriptor metadata;
-    private final LongMap<Type> typeMap;
-    private final TimeConverter timeConverter;
-
-    public ChunkParser(RecordingInput input) throws IOException {
-        this(new ChunkHeader(input));
-    }
-
-    private ChunkParser(ChunkHeader header) throws IOException {
-        this.input = header.getInput();
-        this.chunkHeader = header;
-        this.metadata = header.readMetadata();
-        this.absoluteChunkEnd = header.getEnd();
-        this.timeConverter = new TimeConverter(chunkHeader, metadata.getGMTOffset());
-
-        ParserFactory factory = new ParserFactory(metadata, timeConverter);
-        LongMap<ConstantMap> constantPools = factory.getConstantPools();
-        parsers = factory.getParsers();
-        typeMap = factory.getTypeMap();
-
-        fillConstantPools(parsers, constantPools);
-        constantPools.forEach(ConstantMap::setIsResolving);
-        constantPools.forEach(ConstantMap::resolve);
-        constantPools.forEach(ConstantMap::setResolved);
-
-        input.position(chunkHeader.getEventStart());
-    }
-
-    public RecordedEvent readEvent() throws IOException {
-        while (input.position() < absoluteChunkEnd) {
-            long pos = input.position();
-            int size = input.readInt();
-            if (size == 0) {
-                throw new IOException("Event can't have zero size");
-            }
-            long typeId = input.readLong();
-            if (typeId > CONSTANT_POOL_TYPE_ID) { // also skips metadata (id=0)
-                Parser ep = parsers.get(typeId);
-                if (ep instanceof EventParser) {
-                    return (RecordedEvent) ep.parse(input);
-                }
-            }
-            input.position(pos + size);
-        }
-        return null;
-    }
-
-    private void fillConstantPools(LongMap<Parser> typeParser, LongMap<ConstantMap> constantPools) throws IOException {
-        long nextCP = chunkHeader.getAbsoluteChunkStart();
-        long deltaToNext = chunkHeader.getConstantPoolPosition();
-        while (deltaToNext != 0) {
-            nextCP += deltaToNext;
-            input.position(nextCP);
-            final long position = nextCP;
-            int size = input.readInt(); // size
-            long typeId = input.readLong();
-            if (typeId != CONSTANT_POOL_TYPE_ID) {
-                throw new IOException("Expected check point event (id = 1) at position " + nextCP + ", but found type id = " + typeId);
-            }
-            input.readLong(); // timestamp
-            input.readLong(); // duration
-            deltaToNext = input.readLong();
-            final long delta = deltaToNext;
-            boolean flush = input.readBoolean();
-            int poolCount = input.readInt();
-            Logger.log(LogTag.JFR_SYSTEM_PARSER, LogLevel.TRACE, () -> {
-                return "New constant pool: startPosition=" + position + ", size=" + size + ", deltaToNext=" + delta + ", flush=" + flush + ", poolCount=" + poolCount;
-            });
-
-            for (int i = 0; i < poolCount; i++) {
-                long id = input.readLong(); // type id
-                ConstantMap pool = constantPools.get(id);
-                Type type = typeMap.get(id);
-                if (pool == null) {
-                    Logger.log(LogTag.JFR_SYSTEM_PARSER, LogLevel.INFO, "Found constant pool(" + id + ") that is never used");
-                    if (type == null) {
-                        throw new IOException("Error parsing constant pool type " + getName(id) + " at position " + input.position() + " at check point between [" + nextCP + ", " + nextCP + size + "]");
-                    }
-                    pool = new ConstantMap(ObjectFactory.create(type, timeConverter), type.getName());
-                    constantPools.put(type.getId(), pool);
-                }
-                Parser parser = typeParser.get(id);
-                if (parser == null) {
-                    throw new IOException("Could not find constant pool type with id = " + id);
-                }
-                try {
-                    int count = input.readInt();
-                    Logger.log(LogTag.JFR_SYSTEM_PARSER, LogLevel.TRACE, () -> "Constant: " + getName(id) + "[" + count + "]");
-                    for (int j = 0; j < count; j++) {
-                        long key = input.readLong();
-                        Object value = parser.parse(input);
-                        pool.put(key, value);
-                    }
-                } catch (Exception e) {
-                    throw new IOException("Error parsing constant pool type " + getName(id) + " at position " + input.position() + " at check point between [" + nextCP + ", " + nextCP + size + "]", e);
-                }
-            }
-            if (input.position() != nextCP + size) {
-                throw new IOException("Size of check point event doesn't match content");
-            }
-        }
-    }
-
-    private String getName(long id) {
-        Type type = typeMap.get(id);
-        return type == null ? ("unknown(" + id + ")") : type.getName();
-    }
-
-    public Collection<Type> getTypes() {
-        return metadata.getTypes();
-    }
-
-    public List<EventType> getEventTypes() {
-        return metadata.getEventTypes();
-    }
-
-    public boolean isLastChunk() {
-        return chunkHeader.isLastChunk();
-    }
-
-    public ChunkParser nextChunkParser() throws IOException {
-        return new ChunkParser(chunkHeader.nextHeader());
-    }
-}
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/ConstantMap.java	Wed Oct 30 16:14:56 2019 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,139 +0,0 @@
-/*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.  Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-package jdk.jfr.consumer;
-
-import java.util.ArrayList;
-import java.util.List;
-
-/**
- * Holds mapping between a set of keys and their corresponding object.
- *
- * If the type is a known type, i.e. {@link RecordedThread}, an
- * {@link ObjectFactory} can be supplied which will instantiate a typed object.
- */
-final class ConstantMap {
-    private final static class Reference {
-        private final long key;
-        private final ConstantMap pool;
-
-        Reference(ConstantMap pool, long key) {
-            this.pool = pool;
-            this.key = key;
-        }
-
-        Object resolve() {
-            return pool.get(key);
-        }
-    }
-
-    private final ObjectFactory<?> factory;
-    private final LongMap<Object> objects;
-
-    private LongMap<Boolean> isResolving;
-    private boolean allResolved;
-    private String name;
-
-    ConstantMap(ObjectFactory<?> factory, String name) {
-        this.name = name;
-        this.objects = new LongMap<>();
-        this.factory = factory;
-    }
-
-    Object get(long id) {
-        // fast path, all objects in pool resolved
-        if (allResolved) {
-            return objects.get(id);
-        }
-        // referenced from a pool, deal with this later
-        if (isResolving == null) {
-            return new Reference(this, id);
-        }
-
-        Boolean beingResolved = isResolving.get(id);
-
-        // we are resolved (but not the whole pool)
-        if (Boolean.FALSE.equals(beingResolved)) {
-            return objects.get(id);
-        }
-
-        // resolving ourself, abort to avoid infinite recursion
-        if (Boolean.TRUE.equals(beingResolved)) {
-            return null;
-        }
-
-        // resolve me!
-        isResolving.put(id, Boolean.TRUE);
-        Object resolved = resolve(objects.get(id));
-        isResolving.put(id, Boolean.FALSE);
-        if (factory != null) {
-            Object factorized = factory.createObject(id, resolved);
-            objects.put(id, factorized);
-            return factorized;
-        } else {
-            objects.put(id, resolved);
-            return resolved;
-        }
-    }
-
-    private static Object resolve(Object o) {
-        if (o instanceof Reference) {
-            return resolve(((Reference) o).resolve());
-        }
-        if (o != null && o.getClass().isArray()) {
-            final Object[] array = (Object[]) o;
-            for (int i = 0; i < array.length; i++) {
-                array[i] = resolve(array[i]);
-            }
-            return array;
-        }
-        return o;
-    }
-
-    public void resolve() {
-        List<Long> keyList = new ArrayList<>();
-        objects.keys().forEachRemaining(keyList::add);
-        for (Long l : keyList) {
-            get(l);
-        }
-    }
-
-    public void put(long key, Object value) {
-        objects.put(key, value);
-    }
-
-    public void setIsResolving() {
-        isResolving = new LongMap<>();
-    }
-
-    public void setResolved() {
-        allResolved = true;
-        isResolving = null; // pool finished, release memory
-    }
-
-    public String getName() {
-        return name;
-    }
-}
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/EventParser.java	Wed Oct 30 16:14:56 2019 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,72 +0,0 @@
-/*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.  Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-package jdk.jfr.consumer;
-
-import static jdk.jfr.internal.EventInstrumentation.FIELD_DURATION;
-
-import java.io.IOException;
-import java.util.List;
-
-import jdk.jfr.EventType;
-import jdk.jfr.ValueDescriptor;
-import jdk.jfr.internal.consumer.RecordingInput;
-
-/**
- * Parses an event and returns a {@link RecordedEvent}.
- *
- */
-final class EventParser extends Parser {
-    private final Parser[] parsers;
-    private final EventType eventType;
-    private final TimeConverter timeConverter;
-    private final boolean hasDuration;
-    private final List<ValueDescriptor> valueDescriptors;
-
-    EventParser(TimeConverter timeConverter, EventType type, Parser[] parsers) {
-        this.timeConverter = timeConverter;
-        this.parsers = parsers;
-        this.eventType = type;
-        this.hasDuration = type.getField(FIELD_DURATION) != null;
-        this.valueDescriptors = type.getFields();
-    }
-
-    @Override
-    public Object parse(RecordingInput input) throws IOException {
-        Object[] values = new Object[parsers.length];
-        for (int i = 0; i < parsers.length; i++) {
-            values[i] = parsers[i].parse(input);
-        }
-        Long startTicks = (Long) values[0];
-        long startTime = timeConverter.convertTimestamp(startTicks);
-        if (hasDuration) {
-            long durationTicks = (Long) values[1];
-            long endTime = timeConverter.convertTimestamp(startTicks + durationTicks);
-            return new RecordedEvent(eventType, valueDescriptors, values, startTime, endTime, timeConverter);
-        } else {
-            return new RecordedEvent(eventType, valueDescriptors, values, startTime, startTime, timeConverter);
-        }
-    }
-}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/EventStream.java	Wed Oct 30 19:43:52 2019 +0100
@@ -0,0 +1,364 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.jfr.consumer;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.security.AccessControlContext;
+import java.security.AccessController;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.Objects;
+import java.util.function.Consumer;
+
+import jdk.jfr.internal.SecuritySupport;
+import jdk.jfr.internal.Utils;
+import jdk.jfr.internal.consumer.EventDirectoryStream;
+import jdk.jfr.internal.consumer.EventFileStream;
+import jdk.jfr.internal.consumer.FileAccess;
+
+/**
+ * Represents a stream of events.
+ * <p>
+ * A stream is a sequence of events and the way to interact with a stream is to
+ * register actions. The {@code EventStream} interface is not to be implemented
+ * and future versions of the JDK may prevent this completely.
+ * <p>
+ * To receive a notification when an event arrives, register an action using the
+ * {@link #onEvent(Consumer)} method. To filter the stream for an event with a
+ * specific name, use {@link #onEvent(String, Consumer)} method.
+ * <p>
+ * By default, the same {@code RecordedEvent} object can be used to
+ * represent two or more distinct events. That object can be delivered
+ * multiple times to the same action as well as to other actions. To use an
+ * event object after the action is completed, the
+ * {@link #setReuse(boolean)} method should be set to {@code false} so a
+ * new object is allocated for each event.
+ * <p>
+ * Events are delivered in batches. To receive a notification when a batch is
+ * complete, register an action using the {@link #onFlush(Runnable)} method.
+ * This is an opportunity to aggregate or push data to external systems while
