RFR: 8293922: Extend barrier-less Java thread transitions to native transitions [v2]

[Martin Doerr]

On Fri, 16 Sep 2022 12:24:45 GMT, Robbin Ehn <rehn at openjdk.org> wrote:

>> As suggested by @TheRealMDoerr, avoid the fence for native trans when UseSystemMemoryBarrier is enabled.
>> 
>> Locally I can see methods like Thread.holdsLock() getting a 4 ns speed boost, (~20% faster).
>> 
>> Running t1-5 with UseSystemMemoryBarrier on.
>
> Robbin Ehn has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Use proper accessors for _thread_state

Thanks for cleaning it up!

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Marked as reviewed by mdoerr (Reviewer).

PR: https://git.openjdk.org/jdk/pull/10302