[jdk17u-dev] RFR: 8331405: Shenandoah: Optimize ShenandoahLock with TTAS

[Goetz Lindenmaier]

On Tue, 3 Sep 2024 15:58:53 GMT, Xiaolong Peng <xpeng at openjdk.org> wrote:

> Hi, 
>     This PR is a Backport of [JDK-8331405](https://bugs.openjdk.org/browse/JDK-8331405): Shenandoah: Optimize ShenandoahLock with TTAS, the original commit was authored by Aleksey Shipilev on 2 May 2024 and was reviewed by Zhengyu Gu and Y. S. Ramakrishna, and it had already been backported to jdk21.
>     It is a clean merge w/o any conflicts, overall risk should be very minimal given it is single line change to apply TTAS. 
> 
>    Here is the series of improvements for ShenandoahLock I'm going to backport to JDK17:
> 
> | Bug         | Title                                          | PR         |
> | ----------- | ---------------------------------------------- |------------|
> | [JDK-8325587](https://bugs.openjdk.org/browse/JDK-8325587) | ShenandoahLock should allow blocking in VM     | [2797](https://github.com/openjdk/jdk17u-dev/pull/2797)     |
> | [JDK-8331405](https://bugs.openjdk.org/browse/JDK-8331405) | Optimize ShenandoahLock with TTAS              | [2845](https://github.com/openjdk/jdk17u-dev/pull/2845) |
> | [JDK-8331411](https://bugs.openjdk.org/browse/JDK-8331411) | Reconsider spinning duration in ShenandoahLock |    |
> | [JDK-8335904](https://bugs.openjdk.org/browse/JDK-8335904) | Fix invalid comment in ShenandoahLock          |     |
> 
> ### Additional test
> - [x] Linux AArch64 server fastdebug, hotspot_gc_shenandoah

GHA failure: unrelated, well known ClhsdbFindPC issue.

@pengxiaolong please check the GHA tests before applying for approval.

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PR Comment: https://git.openjdk.org/jdk17u-dev/pull/2845#issuecomment-2345595118