RFR: 8319137: release _object in ObjectMonitor dtor to avoid races [v2]

Mon Nov 20 16:45:14 UTC 2023

On Mon, 20 Nov 2023 16:36:06 GMT, Patricio Chilano Mateo <pchilanomate at openjdk.org> wrote:

>> Please review the following fix which moves the release of the _object WeakHandle back to the ObjectMonitor dtor. Releasing it earlier as we do today introduces a race which can lead to crashes. Tested running tiers123 in mach5.
>> 
>> Thanks,
>> Patricio
>
> Patricio Chilano Mateo has updated the pull request incrementally with one additional commit since the last revision:
> 
>   inline release in ~ObjectMonitor()

Lgtm.

Could potentially remove the `if (_object.is_null())` checks in `ObjectMonitor::object` and `ObjectMonitor::object_peek`. Should never take those branches.

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Marked as reviewed by aboldtch (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/16738#pullrequestreview-1740264434