8330734: JFR: Re-engineer mirror class mechanism

egahlin · egahlin · commit 07facd0420c5 · 2024-04-26T17:15:09.000Z
Reviewed-by: mgronlun
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/DeserializationEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/DeserializationEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2024, 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
@@ -36,9 +36,8 @@
 @Label("Deserialization")
 @Name("jdk.Deserialization")
 @Description("Results of deserialization and ObjectInputFilter checks")
-@MirrorEvent(className = "jdk.internal.event.DeserializationEvent")
 @RemoveFields("duration")
-public final class DeserializationEvent extends AbstractJDKEvent {
+public final class DeserializationEvent extends MirrorEvent {
 
     @Label("Filter Configured")
     public boolean filterConfigured;
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/ErrorThrownEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/ErrorThrownEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2024, 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
@@ -36,9 +36,8 @@
 @Label("Java Error")
 @Category("Java Application")
 @Description("An object derived from java.lang.Error has been created. OutOfMemoryErrors are ignored")
-@MirrorEvent(className = "jdk.internal.event.ErrorThrownEvent")
 @RemoveFields("duration")
-public final class ErrorThrownEvent extends AbstractJDKEvent {
+public final class ErrorThrownEvent extends MirrorEvent {
 
     @Label("Message")
     public String message;
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/ExceptionStatisticsEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/ExceptionStatisticsEvent.java
@@ -31,14 +31,15 @@
 import jdk.jfr.Name;
 import jdk.jfr.StackTrace;
 import jdk.jfr.internal.MirrorEvent;
+import jdk.jfr.internal.RemoveFields;
 import jdk.jfr.internal.Type;
 
 @Name(Type.EVENT_NAME_PREFIX + "ExceptionStatistics")
 @Label("Exception Statistics")
 @Category({ "Java Application", "Statistics" })
 @Description("Number of objects derived from java.lang.Throwable that have been created")
-@MirrorEvent(className = "jdk.internal.event.ExceptionStatisticsEvent")
-public final class ExceptionStatisticsEvent extends AbstractPeriodicEvent {
+@RemoveFields({"duration", "eventThread", "stackTrace"})
+public final class ExceptionStatisticsEvent extends MirrorEvent {
 
     @Label("Exceptions Created")
     public long throwables;
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/ExceptionThrownEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/ExceptionThrownEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2024, 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
@@ -37,9 +37,8 @@
 @Label("Java Exception")
 @Category("Java Application")
 @Description("An object derived from java.lang.Exception has been created")
-@MirrorEvent(className = "jdk.internal.event.ExceptionThrownEvent")
 @RemoveFields("duration")
-public final class ExceptionThrownEvent extends AbstractJDKEvent {
+public final class ExceptionThrownEvent extends MirrorEvent {
 
     @Label("Message")
     public String message;
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/ProcessStartEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/ProcessStartEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, 2024, 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
@@ -36,10 +36,9 @@
 @Label("Process Start")
 @Name("jdk.ProcessStart")
 @Description("Operating system process started")
-@MirrorEvent(className = "jdk.internal.event.ProcessStartEvent")
 @RemoveFields("duration")
 @StackFilter({"java.lang.ProcessBuilder", "java.lang.Runtime::exec"})
-public final class ProcessStartEvent extends AbstractJDKEvent {
+public final class ProcessStartEvent extends MirrorEvent {
     @Label("Process Id")
     public long pid;
 
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/SecurityPropertyModificationEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/SecurityPropertyModificationEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2024, 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
@@ -33,10 +33,9 @@
 @Label("Security Property Modification")
 @Name("jdk.SecurityPropertyModification")
 @Description("Modification of Security property")
-@MirrorEvent(className = "jdk.internal.event.SecurityPropertyModificationEvent")
 @RemoveFields("duration")
 @StackFilter({"java.security.Security::setProperty"})
-public final class SecurityPropertyModificationEvent extends AbstractJDKEvent {
+public final class SecurityPropertyModificationEvent extends MirrorEvent {
     @Label("Key")
     public String key;
 
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/SecurityProviderServiceEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/SecurityProviderServiceEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2022, 2024, 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
@@ -36,10 +36,9 @@
 @Label("Security Provider Instance Request")
 @Name("jdk.SecurityProviderService")
 @Description("Details of Provider.getInstance(String type, String algorithm) calls")
-@MirrorEvent(className = "jdk.internal.event.SecurityProviderServiceEvent")
 @RemoveFields("duration")
 @StackFilter({"java.security.Provider::getService"})
-public final class SecurityProviderServiceEvent extends AbstractJDKEvent {
+public final class SecurityProviderServiceEvent extends MirrorEvent {
     @Label("Type of Service")
     public String type;
 
