RFR: 8292407: Improve Weak CAS VarHandle/Unsafe tests resilience under spurious failures [v4]

[Aleksey Shipilev]

On Mon, 22 Aug 2022 17:43:43 GMT, Paul Sandoz <psandoz at openjdk.org> wrote:

>> Aleksey Shipilev has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains six commits:
>> 
>>  - Rework timeouts
>>  - Merge branch 'master' into JDK-8292407-varhandle-weak-resilient
>>  - Merge branch 'master' into JDK-8292407-varhandle-weak-resilient
>>  - Update copyrights
>>  - Also do Unsafe tests
>>  - Fix
>
> It's awkward to manage this across various hardware, esp. if the hardware is less mature (perhaps combined with a less mature HotSpot implementation). The approach looks reasonable, but it would be nice if we could just increase the retries and waiting values on weak LL/SC hardware or at least follow up with something like that later on.
> 
> As a quick experiment could we annotate fields with `@Contended` and see if that reduces the number of retries?

@PaulSandoz, @TheRealMDoerr -- are you okay with this?

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PR: https://git.openjdk.org/jdk/pull/9889