Support using threadStatus field in JVM native

- Update thread status changes to j.l.Thread fields so getState() API
  can be called without needing to halt the target thread.
- Add support of virtual thread state for JDK24+

Co-authored-by: Nathan Henderson <nathan.henderson@ibm.com>
Signed-off-by: Jack Lu <Jack.S.Lu@ibm.com>

Author: fengxue-IS

runtime/oti/VMHelpers.hpp

@@ -2277,6 +2277,30 @@ class VM_VMHelpers
 		targetThread->privateFlags2 |= J9_PRIVATE_FLAGS2_REENTER_INTERPRETER;
 		indicateAsyncMessagePending(targetThread);
 	}
+
+	static U_32
+	setThreadState(J9VMThread *currentThread, U_32 state)
+	{
+		U_32 oldState = 0;
+#if JAVA_SPEC_VERSION >= 19
+		j9object_t receiverObject = currentThread->carrierThreadObject;
+		if (NULL != receiverObject) {
+			/* Platform threads must have a non-null FieldHolder object. */
+			j9object_t threadHolder = J9VMJAVALANGTHREAD_HOLDER(currentThread, receiverObject);
+			if (NULL != threadHolder) {
+				oldState = J9VMJAVALANGTHREADFIELDHOLDER_THREADSTATUS(currentThread, threadHolder);
+				J9VMJAVALANGTHREADFIELDHOLDER_SET_THREADSTATUS(currentThread, threadHolder, state);
+			}
+		}
+#else /* JAVA_SPEC_VERSION >= 19 */
+		j9object_t receiverObject = currentThread->threadObject;
+		if (NULL != receiverObject) {
+			oldState = J9VMJAVALANGTHREAD_THREADSTATUS(currentThread, receiverObject);
+			J9VMJAVALANGTHREAD_SET_THREADSTATUS(currentThread, receiverObject, state);
+		}
+#endif /* JAVA_SPEC_VERSION >= 19 */
+		return oldState;
+	}
 };
 
 #endif /* VMHELPERS_HPP_ */

runtime/oti/j9nonbuilder.h

@@ -5881,18 +5881,25 @@ typedef struct J9VMThread {
 #endif
 #define J9VMTHREAD_ALIGNMENT  0x100
 #define J9VMTHREAD_RESERVED_C_STACK_FRACTION  8
-#define J9VMTHREAD_STATE_RUNNING  1
-#define J9VMTHREAD_STATE_BLOCKED  2
-#define J9VMTHREAD_STATE_WAITING  4
-#define J9VMTHREAD_STATE_SLEEPING  8
-#define J9VMTHREAD_STATE_SUSPENDED  16
-#define J9VMTHREAD_STATE_DEAD  32
-#define J9VMTHREAD_STATE_WAITING_TIMED  64
-#define J9VMTHREAD_STATE_PARKED  0x80
+
+/* J9VMTHREAD_STATE_* bit flags are used to map vmthread state to
+ * java.lang.Thread.State in Thread.translateJ9VMThreadStateToThreadState().
+ * Any updates to these values must be reflected there.
+ *
+ * Note: 0 is reserved for uninitialized case and cannot be used.
+ */
+#define J9VMTHREAD_STATE_RUNNING       0x1
+#define J9VMTHREAD_STATE_BLOCKED       0x2
+#define J9VMTHREAD_STATE_WAITING       0x4
+#define J9VMTHREAD_STATE_SLEEPING      0x8
+#define J9VMTHREAD_STATE_SUSPENDED     0x10
+#define J9VMTHREAD_STATE_DEAD          0x20
+#define J9VMTHREAD_STATE_WAITING_TIMED 0x40
+#define J9VMTHREAD_STATE_PARKED        0x80
 #define J9VMTHREAD_STATE_PARKED_TIMED  0x100
-#define J9VMTHREAD_STATE_INTERRUPTED  0x200
-#define J9VMTHREAD_STATE_UNKNOWN  0x400
-#define J9VMTHREAD_STATE_UNREADABLE  0x800
+#define J9VMTHREAD_STATE_INTERRUPTED   0x200
+#define J9VMTHREAD_STATE_UNKNOWN       0x400
+#define J9VMTHREAD_STATE_UNREADABLE    0x800
 #define J9VMSTATE_MAJOR  0xFFFF0000
 #define J9VMSTATE_MINOR  0xFFFF
 #define J9VMSTATE_INTERPRETER  0x10000

