Withdrawn: 8317049: GenShen: Very rare loss of function for ShenandoahControlThread::_regulator_lock

[Kelvin Nilsen]

On Thu, 28 Sep 2023 17:06:04 GMT, Kelvin Nilsen <kdnilsen at openjdk.org> wrote:

> We have observed that we very rarely miss _regulator_lock notifications.  We have identified the root cause to be a race, which occurs when the ShenandoahControlThread notifies the _regulator_lock before the ShenandoahRegulatorThread has begun to wait for the notification.
> 
> This change forces the ShenandoahControlThread to wait until the ShenandoahRegulatorThread is inside its wait() invocation.  It does so by acquiring the Mutator lock for _regulator_thread before notifying the control thread.  The control thread must acquire this lock before it can notify.  The control thread will not be able to acquire the lock until the regulator thread releases the lock by invoking ml.wait().

This pull request has been closed without being integrated.

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PR: https://git.openjdk.org/shenandoah/pull/332