RFR (S): 8011891: The vm/gc/heap/heap_summary_after_gc event for CMS contains old data

[Erik Helin]

Hi all,

this change makes sure that the data in vm/gc/heap/heap_summary_after_gc 
trace event is up-to-date for CMS. The bug happened when CMS got a 
concurrent mode failure and had not reached the "Resizing" phase (in 
collect_in_background). The heap summary data would then be the one 
collected in CMSCollector::checkpointRootsInitialPre which by the time 
of concurrent mode failure (or interrupt) could be quite old.

The solution consists of collecting the heap summary in 
CMSCollector::acquire_control_and_collect when checking if an background 
collection failed (or was interrupted).

Webrev:
http://cr.openjdk.java.net/~ehelin/8011891/webrev.00/

Bug:
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8011891

Thanks,
Erik