RFR 8204525: [TESTBUG] runtime/NMT/MallocStressTest.java ran out of java heap

[David Holmes]

Hi Harold,

Fix seems reasonable but the problem suggests that the test could still 
fail spuriously if it runs out of Java heap around the same time as 
malloc'd memory - the println will throw OOME.

Cheers,
David

On 21/11/2018 12:46 am, Harold David Seigel wrote:
> Hi,
> 
> Please review this small change to fix test bug JDK-8204525. Test 
> MallocStressTest quickly allocates lots of malloc memory and slowly 
> releases it.  It checks that NMT properly measures the amount of 
> allocated memory.  The test occasionally fails when it runs out of Java 
> heap before the malloc memory allocations completed.
> 
> The test has several threads that loop, allocating lots of memory.  A 
> thread's allocations stop when its malloc allocation fails, or when a 
> certain amount of time expires.  This fix also stops a thread's 
> allocation when an OutOfMemoryError exception gets thrown.
> 
> Open Webrev: http://cr.openjdk.java.net/~hseigel/bug_8204525/webrev/
> 
> JBS Bug:  https://bugs.openjdk.java.net/browse/JDK-8204525
> 
> The fix was tested on Linux X64, Windows, Solaris, and Mac.  It was also 
> tested on Linux X64 with -Xmx20M, which, before this fix, reliably 
> reproduced the failure.
> 
> Thanks, Harold
>