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

[coleen.phillimore at oracle.com]

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