8316233: VirtualThreadStart events should not be thread-filtered

Reviewed-by: lmesnik, amenkov, cjplummer

Author: Serguei Spitsyn

src/hotspot/share/prims/jvmti.xml

@@ -13041,7 +13041,7 @@ myInit() {
   </event>
 
  <event label="Virtual Thread Start"
-         id="VirtualThreadStart" const="JVMTI_EVENT_VIRTUAL_THREAD_START" filtered="thread" num="87" phase="start" since="21">
+         id="VirtualThreadStart" const="JVMTI_EVENT_VIRTUAL_THREAD_START" num="87" phase="start" since="21">
     <description>
       A virtual thread start event is generated before its initial method executes.
       <p/>

src/hotspot/share/prims/jvmtiEventController.cpp

@@ -99,16 +99,16 @@ static const jlong  VTHREAD_MOUNT_BIT = (((jlong)1) << (EXT_EVENT_VIRTUAL_THREAD
 static const jlong  VTHREAD_UNMOUNT_BIT = (((jlong)1) << (EXT_EVENT_VIRTUAL_THREAD_UNMOUNT - TOTAL_MIN_EVENT_TYPE_VAL));
 
 
-static const jlong  VTHREAD_BITS = VTHREAD_START_BIT | VTHREAD_END_BIT | VTHREAD_MOUNT_BIT | VTHREAD_UNMOUNT_BIT;
+static const jlong  VTHREAD_FILTERED_EVENT_BITS = VTHREAD_END_BIT | VTHREAD_MOUNT_BIT | VTHREAD_UNMOUNT_BIT;
 static const jlong  MONITOR_BITS = MONITOR_CONTENDED_ENTER_BIT | MONITOR_CONTENDED_ENTERED_BIT |
                           MONITOR_WAIT_BIT | MONITOR_WAITED_BIT;
 static const jlong  EXCEPTION_BITS = EXCEPTION_THROW_BIT | EXCEPTION_CATCH_BIT;
 static const jlong  INTERP_EVENT_BITS =  SINGLE_STEP_BIT | METHOD_ENTRY_BIT | METHOD_EXIT_BIT |
                                 FRAME_POP_BIT | FIELD_ACCESS_BIT | FIELD_MODIFICATION_BIT;
-static const jlong  THREAD_FILTERED_EVENT_BITS = INTERP_EVENT_BITS | EXCEPTION_BITS | MONITOR_BITS | VTHREAD_BITS |
+static const jlong  THREAD_FILTERED_EVENT_BITS = INTERP_EVENT_BITS | EXCEPTION_BITS | MONITOR_BITS | VTHREAD_FILTERED_EVENT_BITS |
                                         BREAKPOINT_BIT | CLASS_LOAD_BIT | CLASS_PREPARE_BIT | THREAD_END_BIT |
                                         SAMPLED_OBJECT_ALLOC_BIT;
-static const jlong  NEED_THREAD_LIFE_EVENTS = THREAD_FILTERED_EVENT_BITS | THREAD_START_BIT;
+static const jlong  NEED_THREAD_LIFE_EVENTS = THREAD_FILTERED_EVENT_BITS | THREAD_START_BIT | VTHREAD_START_BIT;
 static const jlong  EARLY_EVENT_BITS = CLASS_FILE_LOAD_HOOK_BIT | CLASS_LOAD_BIT | CLASS_PREPARE_BIT |
                                VM_START_BIT | VM_INIT_BIT | VM_DEATH_BIT | NATIVE_METHOD_BIND_BIT |
                                THREAD_START_BIT | THREAD_END_BIT |

src/hotspot/share/prims/jvmtiExport.cpp

@@ -1549,11 +1549,11 @@ void JvmtiExport::post_thread_end(JavaThread *thread) {
 
     JvmtiEnvThreadStateIterator it(state);
     for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
+      JvmtiEnv *env = ets->get_env();
+      if (env->phase() == JVMTI_PHASE_PRIMORDIAL) {
+        continue;
+      }
       if (ets->is_enabled(JVMTI_EVENT_THREAD_END)) {
-        JvmtiEnv *env = ets->get_env();
-        if (env->phase() == JVMTI_PHASE_PRIMORDIAL) {
-          continue;
-        }
         EVT_TRACE(JVMTI_EVENT_THREAD_END, ("[%s] Evt Thread End event sent",
                      JvmtiTrace::safe_get_thread_name(thread) ));
 