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/SerializationMisdeclarationEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/SerializationMisdeclarationEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2023, 2024, 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
@@ -40,9 +40,8 @@
         " The checks are usually performed just once per serializable class," +
         " the first time it is used by serialization." +
         " Under high memory pressure, a class might be re-checked again.")
-@MirrorEvent(className = "jdk.internal.event.SerializationMisdeclarationEvent")
 @RemoveFields({"duration", "stackTrace", "eventThread"})
-public final class SerializationMisdeclarationEvent extends AbstractJDKEvent {
+public final class SerializationMisdeclarationEvent extends MirrorEvent {
 
     @Label("Misdeclared Class")
     public Class<?> misdeclaredClass;
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/SocketReadEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/SocketReadEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2024, 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
@@ -38,8 +38,7 @@
 @Label("Socket Read")
 @Category("Java Application")
 @Description("Reading data from a socket")
-@MirrorEvent(className = "jdk.internal.event.SocketReadEvent")
-public final class SocketReadEvent extends AbstractJDKEvent {
+public final class SocketReadEvent extends MirrorEvent {
 
     @Label("Remote Host")
     public String host;
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/SocketWriteEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/SocketWriteEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2024, 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
@@ -37,8 +37,7 @@
 @Label("Socket Write")
 @Category("Java Application")
 @Description("Writing data to a socket")
-@MirrorEvent(className = "jdk.internal.event.SocketWriteEvent")
-public final class SocketWriteEvent extends AbstractJDKEvent {
+public final class SocketWriteEvent extends MirrorEvent {
 
     @Label("Remote Host")
     public String host;
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/TLSHandshakeEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/TLSHandshakeEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2024, 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
@@ -37,10 +37,9 @@
 @Label("TLS Handshake")
 @Name("jdk.TLSHandshake")
 @Description("Parameters used in TLS Handshake")
-@MirrorEvent(className = "jdk.internal.event.TLSHandshakeEvent")
 @RemoveFields("duration")
 @StackFilter("sun.security.ssl.Finished::recordEvent")
-public final class TLSHandshakeEvent extends AbstractJDKEvent {
+public final class TLSHandshakeEvent extends MirrorEvent {
     @Label("Peer Host")
     public String peerHost;
 
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/ThreadSleepEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/ThreadSleepEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, 2024, 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
@@ -34,11 +34,10 @@
 @Category("Java Application")
 @Label("Java Thread Sleep")
 @Name("jdk.ThreadSleep")
-@MirrorEvent(className = "jdk.internal.event.ThreadSleepEvent")
 @StackFilter({"java.lang.Thread::afterSleep",
               "java.lang.Thread::sleepNanos",
               "java.lang.Thread::sleep"})
-public final class ThreadSleepEvent extends AbstractJDKEvent {
+public final class ThreadSleepEvent extends MirrorEvent {
     @Label("Sleep Time")
     @Timespan(Timespan.NANOSECONDS)
     public long time;
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/VirtualThreadEndEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/VirtualThreadEndEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2024, 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
@@ -34,9 +34,8 @@
 @Category("Java Application")
 @Label("Virtual Thread End")
 @Name("jdk.VirtualThreadEnd")
-@MirrorEvent(className = "jdk.internal.event.VirtualThreadEndEvent")
 @RemoveFields({"duration", "stackTrace"})
-public final class VirtualThreadEndEvent extends AbstractJDKEvent {
+public final class VirtualThreadEndEvent extends MirrorEvent {
 
     @Label("Thread Id")
     public long javaThreadId;
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/VirtualThreadPinnedEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/VirtualThreadPinnedEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2024, 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
@@ -33,6 +33,5 @@
 @Category("Java Application")
 @Label("Virtual Thread Pinned")
 @Name("jdk.VirtualThreadPinned")
-@MirrorEvent(className = "jdk.internal.event.VirtualThreadPinnedEvent")
-public final class VirtualThreadPinnedEvent extends AbstractJDKEvent {
+public final class VirtualThreadPinnedEvent extends MirrorEvent {
 }
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/VirtualThreadStartEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/VirtualThreadStartEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2024, 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
@@ -34,9 +34,8 @@
 @Category("Java Application")
 @Label("Virtual Thread Start")
 @Name("jdk.VirtualThreadStart")
-@MirrorEvent(className = "jdk.internal.event.VirtualThreadStartEvent")
 @RemoveFields("duration")
-public final class VirtualThreadStartEvent extends AbstractJDKEvent {
+public final class VirtualThreadStartEvent extends MirrorEvent {
 
