8215297: Remove ParallelTaskTerminator

Remove ParallelTaskTerminator as the alternate OWSTTaskTerminator algorithm has worked well for more than a year now.

Reviewed-by: zgu, sjohanss

Author: Thomas Schatzl

src/hotspot/share/gc/g1/g1CollectedHeap.cpp

@@ -76,6 +76,7 @@
 #include "gc/shared/isGCActiveMark.hpp"
 #include "gc/shared/locationPrinter.inline.hpp"
 #include "gc/shared/oopStorageParState.hpp"
+#include "gc/shared/owstTaskTerminator.hpp"
 #include "gc/shared/preservedMarks.inline.hpp"
 #include "gc/shared/suspendibleThreadSet.hpp"
 #include "gc/shared/referenceProcessor.inline.hpp"
@@ -1132,7 +1133,7 @@ void G1CollectedHeap::print_heap_after_full_collection(G1HeapTransition* heap_tr
   print_heap_after_gc();
   print_heap_regions();
 #ifdef TRACESPINNING
-  ParallelTaskTerminator::print_termination_counts();
+  OWSTTaskTerminator::print_termination_counts();
 #endif
 }
 
@@ -3140,7 +3141,7 @@ void G1CollectedHeap::do_collection_pause_at_safepoint_helper(double target_paus
       verify_after_young_collection(verify_type);
 
 #ifdef TRACESPINNING
-      ParallelTaskTerminator::print_termination_counts();
+      OWSTTaskTerminator::print_termination_counts();
 #endif
 
       gc_epilogue(false);
@@ -3476,14 +3477,14 @@ class G1STWRefProcTaskProxy: public AbstractGangTask {
   G1CollectedHeap* _g1h;
   G1ParScanThreadStateSet* _pss;
   RefToScanQueueSet* _task_queues;
-  ParallelTaskTerminator* _terminator;
+  OWSTTaskTerminator* _terminator;
 
 public:
   G1STWRefProcTaskProxy(ProcessTask& proc_task,
                         G1CollectedHeap* g1h,
                         G1ParScanThreadStateSet* per_thread_states,
                         RefToScanQueueSet *task_queues,
-                        ParallelTaskTerminator* terminator) :
+                        OWSTTaskTerminator* terminator) :
     AbstractGangTask("Process reference objects in parallel"),
     _proc_task(proc_task),
     _g1h(g1h),
@@ -3527,8 +3528,8 @@ void G1STWRefProcTaskExecutor::execute(ProcessTask& proc_task, uint ergo_workers
   assert(_workers->active_workers() >= ergo_workers,
          "Ergonomically chosen workers (%u) should be less than or equal to active workers (%u)",
          ergo_workers, _workers->active_workers());
-  TaskTerminator terminator(ergo_workers, _queues);
-  G1STWRefProcTaskProxy proc_task_proxy(proc_task, _g1h, _pss, _queues, terminator.terminator());
+  OWSTTaskTerminator terminator(ergo_workers, _queues);
+  G1STWRefProcTaskProxy proc_task_proxy(proc_task, _g1h, _pss, _queues, &terminator);
 
   _workers->run_task(&proc_task_proxy, ergo_workers);
 }
@@ -3814,7 +3815,7 @@ class G1EvacuateRegionsBaseTask : public AbstractGangTask {
   G1CollectedHeap* _g1h;
   G1ParScanThreadStateSet* _per_thread_states;
   RefToScanQueueSet* _task_queues;
-  TaskTerminator _terminator;
+  OWSTTaskTerminator _terminator;
   uint _num_workers;
 
   void evacuate_live_objects(G1ParScanThreadState* pss,
@@ -3824,7 +3825,7 @@ class G1EvacuateRegionsBaseTask : public AbstractGangTask {
     G1GCPhaseTimes* p = _g1h->phase_times();
 
