8304303: implement VirtualThread class notifyJvmti methods as C2 intr…

…insics Reviewed-by: vlivanov, lmesnik
ibmruntimes · Mar 20, 2023 · b0fd761 · b0fd761
1 parent 917f936
commit b0fd761
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Showing 4 changed files with 31 additions and 56 deletions.
diff --git a/make/data/hotspot-symbols/symbols-unix b/make/data/hotspot-symbols/symbols-unix
@@ -218,10 +218,8 @@ JVM_DefineModule
 JVM_SetBootLoaderUnnamedModule
 
 # Virtual thread notifications for JVMTI
-JVM_VirtualThreadMountBegin
-JVM_VirtualThreadMountEnd
-JVM_VirtualThreadUnmountBegin
-JVM_VirtualThreadUnmountEnd
+JVM_VirtualThreadMount
+JVM_VirtualThreadUnmount
 JVM_VirtualThreadHideFrames
 
 # Scoped values

diff --git a/src/hotspot/share/include/jvm.h b/src/hotspot/share/include/jvm.h
@@ -1144,16 +1144,10 @@ JVM_GetEnclosingMethodInfo(JNIEnv* env, jclass ofClass);
  * Virtual thread support.
  */
 JNIEXPORT void JNICALL
-JVM_VirtualThreadMountBegin(JNIEnv* env, jobject vthread, jboolean first_mount);
+JVM_VirtualThreadMount(JNIEnv* env, jobject vthread, jboolean hide, jboolean first_mount);
 
 JNIEXPORT void JNICALL
-JVM_VirtualThreadMountEnd(JNIEnv* env, jobject vthread, jboolean first_mount);
-
-JNIEXPORT void JNICALL
-JVM_VirtualThreadUnmountBegin(JNIEnv* env, jobject vthread, jboolean last_unmount);
-
-JNIEXPORT void JNICALL
-JVM_VirtualThreadUnmountEnd(JNIEnv* env, jobject vthread, jboolean last_unmount);
+JVM_VirtualThreadUnmount(JNIEnv* env, jobject vthread, jboolean hide, jboolean last_unmount);
 
 JNIEXPORT void JNICALL
 JVM_VirtualThreadHideFrames(JNIEnv* env, jobject vthread, jboolean hide);

diff --git a/src/java.base/share/classes/java/lang/VirtualThread.java b/src/java.base/share/classes/java/lang/VirtualThread.java
@@ -56,6 +56,7 @@
 import jdk.internal.vm.annotation.ChangesCurrentThread;
 import jdk.internal.vm.annotation.ForceInline;
 import jdk.internal.vm.annotation.Hidden;
+import jdk.internal.vm.annotation.IntrinsicCandidate;
 import jdk.internal.vm.annotation.JvmtiMountTransition;
 import sun.nio.ch.Interruptible;
 import sun.security.action.GetPropertyAction;
@@ -210,7 +211,7 @@ private void runContinuation() {
         }
 
         // notify JVMTI before mount
-        if (notifyJvmtiEvents) notifyJvmtiMountBegin(firstRun);
+        notifyJvmtiMount(true, firstRun);
 
         try {
             cont.run();
@@ -287,11 +288,10 @@ private void submitFailed(RejectedExecutionException ree) {
     @ChangesCurrentThread
     private void run(Runnable task) {
         assert state == RUNNING;
-        boolean notifyJvmti = notifyJvmtiEvents;
 
         // first mount
         mount();
-        if (notifyJvmti) notifyJvmtiMountEnd(true);
+        notifyJvmtiMount(false, true);
 
         // emit JFR event if enabled
         if (VirtualThreadStartEvent.isTurnedOn()) {
@@ -319,7 +319,7 @@ private void run(Runnable task) {
 
             } finally {
                 // last unmount
-                if (notifyJvmti) notifyJvmtiUnmountBegin(true);
+                notifyJvmtiUnmount(true, true);
                 unmount();
 
                 // final state
@@ -381,35 +381,27 @@ private void unmount() {
 
     /**
      * Sets the current thread to the current carrier thread.
-     * @return true if JVMTI was notified
      */
     @ChangesCurrentThread
     @JvmtiMountTransition
-    private boolean switchToCarrierThread() {
-        boolean notifyJvmti = notifyJvmtiEvents;
-        if (notifyJvmti) {
-            notifyJvmtiHideFrames(true);
-        }
+    private void switchToCarrierThread() {
+        notifyJvmtiHideFrames(true);
         Thread carrier = this.carrierThread;
         assert Thread.currentThread() == this
                 && carrier == Thread.currentCarrierThread();
         carrier.setCurrentThread(carrier);
-        return notifyJvmti;
     }
 
     /**
      * Sets the current thread to the given virtual thread.
-     * If {@code notifyJvmti} is true then JVMTI is notified.
      */
     @ChangesCurrentThread
     @JvmtiMountTransition
-    private void switchToVirtualThread(VirtualThread vthread, boolean notifyJvmti) {
+    private void switchToVirtualThread(VirtualThread vthread) {
         Thread carrier = vthread.carrierThread;
         assert carrier == Thread.currentCarrierThread();
         carrier.setCurrentThread(vthread);
-        if (notifyJvmti) {
-            notifyJvmtiHideFrames(false);
-        }
+        notifyJvmtiHideFrames(false);
     }
 
