RFR: Adapt upstream object pinning API

[Zhengyu Gu]

On 04/04/2018 01:17 PM, Aleksey Shipilev wrote:
> On 04/04/2018 07:02 PM, Zhengyu Gu wrote:
>> Adapted upstream object pinning API, also made adjustment to critical native support to use new API.
>>
>>
>> Webrev: http://cr.openjdk.java.net/~zgu/shenandoah/pin_interface/webrev.00/
> 
> *) The changeset contains JDK-8200429 only, make sure you are pushing the correct changeset:
>   http://cr.openjdk.java.net/~zgu/shenandoah/pin_interface/webrev.00/shenandoah-jdk10.changeset

Yes, we need this one for new API. The patch is from upstream jdk repo, 
but did not apply cleanly.

> 
> *) Since you are renaming the RT stubs, should you also rename the MacroAssembler entries? Does it
> do something special for arrays, or is it just the stub for the call to
> SharedRuntime::{pin|unpin}_object?
> 
>    MacroAssembler::pin_critical_native_array
>    MacroAssembler::unpin_critical_native_array

No. SharedRuntime::{pin|unpin}_object are generic. 
MacroAssembler::pin/unpin_critical_native_array generate code to make RT 
calls for array arguments.

Thanks,

-Zhengyu

> 
> Thanks,
> -Aleksey
>