RFR: 8264663: Update test SuspendWithCurrentThread.java to verify that suspend doesn't exit until resumed

[Daniel D.Daugherty]

On Fri, 23 Apr 2021 21:07:56 GMT, Leonid Mesnik <lmesnik at openjdk.org> wrote:

> Test test/hotspot/jtreg/serviceability/jvmti/SuspendWithCurrentThread/SuspendWithCurrentThread.java
> doesn't check that thread stops in SuspendThreadList(...).
> 
> Actually, before https://bugs.openjdk.java.net/browse/JDK-8257831 the thread didn't suspend itself but only get a request to be suspended.  So it continued to execute and stopped a little bit later.
> 
> Such behavior is a violation of spec which says " If the calling thread is specified in the request_list array, this function will not return until some other thread resumes it."
> 
> While the bug is fixed it is still useful to verify correct behavior.  If the fix is backported without JDK-8257831 test should start failing.

Thumbs up.

I'm good with the changes. I just a question about the use
of `std::atomic`.

test/hotspot/jtreg/serviceability/jvmti/SuspendWithCurrentThread/libSuspendWithCurrentThread.cpp line 33:

> 31: static jthread* threads = NULL;
> 32: static jsize threads_count = 0;
> 33: static std::atomic<bool> is_exited_from_suspend;

Is use of `std::atomic` permitted in tests?

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Marked as reviewed by dcubed (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/3665