Add support for JFR monitor enter events

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jfr/JfrEvent.java

@@ -53,7 +53,9 @@ public enum JfrEvent {
     GCPhasePauseLevel4Event("jdk.GCPhasePauseLevel4"),
     SafepointBegin("jdk.SafepointBegin"),
     SafepointEnd("jdk.SafepointEnd"),
-    ExecuteVMOperation("jdk.ExecuteVMOperation");
+    ExecuteVMOperation("jdk.ExecuteVMOperation"),
+    JavaMonitorEnter("jdk.JavaMonitorEnter");
+
 
     private final long id;
 

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/jfr/events/JavaMonitorEnterEvent.java

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2022, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2022, 2022, Red Hat Inc. 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 com.oracle.svm.core.jfr.events;
+
+import org.graalvm.nativeimage.StackValue;
+
+import com.oracle.svm.core.annotate.Uninterruptible;
+import com.oracle.svm.core.jfr.JfrEvent;
+import com.oracle.svm.core.jfr.JfrNativeEventWriter;
+import com.oracle.svm.core.jfr.JfrNativeEventWriterData;
+import com.oracle.svm.core.jfr.JfrNativeEventWriterDataAccess;
+import com.oracle.svm.core.jfr.JfrTicks;
+import com.oracle.svm.core.jfr.SubstrateJVM;
+
+public class JavaMonitorEnterEvent {
+
+    @Uninterruptible(reason = "Accesses a JFR buffer.")
+    public static void emit(Object obj, org.graalvm.nativeimage.IsolateThread previousOwner, long startTicks) {
+        emit(obj, com.oracle.svm.core.jfr.SubstrateJVM.get().getThreadId(previousOwner), startTicks);
+    }
+
+    @Uninterruptible(reason = "Accesses a JFR buffer.")
+    public static void emit(Object obj, long previousOwner, long startTicks) {
+        if (SubstrateJVM.isRecording() && SubstrateJVM.get().isEnabled(JfrEvent.JavaMonitorEnter)) {
+            JfrNativeEventWriterData data = StackValue.get(JfrNativeEventWriterData.class);
+            JfrNativeEventWriterDataAccess.initializeThreadLocalNativeBuffer(data);
+
+            JfrNativeEventWriter.beginSmallEvent(data, JfrEvent.JavaMonitorEnter);
+            JfrNativeEventWriter.putLong(data, startTicks);
+            JfrNativeEventWriter.putLong(data, JfrTicks.elapsedTicks() - startTicks);
+            JfrNativeEventWriter.putEventThread(data);
+            JfrNativeEventWriter.putLong(data, SubstrateJVM.get().getStackTraceId(JfrEvent.JavaMonitorEnter.getId(), 0));
+            JfrNativeEventWriter.putClass(data, obj.getClass());
+            JfrNativeEventWriter.putLong(data, previousOwner);
+            JfrNativeEventWriter.putLong(data, org.graalvm.compiler.word.Word.objectToUntrackedPointer(obj).rawValue());
+            JfrNativeEventWriter.endSmallEvent(data);
+
+        }
+    }
+}

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/monitor/JavaMonitor.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2022, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2022, 2022, Red Hat Inc. 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 com.oracle.svm.core.monitor;
+
+import java.util.concurrent.locks.ReentrantLock;
+
+import org.graalvm.nativeimage.CurrentIsolate;
+import com.oracle.svm.core.jfr.SubstrateJVM;
+import com.oracle.svm.core.jfr.events.JavaMonitorEnterEvent;
+import com.oracle.svm.core.jfr.JfrTicks;
+
+public class JavaMonitor extends ReentrantLock {
+    private long ownerTid;
+
+    public long getOwnerTid() {
+        return ownerTid;
+    }
+
+    public JavaMonitor() {
+        super();
+        ownerTid = SubstrateJVM.get().getThreadId(CurrentIsolate.getCurrentThread());
+    }
+
+    public void monitorEnter(Object obj) {
+        if (!tryLock()) {
+            long startTicks = JfrTicks.elapsedTicks();
+            lock();
+            JavaMonitorEnterEvent.emit(obj, getOwnerTid(), startTicks);
+        }
+        ownerTid = SubstrateJVM.get().getThreadId(CurrentIsolate.getCurrentThread());
+    }
+
+
+}

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/monitor/MultiThreadedMonitorSupport.java

@@ -60,6 +60,7 @@
 import com.oracle.svm.core.thread.VMOperationControl;
 import com.oracle.svm.core.util.VMError;
 
+
 import jdk.internal.misc.Unsafe;
 
 /**
@@ -137,7 +138,7 @@ public class MultiThreadedMonitorSupport extends MonitorSupport {
              * java.io.FileInputStream.close() which synchronizes on a 'Object closeLock = new
              * Object()' object. We cannot modify the type of the monitor since it is in JDK code.
              * Adding a monitor slot to java.lang.Object doesn't impact any subtypes.
-             * 
+             *
              * This should also take care of the synchronization in
              * ReferenceInternals.processPendingReferences().
              */
@@ -192,7 +193,7 @@ public class MultiThreadedMonitorSupport extends MonitorSupport {
      * Secondary storage for monitor slots. Synchronized to prevent concurrent access and
      * modification.
      */
-    private final Map<Object, ReentrantLock> additionalMonitors = new WeakIdentityHashMap<>();
+    private final Map<Object, JavaMonitor> additionalMonitors = new WeakIdentityHashMap<>();
     private final ReentrantLock additionalMonitorsLock = new ReentrantLock();
 
