RFR(M): 8039147: Cleanup SuspendibleThreadSet

[Thomas Schatzl]

Hi,

On Tue, 2014-04-08 at 13:32 +0200, Per Liden wrote:
> Hi,
> 
> Here's a attempt to cleanup SuspendibleThreadSet that I'd like to get 
> some reviews on.
> 
> Webrev: http://cr.openjdk.java.net/~pliden/8039147/webrev.0/
> Bug: https://bugs.openjdk.java.net/browse/JDK-8039147

Comment,
 - is it possible to use an uint for anything that is used as a number
of threads? A negative amount of threads seems unusual, and we just
fixed other G1 code to use uints instead of ints everywhere for thread
ids and amounts.

 - I think STS_lock only needs to be initialized when UseG1GC is true.

 - the change removes the start/end messages when yielding during
refinement and G1TraceConcRefinement is true. They seem to be
interesting, more than the other messages enabled by this switch. I
would somewhat prefer to keep them, but I have no real strong opinion.

Otherwise looks good. Thanks for the cleanup.

Thanks,
  Thomas