RFR: 8373118: Test java/lang/Thread/virtual/Starvation.java timed out [v17]

[Doug Lea]

On Fri, 2 Jan 2026 22:56:50 GMT, Viktor Klang <vklang at openjdk.org> wrote:

>> Doug Lea has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains 24 additional commits since the last revision:
>> 
>>  - Merge branch 'openjdk:master' into JDK-8373118
>>  - Not sure why this merge is necessary
>>    Merge remote-tracking branch 'refs/remotes/origin/JDK-8373118' into JDK-8373118
>>  - Merge branch 'openjdk:master' into JDK-8373118
>>  - Fix deactivate; faster quiescence
>>  - recheck avoiding cross-class offsets
>>  - Merge branch 'openjdk:master' into JDK-8373118
>>  - Merge branch 'openjdk:master' into JDK-8373118
>>  - Check reworked ordering control
>>  - Merge branch 'openjdk:master' into JDK-8373118
>>  - Merge branch 'openjdk:master' into JDK-8373118
>>  - ... and 14 more: https://git.openjdk.org/jdk/compare/dd183022...556c5201
>
> src/java.base/share/classes/java/util/concurrent/ForkJoinPool.java line 1307:
> 
>> 1305:             ForkJoinTask<?>[] a = array;
>> 1306:             int b = base, s = top - 1, cap;
>> 1307:             if (a != null && s - b >= 0 && (cap = a.length) > 0) {
> 
> Would it help to make the assignment to `cap` be `(cap = a.length - 1) >= 0` and then eliminate the `(cap - 1)` in the slotOffset calculations on both sides of `fifo`-branches?

There are still some remnants of code coping with annoying fact that C1 needed to have cap (not cap - 1) in a local to do the bounds check elision.  I don't think it is needed anymore.

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PR Review Comment: https://git.openjdk.org/jdk/pull/28797#discussion_r2673038453