RFR: 8275035: Clean up worker thread infrastructure

[David Holmes]

On Mon, 11 Oct 2021 09:21:21 GMT, Per Liden <pliden at openjdk.org> wrote:

> I propose that we clean up our GangWorker/WorkGang and related classes, to remove abstractions we no longer need (after CMS was removed, MutexDispatcher was removed, Parallel is now using WorkGang, etc) and adjusting names as follows:
> 
> * Rename AbstractGangTask to WorkerTask
> * Rename WorkGang to WorkerThreads
> * Fold GangWorker into WorkerThread
> * Fold WorkManager into WorkerThreads
> * Move SubTaskDone and friends to a new workerUtils.hpp/cpp
> 
> I've split things up into several commits to make it easier to review.
> 
> Testing: Passes Tier 1-3 on all Oracle platforms.

Changes to non GC files look fine.

Thanks,
David

-------------

PR: https://git.openjdk.java.net/jdk/pull/5886