Crash when using java debugger and kafka

[Christopher Ng]

yes, it seems to be better.  passes in the test case and my main code base.

On Thu, Oct 31, 2019 at 12:33 PM Aleksey Shipilev <shade at redhat.com> wrote:

> On 10/31/19 11:33 AM, Aleksey Shipilev wrote:
> > On 10/31/19 11:16 AM, Christopher Ng wrote:
> >> Hmm...not great news.  I pulled the latest build
> >> from https://builds.shipilev.net/openjdk-shenandoah-jdk8/
>  (openjdk-shenandoah-jdk8-latest-linux-x86_64-release.tar.xz
> >> 38M 2019-Oct-30 15:14).
> >>
> >> The bug does not occur when running jdb/mvn (as in the test case)...but
> it still occurs when
> >> debugging from Intellij IDEA.  It's slightly better, now only 1 core
> locks up :).  Disabling class
> >> unloading does seem to stop the error occurring.
> >
> > I have a theory about that. In 8u, there is another entry to
> JvmtiExport::weak_oops_do here:
> > <snip>>
> > Let me dig up more details and propose a patch.
>
> Christopher, would you mind trying another bleeding edge build?
>
> You need this patch:
>   http://hg.openjdk.java.net/shenandoah/jdk8/hotspot/rev/a56f86355f8d
>
> $ curl
>
> https://builds.shipilev.net/openjdk-shenandoah-jdk8/openjdk-shenandoah-jdk8-latest-linux-x86_64-release.tar.xz
> | tar xJf -
>
> $ j2sdk-image/bin/java -version
> openjdk version "1.8.0-builds.shipilev.net-openjdk-shenandoah-jdk8"
> OpenJDK Runtime Environment (build
>
> 1.8.0-builds.shipilev.net-openjdk-shenandoah-jdk8-b452-20191031-aarch64-shenandoah-jdk8u232-b09)
> OpenJDK 64-Bit Server VM (build
> 25.71-b452-20191031-aarch64-shenandoah-jdk8u232-09, mixed mode)
>
> $ grep "JvmtiExport::weak_oops_do should not be entered by multiple
> threads" j2sdk-image/bom-*
> j2sdk-image/bom-changesets-hotspot.log:summary:     Shenandoah:
> JvmtiExport::weak_oops_do should not
> be entered by multiple threads
>
> If that does not help, does the failure still reproduce with
> -XX:ConcGCThreads=1
> -XX:ParallelGCThreads=1?
>
> --
> Thanks,
> -Aleksey
>
>