+ * the Java Virtual Machine (JVM) is preparing the next batch.
+ * <p>
+ * Events within a batch are sorted chronologically by their end time.
+ * Well-ordering of events is only maintained for events available to the JVM at
+ * the point of flush, i.e. for the set of events delivered as a unit in a
+ * single batch. Events delivered in a batch could therefore be out-of-order
+ * compared to events delivered in a previous batch, but never out-of-order with
+ * events within the same batch. If ordering is not a concern, sorting can be
+ * disabled using the {@link #setOrdered(boolean)} method.
+ * <p>
+ * To dispatch events to registered actions, the stream must be started. To
+ * start processing in the current thread, invoke the {@link #start()} method.
+ * To process actions asynchronously in a separate thread, invoke the
+ * {@link #startAsync()} method. To await completion of the stream, use the
+ * awaitTermination {@link #awaitTermination()} or the
+ * {@link #awaitTermination(Duration)} method.
+ * <p>
+ * When a stream ends it is automatically closed. To manually stop processing of
+ * events, close the stream by invoking the {@link #close()} method. A stream
+ * can also be automatically closed in exceptional circumstances, for example if
+ * the JVM that is being monitored exits. To receive a notification in any of
+ * these occasions, use the {@link #onClose(Runnable)} method to register an
+ * action.
+ * <p>
+ * If an unexpected exception occurs in an action, it is possible to catch the
+ * exception in an error handler. An error handler can be registered using the
+ * {@link #onError(Runnable)} method. If no error handler is registered, the
+ * default behavior is to print the exception and its backtrace to the standard
+ * error stream.
+ * <p>
+ * The following example shows how an {@code EventStream} can be used to listen
+ * to events on a JVM running Flight Recorder
+ *
+ * <pre>
+ * <code>
+ * try (var es = EventStream.openRepository()) {
+ *   es.onEvent("jdk.CPULoad", event -> {
+ *     System.out.println("CPU Load " + event.getEndTime());
+ *     System.out.println(" Machine total: " + 100 * event.getFloat("machineTotal") + "%");
+ *     System.out.println(" JVM User: " + 100 * event.getFloat("jvmUser") + "%");
+ *     System.out.println(" JVM System: " + 100 * event.getFloat("jvmSystem") + "%");
+ *     System.out.println();
+ *   });
+ *   es.onEvent("jdk.GarbageCollection", event -> {
+ *     System.out.println("Garbage collection: " + event.getLong("gcId"));
+ *     System.out.println(" Cause: " + event.getString("cause"));
+ *     System.out.println(" Total pause: " + event.getDuration("sumOfPauses"));
+ *     System.out.println(" Longest pause: " + event.getDuration("longestPause"));
+ *     System.out.println();
+ *   });
+ *   es.start();
+ * }
+ * </code>
+ * </pre>
+ * <p>
+ * To start recording together with the stream, see {@link RecordingStream}.
+ *
+ * @since 14
+ */
+public interface EventStream extends AutoCloseable {
+    /**
+     * Creates a stream from the repository of the current Java Virtual Machine
+     * (JVM).
+     * <p>
+     * By default, the stream starts with the next event flushed by Flight
+     * Recorder.
+     *
+     * @return an event stream, not {@code null}
+     *
+     * @throws IOException if a stream can't be opened, or an I/O error occurs
+     *         when trying to access the repository
+     *
+     * @throws SecurityException if a security manager exists and the caller
+     *         does not have
+     *         {@code FlightRecorderPermission("accessFlightRecorder")}
+     */
+    public static EventStream openRepository() throws IOException {
+        Utils.checkAccessFlightRecorder();
+        return new EventDirectoryStream(AccessController.getContext(), null, SecuritySupport.PRIVILIGED, false);
+    }
+
+    /**
+     * Creates an event stream from a disk repository.
+     * <p>
+     * By default, the stream starts with the next event flushed by Flight
+     * Recorder.
+     *
+     * @param directory location of the disk repository, not {@code null}
+     *
+     * @return an event stream, not {@code null}
+     *
+     * @throws IOException if a stream can't be opened, or an I/O error occurs
+     *         when trying to access the repository
+     *
+     * @throws SecurityException if a security manager exists and its
+     *         {@code checkRead} method denies read access to the directory, or
+     *         files in the directory.
+     */
+    public static EventStream openRepository(Path directory) throws IOException {
+        Objects.nonNull(directory);
+        AccessControlContext acc = AccessController.getContext();
+        return new EventDirectoryStream(acc, directory, FileAccess.UNPRIVILIGED, false);
+    }
+
+    /**
+     * Creates an event stream from a file.
+     * <p>
+     * By default, the stream starts with the first event in the file.
+     *
+     * @param file location of the file, not {@code null}
+     *
+     * @return an event stream, not {@code null}
+     *
+     * @throws IOException if the file can't be opened, or an I/O error occurs
+     *         during reading
+     *
+     * @throws SecurityException if a security manager exists and its
+     *         {@code checkRead} method denies read access to the file
+     */
+    static EventStream openFile(Path file) throws IOException {
+        return new EventFileStream(AccessController.getContext(), file);
+    }
+
+    /**
+     * Registers an action to perform on all events in the stream.
+     *
+     * @param action an action to perform on each {@code RecordedEvent}, not
+     *        {@code null}
+     */
+    void onEvent(Consumer<RecordedEvent> action);
+
+    /**
+     * Registers an action to perform on all events matching a name.
+     *
+     * @param eventName the name of the event, not {@code null}
+     *
+     * @param action an action to perform on each {@code RecordedEvent} matching
+     *        the event name, not {@code null}
+     */
+    void onEvent(String eventName, Consumer<RecordedEvent> action);
+
+    /**
+     * Registers an action to perform after the stream has been flushed.
+     *
+     * @param action an action to perform after the stream has been
+     *        flushed, not {@code null}
+     */
+    void onFlush(Runnable action);
+
+    /**
+     * Registers an action to perform if an exception occurs.
+     * <p>
+     * if an action is not registered, an exception stack trace is printed to
+     * standard error.
+     * <p>
+     * Registering an action overrides the default behavior. If multiple actions
+     * have been registered, they are performed in the order of registration.
+     * <p>
+     * If this method itself throws an exception, resulting behavior is
+     * undefined.
+     *
+     * @param action an action to perform if an exception occurs, not
+     *        {@code null}
+     */
+    void onError(Consumer<Throwable> action);
+
+    /**
+     * Registers an action to perform when the stream is closed.
+     * <p>
+     * If the stream is already closed, the action will be performed immediately
+     * in the current thread.
+     *
+     * @param action an action to perform after the stream is closed, not
+     *        {@code null}
+     * @see #close()
+     */
+    void onClose(Runnable action);
+
+    /**
+     * Releases all resources associated with this stream.
+     * <p>
+     * Closing a previously closed stream has no effect.
+     */
+    void close();
+
+    /**
+     * Unregisters an action.
+     * <p>
+     * If the action has been registered multiple times, all instances are
+     * unregistered.
+     *
+     * @param action the action to unregister, not {@code null}
+     *
+     * @return {@code true} if the action was unregistered, {@code false}
+     *         otherwise
+     *
+     * @see #onEvent(Consumer)
+     * @see #onEvent(String, Consumer)
+     * @see #onFlush(Runnable)
+     * @see #onClose(Runnable)
+     * @see #onError(Consumer)
+     */
+    boolean remove(Object action);
+
+    /**
+     * Specifies that the event object in an {@link #onEvent(Consumer)} action
+     * can be reused.
+     * <p>
+     * If reuse is set to {@code true), an action should not keep a reference
+     * to the event object after the action has completed.
+     *
+     * @param reuse {@code true} if an event object can be reused, {@code false}
+     * otherwise
+     */
+    void setReuse(boolean reuse);
+
+    /**
+     * Specifies that events arrives in chronological order, sorted by the time
+     * they were committed to the stream.
+     *
+     * @param ordered if event objects arrive in chronological order to
+     *        {@code #onEvent(Consumer)}
+     */
+    void setOrdered(boolean ordered);
+
+    /**
+     * Specifies the start time of the stream.
+     * <p>
+     * The start time must be set before starting the stream
+     *
+     * @param startTime the start time, not {@code null}
+     *
+     * @throws IllegalStateException if the stream is already started
+     *
+     * @see #start()
+     * @see #startAsync()
+     */
+    void setStartTime(Instant startTime);
+
+    /**
+     * Specifies the end time of the stream.
+     * <p>
+     * The end time must be set before starting the stream.
+     * <p>
+     * At end time, the stream is closed.
+     *
+     * @param endTime the end time, not {@code null}
+     *
+     * @throws IllegalStateException if the stream is already started
+     *
+     * @see #start()
+     * @see #startAsync()
+     */
+    void setEndTime(Instant endTime);
+
+    /**
+     * Start processing of actions.
+     * <p>
+     * Actions are performed in the current thread.
+     *
+     * @throws IllegalStateException if the stream is already started or closed
+     */
+    void start();
+
+    /**
+     * Start asynchronous processing of actions.
+     * <p>
+     * Actions are performed in a single separate thread.
+     *
+     * @throws IllegalStateException if the stream is already started or closed
+     */
+    void startAsync();
+
+    /**
+     * Blocks until all actions are completed, or the stream is closed, or the
+     * timeout occurs, or the current thread is interrupted, whichever happens
+     * first.
+     *
+     * @param timeout the maximum time to wait, not {@code null}
+     *
+     * @throws IllegalArgumentException if timeout is negative
+     * @throws InterruptedException if interrupted while waiting
+     *
+     * @see #start()
+     * @see #startAsync()
+     * @see Thread#interrupt()
+     */
+    void awaitTermination(Duration timeout) throws InterruptedException;
+
+    /**
+     * Blocks until all actions are completed, or the stream is closed, or the
+     * current thread is interrupted, whichever happens first.
+     *
+     * @throws InterruptedException if interrupted while waiting
+     *
+     * @see #start()
+     * @see #startAsync()
+     * @see Thread#interrupt()
+     */
+    void awaitTermination() throws InterruptedException;
+}
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/LongMap.java	Wed Oct 30 16:14:56 2019 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,61 +0,0 @@
-/*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.  Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-package jdk.jfr.consumer;
-
-import java.util.HashMap;
-import java.util.Iterator;
-
-/**
- * Commonly used data structure for looking up objects given an id (long value)
- *
- * TODO: Implement without using Map and Long objects, to minimize allocation
- *
- * @param <T>
- */
-final class LongMap<T> implements Iterable<T> {
-    private final HashMap<Long, T> map;
-
-    LongMap() {
-        map = new HashMap<>(101);
-    }
-
-    void put(long id, T object) {
-        map.put(id, object);
-    }
-
-    T get(long id) {
-        return map.get(id);
-    }
-
-    @Override
-    public Iterator<T> iterator() {
-        return map.values().iterator();
-    }
-
-    Iterator<Long> keys() {
-        return map.keySet().iterator();
-    }
-}
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/ObjectFactory.java	Wed Oct 30 16:14:56 2019 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,85 +0,0 @@
-/*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.  Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-package jdk.jfr.consumer;
-
-import java.util.List;
-
-import jdk.jfr.ValueDescriptor;
-import jdk.jfr.internal.Type;
-
-/**
- * Abstract factory for creating specialized types
- */
-abstract class ObjectFactory<T> {
-
-    final static String TYPE_PREFIX_VERSION_1 = "com.oracle.jfr.types.";
-    final static String TYPE_PREFIX_VERSION_2 = Type.TYPES_PREFIX;
-    final static String STACK_FRAME_VERSION_1 = TYPE_PREFIX_VERSION_1 + "StackFrame";
