RFR(S): 8141356: Explicitly stop CMS threads during VM termination.

[Jungwoo Ha]

Unfortunately, we cannot provide the test publicly.
But we do have internal tests that triggers this bug, and got fixed with
this patch.

On Wed, Nov 4, 2015 at 9:25 AM, Jon Masamitsu <jon.masamitsu at oracle.com>
wrote:

>
>
> On 11/3/2015 5:32 PM, Jungwoo Ha wrote:
>
> Somehow I didn't receive Jon's email.
> We've first noticed this on JDK8, but I think the bug is more triggered
> with the tcmalloc + custom launcher.
>
>
> Jungwoo,
>
> Do you have a test that exhibits the bug?
>
> Jon
>
>
>
> On Tue, Nov 3, 2015 at 4:14 PM, Carsten Varming <varming at gmail.com> wrote:
>
>> Dear Jon,
>>
>> I am pretty sure this has been that way for a long time. I have never
>> seen a problem, but I would like to see Hotspot shut down its threads as
>> well.
>>
>> Carsten
>>
>> On Tue, Nov 3, 2015 at 5:40 PM, Jon Masamitsu <
>> <jon.masamitsu at oracle.com>jon.masamitsu at oracle.com> wrote:
>>
>>> Jungwoo,
>>>
>>> Did you first see this bug in jdk8?  I'm wondering if it
>>> was always broken.
>>>
>>> Jon
>>>
>>> On 11/03/2015 01:14 PM, Jungwoo Ha wrote:
>>>
>>> BUG:  <https://bugs.openjdk.java.net/browse/JDK-8141356>
>>> https://bugs.openjdk.java.net/browse/JDK-8141356
>>> Webrev: http://cr.openjdk.java.net/~jwha/8141356/webrev.00/
>>>
>>> Inside before_exit(), it says
>>>
>>>   // Stop concurrent GC threads
>>>   Universe::heap()->stop();
>>>
>>> but GenCollectedHeap never implemented stop() method, and thus calling
>>> empty SharedHeap::stop() method.
>>> This causes CMS threads to run during the VM termination and ends up
>>> crashing.
>>> ConcurrentMarkSweepThread::stop() is currently a dead code and never
>>> gets called.
>>> The patch just implemented GenCollectedHeap::stop() to call
>>> ConcurrentMarkSweepThread::stop().
>>>
>>> Can someone sponsor this patch?
>>>
>>> --
>>> Jungwoo Ha | Google | <jwha at google.com>jwha at google.com
>>>
>>>
>>>
>>
>
>
> --
> Jungwoo Ha | Java Platform Team | jwha at google.com
>
>
>


-- 
Jungwoo Ha | Java Platform Team | jwha at google.com
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