RFR: 8292969: Bad Thread Utilization in ForkJoinPool

[Aleksey Shipilev]

On Wed, 7 Sep 2022 12:44:11 GMT, Doug Lea <dl at openjdk.org> wrote:

> 8292969: This small change in signal propagation rules improves utilization when entry queues are resized,

src/java.base/share/classes/java/util/concurrent/ForkJoinPool.java line 1842:

> 1840:                         signalWork();           // propagate at most twice/run
> 1841:                     w.topLevelExec(t, q);
> 1842:                     return src + (prevSrc << SWIDTH);

Are all of these values (`src`, `prevSrc`) less or equal `0x7FFF`? Otherwise we are playing with sign bits here.

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PR: https://git.openjdk.org/jdk/pull/10198