runtime/oti/vmconstantpool.xml

@@ -262,6 +262,7 @@ SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0-only WITH Classpath-ex
 	<fieldref class="java/lang/Thread" name="priority" signature="I" versions="8-18"/>
 	<fieldref class="java/lang/Thread" name="isDaemon" signature="Z" versions="8-18"/>
 	<fieldref class="java/lang/Thread" name="group" signature="Ljava/lang/ThreadGroup;" versions="8-18"/>
+	<fieldref class="java/lang/Thread" name="threadStatus" signature="I" versions="8-18"/>
 
 	<fieldref class="java/lang/VirtualThread" name="state" signature="I" versions="19-"/>
 	<fieldref class="java/lang/VirtualThread" name="carrierThread" signature="Ljava/lang/Thread;" versions="19-"/>

runtime/vm/ObjectMonitor.cpp

@@ -185,6 +185,7 @@ objectMonitorEnterBlocking(J9VMThread *currentThread)
 
 		if (J9_EVENT_IS_HOOKED(vm->hookInterface, J9HOOK_VM_MONITOR_CONTENDED_ENTER)) {
 			bool frameBuilt = saveBlockingEnterObject(currentThread);
+			VM_VMHelpers::setThreadState(currentThread, J9VMTHREAD_STATE_BLOCKED);
 			VM_VMAccess::setPublicFlags(currentThread, J9_PUBLIC_FLAGS_THREAD_BLOCKED);
 			ALWAYS_TRIGGER_J9HOOK_VM_MONITOR_CONTENDED_ENTER(vm->hookInterface, currentThread, monitor);
 			restoreBlockingEnterObject(currentThread, frameBuilt);
@@ -197,6 +198,7 @@ objectMonitorEnterBlocking(J9VMThread *currentThread)
 			goto releasedAccess;
 		}
 restart:
+		VM_VMHelpers::setThreadState(currentThread, J9VMTHREAD_STATE_BLOCKED);
 		internalReleaseVMAccessSetStatus(currentThread, J9_PUBLIC_FLAGS_THREAD_BLOCKED);
 releasedAccess:
 		omrthread_monitor_enter_using_threadId(monitor, osThread);
@@ -286,6 +288,7 @@ objectMonitorEnterBlocking(J9VMThread *currentThread)
 				J9_STORE_LOCKWORD(currentThread, lwEA, lock);
 				goto done;
 			}
+			VM_VMHelpers::setThreadState(currentThread, J9VMTHREAD_STATE_BLOCKED);
 			internalReleaseVMAccessSetStatus(currentThread, J9_PUBLIC_FLAGS_THREAD_BLOCKED);
 			SET_IGNORE_ENTER(monitor);
 			omrthread_monitor_wait_timed(monitor, (I_64)waitTime, 0);
@@ -297,6 +300,8 @@ objectMonitorEnterBlocking(J9VMThread *currentThread)
 		}
 done:
 		clearEventFlag(currentThread, J9_PUBLIC_FLAGS_THREAD_BLOCKED);
+		VM_VMHelpers::setThreadState(currentThread, J9VMTHREAD_STATE_RUNNING);
+
 		/* Clear the SUPPRESS_CONTENDED_EXITS bit in the monitor saying that CONTENDED EXIT can be sent again */
 		((J9ThreadMonitor*)monitor)->flags &= ~(UDATA)J9THREAD_MONITOR_SUPPRESS_CONTENDED_EXIT;
 		VM_AtomicSupport::subtract(&monitor->pinCount, 1);

