RFR: 8200429: Adjust object pinning interface on CollectedHeap

[Per Liden]

Thanks for reviewing David!

/Per

On 04/03/2018 09:01 AM, David Holmes wrote:
> Hi Per,
> 
> On 3/04/2018 4:42 PM, Per Liden wrote:
>> The recent additions to CollectedHeap to support object pinning didn't 
>> quite fit the bill for what the Shenandoah folks had in mind. Instead 
>> of having CollectedHeap::pin_obejct/unpin_object grab/release the 
>> GCLocker when object pinning is not supported, we add a 
>> CollectedHeap::supports_obejct_pinning() and let the caller take the 
>> appropriate action based on the response.
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8200429
>> Webrev: http://cr.openjdk.java.net/~pliden/8200429/webrev.0
> 
> This looks fine to me. If we ever get a third way of not allowing an 
> object to move we should probably try to think of a good name for that 
> operation. ;-)
> 
> Thanks,
> David
> 
>> /Per