     @Label("Thread Id")
     public long javaThreadId;
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/VirtualThreadSubmitFailedEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/VirtualThreadSubmitFailedEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2024, 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
@@ -36,9 +36,8 @@
 @Label("Virtual Thread Submit Failed")
 @Name("jdk.VirtualThreadSubmitFailed")
 @Description("Submit of task for virtual thread failed")
-@MirrorEvent(className = "jdk.internal.event.VirtualThreadSubmitFailedEvent")
 @RemoveFields("duration")
-public final class VirtualThreadSubmitFailedEvent extends AbstractJDKEvent {
+public final class VirtualThreadSubmitFailedEvent extends MirrorEvent {
 
     @Label("Thread Id")
     public long javaThreadId;
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/X509CertificateEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/X509CertificateEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2024, 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
@@ -33,9 +33,8 @@
 @Label("X509 Certificate")
 @Name("jdk.X509Certificate")
 @Description("Details of X.509 Certificate parsed by JDK")
-@MirrorEvent(className = "jdk.internal.event.X509CertificateEvent")
 @RemoveFields("duration")
-public final class X509CertificateEvent extends AbstractJDKEvent {
+public final class X509CertificateEvent extends MirrorEvent {
     @Label("Signature Algorithm")
     public String algorithm;
 
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/events/X509ValidationEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/events/X509ValidationEvent.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2024, 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
@@ -33,9 +33,8 @@
 @Label("X509 Validation")
 @Name("jdk.X509Validation")
 @Description("Serial numbers from X.509 Certificates forming chain of trust")
-@MirrorEvent(className = "jdk.internal.event.X509ValidationEvent")
 @RemoveFields("duration")
-public final class X509ValidationEvent extends AbstractJDKEvent {
+public final class X509ValidationEvent extends MirrorEvent {
     @CertificateId
     @Label("Certificate Id")
     @Unsigned
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/EventInstrumentation.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/EventInstrumentation.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2024, 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
@@ -90,7 +90,6 @@ private record SettingDesc(ClassDesc paramType, String methodName) {
     private static final ClassDesc TYPE_ISE = Bytecode.classDesc(IllegalStateException.class);
     private static final ClassDesc TYPE_EVENT_WRITER = classDesc(EventWriter.class);
     private static final ClassDesc TYPE_EVENT_WRITER_FACTORY = ClassDesc.of("jdk.jfr.internal.event.EventWriterFactory");
-    private static final ClassDesc TYPE_MIRROR_EVENT = Bytecode.classDesc(MirrorEvent.class);
     private static final ClassDesc TYPE_OBJECT = Bytecode.classDesc(Object.class);
     private static final ClassDesc TYPE_SETTING_DEFINITION = Bytecode.classDesc(SettingDefinition.class);
     private static final MethodDesc METHOD_BEGIN = MethodDesc.of("begin", "()V");
@@ -144,9 +143,7 @@ private record SettingDesc(ClassDesc paramType, String methodName) {
 
     private ImplicitFields determineImplicitFields() {
         if (isJDK) {
-            // For now, only support mirror events in java.base
-            String fullName = "java.base:" + className;
-            Class<?> eventClass = MirrorEvents.find(fullName);
+            Class<?> eventClass = MirrorEvents.find(isJDK, className);
             if (eventClass != null) {
                 return new ImplicitFields(eventClass);
             }
@@ -221,20 +218,6 @@ boolean isEnabled() {
         return true;
     }
 
-    boolean isMirrorEvent() {
-        String typeDescriptor = TYPE_MIRROR_EVENT.descriptorString();
-        for (ClassElement ce : classModel.elements()) {
-            if (ce instanceof RuntimeVisibleAnnotationsAttribute rvaa) {
-                for (var annotation : rvaa.annotations()) {
-                    if (annotation.className().equalsString(typeDescriptor)) {
-                        return true;
-                    }
-                }
-            }
-        }
-        return false;
-    }
-
     @SuppressWarnings("unchecked")
     // Only supports String, String[] and Boolean values
     private static <T> T annotationValue(ClassModel classModel, ClassDesc classDesc, Class<T> type) {
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/JVMUpcalls.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/JVMUpcalls.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 2024, 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
@@ -112,9 +112,6 @@ static byte[] bytesForEagerInstrumentation(long traceId, boolean forceInstrument
                 Logger.log(LogTag.JFR_SYSTEM, LogLevel.INFO, "Skipping instrumentation for " + eventName + " since container support is missing");
                 return oldBytes;
             }
-            if (ei.isMirrorEvent()) {
-                return oldBytes;
-            }
 
             if (!forceInstrumentation) {
                 // Assume we are recording
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/MetadataRepository.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/MetadataRepository.java
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvent.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvent.java
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/MirrorEvents.java
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/TypeLibrary.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/TypeLibrary.java
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/util/ImplicitFields.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/util/ImplicitFields.java
diff --git a/src/jdk.jfr/share/classes/jdk/jfr/internal/util/Utils.java b/src/jdk.jfr/share/classes/jdk/jfr/internal/util/Utils.java
