Integrated: 8286830: ~HandshakeState should not touch oops

Patricio Chilano Mateo pchilanomate at openjdk.java.net
Thu Jun 2 13:36:28 UTC 2022


On Thu, 19 May 2022 19:17:09 GMT, Patricio Chilano Mateo <pchilanomate at openjdk.org> wrote:

> On 8284632 we added ~HandshakeState to cleanup any potential async operations left in the handshake queue. This could trigger the release of an oophandle from its associated oop-storage when trying to delete an AsyncExceptionHandshake object. Since the exiting JT already executed on_thread_detach() this is forbidden. 
> To fix this I used the original approach that @dcubed-ojdk posted on the 8284632 fix, which is cleaning up those operations before on_thread_detach() is executed. To make sure that no other async exception operation is added to the queue after that I did two things:
> - Added a check in install_async_exception() to avoid installing the operation if the target already moved to the _thread_exiting state.
> - Move the setting of the _thread_exiting state to include the case where JavaThread::exit() is called with destroy_vm=true.
> 
> I also added another run to tests StopAtExit.java and SuspendAtExit.java with extra contention on the Threads_lock. That increases the odds of the target being handshake safe while being in the _thread_exiting state which allows testing for more pathological cases.
> 
> I was able to reproduce the issue by running StopAtExit.java with -XX:+UseShenandoahGC and verified that the test now passes. I also run mach5 tiers1-3. Will run the upper tiers also and will do an additional pass after that.
> 
> Thanks,
> Patricio

This pull request has now been integrated.

Changeset: 5acac223
Author:    Patricio Chilano Mateo <pchilanomate at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/5acac2238fdc4ffe6ef290456e01cc559d811557
Stats:     84 lines in 5 files changed: 73 ins; 8 del; 3 mod

8286830: ~HandshakeState should not touch oops

Reviewed-by: dholmes, rehn

-------------

PR: https://git.openjdk.java.net/jdk/pull/8795


More information about the hotspot-runtime-dev mailing list