RFR: 8245022: ParallelGC abuses StarTask to also include partial objarray scan tasks

[Thomas Schatzl]

Hi,

On 20.05.20 10:11, stefan.johansson at oracle.com wrote:
> Hi Kim,
> 
> On 2020-05-20 00:41, Kim Barrett wrote:
>> Please review this change to ParallelGC to also use the recently added
>> ScannerTask (JDK-8244684), eliminating some casts between oop and oop*
>> and use of some misaligned oop* values.
>>
>> Also renamed G1's ScannerTasksQueue[Set] to G1ScannerTasksQueue[Set].
>> I should have used those names in JDK-8244684.  This is consistent
>> with the new PSScannerTasksQueue[Set] now being used by ParallelGC.
>> The types used by G1 and Parallel are currently the same, but don't
>> need to be.
>>
>> Also made a small simplification, reordering the template parameters
>> for PSPromotionManager::copy_and_push_safe_barrier.  By making the
>> promote_immediately flag first and the reference type second we can
>> explicitly specify the non-deduced flag and allow the reference type
>> to be deduced, rather than having to specify both explicitly in calls.
> Nice!
>>
>> CR:
>> https://bugs.openjdk.java.net/browse/JDK-8245022
>>
>> Webrev:
>> https://cr.openjdk.java.net/~kbarrett/8245022/open.00/
>>
> Looks good, one very small nit is the extra spaces left here:
> share/gc/parallel/psPromotionManager.hpp
> ---
>   114  protected:
>   115   static PSScannerTasksQueueSet* stack_array_depth()   { return 
> _stack_array_depth; }
> 
> They were pre-existing, but since we are touching that row, we can 
> remove those spaces that seems to be left from some old alignment.
> ---
> 

agree. Looks good.

Thomas