     Ticks start = Ticks::now();
-    G1ParEvacuateFollowersClosure cl(_g1h, pss, _task_queues, _terminator.terminator(), objcopy_phase);
+    G1ParEvacuateFollowersClosure cl(_g1h, pss, _task_queues, &_terminator, objcopy_phase);
     cl.do_void();
 
     assert(pss->queue_is_empty(), "should be empty");

src/hotspot/share/gc/g1/g1CollectedHeap.hpp

@@ -1482,18 +1482,18 @@ class G1ParEvacuateFollowersClosure : public VoidClosure {
   G1CollectedHeap*              _g1h;
   G1ParScanThreadState*         _par_scan_state;
   RefToScanQueueSet*            _queues;
-  ParallelTaskTerminator*       _terminator;
+  OWSTTaskTerminator*           _terminator;
   G1GCPhaseTimes::GCParPhases   _phase;
 
   G1ParScanThreadState*   par_scan_state() { return _par_scan_state; }
   RefToScanQueueSet*      queues()         { return _queues; }
-  ParallelTaskTerminator* terminator()     { return _terminator; }
+  OWSTTaskTerminator*     terminator()     { return _terminator; }
 
 public:
   G1ParEvacuateFollowersClosure(G1CollectedHeap* g1h,
                                 G1ParScanThreadState* par_scan_state,
                                 RefToScanQueueSet* queues,
-                                ParallelTaskTerminator* terminator,
+                                OWSTTaskTerminator* terminator,
                                 G1GCPhaseTimes::GCParPhases phase)
     : _start_term(0.0), _term_time(0.0), _term_attempts(0),
       _g1h(g1h), _par_scan_state(par_scan_state),

src/hotspot/share/gc/g1/g1ConcurrentMark.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -46,6 +46,7 @@
 #include "gc/shared/gcTraceTime.inline.hpp"
 #include "gc/shared/gcVMOperations.hpp"
 #include "gc/shared/genOopClosures.inline.hpp"
+#include "gc/shared/owstTaskTerminator.hpp"
 #include "gc/shared/referencePolicy.hpp"
 #include "gc/shared/strongRootsScope.hpp"
 #include "gc/shared/suspendibleThreadSet.hpp"
@@ -600,7 +601,7 @@ void G1ConcurrentMark::set_concurrency(uint active_tasks) {
   _num_active_tasks = active_tasks;
   // Need to update the three data structures below according to the
   // number of active threads for this phase.
-  _terminator.terminator()->reset_for_reuse((int) active_tasks);
+  _terminator.reset_for_reuse(active_tasks);
   _first_overflow_barrier_sync.set_n_workers((int) active_tasks);
   _second_overflow_barrier_sync.set_n_workers((int) active_tasks);
 }

src/hotspot/share/gc/g1/g1ConcurrentMark.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -30,6 +30,7 @@
 #include "gc/g1/g1HeapVerifier.hpp"
 #include "gc/g1/g1RegionMarkStatsCache.hpp"
 #include "gc/g1/heapRegionSet.hpp"
+#include "gc/shared/owstTaskTerminator.hpp"
 #include "gc/shared/taskqueue.hpp"
 #include "gc/shared/verifyOption.hpp"
 #include "gc/shared/workgroup.hpp"
@@ -328,7 +329,7 @@ class G1ConcurrentMark : public CHeapObj<mtGC> {
   G1CMTask**              _tasks;            // Task queue array (max_worker_id length)
 
   G1CMTaskQueueSet*       _task_queues; // Task queue set
-  TaskTerminator          _terminator;  // For termination
+  OWSTTaskTerminator      _terminator;  // For termination
 
   // Two sync barriers that are used to synchronize tasks when an
   // overflow occurs. The algorithm is the following. All tasks enter
@@ -414,10 +415,10 @@ class G1ConcurrentMark : public CHeapObj<mtGC> {
   // Prints all gathered CM-related statistics
   void print_stats();
 
-  HeapWord*               finger()           { return _finger;   }
-  bool                    concurrent()       { return _concurrent; }
-  uint                    active_tasks()     { return _num_active_tasks; }
-  ParallelTaskTerminator* terminator() const { return _terminator.terminator(); }
+  HeapWord*           finger()       { return _finger;   }
+  bool                concurrent()   { return _concurrent; }
+  uint                active_tasks() { return _num_active_tasks; }
+  OWSTTaskTerminator* terminator()   { return &_terminator; }
 
   // Claims the next available region to be scanned by a marking
   // task/thread. It might return NULL if the next region is empty or

src/hotspot/share/gc/g1/g1FullGCMarkTask.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -59,7 +59,7 @@ void G1FullGCMarkTask::work(uint worker_id) {
   }
 
