RFR: 8131745: java/lang/management/ThreadMXBean/AllThreadIds.java still fails intermittently

[serguei.spitsyn at oracle.com]

Hi Daniil,

LGTM.

Thanks,
Serguei

On 5/29/20 16:28, Daniil Titov wrote:
> Hi Alex and Serguei,
>
> Please review a new version of the change [1] that makes sure that the test counts
> only the threads it creates and ignores  Internal threads VM might create or  destroy.
>
> Testing: Running this test in Mach5 with Graal on several hundred times ,
>   tier1-tier3 tests  are in progress.
>
> [1] http://cr.openjdk.java.net/~dtitov/8131745/webrev.02/
> [2] https://bugs.openjdk.java.net/browse/JDK-8131745
>
> Thank you,
> Daniil
>
> On 5/22/20, 10:26 AM, "Alex Menkov" <alexey.menkov at oracle.com> wrote:
>
>      Hi Daniil,
>
>      I'm not sure all this retry logic is a good way.
>      As mentioned in jira the most important part of the testing is ensuring
>      that you find all the created threads when they are alive, and you don't
>      find them when they are dead. The actual thread count checking is not
>      that important.
>      I agree with this and I'd just simplify the test by removing checks for
>      thread count. VM may create and destroy internal threads when it needs it.
>
>      --alex
>
>      On 05/18/2020 10:31, Daniil Titov wrote:
>      > Please review the change [1] that fixes an intermittent failure of the test.
>      >
>      > This test creates and destroys a given number of daemon/user threads and validates the count of those started/stopped threads against values returned from ThreadMXBean thread counts.  The problem here is that if some internal threads is started ( e.g. " HotSpotGraalManagement Bean Registration"), or destroyed  (e.g. "JVMCI CompilerThread ") the test hangs waiting for expected number of live threads.
>      >
>      > The fix limits the time the test is waiting for desired number of live threads and in case if this limit is exceeded the test repeats itself.
>      >
>      > Testing. Test with Graal on and Mach5 tier1-tier7 test passed.
>      >
>      > [1] http://cr.openjdk.java.net/~dtitov/8131745/webrev.01
>      > [2] https://bugs.openjdk.java.net/browse/JDK-8131745
>      >
>      > Thank you,
>      > Daniil
>      >
>      >
>      >
>
>