runtime/vm/callin.cpp

@@ -589,6 +589,15 @@ initializeAttachedThreadImpl(J9VMThread *currentThread, const char *name, j9obje
 				currentThread->returnValue = J9_BCLOOP_RUN_METHOD;
 				currentThread->returnValue2 = (UDATA)J9VMJAVALANGTHREAD_INIT_METHOD(vm);
 				c_cInterpreter(currentThread);
+#if JAVA_SPEC_VERSION >= 19
+				j9object_t threadHolder = J9VMJAVALANGTHREAD_HOLDER(currentThread, initializee->threadObject);
+				if (NULL != threadHolder) {
+					J9VMJAVALANGTHREADFIELDHOLDER_SET_THREADSTATUS(currentThread, threadHolder, J9VMTHREAD_STATE_RUNNING);
+				}
+#else /* JAVA_SPEC_VERSION >= 19 */
+				J9VMJAVALANGTHREAD_SET_THREADSTATUS(currentThread, initializee->threadObject, J9VMTHREAD_STATE_RUNNING);
+#endif /* JAVA_SPEC_VERSION >= 19 */
+				/* Thread.started must be set after Thread.threadStatus to avoid timing issue in Thread.getState(). */
 				J9VMJAVALANGTHREAD_SET_STARTED(currentThread, initializee->threadObject, JNI_TRUE);
 			}
 		}

runtime/vm/threadhelp.cpp

@@ -121,10 +121,17 @@ monitorWaitImpl(J9VMThread *vmThread, j9object_t object, I_64 millis, I_32 nanos
 #if JAVA_SPEC_VERSION >= 24
 		J9VM_SEND_VIRTUAL_UNBLOCKER_THREAD_SIGNAL(javaVM);
 #endif /* JAVA_SPEC_VERSION >= 24 */
+		/* Set j.l.Thread status to UNKNOWN since the wait can be notified/interrupted
+		 * but blocked on re-acquiring the monitor.
+		 * In this case, the thread state will have to be determined by looking at
+		 * the vmThread->publicFlags field.
+		 */
+		U_32 oldState = VM_VMHelpers::setThreadState(vmThread, J9VMTHREAD_STATE_UNKNOWN);
 		internalReleaseVMAccessSetStatus(vmThread, thrstate);
 		rc = timeCompensationHelper(vmThread,
 			interruptable ? HELPER_TYPE_MONITOR_WAIT_INTERRUPTABLE : HELPER_TYPE_MONITOR_WAIT_TIMED, monitor, millis, nanos);
 		internalAcquireVMAccessClearStatus(vmThread, thrstate);
+		VM_VMHelpers::setThreadState(vmThread, oldState);
 		J9VMTHREAD_SET_BLOCKINGENTEROBJECT(vmThread, vmThread, NULL);
 		omrthread_monitor_unpin(monitor, vmThread->osThread);
 #if JAVA_SPEC_VERSION >= 24
@@ -197,9 +204,11 @@ threadSleepImpl(J9VMThread *vmThread, I_64 millis, I_32 nanos)
 #endif
 		if (0 == rc) {
 			TRIGGER_J9HOOK_VM_SLEEP(javaVM->hookInterface, vmThread, millis, nanos);
+			U_32 oldState = VM_VMHelpers::setThreadState(vmThread, J9VMTHREAD_STATE_SLEEPING);
 			internalReleaseVMAccessSetStatus(vmThread, J9_PUBLIC_FLAGS_THREAD_SLEEPING);
 			rc = timeCompensationHelper(vmThread, HELPER_TYPE_THREAD_SLEEP, NULL, millis, nanos);
 			internalAcquireVMAccessClearStatus(vmThread, J9_PUBLIC_FLAGS_THREAD_SLEEPING);
+			VM_VMHelpers::setThreadState(vmThread, oldState);
 			TRIGGER_J9HOOK_VM_SLEPT(javaVM->hookInterface, vmThread, millis, nanos, startTicks);
 		}
 