-    final static String STACK_FRAME_VERSION_2 = TYPE_PREFIX_VERSION_2 + "StackFrame";
-
-    public static ObjectFactory<?> create(Type type, TimeConverter timeConverter) {
-        switch (type.getName()) {
-        case "java.lang.Thread":
-            return RecordedThread.createFactory(type, timeConverter);
-        case TYPE_PREFIX_VERSION_1 + "StackFrame":
-        case TYPE_PREFIX_VERSION_2 + "StackFrame":
-            return RecordedFrame.createFactory(type, timeConverter);
-        case TYPE_PREFIX_VERSION_1 + "Method":
-        case TYPE_PREFIX_VERSION_2 + "Method":
-            return RecordedMethod.createFactory(type, timeConverter);
-        case TYPE_PREFIX_VERSION_1 + "ThreadGroup":
-        case TYPE_PREFIX_VERSION_2 + "ThreadGroup":
-            return RecordedThreadGroup.createFactory(type, timeConverter);
-        case TYPE_PREFIX_VERSION_1 + "StackTrace":
-        case TYPE_PREFIX_VERSION_2 + "StackTrace":
-            return RecordedStackTrace.createFactory(type, timeConverter);
-        case TYPE_PREFIX_VERSION_1 + "ClassLoader":
-        case TYPE_PREFIX_VERSION_2 + "ClassLoader":
-            return RecordedClassLoader.createFactory(type, timeConverter);
-        case "java.lang.Class":
-            return RecordedClass.createFactory(type, timeConverter);
-        }
-        return null;
-    }
-
-    private final List<ValueDescriptor> valueDescriptors;
-
-    ObjectFactory(Type type) {
-        this.valueDescriptors = type.getFields();
-    }
-
-    T createObject(long id, Object value) {
-        if (value == null) {
-            return null;
-        }
-        if (value instanceof Object[]) {
-            return createTyped(valueDescriptors, id, (Object[]) value);
-        }
-        throw new InternalError("Object factory must have struct type");
-    }
-
-    abstract T createTyped(List<ValueDescriptor> valueDescriptors, long id, Object[] values);
-}
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/Parser.java	Wed Oct 30 16:14:56 2019 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,45 +0,0 @@
-/*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.  Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-package jdk.jfr.consumer;
-
-import java.io.IOException;
-
-import jdk.jfr.internal.consumer.RecordingInput;
-
-/**
- * Base class for parsing data from a {@link RecordingInput}.
- */
-abstract class Parser {
-    /**
-     * Parses data from a {@link RecordingInput} and return an object.
-     *
-     * @param input input to read from
-     * @return an object
-     * @throws IOException if operation couldn't be completed due to I/O
-     *         problems
-     */
-    abstract Object parse(RecordingInput input) throws IOException;
-}
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/ParserFactory.java	Wed Oct 30 16:14:56 2019 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,303 +0,0 @@
-/*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.  Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-package jdk.jfr.consumer;
-
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Objects;
-
-import jdk.jfr.EventType;
-import jdk.jfr.ValueDescriptor;
-import jdk.jfr.internal.MetadataDescriptor;
-import jdk.jfr.internal.PrivateAccess;
-import jdk.jfr.internal.Type;
-import jdk.jfr.internal.consumer.RecordingInput;
-
-/**
- * Class that create parsers suitable for reading events and constant pools
- */
-final class ParserFactory {
-    private final LongMap<Parser> parsers = new LongMap<>();
-    private final TimeConverter timeConverter;
-    private final LongMap<Type> types = new LongMap<>();
-    private final LongMap<ConstantMap> constantPools;
-
-    public ParserFactory(MetadataDescriptor metadata, TimeConverter timeConverter) throws IOException {
-        this.constantPools = new LongMap<>();
-        this.timeConverter = timeConverter;
-        for (Type t : metadata.getTypes()) {
-            types.put(t.getId(), t);
-        }
-        for (Type t : types) {
-            if (!t.getFields().isEmpty()) { // Avoid primitives
-                CompositeParser cp = createCompositeParser(t);
-                if (t.isSimpleType()) { // Reduce to nested parser
-                   parsers.put(t.getId(), cp.parsers[0]);
-                }
-
-            }
-        }
-        // Override event types with event parsers
-        for (EventType t : metadata.getEventTypes()) {
-            parsers.put(t.getId(), createEventParser(t));
-        }
-    }
-
-    public LongMap<Parser> getParsers() {
-        return parsers;
-    }
-
-    public LongMap<ConstantMap> getConstantPools() {
-        return constantPools;
-    }
-
-    public LongMap<Type> getTypeMap() {
-        return types;
-    }
-
-    private EventParser createEventParser(EventType eventType) throws IOException {
-        List<Parser> parsers = new ArrayList<Parser>();
-        for (ValueDescriptor f : eventType.getFields()) {
-            parsers.add(createParser(f));
-        }
-        return new EventParser(timeConverter, eventType, parsers.toArray(new Parser[0]));
-    }
-
-    private Parser createParser(ValueDescriptor v) throws IOException {
-        boolean constantPool = PrivateAccess.getInstance().isConstantPool(v);
-        if (v.isArray()) {
-            Type valueType = PrivateAccess.getInstance().getType(v);
-            ValueDescriptor element = PrivateAccess.getInstance().newValueDescriptor(v.getName(), valueType, v.getAnnotationElements(), 0, constantPool, null);
-            return new ArrayParser(createParser(element));
-        }
-        long id = v.getTypeId();
-        Type type = types.get(id);
-        if (type == null) {
-            throw new IOException("Type '" + v.getTypeName() + "' is not defined");
-        }
-        if (constantPool) {
-            ConstantMap pool = constantPools.get(id);
-            if (pool == null) {
-                pool = new ConstantMap(ObjectFactory.create(type, timeConverter), type.getName());
-                constantPools.put(id, pool);
-            }
-            return new ConstantMapValueParser(pool);
-        }
-        Parser parser = parsers.get(id);
-        if (parser == null) {
-            if (!v.getFields().isEmpty()) {
-                return createCompositeParser(type);
-            } else {
-                return registerParserType(type, createPrimitiveParser(type));
-            }
-        }
-        return parser;
-    }
-
-    private Parser createPrimitiveParser(Type type) throws IOException {
-        switch (type.getName()) {
-        case "int":
-            return new IntegerParser();
-        case "long":
-            return new LongParser();
-        case "float":
-            return new FloatParser();
-        case "double":
-            return new DoubleParser();
-        case "char":
-            return new CharacterParser();
-        case "boolean":
-            return new BooleanParser();
-        case "short":
-            return new ShortParser();
-        case "byte":
-            return new ByteParser();
-        case "java.lang.String":
-            ConstantMap pool = new ConstantMap(ObjectFactory.create(type, timeConverter), type.getName());
-            constantPools.put(type.getId(), pool);
-            return new StringParser(pool);
-        default:
-            throw new IOException("Unknown primitive type " + type.getName());
-        }
-    }
-
-    private Parser registerParserType(Type t, Parser parser) {
-        Parser p = parsers.get(t.getId());
-        // check if parser exists (known type)
-        if (p != null) {
-            return p;
-        }
-        parsers.put(t.getId(), parser);
-        return parser;
-    }
-
-    private CompositeParser createCompositeParser(Type type) throws IOException {
-        List<ValueDescriptor> vds = type.getFields();
-        Parser[] parsers = new Parser[vds.size()];
-        CompositeParser composite = new CompositeParser(parsers);
-        // need to pre-register so recursive types can be handled
-        registerParserType(type, composite);
-
-        int index = 0;
-        for (ValueDescriptor vd : vds) {
-            parsers[index++] = createParser(vd);
-        }
-        return composite;
-    }
-
-    private static final class BooleanParser extends Parser {
-        @Override
-        public Object parse(RecordingInput input) throws IOException {
-            return input.readBoolean() ? Boolean.TRUE : Boolean.FALSE;
-        }
-    }
-
-    private static final class ByteParser extends Parser {
-        @Override
-        public Object parse(RecordingInput input) throws IOException {
-            return Byte.valueOf(input.readByte());
-        }
-    }
-
-    private static final class LongParser extends Parser {
-        @Override
-        public Object parse(RecordingInput input) throws IOException {
-            return Long.valueOf(input.readLong());
-        }
-    }
-
-    private static final class IntegerParser extends Parser {
-        @Override
-        public Object parse(RecordingInput input) throws IOException {
-            return Integer.valueOf(input.readInt());
-        }
-    }
-
-    private static final class ShortParser extends Parser {
-        @Override
-        public Object parse(RecordingInput input) throws IOException {
-            return Short.valueOf(input.readShort());
-        }
-    }
-
-    private static final class CharacterParser extends Parser {
-        @Override
-        public Object parse(RecordingInput input) throws IOException {
-            return Character.valueOf(input.readChar());
-        }
-    }
-
-    private static final class FloatParser extends Parser {
-        @Override
-        public Object parse(RecordingInput input) throws IOException {
-            return Float.valueOf(input.readFloat());
-        }
-    }
-
-    private static final class DoubleParser extends Parser {
-        @Override
-        public Object parse(RecordingInput input) throws IOException {
-            return Double.valueOf(input.readDouble());
-        }
-    }
-
-    private static final class StringParser extends Parser {
-        private final ConstantMap stringConstantMap;
-        private String last;
-
-        StringParser(ConstantMap stringConstantMap) {
-            this.stringConstantMap = stringConstantMap;
-        }
-
-        @Override
-        public Object parse(RecordingInput input) throws IOException {
-            String s = parseEncodedString(input);
-            if (!Objects.equals(s, last)) {
-                last = s;
-            }
-            return last;
-        }
-
-        private String parseEncodedString(RecordingInput input) throws IOException {
-            byte encoding = input.readByte();
-            if (encoding == RecordingInput.STRING_ENCODING_CONSTANT_POOL) {
-                long id = input.readLong();
-                return (String) stringConstantMap.get(id);
-            } else {
-                return input.readEncodedString(encoding);
-            }
-        }
-    }
-
-    private final static class ArrayParser extends Parser {
-        private final Parser elementParser;
-
-        public ArrayParser(Parser elementParser) {
-            this.elementParser = elementParser;
-        }
-
-        @Override
-        public Object parse(RecordingInput input) throws IOException {
-            final int size = input.readInt();
-            final Object[] array = new Object[size];
-            for (int i = 0; i < size; i++) {
-                array[i] = elementParser.parse(input);
-            }
-            return array;
-        }
-    }
-
-    private final static class CompositeParser extends Parser {
-        private final Parser[] parsers;
-
-        public CompositeParser(Parser[] valueParsers) {
-            this.parsers = valueParsers;
-        }
-
-        @Override
-        public Object parse(RecordingInput input) throws IOException {
-            final Object[] values = new Object[parsers.length];
-            for (int i = 0; i < values.length; i++) {
-                values[i] = parsers[i].parse(input);
-            }
-            return values;
-        }
-    }
-
-    private static final class ConstantMapValueParser extends Parser {
-        private final ConstantMap pool;
-
-        ConstantMapValueParser(ConstantMap pool) {
-            this.pool = pool;
-        }
-
-        @Override
-        public Object parse(RecordingInput input) throws IOException {
-            return pool.get(input.readLong());
-        }
-    }
-}
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedClass.java	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedClass.java	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -26,10 +26,8 @@
 package jdk.jfr.consumer;
 
