RFR: 8307153: JVMTI GetThreadState on carrier should return STATE_WAITING [v3]

[Alex Menkov]

On Tue, 6 Jun 2023 22:07:14 GMT, Serguei Spitsyn <sspitsyn at openjdk.org> wrote:

>> When a virtual thread is mounted, the carrier thread should be reported as "waiting" until the virtual thread unmounts. Right now, GetThreadState reports a state based the JavaThread status when it should return JVMTI_THREAD_STATE_WAITING | JVMTI_THREAD_STATE_WAITING_INDEFINITELY.
>> The fix adds:
>>  - a special case for passive carrier threads
>>  - necessary test coverage to the existing JVMTI test: `serviceability/jvmti/vthread/ThreadStateTest`.
>> 
>> Testing:
>>    - tested with the updated test: `serviceability/jvmti/vthread/ThreadStateTest`
>>    - submitted mach5 tiers 1-5
>>    - TBD: to submit mach5 tier 6
>
> Serguei Spitsyn has updated the pull request incrementally with one additional commit since the last revision:
> 
>   review: removed JVMTI_THREAD_STATE_RUNNABLE from a carrier thread state

src/hotspot/share/prims/jvmtiEnvBase.cpp line 768:

> 766:   }
> 767:   return state;
> 768: }

You don't need to call get_thread_state_base in case "passive carrier thread":

    if (is_passive_carrier_thread(jt, thread_oop)) {
      return JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_WAITING
             | JVMTI_THREAD_STATE_WAITING_INDEFINITELY;
    }
    return get_thread_state_base(thread_oop, jt);

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

PR Review Comment: https://git.openjdk.org/jdk/pull/14298#discussion_r1220447606