runtime/vm/threadpark.cpp

@@ -98,6 +98,9 @@ threadParkImpl(J9VMThread *vmThread, BOOLEAN timeoutIsEpochRelative, I_64 timeou
 		/* vmThread->threadObject != NULL because vmThread must be the current thread */
 		J9VMTHREAD_SET_BLOCKINGENTEROBJECT(vmThread, vmThread, J9VMJAVALANGTHREAD_PARKBLOCKER(vmThread, vmThread->threadObject));
 		TRIGGER_J9HOOK_VM_PARK(vm->hookInterface, vmThread, millis, nanos);
+		U_32 oldState = J9_ARE_ANY_BITS_SET(thrstate, J9_PUBLIC_FLAGS_THREAD_TIMED)
+				? VM_VMHelpers::setThreadState(vmThread, J9VMTHREAD_STATE_PARKED_TIMED)
+				: VM_VMHelpers::setThreadState(vmThread, J9VMTHREAD_STATE_PARKED);
 		internalReleaseVMAccessSetStatus(vmThread, thrstate);
 
 		while (1) {
@@ -116,6 +119,7 @@ threadParkImpl(J9VMThread *vmThread, BOOLEAN timeoutIsEpochRelative, I_64 timeou
 		}
 
 		internalAcquireVMAccessClearStatus(vmThread, thrstate);
+		VM_VMHelpers::setThreadState(vmThread, oldState);
 		TRIGGER_J9HOOK_VM_UNPARKED(vm->hookInterface, vmThread, millis, nanos, startTicks, (UDATA) parkedAddress, VM_VMHelpers::currentClass(parkedClass));
 		J9VMTHREAD_SET_BLOCKINGENTEROBJECT(vmThread, vmThread, NULL);
 	}

runtime/vm/vmthread.cpp

@@ -44,6 +44,7 @@
 #include "ut_j9vm.h"
 #include "vm_internal.h"
 #include "vmaccess.h"
+#include "VMHelpers.hpp"
 #include "vmhook_internal.h"
 
 #include "HeapIteratorAPI.h"
@@ -459,6 +460,7 @@ void threadCleanup(J9VMThread * vmThread, UDATA forkedByVM)
 		/* Safe to call this whether handleUncaughtException clears the exception or not */
 		internalExceptionDescribe(vmThread);
 	}
+	VM_VMHelpers::setThreadState(vmThread, J9VMTHREAD_STATE_DEAD);
 	releaseVMAccess(vmThread);
 
 	/* Mark this thread as dead */
@@ -1921,8 +1923,19 @@ startJavaThread(J9VMThread * currentThread, j9object_t threadObject, UDATA priva
 	privateFlags &= ~J9_PRIVATE_FLAGS_NO_EXCEPTION_IN_START_JAVA_THREAD;
 
 #ifndef J9VM_IVE_RAW_BUILD /* J9VM_IVE_RAW_BUILD is not enabled by default */
+#if JAVA_SPEC_VERSION >= 19
+	j9object_t threadHolder = J9VMJAVALANGTHREAD_HOLDER(currentThread, threadObject);
+	if (NULL != threadHolder) {
+		J9VMJAVALANGTHREADFIELDHOLDER_SET_THREADSTATUS(currentThread, threadHolder, J9VMTHREAD_STATE_RUNNING);
+	}
+#else /* JAVA_SPEC_VERSION >= 19 */
+	J9VMJAVALANGTHREAD_SET_THREADSTATUS(currentThread, threadObject, J9VMTHREAD_STATE_RUNNING);
+#endif /* JAVA_SPEC_VERSION >= 19 */
 	/* Any attempt to start a Thread makes it illegal to attempt to start it again.
-	 * Oracle class libraries don't have the 'started' field */
+	 * Oracle class libraries don't have the 'started' field.
+	 *
+	 * Thread.started must be set after Thread.threadStatus to avoid timing issue in Thread.getState().
+	 */
 	J9VMJAVALANGTHREAD_SET_STARTED(currentThread, threadObject, TRUE);
 #endif /* !J9VM_IVE_RAW_BUILD */