RFR: 8338658: New Object to ObjectMonitor mapping: s390x implementation [v2]

[Martin Doerr]

On Mon, 9 Sep 2024 07:05:31 GMT, Axel Boldt-Christmas <aboldtch at openjdk.org> wrote:

>> @xmas92: Can the 1st entry be 0 and the 2nd one contain garbage which matches the object by chance?
>
> No, the oops in the cache are either valid entries or null. They may be stale, as in the monitor has been deflated, but that will cause the slow path to be taken and the cache entry is replaced inside the runtime call.

Ok, the owner won't be 0 in this case, the cmpxchg attempt will fail and the slow path will handle it correctly. Thanks for the explanation!

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PR Review Comment: https://git.openjdk.org/jdk/pull/20740#discussion_r1750022201