@@ -1575,25 +1575,20 @@ void JvmtiExport::post_vthread_start(jobject vthread) {
   }
   EVT_TRIG_TRACE(JVMTI_EVENT_VIRTUAL_THREAD_START, ("[%p] Trg Virtual Thread Start event triggered", vthread));
 
-  JavaThread *cur_thread = JavaThread::current();
-  JvmtiThreadState *state = get_jvmti_thread_state(cur_thread);
-  if (state == nullptr) {
-    return;
-  }
-
-  if (state->is_enabled(JVMTI_EVENT_VIRTUAL_THREAD_START)) {
-    JvmtiEnvThreadStateIterator it(state);
+  JavaThread *thread = JavaThread::current();
+  assert(!thread->is_hidden_from_external_view(), "carrier threads can't be hidden");
 
-    for (JvmtiEnvThreadState* ets = it.first(); ets != nullptr; ets = it.next(ets)) {
-      JvmtiEnv *env = ets->get_env();
+  if (JvmtiEventController::is_enabled(JVMTI_EVENT_VIRTUAL_THREAD_START)) {
+    JvmtiEnvIterator it;
+    for (JvmtiEnv* env = it.first(); env != nullptr; env = it.next(env)) {
       if (env->phase() == JVMTI_PHASE_PRIMORDIAL) {
         continue;
       }
-      if (ets->is_enabled(JVMTI_EVENT_VIRTUAL_THREAD_START)) {
+      if (env->is_enabled(JVMTI_EVENT_VIRTUAL_THREAD_START)) {
         EVT_TRACE(JVMTI_EVENT_VIRTUAL_THREAD_START, ("[%p] Evt Virtual Thread Start event sent", vthread));
 
-        JvmtiVirtualThreadEventMark jem(cur_thread);
-        JvmtiJavaThreadEventTransition jet(cur_thread);
+        JvmtiVirtualThreadEventMark jem(thread);
+        JvmtiJavaThreadEventTransition jet(thread);
         jvmtiEventVirtualThreadStart callback = env->callbacks()->VirtualThreadStart;
         if (callback != nullptr) {
           (*callback)(env->jvmti_external(), jem.jni_env(), jem.jni_thread());
@@ -1609,8 +1604,10 @@ void JvmtiExport::post_vthread_end(jobject vthread) {
   }
   EVT_TRIG_TRACE(JVMTI_EVENT_VIRTUAL_THREAD_END, ("[%p] Trg Virtual Thread End event triggered", vthread));
 
-  JavaThread *cur_thread = JavaThread::current();
-  JvmtiThreadState *state = get_jvmti_thread_state(cur_thread);
+  JavaThread *thread = JavaThread::current();
+  assert(!thread->is_hidden_from_external_view(), "carrier threads can't be hidden");
+
+  JvmtiThreadState *state = get_jvmti_thread_state(thread);
   if (state == nullptr) {
     return;
   }
@@ -1626,8 +1623,8 @@ void JvmtiExport::post_vthread_end(jobject vthread) {
       if (ets->is_enabled(JVMTI_EVENT_VIRTUAL_THREAD_END)) {
         EVT_TRACE(JVMTI_EVENT_VIRTUAL_THREAD_END, ("[%p] Evt Virtual Thread End event sent", vthread));
 
-        JvmtiVirtualThreadEventMark jem(cur_thread);
-        JvmtiJavaThreadEventTransition jet(cur_thread);
+        JvmtiVirtualThreadEventMark jem(thread);
+        JvmtiJavaThreadEventTransition jet(thread);
         jvmtiEventVirtualThreadEnd callback = env->callbacks()->VirtualThreadEnd;
         if (callback != nullptr) {
           (*callback)(env->jvmti_external(), jem.jni_env(), vthread);