RFR: 8261473: Shenandoah: Add breakpoint suppoprt [v2]

[Zhengyu Gu]

On Thu, 18 Feb 2021 13:19:18 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> Zhengyu Gu has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains three commits:
>> 
>>  - Merge
>>  - update
>>  - init update
>
> src/hotspot/share/gc/shenandoah/shenandoahConcurrentGC.cpp line 52:
> 
>> 50: 
>> 51: // Breakpoint support
>> 52: class ShenandoahConcurrentGCScope : public StackObj {
> 
> Let's call these `ShenandoahGCBreakpointScope` and `ShenandoahMarkBreakpointScope`?

Done

> src/hotspot/share/gc/shenandoah/shenandoahControlThread.cpp line 476:
> 
>> 474: bool ShenandoahControlThread::is_async_gc(GCCause::Cause cause) const {
>> 475:   return cause == GCCause::_wb_breakpoint;
>> 476: }
> 
> Do we really need this method? What is "async gc" anyway? I think you can just inline the method at its only use.

Done

-------------

PR: https://git.openjdk.java.net/jdk/pull/2489