Merge pull request #21774 from fengxue-IS/21183

Account for VirtualThread's SUSPENDED bit flag during transition

Author: babsingh

runtime/oti/ContinuationHelpers.hpp

@@ -360,18 +360,25 @@ class VM_ContinuationHelpers {
 		omrthread_monitor_enter(vm->blockedVirtualThreadsMutex);
 		J9VMContinuation **link = &objectMonitor->waitingContinuations;
 		J9VMContinuation *current = NULL;
+		j9object_t vthread = NULL;
 
 		while (NULL != *link) {
 			current = *link;
-			if (J9VMJAVALANGTHREAD_DEADINTERRUPT(vmThread, current->vthread)) {
+			vthread = current->vthread;
+			if (J9VMJAVALANGTHREAD_DEADINTERRUPT(vmThread, vthread)) {
 				/* Remove virtual threads that have been interrupted. */
 				*link = current->nextWaitingContinuation;
 				current->nextWaitingContinuation = NULL;
 			} else {
 				/* Set the notified and onWaitingList flags for virtual threads that have not been interrupted. */
-				J9VMJAVALANGVIRTUALTHREAD_SET_NOTIFIED(vmThread, current->vthread, JNI_TRUE);
-				/* Update the thread state to BLOCKED. */
-				J9VMJAVALANGVIRTUALTHREAD_SET_STATE(vmThread, current->vthread, JAVA_LANG_VIRTUALTHREAD_BLOCKED);
+				J9VMJAVALANGVIRTUALTHREAD_SET_NOTIFIED(vmThread, vthread, JNI_TRUE);
+
+				U_32 state = J9VMJAVALANGVIRTUALTHREAD_STATE(vmThread, vthread);
+				if ((JAVA_LANG_VIRTUALTHREAD_WAIT == state) || (JAVA_LANG_VIRTUALTHREAD_TIMED_WAIT == state)) {
+					/* Update the thread state to BLOCKED. */
+					J9VMJAVALANGVIRTUALTHREAD_SET_STATE(vmThread, vthread, JAVA_LANG_VIRTUALTHREAD_BLOCKED);
+				}
+
 				current->objectWaitMonitor->virtualThreadWaitCount += 1;
 				notified = true;
 

runtime/oti/j9nonbuilder.h

@@ -310,6 +310,7 @@ typedef void(*j9_tls_finalizer_t)(void *);
 #define JAVA_LANG_VIRTUALTHREAD_WAIT     16
 #define JAVA_LANG_VIRTUALTHREAD_TIMED_WAITING 17
 #define JAVA_LANG_VIRTUALTHREAD_TIMED_WAIT 18
+#define JAVA_LANG_VIRTUALTHREAD_SUSPENDED (1 << 8)
 #endif /* JAVA_SPEC_VERSION >= 24 */
 
 typedef enum {

runtime/vm/ContinuationHelpers.cpp

@@ -1227,9 +1227,16 @@ takeVirtualThreadListToUnblock(J9VMThread *currentThread)
 					break;
 				}
 				default:
-					/* Thread must be unblocked by AfterYield(), hence it can only be UNBLOCKED or RUNNING. */
-					Assert_VM_true((JAVA_LANG_VIRTUALTHREAD_RUNNING == state) || (JAVA_LANG_VIRTUALTHREAD_UNBLOCKED == state));
+				{
+					if (J9_ARE_ANY_BITS_SET(state, JAVA_LANG_VIRTUALTHREAD_SUSPENDED)) {
+						J9VMJAVALANGVIRTUALTHREAD_SET_BLOCKPERMIT(currentThread, current->vthread, JNI_TRUE);
+					} else {
+						/* Thread must be unblocked by AfterYield(), hence it can only be UNBLOCKED or RUNNING. */
+						Assert_VM_true((JAVA_LANG_VIRTUALTHREAD_RUNNING == state) || (JAVA_LANG_VIRTUALTHREAD_UNBLOCKED == state));
+					}
+					break;
 				}
+				} /* switch (state) */
 
 				if (unblocked) {
 					/* Add to Java unblock list. */