RFR (S): 8191894: Refactor weak references in JvmtiTagHashmap to use the Access API

[Erik Österlund]

Hi Serguei,

Thanks for the review.

/Erik

On 2017-11-28 06:43, serguei.spitsyn at oracle.com wrote:
> Hi Erik,
>
> This looks good to me.
>
> Thanks,
> Serguei
>
>
> On 11/27/17 05:22, Daniel D. Daugherty wrote:
>> Adding serviceability-dev at ... since this is JVM/TI related...
>>
>> Dan
>>
>>
>> On 11/27/17 6:28 AM, Erik Österlund wrote:
>>> Hi,
>>>
>>> The JVMTI tag hashmap has weak oop references that are handled using 
>>> raw oop accesses and a G1-specific SATB enqueue call when leaking 
>>> out objects from the tag map, requiring them to be marked as live by 
>>> G1.
>>>
>>> This should now be refactored to use the Access API to annotate that 
>>> these are ON_PHANTOM_OOP_REF, and refactor the raw oop loads to use 
>>> ON_PHANTOM_OOP_REF | AS_NO_KEEPALIVE.
>>>
>>> Webrev:
>>> http://cr.openjdk.java.net/~eosterlund/8191894/webrev.00/
>>>
>>> Bug:
>>> https://bugs.openjdk.java.net/browse/JDK-8191894
>>>
>>> Thanks,
>>> /Erik
>>
>