Inconsistent execution behaviour leads to a jtreg test timeout.

In some instances the test is marked as passed BUT test has not terminated gracefully with threads remain executing and have not completed their task execution

Other instances the test is stuck in the startup iteration and the test is moribund
 extract below
----------messages:(8/289)----------
command: main ParkALot 500000
reason: User specified action: run main/othervm ParkALot 500000
started: Thu Sep 21 15:32:04 UTC 2023
Mode: othervm [/othervm specified]
Timeout information:
--- Timeout information end.
finished: Thu Sep 21 15:40:50 UTC 2023
elapsed time (seconds): 525.827
----------configuration:(0/0)----------
----------System.out:(33/1499)----------
2023-09-21T15:32:04.411187696Z 1 threads ...
2023-09-21T15:32:06.243404694Z 2 threads ...
2023-09-21T15:32:08.334409048Z 3 threads ...
2023-09-21T15:32:10.797923912Z 4 threads ...
2023-09-21T15:32:13.861938532Z 5 threads ...
2023-09-21T15:32:17.809720497Z 6 threads ...
2023-09-21T15:32:23.305455821Z 7 threads ...
2023-09-21T15:32:30.054651730Z 8 threads ...
2023-09-21T15:32:38.691064971Z 9 threads ...
2023-09-21T15:32:48.688304398Z 10 threads ...
2023-09-21T15:32:58.963760433Z 11 threads ...
2023-09-21T15:33:07.805807140Z 12 threads ...
2023-09-21T15:33:16.660177008Z 13 threads ...
2023-09-21T15:33:27.716685491Z 14 threads ...
2023-09-21T15:33:39.170794058Z 15 threads ...
2023-09-21T15:33:53.489750556Z 16 threads ...
2023-09-21T15:34:11.380673436Z 17 threads ...
2023-09-21T15:34:30.943381201Z 18 threads ...
2023-09-21T15:34:50.278798259Z 19 threads ...
2023-09-21T15:35:10.190032985Z 20 threads ...
2023-09-21T15:35:31.109356765Z 21 threads ...
2023-09-21T15:35:51.139607996Z 22 threads ...
2023-09-21T15:36:11.584651552Z 23 threads ...
2023-09-21T15:36:32.447378200Z 24 threads ...
2023-09-21T15:36:54.518852830Z 25 threads ...
2023-09-21T15:37:17.470204912Z 26 threads ...
2023-09-21T15:37:42.300813763Z 27 threads ...
2023-09-21T15:38:08.437603958Z 28 threads ...
2023-09-21T15:38:35.754687548Z 29 threads ...
2023-09-21T15:39:04.156057341Z 30 threads ...
2023-09-21T15:39:32.658074312Z 31 threads ...
2023-09-21T15:40:02.006672023Z 32 threads ...
Timeout signalled after 480 seconds
----------System.err:(0/0)----------
----------rerun:(36/5799)*----------

test result: Error. Program `/opt/mach5/mesos/work_dir/jib-master/install/jdk-22+16-1247/linux-x64.jdk/jdk-22/bin/java' timed out (timeout set to 480000ms, elapsed time including timeout handling was 525822ms).


"MainThread" #34 [2683474] prio=5 os_prio=0 cpu=97.56ms elapsed=490.64s allocated=983K defined_classes=48 tid=0x00007f4e804350d0 nid=2683474 waiting on condition [0x00007f4e55887000]
   java.lang.Thread.State: TIMED_WAITING (parking)
at jdk.internal.misc.Unsafe.park(java.base@22-ea/Native Method)
- parking to wait for <0x00000000d1400ab8> (a java.util.concurrent.CountDownLatch$Sync)
at java.util.concurrent.locks.LockSupport.parkNanos(java.base@22-ea/LockSupport.java:269)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(java.base@22-ea/AbstractQueuedSynchronizer.java:756)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.tryAcquireSharedNanos(java.base@22-ea/AbstractQueuedSynchronizer.java:1126)
at java.util.concurrent.CountDownLatch.await(java.base@22-ea/CountDownLatch.java:276)
at java.util.concurrent.ThreadPerTaskExecutor.awaitTermination(java.base@22-ea/ThreadPerTaskExecutor.java:181)
at java.util.concurrent.ThreadPerTaskExecutor.awaitTermination(java.base@22-ea/ThreadPerTaskExecutor.java:195)
at java.util.concurrent.ThreadPerTaskExecutor.close(java.base@22-ea/ThreadPerTaskExecutor.java:212)
at ParkALot.main(ParkALot.java:61)
at java.lang.invoke.LambdaForm$DMH/0x00007f4e07002000.invokeStatic(java.base@22-ea/LambdaForm$DMH)
at java.lang.invoke.LambdaForm$MH/0x00007f4e07003400.invoke(java.base@22-ea/LambdaForm$MH)
at java.lang.invoke.Invokers$Holder.invokeExact_MT(java.base@22-ea/Invokers$Holder)
at jdk.internal.reflect.DirectMethodHandleAccessor.invokeImpl(java.base@22-ea/DirectMethodHandleAccessor.java:154)
at jdk.internal.reflect.DirectMethodHandleAccessor.invoke(java.base@22-ea/DirectMethodHandleAccessor.java:103)
at java.lang.reflect.Method.invoke(java.base@22-ea/Method.java:580)
at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
at java.lang.Thread.runWith(java.base@22-ea/Thread.java:1583)
at java.lang.Thread.run(java.base@22-ea/Thread.java:1570)