 import java.lang.reflect.Modifier;
-import java.util.List;
 
-import jdk.jfr.ValueDescriptor;
-import jdk.jfr.internal.Type;
+import jdk.jfr.internal.consumer.ObjectContext;
 
 /**
  * A recorded Java type, such as a class or an interface.
@@ -37,21 +35,11 @@
  * @since 9
  */
 public final class RecordedClass extends RecordedObject {
-
-    static ObjectFactory<RecordedClass> createFactory(Type type, TimeConverter timeConverter) {
-        return new ObjectFactory<RecordedClass>(type) {
-            @Override
-            RecordedClass createTyped(List<ValueDescriptor> desc, long id, Object[] object) {
-                return new RecordedClass(desc, id, object, timeConverter);
-            }
-        };
-    }
-
     private final long uniqueId;
 
     // package private
-    private RecordedClass(List<ValueDescriptor> descriptors, long id, Object[] values, TimeConverter timeConverter) {
-        super(descriptors, values, timeConverter);
+    RecordedClass(ObjectContext objectContext, long id, Object[] values) {
+        super(objectContext, values);
         this.uniqueId = id;
     }
 
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedClassLoader.java	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedClassLoader.java	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,10 +25,7 @@
 
 package jdk.jfr.consumer;
 
-import java.util.List;
-
-import jdk.jfr.ValueDescriptor;
-import jdk.jfr.internal.Type;
+import jdk.jfr.internal.consumer.ObjectContext;
 
 /**
  * A recorded Java class loader.
@@ -36,21 +33,11 @@
  * @since 9
  */
 public final class RecordedClassLoader extends RecordedObject {
-
-    static ObjectFactory<RecordedClassLoader> createFactory(Type type, TimeConverter timeConverter) {
-        return new ObjectFactory<RecordedClassLoader>(type) {
-            @Override
-            RecordedClassLoader createTyped(List<ValueDescriptor> desc, long id, Object[] object) {
-                return new RecordedClassLoader(desc, id, object, timeConverter);
-            }
-        };
-    }
-
     private final long uniqueId;
 
     // package private
-    private RecordedClassLoader(List<ValueDescriptor> descriptors, long id, Object[] values, TimeConverter timeConverter) {
-        super(descriptors, values, timeConverter);
+    RecordedClassLoader(ObjectContext objectContext, long id, Object[] values) {
+        super(objectContext, values);
         this.uniqueId = id;
     }
 
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedEvent.java	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedEvent.java	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -32,6 +32,7 @@
 import jdk.jfr.EventType;
 import jdk.jfr.ValueDescriptor;
 import jdk.jfr.internal.EventInstrumentation;
+import jdk.jfr.internal.consumer.ObjectContext;
 
 /**
  * A recorded event.
@@ -39,17 +40,14 @@
  * @since 9
  */
 public final class RecordedEvent extends RecordedObject {
-    private final EventType eventType;
-    private final long startTime;
-    // package private needed for efficient sorting
-    final long endTime;
+    long startTimeTicks;
+    long endTimeTicks;
 
     // package private
-    RecordedEvent(EventType type, List<ValueDescriptor> vds, Object[] values, long startTime, long endTime, TimeConverter timeConverter) {
-        super(vds, values, timeConverter);
-        this.eventType = type;
-        this.startTime = startTime;
-        this.endTime = endTime;
+    RecordedEvent(ObjectContext objectContext, Object[] values, long startTimeTicks, long endTimeTicks) {
+        super(objectContext, values);
+        this.startTimeTicks = startTimeTicks;
+        this.endTimeTicks = endTimeTicks;
     }
 
     /**
@@ -78,7 +76,7 @@
      * @return the event type, not {@code null}
      */
     public EventType getEventType() {
-        return eventType;
+        return objectContext.eventType;
     }
 
     /**
@@ -89,7 +87,7 @@
      * @return the start time, not {@code null}
      */
     public Instant getStartTime() {
-        return Instant.ofEpochSecond(0, startTime);
+        return Instant.ofEpochSecond(0, getStartTimeNanos());
     }
 
     /**
@@ -100,7 +98,7 @@
      * @return the end time, not {@code null}
      */
     public Instant getEndTime() {
-        return Instant.ofEpochSecond(0, endTime);
+        return Instant.ofEpochSecond(0, getEndTimeNanos());
     }
 
     /**
@@ -109,7 +107,7 @@
      * @return the duration in nanoseconds, not {@code null}
      */
     public Duration getDuration() {
-        return Duration.ofNanos(endTime - startTime);
+        return Duration.ofNanos(getEndTimeNanos() - getStartTimeNanos());
     }
 
     /**
@@ -119,6 +117,31 @@
      */
     @Override
     public List<ValueDescriptor> getFields() {
-        return getEventType().getFields();
+        return objectContext.fields;
+    }
+
+    protected final Object objectAt(int index) {
+        if (index == 0) {
+            return startTimeTicks;
+        }
+        if (hasDuration()) {
+            if (index == 1) {
+                return endTimeTicks - startTimeTicks;
+            }
+            return objects[index - 2];
+        }
+        return objects[index - 1];
+    }
+
+    private boolean hasDuration() {
+        return objects.length + 2 == objectContext.fields.size();
+    }
+
+    private long getStartTimeNanos() {
+        return objectContext.convertTimestamp(startTimeTicks);
+    }
+
+    private long getEndTimeNanos() {
+        return objectContext.convertTimestamp(endTimeTicks);
     }
 }
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedFrame.java	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedFrame.java	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -26,10 +26,8 @@
 package jdk.jfr.consumer;
 
 import java.lang.reflect.Modifier;
-import java.util.List;
 
-import jdk.jfr.ValueDescriptor;
-import jdk.jfr.internal.Type;
+import jdk.jfr.internal.consumer.ObjectContext;
 
 /**
  * A recorded frame in a stack trace.
@@ -37,19 +35,9 @@
  * @since 9
  */
 public final class RecordedFrame extends RecordedObject {
-
-    static ObjectFactory<RecordedFrame> createFactory(Type type, TimeConverter timeConverter) {
-        return new ObjectFactory<RecordedFrame>(type) {
-            @Override
-            RecordedFrame createTyped(List<ValueDescriptor> desc, long id, Object[] object) {
-                return new RecordedFrame(desc, object, timeConverter);
-            }
-        };
-    }
-
     // package private
-    RecordedFrame(List<ValueDescriptor> desc, Object[] objects, TimeConverter timeConverter) {
-        super(desc, objects, timeConverter);
+    RecordedFrame(ObjectContext objectContext, Object[] values) {
+        super(objectContext, values);
     }
 
     /**
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedMethod.java	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedMethod.java	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -26,10 +26,8 @@
 package jdk.jfr.consumer;
 
 import java.lang.reflect.Modifier;
-import java.util.List;
 
-import jdk.jfr.ValueDescriptor;
-import jdk.jfr.internal.Type;
+import jdk.jfr.internal.consumer.ObjectContext;
 
 /**
  * A recorded method.
@@ -38,17 +36,9 @@
  */
 public final class RecordedMethod extends RecordedObject {
 
-    static ObjectFactory<RecordedMethod> createFactory(Type type, TimeConverter timeConverter) {
-        return new ObjectFactory<RecordedMethod>(type) {
-            @Override
-            RecordedMethod createTyped(List<ValueDescriptor> desc, long id, Object[] object) {
-                return new RecordedMethod(desc, object, timeConverter);
-            }
-        };
-    }
-
-    private RecordedMethod(List<ValueDescriptor> descriptors, Object[] objects, TimeConverter timeConverter) {
-        super(descriptors, objects, timeConverter);
+    // package private
+    RecordedMethod(ObjectContext objectContext, Object[] values) {
+        super(objectContext, values);
     }
 
     /**
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedObject.java	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedObject.java	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,18 +25,24 @@
 
 package jdk.jfr.consumer;
 
+import java.io.IOException;
 import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.time.Duration;
 import java.time.Instant;
 import java.time.OffsetDateTime;
+import java.util.Comparator;
 import java.util.List;
 import java.util.Objects;
 
 import jdk.jfr.Timespan;
 import jdk.jfr.Timestamp;
 import jdk.jfr.ValueDescriptor;
+import jdk.jfr.internal.consumer.JdkJfrConsumer;
+import jdk.jfr.internal.consumer.ObjectFactory;
 import jdk.jfr.internal.PrivateAccess;
+import jdk.jfr.internal.Type;
+import jdk.jfr.internal.consumer.ObjectContext;
 import jdk.jfr.internal.tool.PrettyWriter;
 
 /**
@@ -51,6 +57,89 @@
  */
 public class RecordedObject {
 
+    static{
+        JdkJfrConsumer access = new JdkJfrConsumer() {
+            public List<Type> readTypes(RecordingFile file) throws IOException {
+                return file.readTypes();
+            }
+
+            public boolean isLastEventInChunk(RecordingFile file) {
+                return file.isLastEventInChunk();
+            }
+
+            @Override
+            public Object getOffsetDataTime(RecordedObject event, String name) {
+                return event.getOffsetDateTime(name);
+            }
+
+            @Override
+            public RecordedClass newRecordedClass(ObjectContext objectContext, long id, Object[] values) {
+                return new RecordedClass(objectContext, id, values);
+            }
+
+            @Override
+            public RecordedClassLoader newRecordedClassLoader(ObjectContext objectContext, long id, Object[] values) {
+                return new RecordedClassLoader(objectContext, id, values);
+            }
+
+            @Override
+            public Comparator<? super RecordedEvent> eventComparator() {
+                return new Comparator<RecordedEvent>()  {
+                    @Override
+                    public int compare(RecordedEvent e1, RecordedEvent e2) {
+                        return Long.compare(e1.endTimeTicks, e2.endTimeTicks);
+                    }
+                };
+            }
+
+            @Override
+            public RecordedStackTrace newRecordedStackTrace(ObjectContext objectContext, Object[] values) {
+                return new RecordedStackTrace(objectContext, values);
+            }
+
+            @Override
+            public RecordedThreadGroup newRecordedThreadGroup(ObjectContext objectContext, Object[] values) {
+                return new RecordedThreadGroup(objectContext, values);
+            }
+
+            @Override
+            public RecordedFrame newRecordedFrame(ObjectContext objectContext, Object[] values) {
+                return new RecordedFrame(objectContext, values);
+            }
+
+            @Override
+            public RecordedThread newRecordedThread(ObjectContext objectContext, long id, Object[] values) {
+                return new RecordedThread(objectContext, id, values);
+            }
+
+            @Override
+            public RecordedMethod newRecordedMethod(ObjectContext objectContext, Object[] values) {
+                return new RecordedMethod(objectContext, values);
+            }
+
+            @Override
+            public RecordedEvent newRecordedEvent(ObjectContext objectContext, Object[] values, long startTimeTicks, long endTimeTicks) {
+                return new RecordedEvent(objectContext, values, startTimeTicks, endTimeTicks);
+            }
+
+            @Override
+            public void setStartTicks(RecordedEvent event, long startTicks) {
+               event.startTimeTicks = startTicks;
+            }
+
+            @Override
+            public void setEndTicks(RecordedEvent event, long endTicks) {
+               event.endTimeTicks = endTicks;
+            }
+
+            @Override
+            public Object[] eventValues(RecordedEvent event) {
+                return event.objects;
+            }
+        };
+        JdkJfrConsumer.setAccess(access);
+    }
+
     private final static class UnsignedValue {
         private final Object o;
 
@@ -63,15 +152,13 @@
         }
     }
 
-    private final Object[] objects;
-    private final List<ValueDescriptor> descriptors;
-    private final TimeConverter timeConverter;
+    final Object[] objects;
+    final ObjectContext objectContext;
 