   // Mark stack is populated, now process and drain it.
-  marker->complete_marking(collector()->oop_queue_set(), collector()->array_queue_set(), _terminator.terminator());
+  marker->complete_marking(collector()->oop_queue_set(), collector()->array_queue_set(), &_terminator);
 
   // This is the point where the entire marking should have completed.
   assert(marker->oop_stack()->is_empty(), "Marking should have completed");

src/hotspot/share/gc/g1/g1FullGCMarkTask.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -36,7 +36,7 @@
 
 class G1FullGCMarkTask : public G1FullGCTask {
   G1RootProcessor          _root_processor;
-  TaskTerminator           _terminator;
+  OWSTTaskTerminator       _terminator;
 
 public:
   G1FullGCMarkTask(G1FullCollector* collector);

src/hotspot/share/gc/g1/g1FullGCMarker.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,6 +25,7 @@
 #include "precompiled.hpp"
 #include "classfile/classLoaderData.hpp"
 #include "gc/g1/g1FullGCMarker.inline.hpp"
+#include "gc/shared/owstTaskTerminator.hpp"
 #include "gc/shared/referenceProcessor.hpp"
 #include "gc/shared/verifyOption.hpp"
 #include "memory/iterator.inline.hpp"
@@ -49,7 +50,7 @@ G1FullGCMarker::~G1FullGCMarker() {
 
 void G1FullGCMarker::complete_marking(OopQueueSet* oop_stacks,
                                       ObjArrayTaskQueueSet* array_stacks,
-                                      ParallelTaskTerminator* terminator) {
+                                      OWSTTaskTerminator* terminator) {
   do {
     drain_stack();
     ObjArrayTask steal_array;

src/hotspot/share/gc/g1/g1FullGCMarker.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -87,7 +87,7 @@ class G1FullGCMarker : public CHeapObj<mtGC> {
   inline void drain_stack();
   void complete_marking(OopQueueSet* oop_stacks,
                         ObjArrayTaskQueueSet* array_stacks,
-                        ParallelTaskTerminator* terminator);
+                        OWSTTaskTerminator* terminator);
 
   // Closure getters
   CLDToOopClosure*      cld_closure()   { return &_cld_closure; }

src/hotspot/share/gc/g1/g1FullGCReferenceProcessorExecutor.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -61,7 +61,7 @@ class G1FullGCReferenceProcessingExecutor: public AbstractRefProcTaskExecutor {
     typedef AbstractRefProcTaskExecutor::ProcessTask ProcessTask;
     ProcessTask&                  _proc_task;
     G1FullCollector*              _collector;
-    TaskTerminator                _terminator;
+    OWSTTaskTerminator            _terminator;
 
   public:
     G1RefProcTaskProxy(ProcessTask& proc_task,

src/hotspot/share/gc/parallel/psCompactionManager.hpp

@@ -38,7 +38,6 @@ class ParallelCompactData;
 class ParMarkBitMap;
 
 class ParCompactionManager : public CHeapObj<mtGC> {
-  friend class ParallelTaskTerminator;
   friend class ParMarkBitMap;
   friend class PSParallelCompact;
   friend class CompactionWithStealingTask;
@@ -96,7 +95,7 @@ class ParCompactionManager : public CHeapObj<mtGC> {
   static void initialize(ParMarkBitMap* mbm);
 
  protected:
-  // Array of tasks.  Needed by the ParallelTaskTerminator.
+  // Array of task queues.  Needed by the task terminator.
   static RegionTaskQueueSet* region_array()      { return _region_array; }
   OverflowTaskQueue<oop, mtGC>*  marking_stack()       { return &_marking_stack; }
 

src/hotspot/share/gc/parallel/psParallelCompact.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -49,6 +49,7 @@
 #include "gc/shared/gcTrace.hpp"
 #include "gc/shared/gcTraceTime.inline.hpp"
 #include "gc/shared/isGCActiveMark.hpp"
+#include "gc/shared/owstTaskTerminator.hpp"
 #include "gc/shared/referencePolicy.hpp"
 #include "gc/shared/referenceProcessor.hpp"
 #include "gc/shared/referenceProcessorPhaseTimes.hpp"
@@ -1969,7 +1970,7 @@ bool PSParallelCompact::invoke_no_policy(bool maximum_heap_compaction) {
                          collection_exit.ticks());
 
