RFR(XS): JDK-8212122: Allow ReferenceProcessor to always be MT processing

[Kim Barrett]

> On Oct 12, 2018, at 10:56 AM, Roman Kennke <rkennke at redhat.com> wrote:
> (If it was me, I'd rework this whole execution scheme to always call the
> MT config, and let RP figure out and execute directly in VMThread if
> it's only 1 worker, and not put this burden on the caller to set up both
> for 1-threaded and N-threaded execution. This is just an ugly mess.)

The ugliness here is, I think, largely a result of ParallelGC having it’s very
own parallelization framework.  There’s an RFE to make it use WorkGangs:
https://bugs.openjdk.java.net/browse/JDK-8204951

Personally, I’d like to see that get worked on rather than piling on more
cruft to work around that problem.

And yes, I realize that’s a largish amount of work to take on in order to
make progress on your immediate problem.  So I’m not going to insist
on such a path; you wouldn’t be the first person to kick this particular
can down the road.  But it sure would be nice…