     // package private, not to be subclassed outside this package
-    RecordedObject(List<ValueDescriptor> descriptors, Object[] objects, TimeConverter timeConverter) {
-        this.descriptors = descriptors;
+    RecordedObject(ObjectContext objectContext, Object[] objects) {
+        this.objectContext = objectContext;
         this.objects = objects;
-        this.timeConverter = timeConverter;
     }
 
     // package private
@@ -101,7 +188,7 @@
      */
     public boolean hasField(String name) {
         Objects.requireNonNull(name);
-        for (ValueDescriptor v : descriptors) {
+        for (ValueDescriptor v : objectContext.fields) {
             if (v.getName().equals(name)) {
                 return true;
             }
@@ -109,7 +196,7 @@
         int dotIndex = name.indexOf(".");
         if (dotIndex > 0) {
             String structName = name.substring(0, dotIndex);
-            for (ValueDescriptor v : descriptors) {
+            for (ValueDescriptor v : objectContext.fields) {
                 if (!v.getFields().isEmpty() && v.getName().equals(structName)) {
                     RecordedObject child = getValue(structName);
                     if (child != null) {
@@ -169,12 +256,16 @@
         return t;
     }
 
+    protected Object objectAt(int index) {
+        return objects[index];
+    }
+
     private Object getValue(String name, boolean allowUnsigned) {
         Objects.requireNonNull(name);
         int index = 0;
-        for (ValueDescriptor v : descriptors) {
+        for (ValueDescriptor v : objectContext.fields) {
             if (name.equals(v.getName())) {
-                Object object = objects[index];
+                Object object = objectAt(index);
                 if (object == null) {
                     // error or missing
                     return null;
@@ -200,7 +291,7 @@
                         return structifyArray(v, array, 0);
                     }
                     // struct
-                    return new RecordedObject(v.getFields(), (Object[]) object, timeConverter);
+                    return new RecordedObject(objectContext.getInstance(v), (Object[]) object);
                 }
             }
             index++;
@@ -209,7 +300,7 @@
         int dotIndex = name.indexOf(".");
         if (dotIndex > 0) {
             String structName = name.substring(0, dotIndex);
-            for (ValueDescriptor v : descriptors) {
+            for (ValueDescriptor v : objectContext.fields) {
                 if (!v.getFields().isEmpty() && v.getName().equals(structName)) {
                     RecordedObject child = getValue(structName);
                     String subName = name.substring(dotIndex + 1);
@@ -261,7 +352,7 @@
     private <T> T getTypedValue(String name, String typeName) {
         Objects.requireNonNull(name);
         // Validate name and type first
-        getValueDescriptor(descriptors, name, typeName);
+        getValueDescriptor(objectContext.fields, name, typeName);
         return getValue(name);
     }
 
@@ -270,15 +361,16 @@
             return null;
         }
         Object[] structArray = new Object[array.length];
+        ObjectContext objContext = objectContext.getInstance(v);
         for (int i = 0; i < structArray.length; i++) {
             Object arrayElement = array[i];
             if (dimension == 0) {
                 // No general way to handle structarrays
                 // without invoking ObjectFactory for every instance (which may require id)
                 if (isStackFrameType(v.getTypeName())) {
-                    structArray[i] = new RecordedFrame(v.getFields(), (Object[]) arrayElement, timeConverter);
+                    structArray[i] = new RecordedFrame(objContext, (Object[]) arrayElement);
                 } else {
-                    structArray[i] = new RecordedObject(v.getFields(), (Object[]) arrayElement, timeConverter);
+                    structArray[i] = new RecordedObject(objContext, (Object[]) arrayElement);
                 }
             } else {
                 structArray[i] = structifyArray(v, (Object[]) arrayElement, dimension - 1);
@@ -303,7 +395,7 @@
      * @return the fields, not {@code null}
      */
     public List<ValueDescriptor> getFields() {
-        return descriptors;
+        return objectContext.fields;
     }
 
     /**
@@ -725,7 +817,7 @@
     }
 
     private Duration getDuration(long timespan, String name) throws InternalError {
-        ValueDescriptor v = getValueDescriptor(descriptors, name, null);
+        ValueDescriptor v = getValueDescriptor(objectContext.fields, name, null);
         if (timespan == Long.MIN_VALUE) {
             return Duration.ofSeconds(Long.MIN_VALUE, 0);
         }
@@ -741,7 +833,7 @@
             case Timespan.NANOSECONDS:
                 return Duration.ofNanos(timespan);
             case Timespan.TICKS:
-                return Duration.ofNanos(timeConverter.convertTimespan(timespan));
+                return Duration.ofNanos(objectContext.convertTimespan(timespan));
             }
             throw new IllegalArgumentException("Attempt to get " + v.getTypeName() + " field \"" + name + "\" with illegal timespan unit " + ts.value());
         }
@@ -804,7 +896,7 @@
     }
 
     private Instant getInstant(long timestamp, String name) {
-        ValueDescriptor v = getValueDescriptor(descriptors, name, null);
+        ValueDescriptor v = getValueDescriptor(objectContext.fields, name, null);
         Timestamp ts = v.getAnnotation(Timestamp.class);
         if (ts != null) {
             if (timestamp == Long.MIN_VALUE) {
@@ -814,7 +906,7 @@
             case Timestamp.MILLISECONDS_SINCE_EPOCH:
                 return Instant.ofEpochMilli(timestamp);
             case Timestamp.TICKS:
-                return Instant.ofEpochSecond(0, timeConverter.convertTimestamp(timestamp));
+                return Instant.ofEpochSecond(0, objectContext.convertTimestamp(timestamp));
             }
             throw new IllegalArgumentException("Attempt to get " + v.getTypeName() + " field \"" + name + "\" with illegal timestamp unit " + ts.value());
         }
@@ -889,12 +981,12 @@
     }
 
     // package private for now. Used by EventWriter
-    OffsetDateTime getOffsetDateTime(String name) {
+    private OffsetDateTime getOffsetDateTime(String name) {
         Instant instant = getInstant(name);
         if (instant.equals(Instant.MIN)) {
             return OffsetDateTime.MIN;
         }
-        return OffsetDateTime.ofInstant(getInstant(name), timeConverter.getZoneOffset());
+        return OffsetDateTime.ofInstant(getInstant(name), objectContext.getZoneOffset());
     }
 
     private static IllegalArgumentException newIllegalArgumentException(String name, String typeName) {
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedStackTrace.java	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedStackTrace.java	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -29,8 +29,7 @@
 import java.util.Collections;
 import java.util.List;
 
-import jdk.jfr.ValueDescriptor;
-import jdk.jfr.internal.Type;
+import jdk.jfr.internal.consumer.ObjectContext;
 
 /**
  * A recorded stack trace.
@@ -38,18 +37,9 @@
  * @since 9
  */
 public final class RecordedStackTrace extends RecordedObject {
-
-    static ObjectFactory<RecordedStackTrace> createFactory(Type type, TimeConverter timeConverter) {
-        return new ObjectFactory<RecordedStackTrace>(type) {
-            @Override
-            RecordedStackTrace createTyped(List<ValueDescriptor> desc, long id, Object[] object) {
-                return new RecordedStackTrace(desc, object, timeConverter);
-            }
-        };
-    }
-
-    private RecordedStackTrace(List<ValueDescriptor> desc, Object[] values, TimeConverter timeConverter) {
-        super(desc, values, timeConverter);
+    // package private
+    RecordedStackTrace(ObjectContext objectContext, Object[] values) {
+        super(objectContext, values);
     }
 
     /**
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedThread.java	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedThread.java	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,10 +25,7 @@
 
 package jdk.jfr.consumer;
 
-import java.util.List;
-
-import jdk.jfr.ValueDescriptor;
-import jdk.jfr.internal.Type;
+import jdk.jfr.internal.consumer.ObjectContext;
 
 /**
  * A recorded thread.
@@ -36,20 +33,11 @@
  * @since 9
  */
 public final class RecordedThread extends RecordedObject {
-
-    static ObjectFactory<RecordedThread> createFactory(Type type, TimeConverter timeConverter) {
-        return new ObjectFactory<RecordedThread>(type) {
-            @Override
-            RecordedThread createTyped(List<ValueDescriptor> desc, long id, Object[] object) {
-                return new RecordedThread(desc, id, object, timeConverter);
-            }
-        };
-    }
-
     private final long uniqueId;
 
-    private RecordedThread(List<ValueDescriptor> descriptors, long id, Object[] values,  TimeConverter timeConverter) {
-        super(descriptors, values, timeConverter);
+    // package private
+    RecordedThread(ObjectContext objectContext, long id, Object[] values) {
+        super(objectContext, values);
         this.uniqueId = id;
     }
 
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedThreadGroup.java	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordedThreadGroup.java	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,10 +25,7 @@
 
 package jdk.jfr.consumer;
 
-import java.util.List;
-
-import jdk.jfr.ValueDescriptor;
-import jdk.jfr.internal.Type;
+import jdk.jfr.internal.consumer.ObjectContext;
 
 /**
  * A recorded Java thread group.
@@ -36,18 +33,9 @@
  * @since 9
  */
 public final class RecordedThreadGroup extends RecordedObject {
-
-    static ObjectFactory<RecordedThreadGroup> createFactory(Type type, TimeConverter timeConverter) {
-        return new ObjectFactory<RecordedThreadGroup>(type) {
-            @Override
-            RecordedThreadGroup createTyped(List<ValueDescriptor> desc, long id, Object[] object) {
-                return new RecordedThreadGroup(desc, object, timeConverter);
-            }
-        };
-    }
-
-    private RecordedThreadGroup(List<ValueDescriptor> descriptors, Object[] objects, TimeConverter timeConverter) {
-        super(descriptors, objects, timeConverter);
+    // package private
+    RecordedThreadGroup(ObjectContext objectContext, Object[] values) {
+        super(objectContext, values);
     }
 
     /**
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordingFile.java	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordingFile.java	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -32,7 +32,6 @@
 import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 
@@ -40,8 +39,9 @@
 import jdk.jfr.internal.MetadataDescriptor;
 import jdk.jfr.internal.Type;
 import jdk.jfr.internal.consumer.ChunkHeader;
+import jdk.jfr.internal.consumer.ChunkParser;
+import jdk.jfr.internal.consumer.FileAccess;
 import jdk.jfr.internal.consumer.RecordingInput;
-import jdk.jfr.internal.consumer.RecordingInternals;
 
 /**
  * A recording file.
@@ -62,27 +62,6 @@
  * @since 9
  */
 public final class RecordingFile implements Closeable {
-    static{
-        RecordingInternals.INSTANCE = new RecordingInternals() {
-            public List<Type> readTypes(RecordingFile file) throws IOException {
-                return file.readTypes();
-            }
-
-            public boolean isLastEventInChunk(RecordingFile file) {
-                return file.isLastEventInChunk;
-            }
-
-            @Override
-            public Object getOffsetDataTime(RecordedObject event, String name) {
-                return event.getOffsetDateTime(name);
-            }
-
-            @Override
-            public void sort(List<RecordedEvent> events) {
-               Collections.sort(events, (e1, e2) -> Long.compare(e1.endTime, e2.endTime));
-            }
-        };
-    }
 
     private boolean isLastEventInChunk;
     private final File file;
@@ -104,7 +83,7 @@
      */
     public RecordingFile(Path file) throws IOException {
         this.file = file.toFile();
-        this.input = new RecordingInput(this.file);
+        this.input = new RecordingInput(this.file, FileAccess.UNPRIVILIGED);
         findNext();
     }
 
