RFR (S): 8191888: Refactor ClassLoaderData::remove_handle to use the Access API

[Erik Österlund]

Hi Coleen,

Thank you for the review.

/Erik

On 2017-11-27 19:08, coleen.phillimore at oracle.com wrote:
>
> This looks good!
> Coleen
>
> On 11/27/17 4:06 AM, Erik Österlund wrote:
>> Hi,
>>
>> The ClassLoaderData::remove_handle() member function currently uses 
>> explicit G1 SATB barriers to remove an oop from the root set, as 
>> these handles are not necessarily walked by the GC in a safepoint. 
>> Therefore G1 needs pre-write barriers.
>>
>> This should now be modeled as a 
>> RootAccess<IN_CONCURRENT_ROOT>::oop_store instead. This maps to 
>> performing a pre-write SATB barrier with G1, but other GCs are free 
>> to do other things as necessary.
>>
>> Webrev:
>> http://cr.openjdk.java.net/~eosterlund/8191888/webrev.00/
>>
>> Bug:
>> https://bugs.openjdk.java.net/browse/JDK-8191888
>>
>> Thanks,
>> /Erik
>