RFR: Cleanup UseShenandoahOWST blocks

[Roman Kennke]

> 
> On 07/09/2018 05:12 AM, Roman Kennke wrote:
>> Looks good, thank you!
>>
>> We should soon consider to go for OWST by default. It's baked long
>> enough. The only thing to wait for is current upstreaming efforts by
>> Zhengyu, at which point we can just use upstreams TQ stuff.
> 
> Looks like that Thomas Schatzl is playing it. He mentioned that he ran
> into unexplainable hung with source code we probably don't know about.

Hmm. That might be related to TQs stuff, or maybe not. 1. I've seen an
upstream bug (but don't remember what it was) about a freeze. 2. What
you're upstreaming is not what we have in Shenandoah, right?

Thanks, Roman

> 
> -Zhengyu
> 
>>
>> Roman
>>
>>
>>> This applies a few trivial cleanups around UseShenandoahOWST blocks.
>>> Mostly renames "*_task" ->
>>> task, and cleaning up useless UseShenandoahOWST in
>>> ShenandoahTraversalGC::init_traversal_collection:
>>>
>>> diff -r fde9a873d896
>>> src/hotspot/share/gc/shenandoah/shenandoahConcurrentMark.cpp
>>> --- a/src/hotspot/share/gc/shenandoah/shenandoahConcurrentMark.cpp   
>>> Mon Jul 09 10:29:38 2018 +0200
>>> +++ b/src/hotspot/share/gc/shenandoah/shenandoahConcurrentMark.cpp   
>>> Mon Jul 09 10:34:32 2018 +0200
>>> @@ -419,16 +419,16 @@
>>>
>>>     task_queues()->reserve(nworkers);
>>>
>>>     if (UseShenandoahOWST) {
>>>       ShenandoahTaskTerminator terminator(nworkers, task_queues());
>>> -    ShenandoahConcurrentMarkingTask markingTask =
>>> ShenandoahConcurrentMarkingTask(this,
>>> &terminator, update_refs);
>>> -    workers->run_task(&markingTask);
>>> +    ShenandoahConcurrentMarkingTask task(this, &terminator,
>>> update_refs);
>>> +    workers->run_task(&task);
>>>     } else {
>>>       ParallelTaskTerminator terminator(nworkers, task_queues());
>>> -    ShenandoahConcurrentMarkingTask markingTask =
>>> ShenandoahConcurrentMarkingTask(this,
>>> &terminator, update_refs);
>>> -    workers->run_task(&markingTask);
>>> +    ShenandoahConcurrentMarkingTask task(this, &terminator,
>>> update_refs);
>>> +    workers->run_task(&task);
>>>     }
>>>
>>>     assert(task_queues()->is_empty() || sh->cancelled_gc(), "Should
>>> be empty when not cancelled");
>>>   }
>>>
>>> diff -r fde9a873d896
>>> src/hotspot/share/gc/shenandoah/shenandoahTraversalGC.cpp
>>> --- a/src/hotspot/share/gc/shenandoah/shenandoahTraversalGC.cpp   
>>> Mon Jul 09 10:29:38 2018 +0200
>>> +++ b/src/hotspot/share/gc/shenandoah/shenandoahTraversalGC.cpp   
>>> Mon Jul 09 10:34:32 2018 +0200
>>> @@ -417,19 +417,12 @@
>>>       {
>>>         uint nworkers = _heap->workers()->active_workers();
>>>         task_queues()->reserve(nworkers);
>>>         ShenandoahRootProcessor rp(_heap, nworkers,
>>> ShenandoahPhaseTimings::init_traversal_gc_work);
>>>
>>> -      if (UseShenandoahOWST) {
>>> -        ShenandoahTaskTerminator terminator(nworkers, task_queues());
>>> -        ShenandoahInitTraversalCollectionTask traversal_task(&rp);
>>> -        _heap->workers()->run_task(&traversal_task);
>>> -      } else {
>>> -        ParallelTaskTerminator terminator(nworkers, task_queues());
>>> -        ShenandoahInitTraversalCollectionTask traversal_task(&rp);
>>> -        _heap->workers()->run_task(&traversal_task);
>>> -      }
>>> +      ShenandoahInitTraversalCollectionTask traversal_task(&rp);
>>> +      _heap->workers()->run_task(&traversal_task);
>>>       }
>>>
>>>   #if defined(COMPILER2) || INCLUDE_JVMCI
>>>       DerivedPointerTable::update_pointers();
>>>   #endif
>>> @@ -641,16 +634,16 @@
>>>     if (!_heap->cancelled_gc()) {
>>>       uint nworkers = _heap->workers()->active_workers();
>>>       task_queues()->reserve(nworkers);
>>>       if (UseShenandoahOWST) {
>>>         ShenandoahTaskTerminator terminator(nworkers, task_queues());
>>> -      ShenandoahConcurrentTraversalCollectionTask
>>> traversal_task(&terminator);
>>> -      _heap->workers()->run_task(&traversal_task);
>>> +      ShenandoahConcurrentTraversalCollectionTask task(&terminator);
>>> +      _heap->workers()->run_task(&task);
>>>       } else {
>>>         ParallelTaskTerminator terminator(nworkers, task_queues());
>>> -      ShenandoahConcurrentTraversalCollectionTask
>>> traversal_task(&terminator);
>>> -      _heap->workers()->run_task(&traversal_task);
>>> +      ShenandoahConcurrentTraversalCollectionTask task(&terminator);
>>> +      _heap->workers()->run_task(&task);
>>>       }
>>>     }
>>>
>>>     if (!_heap->cancelled_gc() && ShenandoahPreclean &&
>>> _heap->process_references()) {
>>>       ShenandoahEvacOOMScope oom_evac_scope;
>>> @@ -672,16 +665,16 @@
>>>
>>>       // Finish traversal
>>>       ShenandoahRootProcessor rp(_heap, nworkers,
>>> ShenandoahPhaseTimings::final_traversal_gc_work);
>>>       if (UseShenandoahOWST) {
>>>         ShenandoahTaskTerminator terminator(nworkers, task_queues());
>>> -      ShenandoahFinalTraversalCollectionTask traversal_task(&rp,
>>> &terminator);
>>> -      _heap->workers()->run_task(&traversal_task);
>>> +      ShenandoahFinalTraversalCollectionTask task(&rp, &terminator);
>>> +      _heap->workers()->run_task(&task);
>>>       } else {
>>>         ParallelTaskTerminator terminator(nworkers, task_queues());
>>> -      ShenandoahFinalTraversalCollectionTask traversal_task(&rp,
>>> &terminator);
>>> -      _heap->workers()->run_task(&traversal_task);
>>> +      ShenandoahFinalTraversalCollectionTask task(&rp, &terminator);
>>> +      _heap->workers()->run_task(&task);
>>>       }
>>>   #if defined(COMPILER2) || INCLUDE_JVMCI
>>>       DerivedPointerTable::update_pointers();
>>>   #endif
>>>     }
>>>
>>>
>>> Testing: tier1_gc_shenandoah
>>>
>>> Thanks,
>>> -Aleksey
>>>
>>
>>