RFR: 8321815: Shenandoah: gc state should be synchronized to java threads only once per safepoint [v2]

[Y. Srinivas Ramakrishna]

On Fri, 15 Dec 2023 19:20:50 GMT, William Kemper <wkemper at openjdk.org> wrote:

>> Presently, every change to the gc change is distributed to all java threads. The gc state is only changed on safepoints. For applications with a very large number of java threads this may increase time on the safepoint. It would be better to synchronize the gc state only once per safepoint.
>
> William Kemper has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Extra assertions that gc state synchronization is correct

Looks good; thanks for the data and for the extra verification checks.
🚢

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Marked as reviewed by ysr (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/17112#pullrequestreview-1784889900