 #ifdef TRACESPINNING
-  ParallelTaskTerminator::print_termination_counts();
+  OWSTTaskTerminator::print_termination_counts();
 #endif
 
   AdaptiveSizePolicyOutput::print(size_policy, heap->total_collections());
@@ -2149,7 +2150,7 @@ static void mark_from_roots_work(ParallelRootType::Value root_type, uint worker_
   cm->follow_marking_stacks();
 }
 
-static void steal_marking_work(ParallelTaskTerminator& terminator, uint worker_id) {
+static void steal_marking_work(OWSTTaskTerminator& terminator, uint worker_id) {
   assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");
 
   ParCompactionManager* cm =
@@ -2173,7 +2174,7 @@ class MarkFromRootsTask : public AbstractGangTask {
   typedef AbstractRefProcTaskExecutor::ProcessTask ProcessTask;
   StrongRootsScope _strong_roots_scope; // needed for Threads::possibly_parallel_threads_do
   SequentialSubTasksDone _subtasks;
-  TaskTerminator _terminator;
+  OWSTTaskTerminator _terminator;
   uint _active_workers;
 
 public:
@@ -2197,7 +2198,7 @@ class MarkFromRootsTask : public AbstractGangTask {
     Threads::possibly_parallel_threads_do(true /*parallel */, &closure);
 
     if (_active_workers > 1) {
-      steal_marking_work(*_terminator.terminator(), worker_id);
+      steal_marking_work(_terminator, worker_id);
     }
   }
 };
@@ -2206,7 +2207,7 @@ class PCRefProcTask : public AbstractGangTask {
   typedef AbstractRefProcTaskExecutor::ProcessTask ProcessTask;
   ProcessTask& _task;
   uint _ergo_workers;
-  TaskTerminator _terminator;
+  OWSTTaskTerminator _terminator;
 
 public:
   PCRefProcTask(ProcessTask& task, uint ergo_workers) :
@@ -2227,7 +2228,7 @@ class PCRefProcTask : public AbstractGangTask {
     _task.work(worker_id, *PSParallelCompact::is_alive_closure(),
                mark_and_push_closure, follow_stack_closure);
 
-    steal_marking_work(*_terminator.terminator(), worker_id);
+    steal_marking_work(_terminator, worker_id);
   }
 };
 
@@ -2586,7 +2587,7 @@ void PSParallelCompact::write_block_fill_histogram()
 }
 #endif // #ifdef ASSERT
 
-static void compaction_with_stealing_work(ParallelTaskTerminator* terminator, uint worker_id) {
+static void compaction_with_stealing_work(OWSTTaskTerminator* terminator, uint worker_id) {
   assert(ParallelScavengeHeap::heap()->is_gc_active(), "called outside gc");
 
   ParCompactionManager* cm =
@@ -2622,7 +2623,7 @@ static void compaction_with_stealing_work(ParallelTaskTerminator* terminator, ui
 class UpdateDensePrefixAndCompactionTask: public AbstractGangTask {
   typedef AbstractRefProcTaskExecutor::ProcessTask ProcessTask;
   TaskQueue& _tq;
-  TaskTerminator _terminator;
+  OWSTTaskTerminator _terminator;
   uint _active_workers;
 
 public:
@@ -2644,7 +2645,7 @@ class UpdateDensePrefixAndCompactionTask: public AbstractGangTask {
 
     // Once a thread has drained it's stack, it should try to steal regions from
     // other threads.
-    compaction_with_stealing_work(_terminator.terminator(), worker_id);
+    compaction_with_stealing_work(&_terminator, worker_id);
   }
 };
 

src/hotspot/share/gc/parallel/psParallelCompact.hpp

@@ -40,9 +40,7 @@ class PSAdaptiveSizePolicy;
 class PSYoungGen;
 class PSOldGen;
 class ParCompactionManager;
-class ParallelTaskTerminator;
 class PSParallelCompact;
-class PreGCValues;
 class MoveAndUpdateClosure;
 class RefProcTaskExecutor;
 class ParallelOldTracer;