RFR: 8312498: Thread::getState and JVM TI GetThreadState should return TIMED_WAITING virtual thread is timed parked

[David Holmes]

On Wed, 26 Jul 2023 09:42:10 GMT, Serguei Spitsyn <sspitsyn at openjdk.org> wrote:

>> Thread::getState is an API for monitoring and management purposes to report the thread state. If a virtual thread is parked with LockSupport.parkNanos, its state is reported as  WAITING when it should be TIMED_WAITING. JVM TI GetThreadState has the same issue in that it returns JVMTI_THREAD_STATE_WAITING_INDEFINITELY instead of the JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT bit set. Not a very visible issue because JDWP maps both states to "WAIT" but it may be noticed by tools using other JVM TI agents.
>> 
>> The change is straight-forward, it's just additional state bit to indicate that park is timed. The existing virtual/ThreadAPI.java test is expanded to this scenario. A new test is added for JVM TI GetThreadState to test waiting/timed-waited cases (including pinned) as test coverage seems patchy here.
>
> test/hotspot/jtreg/serviceability/jvmti/vthread/GetThreadState/GetThreadStateTest.java line 133:
> 
>> 131:         } finally {
>> 132:             thread.join();
>> 133:             Reference.reachabilityFence(lock);
> 
> It would be nice to add a short comment why this is needed.

I can't see why it would be needed.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/14978#discussion_r1274874943