Shenandoah crash

[Aleksey Shipilev]

On 02/01/2018 02:53 PM, Aleksey Shipilev wrote:
> Thanks for the bug report!
> 
> On 02/01/2018 01:05 PM, Lennart Börjeson wrote:
>> #
>> # A fatal error has been detected by the Java Runtime Environment:
>> #
>> #  Internal Error (/Users/lennartb/RaT/openJDK/shenandoah-jdk10/src/hotspot/share/gc/shenandoah/shenandoahVerifier.cpp:184), pid=37194, tid=11267
>> #  Error: Shenandoah verification failed; After Mark, Roots: Must be marked in complete bitmap
>>
>> Referenced from:
>>   interior location: 0x00007faf6cd0d3c0
>>   outside of Java heap
>>   0x00007faf6cd0d3c0 is a weak global jni handle
> 
>                             ^^^^^^^^^^^^^^^^^^^^^^
> 
> This one seems enough of the smoking gun to chase the bug for now. It must be the bug in handling
> the weak global JNI handles: we apparently miss that root during mark?
> 
> If we cannot find any obvious bugs there and/or fail to write a reproducer, we would need to work to
> understanding the failing application better. We are going to FOSDEM for the rest of the week, so --
> barring heroics of anyone here -- we would be able to look at it next week.

You might want to test this patch:
  http://mail.openjdk.java.net/pipermail/shenandoah-dev/2018-February/004924.html

-Aleksey