RFR: 8297286: runtime/vthread tests crashing after JDK-8296324 [v13]

[Serguei Spitsyn]

On Thu, 30 Mar 2023 22:31:02 GMT, Chris Plummer <cjplummer at openjdk.org> wrote:

>> Serguei Spitsyn has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   review: tweak in count_transitions_and_correct_jvmti_thread_states
>
> test/hotspot/jtreg/serviceability/jvmti/vthread/ToggleNotifyJvmtiTest/ToggleNotifyJvmtiTest.java line 170:
> 
>> 168:         // Disable notifyJvmti events mode at test cycle start.
>> 169:         // It is unsafe to do so if any virtual threads are executed.
>> 170:         setVirtualThreadsNotifyJvmtiMode(iter, false);
> 
> What happens if the main thread is a virtual thread because the virtual thread wrapper is being used? Is there any concern with disabling notifications in this case?

I've tested it and it is kind of working now.
But I'd like to minimize risk now and avoid testing something which is not really needed.
So, this is why the testing cycles are still there.
The `serviceability/jvmti/vthread` tests are not supposed to be run with the virtual thread wrapper.
It is why we have the special problem list `ProblemList-vthread.txt` in Loom repository.
I guess, we should replicate the same or alike approach in the main line when virtual thread wrapper is introduced.

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PR Review Comment: https://git.openjdk.org/jdk/pull/13133#discussion_r1154034742