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

[serguei.spitsyn at oracle.com]

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
>