RFR: 8325187: JVMTI GetThreadState says virtual thread is JVMTI_THREAD_STATE_INTERRUPTED when it no longer is [v5]

[Alan Bateman]

On Wed, 6 Mar 2024 09:14:18 GMT, Serguei Spitsyn <sspitsyn at openjdk.org> wrote:

>> Please, review this fix correcting the JVMTI  `RawMonitorWait()` implementation.
>> The `RawMonitorWait()` is using the the  `jt->is_interrupted(true)` to update the interrupt status of the interrupted waiting thread.  The issue is that when it calls `jt->is_interrupted(true)` to fetch and clear the `interrupt status` of the virtual thread, this information is not propagated to the `java.lang.Thread` instance.
>> In the `VirtualThread` class implementation the `interrupt status` for virtual thread is stored for both virtual and carrier threads. It is because the implementation of object monitors for virtual threads is based on pinning virtual threads, and so, always operates on carrier thread. The fix is to clear the interrupt status for both virtual and carrier  `java.lang.Thread` instances.
>> 
>> Testing:
>>  - tested with new test `hotspot/jtreg/serviceability/jvmti/vthread/InterruptRawMonitor` which is passed with the fix and failed without it
>>  - ran mach5 tiers 1-6
>
> Serguei Spitsyn has updated the pull request incrementally with one additional commit since the last revision:
> 
>   removed trailing spaces in javaClasses.cpp and libInterruptRawMonitor.cpp

src/hotspot/share/runtime/javaThread.cpp line 573:

> 571: 
> 572:   Handle thread_h(current, vthread_or_thread());
> 573:   ObjectLocker lock(Handle(current, java_lang_Thread::interrupt_lock(thread_h())), current);

For this version then I assume you should limit it when its a virtual thread and when clear_interrupted is true.

Also need to think through if Object.wait will need to be changed as part of this.

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PR Review Comment: https://git.openjdk.org/jdk/pull/18093#discussion_r1514126817