RFR(S) 8054368: nsk/jdi/VirtualMachine/exit/exit002 crash with detail tracking on (NMT2)

[Coleen Phillimore]

I agree.  This looks good.  Was it found with an existing test and/or 
would it be possible to write one?

Thanks,
Coleen

On 8/14/14, 6:33 AM, David Holmes wrote:
> On 14/08/2014 5:54 AM, Zhengyu Gu wrote:
>> The crash is caused by debugee exiting process by calling ::exit(),
>> which causes C runtime to destroy static object
>> (VirtualMemoryTracker::_reserved_regions)  while threads still access 
>> it.
>
> Non-trivial static C++ objects plus multi-threading just don't mix.
>
>> The solution is to replace it with pointer type, allocates the object
>> during NMT initialization and deallocate it during shutdown.
>
> Looks okay to me.
>
> Thanks,
> David
>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8054368
>> Webrev: http://cr.openjdk.java.net/~zgu/8054368/webrev.00/
>> <http://cr.openjdk.java.net/%7Ezgu/8054368/webrev.00/>
>>
>> Test:
>>     Ran nsk/jdi/VirtualMachine/exit/exit002 in a loop for 1+ hour on
>> Solaris x64, no crash.
>>     Without the fix, it crashes within 5 minutes.
>>
>>
>> Thanks,
>>
>> -Zhengyu
>>