 ....

"VirtualThread-unparker" #38 [2683510] daemon prio=5 os_prio=0 cpu=17832.85ms elapsed=490.59s allocated=56657K defined_classes=0 tid=0x00007f4dc8002440 nid=2683510 waiting on condition [0x00007f4e55584000]
   java.lang.Thread.State: TIMED_WAITING (parking)
at jdk.internal.misc.Unsafe.park(java.base@22-ea/Native Method)
- parking to wait for <0x00000000d0003048> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
at java.util.concurrent.locks.LockSupport.parkNanos(java.base@22-ea/LockSupport.java:269)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(java.base@22-ea/AbstractQueuedSynchronizer.java:1758)
at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(java.base@22-ea/ScheduledThreadPoolExecutor.java:1182)
at java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(java.base@22-ea/ScheduledThreadPoolExecutor.java:899)
at java.util.concurrent.ThreadPoolExecutor.getTask(java.base@22-ea/ThreadPoolExecutor.java:1070)
at java.util.concurrent.ThreadPoolExecutor.runWorker(java.base@22-ea/ThreadPoolExecutor.java:1130)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(java.base@22-ea/ThreadPoolExecutor.java:642)
at java.lang.Thread.runWith(java.base@22-ea/Thread.java:1583)
at java.lang.Thread.run(java.base@22-ea/Thread.java:1570)
at jdk.internal.misc.InnocuousThread.run(java.base@22-ea/InnocuousThread.java:186)

....

"Thread-527" #1175 [2813272] prio=5 os_prio=0 cpu=12953.29ms elapsed=13.03s allocated=4399K defined_classes=0 tid=0x00007f4dd005f1f0 nid=2813272 runnable [0x00007f4cb98d6000]
   java.lang.Thread.State: RUNNABLE
at java.lang.System$2.unparkVirtualThread(java.base@22-ea/System.java:2657)
at jdk.internal.misc.VirtualThreads.unpark(java.base@22-ea/VirtualThreads.java:93)
at java.util.concurrent.locks.LockSupport.unpark(java.base@22-ea/LockSupport.java:179)
at ParkALot.parkALot(ParkALot.java:88)
at ParkALot.lambda$main$0(ParkALot.java:59)
at ParkALot$$Lambda/0x00007f4e07001200.run(Unknown Source)
at java.util.concurrent.Executors$RunnableAdapter.call(java.base@22-ea/Executors.java:572)
at java.util.concurrent.FutureTask.run(java.base@22-ea/FutureTask.java:317)
at java.lang.Thread.runWith(java.base@22-ea/Thread.java:1583)
at java.lang.Thread.run(java.base@22-ea/Thread.java:1570)

   Locked ownable synchronizers:
- None

"Thread-528" #1177 [2813273] prio=5 os_prio=0 cpu=12952.30ms elapsed=13.03s allocated=4425K defined_classes=0 tid=0x00007f4dd0060200 nid=2813273 runnable [0x00007f4cb8ecc000]
   java.lang.Thread.State: RUNNABLE
at java.lang.System$2.unparkVirtualThread(java.base@22-ea/System.java:2657)
at jdk.internal.misc.VirtualThreads.unpark(java.base@22-ea/VirtualThreads.java:93)
at java.util.concurrent.locks.LockSupport.unpark(java.base@22-ea/LockSupport.java:179)
at ParkALot.parkALot(ParkALot.java:88)
at ParkALot.lambda$main$0(ParkALot.java:59)
at ParkALot$$Lambda/0x00007f4e07001200.run(Unknown Source)
at java.util.concurrent.Executors$RunnableAdapter.call(java.base@22-ea/Executors.java:572)
at java.util.concurrent.FutureTask.run(java.base@22-ea/FutureTask.java:317)
at java.lang.Thread.runWith(java.base@22-ea/Thread.java:1583)
at java.lang.Thread.run(java.base@22-ea/Thread.java:1570)