RFR: 8041946 - CMM Testing: 8u40 an allocated humongous object at the end of the heap should not prevents shrinking the heap

Andrey Zakharov andrey.x.zakharov at oracle.com
Mon Jun 9 14:31:29 UTC 2014

Hi, everyone!
Please, review this test for new feature in G1 - sorted free list which 
make possible shrinking of the defragmented heap.
To proper testing of free list sorting we need to defragment memory with 
small young and humongous objects.
This is test scenario:
  - make enough space for new objects to prevent it going old.
  - allocate bunch of small objects, and a bit of humongous several 
times (ssssHssssHssssHssssHssssHssssHssssHssssH)
  - free almost all of allocated stuff. Check that heap shrinks after 
GC. (-----------H)

Webrev: http://cr.openjdk.java.net/~fzhinkin/azakharov/8041946/webrev.00/
Bug: https://bugs.openjdk.java.net/browse/JDK-8041946

I have tested it along all major platforms and it works fine. There is 
lag on Solaris MXBeans about memory usage, so I need sleep by 1s.
It will be very nicely if somebody advice me about method which "flush" 
memory usage info to remove this sleep.

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