     /**
@@ -419,17 +411,15 @@ private void switchToVirtualThread(VirtualThread vthread, boolean notifyJvmti) {
      */
     @ChangesCurrentThread
     private boolean yieldContinuation() {
-        boolean notifyJvmti = notifyJvmtiEvents;
-
         // unmount
-        if (notifyJvmti) notifyJvmtiUnmountBegin(false);
+        notifyJvmtiUnmount(true, false);
         unmount();
         try {
             return Continuation.yield(VTHREAD_SCOPE);
         } finally {
             // re-mount
             mount();
-            if (notifyJvmti) notifyJvmtiMountEnd(false);
+            notifyJvmtiMount(false, false);
         }
     }
 
@@ -446,7 +436,7 @@ private void afterYield() {
             setState(PARKED);
 
             // notify JVMTI that unmount has completed, thread is parked
-            if (notifyJvmtiEvents) notifyJvmtiUnmountEnd(false);
+            notifyJvmtiUnmount(false, false);
 
             // may have been unparked while parking
             if (parkPermit && compareAndSetState(PARKED, RUNNABLE)) {
@@ -462,7 +452,7 @@ private void afterYield() {
             setState(RUNNABLE);
 
             // notify JVMTI that unmount has completed, thread is runnable
-            if (notifyJvmtiEvents) notifyJvmtiUnmountEnd(false);
+            notifyJvmtiUnmount(false, false);
 
             // external submit if there are no tasks in the local task queue
             if (currentThread() instanceof CarrierThread ct && ct.getQueuedTaskCount() == 0) {
@@ -483,7 +473,7 @@ private void afterTerminate(boolean executed) {
         assert (state() == TERMINATED) && (carrierThread == null);
 
         if (executed) {
-            if (notifyJvmtiEvents) notifyJvmtiUnmountEnd(true);
+            notifyJvmtiUnmount(false, true);
         }
 
         // notify anyone waiting for this virtual thread to terminate
@@ -651,11 +641,11 @@ private void parkOnCarrierThread(boolean timed, long nanos) {
     @ChangesCurrentThread
     private Future<?> scheduleUnpark(Runnable unparker, long nanos) {
         // need to switch to current carrier thread to avoid nested parking
-        boolean notifyJvmti = switchToCarrierThread();
+        switchToCarrierThread();
         try {
             return UNPARKER.schedule(unparker, nanos, NANOSECONDS);
         } finally {
-            switchToVirtualThread(this, notifyJvmti);
+            switchToVirtualThread(this);
         }
     }
 
@@ -666,11 +656,11 @@ private Future<?> scheduleUnpark(Runnable unparker, long nanos) {
     private void cancel(Future<?> future) {
         if (!future.isDone()) {
             // need to switch to current carrier thread to avoid nested parking
-            boolean notifyJvmti = switchToCarrierThread();
+            switchToCarrierThread();
             try {
                 future.cancel(false);
             } finally {
-                switchToVirtualThread(this, notifyJvmti);
+                switchToVirtualThread(this);
             }
         }
     }
@@ -690,11 +680,11 @@ void unpark() {
             int s = state();
             if (s == PARKED && compareAndSetState(PARKED, RUNNABLE)) {
                 if (currentThread instanceof VirtualThread vthread) {
-                    boolean notifyJvmti = vthread.switchToCarrierThread();
+                    vthread.switchToCarrierThread();
                     try {
                         submitRunContinuation();
                     } finally {
-                        switchToVirtualThread(vthread, notifyJvmti);
+                        switchToVirtualThread(vthread);
                     }
                 } else {
                     submitRunContinuation();
@@ -1055,20 +1045,15 @@ private void setCarrierThread(Thread carrier) {
 
     // -- JVM TI support --
 
-    private static volatile boolean notifyJvmtiEvents;  // set by VM
-
-    @JvmtiMountTransition
-    private native void notifyJvmtiMountBegin(boolean firstMount);
-
-    @JvmtiMountTransition
-    private native void notifyJvmtiMountEnd(boolean firstMount);
-
+    @IntrinsicCandidate
     @JvmtiMountTransition
-    private native void notifyJvmtiUnmountBegin(boolean lastUnmount);
+    private native void notifyJvmtiMount(boolean hide, boolean firstMount);
 
+    @IntrinsicCandidate
     @JvmtiMountTransition
-    private native void notifyJvmtiUnmountEnd(boolean lastUnmount);
+    private native void notifyJvmtiUnmount(boolean hide, boolean lastUnmount);
 
+    @IntrinsicCandidate
     @JvmtiMountTransition
     private native void notifyJvmtiHideFrames(boolean hide);
 

diff --git a/src/java.base/share/native/libjava/VirtualThread.c b/src/java.base/share/native/libjava/VirtualThread.c
@@ -32,11 +32,9 @@
 #define VIRTUAL_THREAD  "Ljava/lang/VirtualThread;"
 
 static JNINativeMethod methods[] = {
-    { "notifyJvmtiMountBegin",   "(Z)V", (void *)&JVM_VirtualThreadMountBegin },
-    { "notifyJvmtiMountEnd",     "(Z)V", (void *)&JVM_VirtualThreadMountEnd },
-    { "notifyJvmtiUnmountBegin", "(Z)V", (void *)&JVM_VirtualThreadUnmountBegin },
-    { "notifyJvmtiUnmountEnd",   "(Z)V", (void *)&JVM_VirtualThreadUnmountEnd },
-    { "notifyJvmtiHideFrames",   "(Z)V", (void *)&JVM_VirtualThreadHideFrames },
+    { "notifyJvmtiMount",        "(ZZ)V", (void *)&JVM_VirtualThreadMount },
+    { "notifyJvmtiUnmount",      "(ZZ)V", (void *)&JVM_VirtualThreadUnmount },
+    { "notifyJvmtiHideFrames",   "(Z)V",  (void *)&JVM_VirtualThreadHideFrames },
 };
 
 JNIEXPORT void JNICALL