RFR: 8150134: Simplify concurrent refinement thread deactivation

[Thomas Schatzl]

Hi Kim,

On Do, 2016-02-18 at 15:20 -0500, Kim Barrett wrote:
> Please review this simplification of the deactivation of concurrent
> refinement threads.
> 
> I also took the opportunity to move the activate/deactivate logging
> messages for those threads.  One benefit of this is that the primary
> thread (worker_id 0) now generates such log messages.  Note that just
> moving the logging within the activate/deactivate functions wouldn't
> have fixed that, since the primary thread is not currently activated
> via a call to the activate function.  That's an oddity that I plan to
> fix later.
> 
> One side effect of the logging change: it is now apparent that the
> primary refinement thread gets activated during a pause, though
> fortunately immediately blocks on the SuspendibleThreadSetJoiner.
> That's another problem that I plan to fix later.
> 
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8150134
> 
> Webrev:
> http://cr.openjdk.java.net/~kbarrett/8150134/webrev.00/
> 

  looks good.

Thanks,
  Thomas