RFR: 8214784: Adjust Dictionary and JNIHandle verification

[Per Liden]

Thanks Erik!

/Per


On 12/5/18 12:09 PM, Erik Österlund wrote:
> Hi Per,
> 
> Looks good.
> 
> Thanks,
> /Erik
> 
> On 2018-12-04 13:53, Per Liden wrote:
>> Dictionary::verify() and JNIHandles::verify() currently do 
>> verification that is unnecessary and incorrect. It currently calls 
>> oopDesc::verify(), which not only checks the oop, but also steps out 
>> into the heap to verify the actual object and its fields. This is 
>> unnecessary because this is already taken care of by 
>> CollectedHeap::verify(). It's also incorrect, because when stepping 
>> out into the heap you need to ahead to various Barrier/GC 
>> restrictions, which the code currently doesn't do. To fix this, the 
>> verification done in Dictionary::verify() and JNIHandles::verify() 
>> should only check the oop, not the object and its fields.
>>
>> In this patch, I'm also cleaning out a ZGC specific check in the JNI 
>> verification, which skipped verification of JNI weaks. This check is 
>> no longer needed after JDK-8212921.
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8214784
>> Webrev: http://cr.openjdk.java.net/~pliden/8214784/webrev.0
>>
>> /Per