Merge pull request #16365 from tajila/loom2

Add assertions to virtual thread mount and unmount
eclipse-openj9 · Dec 1, 2022 · e548ed4 · e548ed4
2 parents 73cb648 + 6bbc66b
commit e548ed4
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Showing 3 changed files with 14 additions and 0 deletions.
diff --git a/runtime/j9vm/j9scar.tdf b/runtime/j9vm/j9scar.tdf
@@ -364,3 +364,5 @@ TraceEntry=Trc_SC_VirtualThreadUnmountEnd_Entry Overhead=1 Level=3 Template="thr
 TraceExit=Trc_SC_VirtualThreadUnmountEnd_Exit Overhead=1 Level=3 Template="thread = 0x%p, lastUnmount = %d"
 
 TraceEvent=Trc_SC_VirtualThread_Info Overhead=1 Level=3 Test Template="virtualThreadObj = 0x%p, virtualThreadState = 0x%p, virtualThreadInspectorCount = %lld, carrierThreadObj = 0x%p, continuationObj = 0x%p, J9VMContinuation = 0x%p"
+
+TraceEvent=Trc_SC_VirtualThread_RootNodeSet Overhead=1 Level=1 Test Template="Virtual threadlist root node set, global ref = 0x%p"
diff --git a/runtime/j9vm/javanextvmi.cpp b/runtime/j9vm/javanextvmi.cpp
@@ -312,6 +312,8 @@ JVM_VirtualThreadMountEnd(JNIEnv *env, jobject thread, jboolean firstMount)
 	f_monitorEnter(vm->liveVirtualThreadListMutex);
 	j9object_t threadObj = J9_JNI_UNWRAP_REFERENCE(thread);
 
+	Assert_SC_true(IS_JAVA_LANG_VIRTUALTHREAD(currentThread, threadObj));
+
 	if (TrcEnabled_Trc_SC_VirtualThread_Info) {
 		j9object_t continuationObj = J9VMJAVALANGVIRTUALTHREAD_CONT(currentThread, threadObj);
 		Trc_SC_VirtualThread_Info(
@@ -333,10 +335,14 @@ JVM_VirtualThreadMountEnd(JNIEnv *env, jobject thread, jboolean firstMount)
 			 * This prevents the root reference from becoming stale if the GC moves the object.
 			 */
 			j9object_t rootVirtualThread = mmFuncs->J9AllocateObject(currentThread, virtualThreadClass, J9_GC_ALLOCATE_OBJECT_NON_INSTRUMENTABLE);
+
+			J9VMJAVALANGVIRTUALTHREAD_SET_STATE(currentThread, rootVirtualThread, J9VM_VIRTUALTHREAD_ROOT_NODE_STATE);
+
 			if (NULL != rootVirtualThread) {
 				/* The global ref will be freed at vm death. */
 				jobject globalRef = vmFuncs->j9jni_createGlobalRef((JNIEnv *)currentThread, rootVirtualThread, JNI_FALSE);
 				if (NULL != globalRef) {
+					Trc_SC_VirtualThread_RootNodeSet(currentThread, globalRef);
 					vm->liveVirtualThreadList = (j9object_t *)globalRef;
 
 					/* Set linkNext/linkPrevious to itself. */
@@ -406,6 +412,8 @@ JVM_VirtualThreadUnmountBegin(JNIEnv *env, jobject thread, jboolean lastUnmount)
 	f_monitorEnter(vm->liveVirtualThreadListMutex);
 	j9object_t threadObj = J9_JNI_UNWRAP_REFERENCE(thread);
 
+	Assert_SC_true(IS_JAVA_LANG_VIRTUALTHREAD(currentThread, threadObj));
+
 	if (TrcEnabled_Trc_SC_VirtualThread_Info) {
 		j9object_t continuationObj = J9VMJAVALANGVIRTUALTHREAD_CONT(currentThread, threadObj);
 		Trc_SC_VirtualThread_Info(
@@ -479,6 +487,8 @@ JVM_VirtualThreadUnmountEnd(JNIEnv *env, jobject thread, jboolean lastUnmount)
 	f_monitorEnter(vm->liveVirtualThreadListMutex);
 	j9object_t threadObj = J9_JNI_UNWRAP_REFERENCE(thread);
 
+	Assert_SC_true(IS_JAVA_LANG_VIRTUALTHREAD(currentThread, threadObj));
+
 	if (TrcEnabled_Trc_SC_VirtualThread_Info) {
 		j9object_t continuationObj = J9VMJAVALANGVIRTUALTHREAD_CONT(currentThread, threadObj);
 		Trc_SC_VirtualThread_Info(

diff --git a/runtime/oti/j9.h b/runtime/oti/j9.h
@@ -367,6 +367,8 @@ static const struct { \
 #define IS_JAVA_LANG_THREAD(vmThread, object) \
 	isSameOrSuperClassOf(J9VMJAVALANGTHREAD_OR_NULL((vmThread)->javaVM), J9OBJECT_CLAZZ(vmThread, object))
 
+#define J9VM_VIRTUALTHREAD_ROOT_NODE_STATE ((I_32)0xBAADF00D)
+
 #if defined(OPENJ9_BUILD)
 #define J9_SHARED_CACHE_DEFAULT_BOOT_SHARING(vm) TRUE
 #else /* defined(OPENJ9_BUILD) */