RFR(S): 7189971: Implement CMSWaitDuration for non-incremental mode of CMS

[John Cuthbertson]

Hi Everyone,

Can I have a couple of volunteers review this change that was submitted 
by Michal Frajt? The webrev can be found at: 
http://cr.openjdk.java.net/~johnc/7189971/webrev.0/

In the original patch, Michal was returning (if the CMS thread was 
terminating or if a foreground collection was scheduled) after setting 
the CMS flag. Michal incorporated my suggestion to change that and 
return before setting the CMS flag.

I'm not an expert in the inner workings of CMS so I'd appreciate further 
reviews from those more familiar with  CMS' operation.

Testing:
Functional testing was performed using the GC test suite in both 
incremental and non-incremental modes with various values of 
CMSWaitDuration and checking the log files.  Additional tests: nsk, jprt.

Thanks,

JohnC