8286490: JvmtiEventControllerPrivate::set_event_callbacks CLEARING_MASK computation is incorrect

Reviewed-by: jbachorik, lmesnik, amenkov

src/hotspot/share/prims/jvmtiEventController.cpp

@@ -771,15 +771,15 @@ void JvmtiEventControllerPrivate::set_event_callbacks(JvmtiEnvBase *env,
   flush_object_free_events(env);
 
   env->set_event_callbacks(callbacks, size_of_callbacks);
-  // Mask to clear normal event bits.
-  const jlong CLEARING_MASK = (1L >> (TOTAL_MIN_EVENT_TYPE_VAL - TOTAL_MIN_EVENT_TYPE_VAL)) - 1L;
-  // Avoid cleaning extension event bits.
-  jlong enabled_bits = CLEARING_MASK & env->env_event_enable()->_event_callback_enabled.get_bits();
 
+  jlong enabled_bits = env->env_event_enable()->_event_callback_enabled.get_bits();
   for (int ei = JVMTI_MIN_EVENT_TYPE_VAL; ei <= JVMTI_MAX_EVENT_TYPE_VAL; ++ei) {
     jvmtiEvent evt_t = (jvmtiEvent)ei;
+    jlong bit_for = JvmtiEventEnabled::bit_for(evt_t);
     if (env->has_callback(evt_t)) {
-      enabled_bits |= JvmtiEventEnabled::bit_for(evt_t);
+      enabled_bits |= bit_for;
+    } else {
+      enabled_bits &= ~bit_for;
     }
   }
   env->env_event_enable()->_event_callback_enabled.set_bits(enabled_bits);

test/hotspot/jtreg/serviceability/jvmti/vthread/VThreadTest/VThreadTest.java

@@ -36,6 +36,8 @@ public class VThreadTest {
     static final int MSG_COUNT = 10*1000;
     static final SynchronousQueue<String> QUEUE = new SynchronousQueue<>();
 
+    static native boolean check();
+
     static void producer(String msg) throws InterruptedException {
         int ii = 1;
         long ll = 2*(long)ii;
@@ -66,6 +68,9 @@ public class VThreadTest {
         Thread consumer = Thread.ofVirtual().name("VThread-Consumer").start(CONSUMER);
         producer.join();
         consumer.join();
+        if (!check()) {
+            throw new RuntimeException("VThreadTest failed!");
+        }
     }
 
     void runTest() throws Exception {

test/hotspot/jtreg/serviceability/jvmti/vthread/VThreadTest/libVThreadTest.cpp

@@ -40,6 +40,9 @@ static jvmtiEnv *jvmti = NULL;
 static jrawMonitorID events_monitor = NULL;
 static Tinfo tinfo[MAX_WORKER_THREADS];
 
+static int vthread_mount_count = 0;
+static int vthread_unmount_count = 0;
+static jboolean passed = JNI_TRUE;
 
 static Tinfo*
 find_tinfo(JNIEnv* jni, const char* tname) {
@@ -535,6 +538,7 @@ VirtualThreadMount(jvmtiEnv *jvmti, ...) {
   va_end(ap);
 
   RawMonitorLocker rml(jvmti, jni, events_monitor);
+  vthread_mount_count++;
   processVThreadEvent(jvmti, jni, thread, "VirtualThreadMount");
 }
 
@@ -551,6 +555,7 @@ VirtualThreadUnmount(jvmtiEnv *jvmti, ...) {
   va_end(ap);
 
   RawMonitorLocker rml(jvmti, jni, events_monitor);
+  vthread_unmount_count++;
   processVThreadEvent(jvmti, jni, thread, "VirtualThreadUnmount");
 }
 
@@ -628,4 +633,25 @@ Agent_OnLoad(JavaVM *jvm, char *options,
   return JNI_OK;
 }
 
+JNIEXPORT jboolean JNICALL
+Java_VThreadTest_check(JNIEnv *jni, jclass cls) {
+  LOG("\n");
+  LOG("check: started\n");
+
+  LOG("check: vthread_mount_count:   %d\n", vthread_mount_count);
+  LOG("check: vthread_unmount_count: %d\n", vthread_unmount_count);
+
+  if (vthread_mount_count == 0) {
+    passed = JNI_FALSE;
+    LOG("FAILED: vthread_mount_count == 0\n");
+  }
+  if (vthread_unmount_count == 0) {
+    passed = JNI_FALSE;
+    LOG("FAILED: vthread_unmount_count == 0\n");
+  }
+  LOG("check: finished\n");
+  LOG("\n");
+  return passed;
+}
+
 } // extern "C"