@@ -154,14 +133,15 @@
      */
     public List<EventType> readEventTypes() throws IOException {
         ensureOpen();
+        MetadataDescriptor previous = null;
         List<EventType> types = new ArrayList<>();
         HashSet<Long> foundIds = new HashSet<>();
-        try (RecordingInput ri = new RecordingInput(file)) {
+        try (RecordingInput ri = new RecordingInput(file, FileAccess.UNPRIVILIGED)) {
             ChunkHeader ch = new ChunkHeader(ri);
-            aggregateEventTypeForChunk(ch, types, foundIds);
+            aggregateEventTypeForChunk(ch, null, types, foundIds);
             while (!ch.isLastChunk()) {
                 ch = ch.nextHeader();
-                aggregateEventTypeForChunk(ch, types, foundIds);
+                previous = aggregateEventTypeForChunk(ch, previous, types, foundIds);
             }
         }
         return types;
@@ -169,37 +149,41 @@
 
     List<Type> readTypes() throws IOException  {
         ensureOpen();
+        MetadataDescriptor previous = null;
         List<Type> types = new ArrayList<>();
         HashSet<Long> foundIds = new HashSet<>();
-        try (RecordingInput ri = new RecordingInput(file)) {
+        try (RecordingInput ri = new RecordingInput(file, FileAccess.UNPRIVILIGED)) {
             ChunkHeader ch = new ChunkHeader(ri);
-            aggregateTypeForChunk(ch, types, foundIds);
+            ch.awaitFinished();
+            aggregateTypeForChunk(ch, null, types, foundIds);
             while (!ch.isLastChunk()) {
                 ch = ch.nextHeader();
-                aggregateTypeForChunk(ch, types, foundIds);
+                previous = aggregateTypeForChunk(ch, previous, types, foundIds);
             }
         }
         return types;
     }
 
-    private void aggregateTypeForChunk(ChunkHeader ch, List<Type> types, HashSet<Long> foundIds) throws IOException {
-        MetadataDescriptor m = ch.readMetadata();
+    private MetadataDescriptor aggregateTypeForChunk(ChunkHeader ch, MetadataDescriptor previous, List<Type> types, HashSet<Long> foundIds) throws IOException {
+        MetadataDescriptor m = ch.readMetadata(previous);
         for (Type t : m.getTypes()) {
             if (!foundIds.contains(t.getId())) {
                 types.add(t);
                 foundIds.add(t.getId());
             }
         }
+        return m;
     }
 
-    private static void aggregateEventTypeForChunk(ChunkHeader ch, List<EventType> types, HashSet<Long> foundIds) throws IOException {
-        MetadataDescriptor m = ch.readMetadata();
+    private static MetadataDescriptor aggregateEventTypeForChunk(ChunkHeader ch,  MetadataDescriptor previous, List<EventType> types, HashSet<Long> foundIds) throws IOException {
+        MetadataDescriptor m = ch.readMetadata(previous);
         for (EventType t : m.getEventTypes()) {
             if (!foundIds.contains(t.getId())) {
                 types.add(t);
                 foundIds.add(t.getId());
             }
         }
+        return m;
     }
 
     /**
@@ -246,6 +230,17 @@
         }
     }
 
+    // package protected
+    File getFile() {
+        return file;
+    }
+
+    // package protected
+    boolean isLastEventInChunk() {
+        return isLastEventInChunk;
+    }
+
+
     // either sets next to an event or sets eof to true
     private void findNext() throws IOException {
         while (nextEvent == null) {
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/RecordingStream.java	Wed Oct 30 19:43:52 2019 +0100
@@ -0,0 +1,362 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.jfr.consumer;
+
+import java.io.IOException;
+import java.security.AccessControlContext;
+import java.security.AccessController;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.Map;
+import java.util.function.Consumer;
+
+import jdk.jfr.Configuration;
+import jdk.jfr.Event;
+import jdk.jfr.EventSettings;
+import jdk.jfr.EventType;
+import jdk.jfr.Recording;
+import jdk.jfr.internal.PlatformRecording;
+import jdk.jfr.internal.PrivateAccess;
+import jdk.jfr.internal.SecuritySupport;
+import jdk.jfr.internal.Utils;
+import jdk.jfr.internal.consumer.EventDirectoryStream;
+
+/**
+ * A recording stream produces events from the current JVM (Java Virtual
+ * Machine).
+ * <p>
+ * The following example shows how to record events using the default
+ * configuration and print the Garbage Collection, CPU Load and JVM Information
+ * event to standard out.
+ * <pre>
+ * <code>
+ * Configuration c = Configuration.getConfiguration("default");
+ * try (var rs = new RecordingStream(c)) {
+ *     rs.onEvent("jdk.GarbageCollection", System.out::println);
+ *     rs.onEvent("jdk.CPULoad", System.out::println);
+ *     rs.onEvent("jdk.JVMInformation", System.out::println);
+ *     rs.start();
+ *   }
+ * }
+ * </code>
+ * </pre>
+ *
+ * @since 14
+ */
+public final class RecordingStream implements AutoCloseable, EventStream {
+
+    private final Recording recording;
+    private final EventDirectoryStream directoryStream;
+
+    /**
+     * Creates an event stream for the current JVM (Java Virtual Machine).
+     *
+     * @throws IllegalStateException if Flight Recorder can't be created (for
+     *         example, if the Java Virtual Machine (JVM) lacks Flight Recorder
+     *         support, or if the file repository can't be created or accessed)
+     *
+     * @throws SecurityException if a security manager exists and the caller
+     *         does not have
+     *         {@code FlightRecorderPermission("accessFlightRecorder")}
+     */
+    public RecordingStream() {
+        Utils.checkAccessFlightRecorder();
+        AccessControlContext acc = AccessController.getContext();
+        this.recording = new Recording();
+        this.recording.setFlushInterval(Duration.ofMillis(1000));
+        try {
+            this.directoryStream = new EventDirectoryStream(acc, null, SecuritySupport.PRIVILIGED, true);
+        } catch (IOException ioe) {
+            this.recording.close();
+            throw new IllegalStateException(ioe.getMessage());
+        }
+    }
+
+    /**
+     * Creates a recording stream using settings from a configuration.
+     * <p>
+     * The following example shows how to create a recording stream that uses a
+     * predefined configuration.
+     *
+     * <pre>
+     * <code>
+     * var c = Configuration.getConfiguration("default");
+     * try (var rs = new RecordingStream(c)) {
+     *   rs.onEvent(System.out::println);
+     *   rs.start();
+     * }
+     * </code>
+     * </pre>
+     *
+     * @param configuration configuration that contains the settings to use,
+     *        not {@code null}
+     *
+     * @throws IllegalStateException if Flight Recorder can't be created (for
+     *         example, if the Java Virtual Machine (JVM) lacks Flight Recorder
+     *         support, or if the file repository can't be created or accessed)
+     *
+     * @throws SecurityException if a security manager is used and
+     *         FlightRecorderPermission "accessFlightRecorder" is not set.
+     *
+     * @see Configuration
+     */
+    public RecordingStream(Configuration configuration) {
+        this();
+        recording.setSettings(configuration.getSettings());
+    }
+
+    /**
+     * Enables the event with the specified name.
+     * <p>
+     * If multiple events have the same name (for example, the same class is
+     * loaded in different class loaders), then all events that match the name
+     * are enabled. To enable a specific class, use the {@link #enable(Class)}
+     * method or a {@code String} representation of the event type ID.
+     *
+     * @param name the settings for the event, not {@code null}
+     *
+     * @return an event setting for further configuration, not {@code null}
+     *
+     * @see EventType
+     */
+    public EventSettings enable(String name) {
+        return recording.enable(name);
+    }
+
+    /**
+     * Replaces all settings for this recording stream.
+     * <p>
+     * The following example records 20 seconds using the "default" configuration
+     * and then changes settings to the "profile" configuration.
+     *
+     * <pre>
+     * <code>
+     *     Configuration defaultConfiguration = Configuration.getConfiguration("default");
+     *     Configuration profileConfiguration = Configuration.getConfiguration("profile");
+     *     try (var rs = new RecordingStream(defaultConfiguration) {
+     *        rs.onEvent(System.out::println);
+     *        rs.startAsync();
+     *        Thread.sleep(20_000);
+     *        rs.setSettings(profileConfiguration.getSettings());
+     *        Thread.sleep(20_000);
+     *     }
+     * </code>
+     * </pre>
+     *
+     * @param settings the settings to set, not {@code null}
+     *
+     * @see Recording#setSettings(Map)
+     */
+    public void setSettings(Map<String, String> settings) {
+        recording.setSettings(settings);
+    };
+
+    /**
+     * Enables event.
+     *
+     * @param eventClass the event to enable, not {@code null}
+     *
+     * @throws IllegalArgumentException if {@code eventClass} is an abstract
+     *         class or not a subclass of {@link Event}
+     *
+     * @return an event setting for further configuration, not {@code null}
+     */
+    public EventSettings enable(Class<? extends Event> eventClass) {
+        return recording.enable(eventClass);
+    }
+
+    /**
+     * Disables event with the specified name.
+     * <p>
+     * If multiple events with same name (for example, the same class is loaded
+     * in different class loaders), then all events that match the name are
+     * disabled. To disable a specific class, use the {@link #disable(Class)}
+     * method or a {@code String} representation of the event type ID.
+     *
+     * @param name the settings for the event, not {@code null}
+     *
+     * @return an event setting for further configuration, not {@code null}
+     *
+     */
+    public EventSettings disable(String name) {
+        return recording.disable(name);
+    }
+
+    /**
+     * Disables event.
+     *
+     * @param eventClass the event to enable, not {@code null}
+     *
+     * @throws IllegalArgumentException if {@code eventClass} is an abstract
+     *         class or not a subclass of {@link Event}
+     *
+     * @return an event setting for further configuration, not {@code null}
+     *
+     */
+    public EventSettings disable(Class<? extends Event> eventClass) {
+        return recording.disable(eventClass);
+    }
+
+    /**
+     * Determines how far back data is kept for the stream.
+     * <p>
+     * To control the amount of recording data stored on disk, the maximum
+     * length of time to retain the data can be specified. Data stored on disk
+     * that is older than the specified length of time is removed by the Java
+     * Virtual Machine (JVM).
+     * <p>
+     * If neither maximum limit or the maximum age is set, the size of the
+     * recording may grow indefinitely if events are on
+     *
+     * @param maxAge the length of time that data is kept, or {@code null} if
+     *        infinite
+     *
+     * @throws IllegalArgumentException if {@code maxAge} is negative
+     *
+     * @throws IllegalStateException if the recording is in the {@code CLOSED}
+     *         state
+     */
+    public void setMaxAge(Duration maxAge) {
+        recording.setMaxAge(maxAge);
+    }
+
+    /**
+     * Determines how much data is kept for the stream.
+     * <p>
+     * To control the amount of recording data that is stored on disk, the
+     * maximum amount of data to retain can be specified. When the maximum limit
+     * is exceeded, the Java Virtual Machine (JVM) removes the oldest chunk to
+     * make room for a more recent chunk.
+     * <p>
+     * If neither maximum limit or the maximum age is set, the size of the
+     * recording may grow indefinitely.
+     * <p>
+     * The size is measured in bytes.
+     *
+     * @param maxSize the amount of data to retain, {@code 0} if infinite
+     *
+     * @throws IllegalArgumentException if {@code maxSize} is negative
+     *
+     * @throws IllegalStateException if the recording is in {@code CLOSED} state
+     */
+    public void setMaxSize(long maxSize) {
+        recording.setMaxSize(maxSize);
+    }
+
+    /**
+     * Determines how often events are made available for streaming.
+     *
+     * @param interval the interval at which events are made available to the
+     *        stream, no {@code null}
+     *
+     * @throws IllegalArgumentException if {@code interval} is negative
+     *
+     * @throws IllegalStateException if the stream is closed
+     */
+    public void setFlushInterval(Duration interval) {
+        recording.setFlushInterval(interval);
+    }
+
+    @Override
+    public void setReuse(boolean reuse) {
+        directoryStream.setReuse(reuse);
+    }
+
+    @Override
+    public void setOrdered(boolean ordered) {
+        directoryStream.setOrdered(ordered);
+    }
+
+    @Override
+    public void setStartTime(Instant startTime) {
+        directoryStream.setStartTime(startTime);
+    }
+
+    @Override
+    public void setEndTime(Instant endTime) {
+        directoryStream.setEndTime(endTime);
+    }
+
+    @Override
+    public void onEvent(String eventName, Consumer<RecordedEvent> action) {
+        directoryStream.onEvent(eventName, action);
+    }
+
+    @Override
+    public void onEvent(Consumer<RecordedEvent> action) {
+        directoryStream.onEvent(action);
+    }
+
+    @Override
+    public void onFlush(Runnable action) {
+        directoryStream.onFlush(action);
+    }
+
+    @Override
+    public void onClose(Runnable action) {
+        directoryStream.onClose(action);
+    }
+
+    @Override
+    public void onError(Consumer<Throwable> action) {
+        directoryStream.onError(action);
+    }
+
+    @Override
+    public void close() {
+        recording.close();
+        directoryStream.close();
+    }
+
+    @Override
+    public boolean remove(Object action) {
+        return directoryStream.remove(action);
+    }
+
+    @Override
+    public void start() {
+        PlatformRecording pr = PrivateAccess.getInstance().getPlatformRecording(recording);
+        long startNanos = pr.start();
+        directoryStream.start(startNanos);
+    }
+
+    @Override
+    public void startAsync() {
+        PlatformRecording pr = PrivateAccess.getInstance().getPlatformRecording(recording);
+        long startNanos = pr.start();
+        directoryStream.startAsync(startNanos);
+    }
+
+    @Override
+    public void awaitTermination(Duration timeout) throws InterruptedException {
+        directoryStream.awaitTermination(timeout);
+    }
+
+    @Override
+    public void awaitTermination() throws InterruptedException {
+        directoryStream.awaitTermination();
+    }
+}
--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/TimeConverter.java	Wed Oct 30 16:14:56 2019 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,72 +0,0 @@
-/*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.  Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-package jdk.jfr.consumer;
-
-import java.time.DateTimeException;
-import java.time.ZoneOffset;
-
-import jdk.jfr.internal.LogLevel;
-import jdk.jfr.internal.LogTag;
-import jdk.jfr.internal.Logger;
-import jdk.jfr.internal.consumer.ChunkHeader;
-
-/**
- * Converts ticks to nanoseconds
- */
-final class TimeConverter {
-    private final long startTicks;
-    private final long startNanos;
-    private final double divisor;
-    private final ZoneOffset zoneOffet;
-
-    TimeConverter(ChunkHeader chunkHeader, int rawOffset) {
-        this.startTicks = chunkHeader.getStartTicks();
-        this.startNanos = chunkHeader.getStartNanos();
-        this.divisor = chunkHeader.getTicksPerSecond() / 1000_000_000L;
-        this.zoneOffet = zoneOfSet(rawOffset);
-    }
-
-    private ZoneOffset zoneOfSet(int rawOffset) {
-        try {
-            return ZoneOffset.ofTotalSeconds(rawOffset / 1000);
-        } catch (DateTimeException dte) {
-            Logger.log(LogTag.JFR_SYSTEM_PARSER, LogLevel.INFO, "Could not create ZoneOffset from raw offset " + rawOffset);
-        }
-        return ZoneOffset.UTC;
-    }
-
-    public long convertTimestamp(long ticks) {
-        return startNanos + (long) ((ticks - startTicks) / divisor);
-    }
-
-    public long convertTimespan(long ticks) {
-        return (long) (ticks / divisor);
-    }
-
-    public ZoneOffset getZoneOffset() {
-        return zoneOffet;
-    }
-}
--- a/src/jdk.jfr/share/classes/jdk/jfr/events/ActiveRecordingEvent.java	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/jdk.jfr/share/classes/jdk/jfr/events/ActiveRecordingEvent.java	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -40,6 +40,13 @@
 @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;
 
