RFR: Concurrent uncommit should be recorded as GC event + perf

[Aleksey Shipilev]

On 07/06/2018 07:20 PM, Aleksey Shipilev wrote:
> On 07/06/2018 07:17 PM, Zhengyu Gu wrote:
>> Is this right?
>>
>>      ShenandoahHeapRegion* r = get_region(i);
>>      if (r->is_empty_committed() && (r->empty_time() < shrink_before)) {
>> +      ShenandoahHeapLocker locker(lock());
>> +      if (r->is_empty_uncommitted()) {
>>        r->make_uncommitted();
>>        count++;
>>
>> should it be?
>>
>> +      if (r->is_empty_committed()) {
>>        r->make_uncommitted();
>>        count++;
>>
> 
> Damn. Good spot! I tested the previous incarnation of the patch, which does what you suggested.
> Re-testing again...

Retested. tier3_gc_shenandoah is fine, adhoc tests are fine.

-Aleksey