RFR: 8178813: Add test for G1 pre-barrier on dereference of weak JNI handles

[Mikael Gerdin]

Hi Kim,

On 2017-05-05 07:45, Kim Barrett wrote:
> Still looking for reviewers.
>
>> On Apr 14, 2017, at 4:41 PM, Kim Barrett <kim.barrett at oracle.com> wrote:
>>
>> Please review this new test of the handling of weak JNI handles during
>> G1 concurrent mark.
>>
>> CR:
>> https://bugs.openjdk.java.net/browse/JDK-8178813
>>
>> Webrev:
>> http://cr.openjdk.java.net/~kbarrett/8178813/hotspot.00/

Test seems ok to me, I might have made the "static boolean resolve" an 
instance member and created two different instances of the test class 
because I dislike that kind of state in static members but I'm not going 
to block the change because of it.

Reviewed.
/Mikael

>>
>> Testing:
>> JPRT
>>
>> Locally ran new test with G1-specific code in JNIHandles::resolve and
>> MacroAssembler::resolve_jobject temporarily removed, and verified
>> expected failures.
>
>