@@ -53,6 +60,10 @@
     @Timespan(Timespan.MILLISECONDS)
     public long maxAge;
 
+    @Label("Flush Interval")
+    @Timespan(Timespan.MILLISECONDS)
+    public long flushInterval;
+
     @Label("Max Size")
     @DataAmount
     public long maxSize;
--- a/src/jdk.jfr/share/classes/jdk/jfr/events/ActiveSettingEvent.java	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/jdk.jfr/share/classes/jdk/jfr/events/ActiveSettingEvent.java	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -37,6 +37,13 @@
 @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;
 
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/EventControl.java	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/EventControl.java	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -32,11 +32,7 @@
 import java.lang.reflect.Modifier;
 import java.util.ArrayList;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
-import java.util.Map.Entry;
-import java.util.Set;
 
 import jdk.internal.module.Modules;
 import jdk.jfr.AnnotationElement;
@@ -59,7 +55,14 @@
 // holds SettingControl instances that need to be released
 // when a class is unloaded (to avoid memory leaks).
 public final class EventControl {
-
+    final static class NamedControl {
+        public final String name;
+        public final Control control;
+        NamedControl(String name, Control control) {
+            this.name = name;
+            this.control = control;
+        }
+    }
     static final String FIELD_SETTING_PREFIX = "setting";
     private static final Type TYPE_ENABLED = TypeLibrary.createType(EnabledSetting.class);
     private static final Type TYPE_THRESHOLD = TypeLibrary.createType(ThresholdSetting.class);
@@ -67,24 +70,24 @@
     private static final Type TYPE_PERIOD = TypeLibrary.createType(PeriodSetting.class);
     private static final Type TYPE_CUTOFF = TypeLibrary.createType(CutoffSetting.class);
 
-    private final List<SettingInfo> settingInfos = new ArrayList<>();
-    private final Map<String, Control> eventControls = new HashMap<>(5);
+    private final ArrayList<SettingInfo> settingInfos = new ArrayList<>();
+    private final ArrayList<NamedControl> namedControls = new ArrayList<>(5);
     private final PlatformEventType type;
     private final String idName;
 
     EventControl(PlatformEventType eventType) {
-        eventControls.put(Enabled.NAME, defineEnabled(eventType));
+        addControl(Enabled.NAME, defineEnabled(eventType));
         if (eventType.hasDuration()) {
-            eventControls.put(Threshold.NAME, defineThreshold(eventType));
+            addControl(Threshold.NAME, defineThreshold(eventType));
         }
         if (eventType.hasStackTrace()) {
-            eventControls.put(StackTrace.NAME, defineStackTrace(eventType));
+            addControl(StackTrace.NAME, defineStackTrace(eventType));
         }
         if (eventType.hasPeriod()) {
-            eventControls.put(Period.NAME, definePeriod(eventType));
+            addControl(Period.NAME, definePeriod(eventType));
         }
         if (eventType.hasCutoff()) {
-            eventControls.put(Cutoff.NAME, defineCutoff(eventType));
+            addControl(Cutoff.NAME, defineCutoff(eventType));
         }
 
         ArrayList<AnnotationElement> aes = new ArrayList<>(eventType.getAnnotationElements());
@@ -99,6 +102,19 @@
         this.idName = String.valueOf(eventType.getId());
     }
 
+    private boolean hasControl(String name) {
+        for (NamedControl nc : namedControls) {
+            if (name.equals(nc.name)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private void addControl(String name, Control control) {
+        namedControls.add(new NamedControl(name, control));
+    }
+
     static void remove(PlatformEventType type, List<AnnotationElement> aes, Class<? extends java.lang.annotation.Annotation> clazz) {
         long id = Type.getTypeId(clazz);
         for (AnnotationElement a : type.getAnnotationElements()) {
@@ -131,7 +147,8 @@
                             if (n != null) {
                                 name = n.value();
                             }
-                            if (!eventControls.containsKey(name)) {
+
+                            if (!hasControl(name)) {
                                 defineSetting((Class<? extends SettingControl>) settingClass, m, type, name);
                             }
                         }
@@ -163,7 +180,7 @@
                     }
                 }
                 aes.trimToSize();
-                eventControls.put(settingName, si.settingControl);
+                addControl(settingName, si.settingControl);
                 eventType.add(PrivateAccess.getInstance().newSettingDescriptor(settingType, settingName, defaultValue, aes));
                 settingInfos.add(si);
             }
@@ -247,9 +264,9 @@
     }
 
     void disable() {
-        for (Control c : eventControls.values()) {
-            if (c instanceof EnabledSetting) {
-                c.setValueSafe("false");
+        for (NamedControl nc : namedControls) {
+            if (nc.control instanceof EnabledSetting) {
+                nc.control.setValueSafe("false");
                 return;
             }
         }
@@ -259,24 +276,23 @@
         if (!type.isRegistered()) {
             return;
         }
-        for (Map.Entry<String, Control> entry : eventControls.entrySet()) {
-            Control c = entry.getValue();
-            if (Utils.isSettingVisible(c, type.hasEventHook())) {
-                String value = c.getLastValue();
+        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 = c.getDefaultValue();
+                    value = nc.control.getDefaultValue();
                 }
-                ActiveSettingEvent ase = new ActiveSettingEvent();
-                ase.id = type.getId();
-                ase.name = entry.getKey();
-                ase.value = value;
-                ase.commit();
+                event.id = type.getId();
+                event.name = nc.name;
+                event.value = value;
+                event.commit();
             }
         }
     }
 
-    public Set<Entry<String, Control>> getEntries() {
-        return eventControls.entrySet();
+    public ArrayList<NamedControl> getNamedControls() {
+        return namedControls;
     }
 
     public PlatformEventType getEventType() {
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/EventInstrumentation.java	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/EventInstrumentation.java	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -363,74 +363,72 @@
             methodVisitor.visitMaxs(0, 0);
         });
 