     @Override
@@ -255,8 +256,8 @@ private static void slowPathMonitorEnter(Object obj) {
     @RestrictHeapAccess(reason = NO_LONGER_UNINTERRUPTIBLE, access = Access.UNRESTRICTED)
     @Override
     public void monitorEnter(Object obj) {
-        ReentrantLock lockObject = getOrCreateMonitor(obj, true);
-        lockObject.lock();
+        JavaMonitor lockObject = getOrCreateMonitor(obj, true);
+        lockObject.monitorEnter(obj);
     }
 
     @SubstrateForeignCallTarget(stubCallingConvention = false)
@@ -301,13 +302,13 @@ public Object prepareRelockObject(Object obj) {
         /*
          * We ensure that the lock for the object exists, so that the actual re-locking during
          * deoptimization can be uninterruptible.
-         * 
+         *
          * Unfortunately, we cannot do any assertion checking in this method: deoptimization can run
          * in any thread, i.e., not necessarily in the thread that the lock will be for. And while
          * the frame that is deoptimized must have had the object locked, the thread could have
          * given up the lock as part of a wait() - so at this time any thread is allowed to hold the
          * lock.
-         * 
+         *
          * Because any thread can hold the lock at this time, there is no way we can patch any
          * internal state of the lock immediately here. The actual state patching therefore happens
          * later in doRelockObject.
@@ -421,7 +422,7 @@ protected static Object replaceObject(Object unreplacedObject) {
         return unreplacedObject;
     }
 
-    protected final ReentrantLock getOrCreateMonitor(Object unreplacedObject, boolean createIfNotExisting) {
+    protected final JavaMonitor getOrCreateMonitor(Object unreplacedObject, boolean createIfNotExisting) {
         Object obj = replaceObject(unreplacedObject);
         assert obj != null;
         int monitorOffset = getMonitorOffset(obj);
@@ -434,48 +435,48 @@ protected final ReentrantLock getOrCreateMonitor(Object unreplacedObject, boolea
         }
     }
 
-    protected ReentrantLock getOrCreateMonitorFromObject(Object obj, boolean createIfNotExisting, int monitorOffset) {
-        ReentrantLock existingMonitor = (ReentrantLock) BarrieredAccess.readObject(obj, monitorOffset);
+    protected JavaMonitor getOrCreateMonitorFromObject(Object obj, boolean createIfNotExisting, int monitorOffset) {
+        JavaMonitor existingMonitor = (JavaMonitor) BarrieredAccess.readObject(obj, monitorOffset);
         if (existingMonitor != null || !createIfNotExisting) {
             assert existingMonitor == null || isMonitorLock(existingMonitor);
             return existingMonitor;
         }
         /* Atomically put a new lock in place of the null at the monitorOffset. */
-        ReentrantLock newMonitor = newMonitorLock();
+        JavaMonitor newMonitor = newMonitorLock();
         if (UNSAFE.compareAndSetObject(obj, monitorOffset, null, newMonitor)) {
             return newMonitor;
         }
         /* We lost the race, use the lock some other thread installed. */
-        return (ReentrantLock) BarrieredAccess.readObject(obj, monitorOffset);
+        return (JavaMonitor) BarrieredAccess.readObject(obj, monitorOffset);
     }
 
-    protected ReentrantLock getOrCreateMonitorFromMap(Object obj, boolean createIfNotExisting) {
+    protected JavaMonitor getOrCreateMonitorFromMap(Object obj, boolean createIfNotExisting) {
         assert obj.getClass() != Target_java_lang_ref_ReferenceQueue_Lock.class : "ReferenceQueue.Lock must have a monitor field or we can deadlock accessing WeakIdentityHashMap below";
         VMError.guarantee(!additionalMonitorsLock.isHeldByCurrentThread(),
-                        "Recursive manipulation of the additionalMonitors map can lead to table corruptions and double insertion of a monitor for the same object");
+                    "Recursive manipulation of the additionalMonitors map can lead to table corruptions and double insertion of a monitor for the same object");
 
         /*
          * Lock the monitor map and maybe add a monitor for this object. This serialization might be
          * a scalability problem.
          */
         additionalMonitorsLock.lock();
         try {
-            ReentrantLock existingMonitor = additionalMonitors.get(obj);
+            JavaMonitor existingMonitor = additionalMonitors.get(obj);
             if (existingMonitor != null || !createIfNotExisting) {
                 assert existingMonitor == null || isMonitorLock(existingMonitor);
                 return existingMonitor;
             }
-            ReentrantLock newMonitor = newMonitorLock();
-            ReentrantLock previousEntry = additionalMonitors.put(obj, newMonitor);
+            JavaMonitor newMonitor = newMonitorLock();
+            JavaMonitor previousEntry = additionalMonitors.put(obj, newMonitor);
             VMError.guarantee(previousEntry == null, "Replaced monitor in secondary storage map");
             return newMonitor;
         } finally {
             additionalMonitorsLock.unlock();
         }
     }
 
-    protected static ReentrantLock newMonitorLock() {
-        ReentrantLock newMonitor = new ReentrantLock();
+    protected static JavaMonitor newMonitorLock() {
+        JavaMonitor newMonitor = new JavaMonitor();
         Target_java_util_concurrent_locks_ReentrantLock lock = SubstrateUtil.cast(newMonitor, Target_java_util_concurrent_locks_ReentrantLock.class);
         Target_java_util_concurrent_locks_ReentrantLock_NonfairSync sync = SubstrateUtil.cast(lock.sync, Target_java_util_concurrent_locks_ReentrantLock_NonfairSync.class);
         sync.objectMonitorCondition = SubstrateUtil.cast(MONITOR_WITHOUT_CONDITION, Target_java_util_concurrent_locks_AbstractQueuedSynchronizer_ConditionObject.class);