RFR(XS) 8055236: Deadlock during NMT2 shutdown on Windows

[Daniel D. Daugherty]

On 8/20/14 7:21 AM, Zhengyu Gu wrote:
> The problem is caused by acquiring locks inside 
> MemTracker::shutdown(), which could be held by threads that have been 
> already killed.
>
> Given the MemTracker::shutdown() call is on JVM exiting path, the call 
> is not necessary, should be removed.
>
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8055236
> Webrev: http://cr.openjdk.java.net/~zgu/8055236/webrev.00/ 
> <http://cr.openjdk.java.net/%7Ezgu/8055236/webrev.00/>

src/os/windows/vm/os_windows.cpp
     No comments.

I have no issues with removing the work around code, but there is
no analysis here or in the bug report that explains why this work
around is no longer necessary. There's also no explanation about
why this deadlock is seen now and why it wasn't seen before NMT2.

I'll hold off on a thumbs up until I see some reasonable analysis.

Dan


>
>
> Test:
>    Tested on Windows x64 with following tests:
>      nsk/jvmti/scenarios/allocation
>      runtime/ParallelClassLoading
>
>
> Thanks,
>
> -Zhengyu
>