RFR: Cleanup UseShenandoahOWST blocks

[Aleksey Shipilev]

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