RFR: 8316401: sun/tools/jhsdb/JStackStressTest.java failed with "InternalError: We should have found a thread that owns the anonymous lock"

[Chris Plummer]

On Tue, 26 Sep 2023 22:55:27 GMT, Chris Plummer <cjplummer at openjdk.org> wrote:

>> Yeah, I also haven't seen a good explanation for why this is happening yet. I'll also look into SA, but I don't understand the hotspot code it is trying to emulate that well so not sure how useful I'll be.
>
> I made a pass over the deadlock detection code involved. Nothing stuck out. There's not much in the way of SA-isms in this code. I think anyone with an understanding of how hotspot locking works should be able to navigate it pretty easily and maybe conjure a hypothesis as to why this happens as frequently as it does.

I wonder if we are in the middle of a GC, the object has been moved, and the lock stack object reference has been updated but the monitor reference has not (or vice versa).

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PR Review Comment: https://git.openjdk.org/jdk/pull/15907#discussion_r1337908791