-        // MyEvent#commit() - Java event writer
         updateMethod(METHOD_COMMIT, methodVisitor -> {
-                // if (!isEnable()) {
-                // return;
-                // }
-                methodVisitor.visitCode();
+            // if (!isEnable()) {
+            // return;
+            // }
+            methodVisitor.visitCode();
+            methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
+            methodVisitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, getInternalClassName(), METHOD_IS_ENABLED.getName(), METHOD_IS_ENABLED.getDescriptor(), false);
+            Label l0 = new Label();
+            methodVisitor.visitJumpInsn(Opcodes.IFNE, l0);
+            methodVisitor.visitInsn(Opcodes.RETURN);
+            methodVisitor.visitLabel(l0);
+            methodVisitor.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
+            // if (startTime == 0) {
+            // startTime = EventWriter.timestamp();
+            // } else {
+            methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
+            methodVisitor.visitFieldInsn(Opcodes.GETFIELD, getInternalClassName(), FIELD_START_TIME, "J");
+            methodVisitor.visitInsn(Opcodes.LCONST_0);
+            methodVisitor.visitInsn(Opcodes.LCMP);
+            Label durationalEvent = new Label();
+            methodVisitor.visitJumpInsn(Opcodes.IFNE, durationalEvent);
+            methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
+            methodVisitor.visitMethodInsn(Opcodes.INVOKESTATIC, TYPE_EVENT_HANDLER.getInternalName(), METHOD_TIME_STAMP.getName(), METHOD_TIME_STAMP.getDescriptor(), false);
+            methodVisitor.visitFieldInsn(Opcodes.PUTFIELD, getInternalClassName(), FIELD_START_TIME, "J");
+            Label commit = new Label();
+            methodVisitor.visitJumpInsn(Opcodes.GOTO, commit);
+            // if (duration == 0) {
+            // duration = EventWriter.timestamp() - startTime;
+            // }
+            // }
+            methodVisitor.visitLabel(durationalEvent);
+            methodVisitor.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
+            methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
+            methodVisitor.visitFieldInsn(Opcodes.GETFIELD, getInternalClassName(), FIELD_DURATION, "J");
+            methodVisitor.visitInsn(Opcodes.LCONST_0);
+            methodVisitor.visitInsn(Opcodes.LCMP);
+            methodVisitor.visitJumpInsn(Opcodes.IFNE, commit);
+            methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
+            methodVisitor.visitMethodInsn(Opcodes.INVOKESTATIC, TYPE_EVENT_HANDLER.getInternalName(), METHOD_TIME_STAMP.getName(), METHOD_TIME_STAMP.getDescriptor(), false);
+            methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
+            methodVisitor.visitFieldInsn(Opcodes.GETFIELD, getInternalClassName(), FIELD_START_TIME, "J");
+            methodVisitor.visitInsn(Opcodes.LSUB);
+            methodVisitor.visitFieldInsn(Opcodes.PUTFIELD, getInternalClassName(), FIELD_DURATION, "J");
+            methodVisitor.visitLabel(commit);
+            // if (shouldCommit()) {
+            methodVisitor.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
+            methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
+            methodVisitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, getInternalClassName(), METHOD_EVENT_SHOULD_COMMIT.getName(), METHOD_EVENT_SHOULD_COMMIT.getDescriptor(), false);
+            Label end = new Label();
+            // eventHandler.write(...);
+            // }
+            methodVisitor.visitJumpInsn(Opcodes.IFEQ, end);
+            getEventHandler(methodVisitor);
+
+            methodVisitor.visitTypeInsn(Opcodes.CHECKCAST, eventHandlerXInternalName);
+            for (FieldInfo fi : fieldInfos) {
                 methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
-                methodVisitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, getInternalClassName(), METHOD_IS_ENABLED.getName(), METHOD_IS_ENABLED.getDescriptor(), false);
-                Label l0 = new Label();
-                methodVisitor.visitJumpInsn(Opcodes.IFNE, l0);
-                methodVisitor.visitInsn(Opcodes.RETURN);
-                methodVisitor.visitLabel(l0);
-                methodVisitor.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
-                // if (startTime == 0) {
-                // startTime = EventWriter.timestamp();
-                // } else {
-                methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
-                methodVisitor.visitFieldInsn(Opcodes.GETFIELD, getInternalClassName(), FIELD_START_TIME, "J");
-                methodVisitor.visitInsn(Opcodes.LCONST_0);
-                methodVisitor.visitInsn(Opcodes.LCMP);
-                Label durationalEvent = new Label();
-                methodVisitor.visitJumpInsn(Opcodes.IFNE, durationalEvent);
-                methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
-                methodVisitor.visitMethodInsn(Opcodes.INVOKESTATIC, TYPE_EVENT_HANDLER.getInternalName(), METHOD_TIME_STAMP.getName(),
-                        METHOD_TIME_STAMP.getDescriptor(), false);
-                methodVisitor.visitFieldInsn(Opcodes.PUTFIELD, getInternalClassName(), FIELD_START_TIME, "J");
-                Label commit = new Label();
-                methodVisitor.visitJumpInsn(Opcodes.GOTO, commit);
-                // if (duration == 0) {
-                // duration = EventWriter.timestamp() - startTime;
-                // }
-                // }
-                methodVisitor.visitLabel(durationalEvent);
-                methodVisitor.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
-                methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
-                methodVisitor.visitFieldInsn(Opcodes.GETFIELD, getInternalClassName(), FIELD_DURATION, "J");
-                methodVisitor.visitInsn(Opcodes.LCONST_0);
-                methodVisitor.visitInsn(Opcodes.LCMP);
-                methodVisitor.visitJumpInsn(Opcodes.IFNE, commit);
-                methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
-                methodVisitor.visitMethodInsn(Opcodes.INVOKESTATIC, TYPE_EVENT_HANDLER.getInternalName(), METHOD_TIME_STAMP.getName(), METHOD_TIME_STAMP.getDescriptor(), false);
-                methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
-                methodVisitor.visitFieldInsn(Opcodes.GETFIELD, getInternalClassName(), FIELD_START_TIME, "J");
-                methodVisitor.visitInsn(Opcodes.LSUB);
-                methodVisitor.visitFieldInsn(Opcodes.PUTFIELD, getInternalClassName(), FIELD_DURATION, "J");
-                methodVisitor.visitLabel(commit);
-                // if (shouldCommit()) {
-                methodVisitor.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
-                methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
-                methodVisitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, getInternalClassName(), METHOD_EVENT_SHOULD_COMMIT.getName(), METHOD_EVENT_SHOULD_COMMIT.getDescriptor(), false);
-                Label end = new Label();
-                // eventHandler.write(...);
-                // }
-                methodVisitor.visitJumpInsn(Opcodes.IFEQ, end);
-                getEventHandler(methodVisitor);
+                methodVisitor.visitFieldInsn(Opcodes.GETFIELD, fi.internalClassName, fi.fieldName, fi.fieldDescriptor);
+            }
 
-                methodVisitor.visitTypeInsn(Opcodes.CHECKCAST, eventHandlerXInternalName);
-                for (FieldInfo fi : fieldInfos) {
-                    methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
-                    methodVisitor.visitFieldInsn(Opcodes.GETFIELD, fi.internalClassName, fi.fieldName, fi.fieldDescriptor);
-                }
-
-                methodVisitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, eventHandlerXInternalName, writeMethod.getName(), writeMethod.getDescriptor(), false);
-                methodVisitor.visitLabel(end);
-                methodVisitor.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
-                methodVisitor.visitInsn(Opcodes.RETURN);
-                methodVisitor.visitEnd();
-            });
+            methodVisitor.visitMethodInsn(Opcodes.INVOKEVIRTUAL, eventHandlerXInternalName, writeMethod.getName(), writeMethod.getDescriptor(), false);
+            methodVisitor.visitLabel(end);
+            methodVisitor.visitFrame(Opcodes.F_SAME, 0, null, 0, null);
+            methodVisitor.visitInsn(Opcodes.RETURN);
+            methodVisitor.visitEnd();
+        });
 
         // MyEvent#shouldCommit()
         updateMethod(METHOD_EVENT_SHOULD_COMMIT, methodVisitor -> {
@@ -469,6 +467,7 @@
         });
     }
 
+
     private void getEventHandler(MethodVisitor methodVisitor) {
         if (untypedEventHandler) {
             methodVisitor.visitFieldInsn(Opcodes.GETSTATIC, getInternalClassName(), FIELD_EVENT_HANDLER, TYPE_OBJECT.getDescriptor());
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/EventWriter.java	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/EventWriter.java	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -26,7 +26,7 @@
 package jdk.jfr.internal;
 
 import jdk.internal.misc.Unsafe;
-import jdk.jfr.internal.consumer.RecordingInput;
+import jdk.jfr.internal.consumer.StringParser;
 
 /**
  * Class must reside in a package with package restriction.
@@ -115,18 +115,18 @@
 
     public void putString(String s, StringPool pool) {
         if (s == null) {
-            putByte(RecordingInput.STRING_ENCODING_NULL);
+            putByte(StringParser.Encoding.NULL.byteValue());
             return;
         }
         int length = s.length();
         if (length == 0) {
-            putByte(RecordingInput.STRING_ENCODING_EMPTY_STRING);
+            putByte(StringParser.Encoding.EMPTY_STRING.byteValue());
             return;
         }
         if (length > StringPool.MIN_LIMIT && length < StringPool.MAX_LIMIT) {
             long l = StringPool.addString(s);
             if (l > 0) {
-                putByte(RecordingInput.STRING_ENCODING_CONSTANT_POOL);
+                putByte(StringParser.Encoding.CONSTANT_POOL.byteValue());
                 putLong(l);
                 return;
             }
@@ -138,7 +138,7 @@
     private void putStringValue(String s) {
         int length = s.length();
         if (isValidForSize(1 + 5 + 3 * length)) {
-            putUncheckedByte(RecordingInput.STRING_ENCODING_CHAR_ARRAY); // 1 byte
+            putUncheckedByte(StringParser.Encoding.CHAR_ARRAY.byteValue()); // 1 byte
             putUncheckedInt(length); // max 5 bytes
             for (int i = 0; i < length; i++) {
                 putUncheckedChar(s.charAt(i)); // max 3 bytes
@@ -197,11 +197,7 @@
         if (currentPosition + requestedSize > maxPosition) {
             flushOnEnd = flush(usedSize(), requestedSize);
             // retry
-            if (currentPosition + requestedSize > maxPosition) {
-                Logger.log(LogTag.JFR_SYSTEM,
-                           LogLevel.WARN, () ->
-                               "Unable to commit. Requested size " + requestedSize + " too large");
-                valid = false;
+            if (!valid) {
                 return false;
             }
         }
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/FilePurger.java	Wed Oct 30 19:43:52 2019 +0100
@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.jfr.internal;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.LinkedHashSet;
+import java.util.Set;
+
+import jdk.jfr.internal.SecuritySupport.SafePath;
+
+// This class keeps track of files that can't be deleted
+// so they can a later staged be removed.
+final class FilePurger {
+
+    private final static Set<SafePath> paths = new LinkedHashSet<>();
+
+    public synchronized static void add(SafePath p) {
+        paths.add(p);
+        if (paths.size() > 1000) {
+            removeOldest();
+        }
+    }
+
+    public synchronized static void purge() {
+        if (paths.isEmpty()) {
+            return;
+        }
+
+        for (SafePath p : new ArrayList<>(paths)) {
+            if (delete(p)) {
+                paths.remove(p);
+            }
+        }
+    }
+
+    private static void removeOldest() {
+        SafePath oldest = paths.iterator().next();
+        paths.remove(oldest);
+    }
+
+    private static boolean delete(SafePath p) {
+        try {
+            SecuritySupport.delete(p);
+            return true;
+        } catch (IOException e) {
+            return false;
+        }
+    }
+}
--- a/src/jdk.jfr/share/classes/jdk/jfr/internal/JVM.java	Wed Oct 30 16:14:56 2019 +0100
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/JVM.java	Wed Oct 30 19:43:52 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -270,7 +270,6 @@
      *
      * @param file the file where data should be written, or null if it should
      *        not be copied out (in memory).
-     *
      * @throws IOException
      */
     public native void setOutput(String file);
@@ -460,6 +459,16 @@
     public static native boolean flush(EventWriter writer, int uncommittedSize, int requestedSize);
 
     /**
+     * Flushes all thread buffers to disk and the constant pool data needed to read
+     * them.
+     * <p>
+     * When the method returns, the chunk header should be updated with valid
+     * pointers to the metadata event, last check point event, correct file size and
+     * the generation id.
+     *
+     */
+    public native void flush();
+    /**
      * Sets the location of the disk repository, to be used at an emergency
      * dump.
      *
@@ -523,4 +532,30 @@
      * @return if it is time to perform a chunk rotation
      */
     public native boolean shouldRotateDisk();
+
+    /**
+     * Exclude a thread from the jfr system
+     *
+     */
+    public native void exclude(Thread thread);
+