Crash when using java debugger and kafka

[Aleksey Shipilev]

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