Merge pull request #22723 from lzhou2025/hang

RAM Class Persistence: Fix Open liberty server hangs

Author: babsingh

runtime/vm/KeyHashTable.c

@@ -349,6 +349,12 @@ hashClassTableAt(J9ClassLoader *classLoader, U_8 *className, UDATA classNameLeng
 		if (J9ROMCLASS_IS_HIDDEN(clazz->romClass)) {
 			return NULL;
 		}
+		/* Frozen classes are not loaded, so they should not be returned with J9_FINDCLASS_FLAG_EXISTING_ONLY. */
+		if (J9_ARE_ANY_BITS_SET(flags, J9_FINDCLASS_FLAG_EXISTING_ONLY)
+			&& J9_ARE_ANY_BITS_SET(clazz->classFlags, J9ClassIsFrozen)
+		) {
+			return NULL;
+		}
 		if (J9_ARE_NO_BITS_SET(flags, J9_FINDCLASS_FLAG_DONT_SKIP_FROZEN_JCL_DEFINE_CLASS)
 			&& J9_ARE_ALL_BITS_SET(clazz->classFlags, J9ClassIsJCLDefineClass | J9ClassIsFrozen)
 		) {
@@ -753,6 +759,12 @@ hashClassTableAtString(J9ClassLoader *classLoader, j9object_t stringObject, UDAT
 		if (J9ROMCLASS_IS_HIDDEN(clazz->romClass)) {
 			return NULL;
 		}
+		/* Frozen classes are not loaded, so they should not be returned with J9_FINDCLASS_FLAG_EXISTING_ONLY. */
+		if (J9_ARE_ANY_BITS_SET(flags, J9_FINDCLASS_FLAG_EXISTING_ONLY)
+			&& J9_ARE_ANY_BITS_SET(clazz->classFlags, J9ClassIsFrozen)
+		) {
+			return NULL;
+		}
 		if (J9_ARE_NO_BITS_SET(flags, J9_FINDCLASS_FLAG_DONT_SKIP_FROZEN_JCL_DEFINE_CLASS)
 			&& J9_ARE_ALL_BITS_SET(clazz->classFlags, J9ClassIsJCLDefineClass | J9ClassIsFrozen)
 		) {

runtime/vm/classsupport.c

@@ -324,7 +324,7 @@ internalFindClassString(J9VMThread* currentThread, j9object_t moduleName, j9obje
 	if (!fastMode) {
 		omrthread_monitor_enter(vm->classTableMutex);
 	}
-	result = hashClassTableAtString(classLoader, (j9object_t) className, 0);
+	result = hashClassTableAtString(classLoader, (j9object_t) className, options);
 #if defined(J9VM_OPT_SNAPSHOTS)
 	if ((NULL != result) && IS_RESTORE_RUN(vm)) {
 		if (!loadWarmClassFromSnapshot(currentThread, classLoader, result)) {
@@ -1183,7 +1183,7 @@ loadNonArrayClass(J9VMThread* vmThread, J9Module *j9module, U_8* className, UDAT
 		omrthread_monitor_enter(vm->classTableMutex);
 	}
 
-	foundClass = hashClassTableAt(classLoader, className, classNameLength, 0);
+	foundClass = hashClassTableAt(classLoader, className, classNameLength, options);
 	if (NULL != foundClass) {
 #if defined(J9VM_OPT_SNAPSHOTS)
 		if (IS_RESTORE_RUN(vm)) {
@@ -1214,7 +1214,7 @@ loadNonArrayClass(J9VMThread* vmThread, J9Module *j9module, U_8* className, UDAT
 				omrthread_monitor_enter(vm->classTableMutex);
 
 				/* check again if somebody else already loaded the class */
-				foundClass = hashClassTableAt(classLoader, className, classNameLength, 0);
+				foundClass = hashClassTableAt(classLoader, className, classNameLength, options);
 				if (NULL != foundClass) {
 #if defined(J9VM_OPT_SNAPSHOTS)
 					if (IS_RESTORE_RUN(vm)