--- old/src/share/vm/gc/g1/g1ConcurrentMark.cpp	2017-03-21 16:20:13.690067297 -0400
+++ new/src/share/vm/gc/g1/g1ConcurrentMark.cpp	2017-03-21 16:20:12.461996350 -0400
@@ -646,7 +646,7 @@
   ShouldNotReachHere();
 }
 
-class G1ClearBitMapTask : public AbstractGangTask {
+class G1ClearBitMapTask : public G1ParallelizeByRegionsTask {
 public:
   static size_t chunk_size() { return M; }
 
@@ -690,20 +690,18 @@
   };
 
   G1ClearBitmapHRClosure _cl;
-  HeapRegionClaimer _hr_claimer;
   bool _suspendible; // If the task is suspendible, workers must join the STS.
 
 public:
   G1ClearBitMapTask(G1CMBitMap* bitmap, G1ConcurrentMark* cm, uint n_workers, bool suspendible) :
-    AbstractGangTask("G1 Clear Bitmap"),
+    G1ParallelizeByRegionsTask("G1 Clear Bitmap", n_workers),
     _cl(bitmap, suspendible ? cm : NULL),
-    _hr_claimer(n_workers),
     _suspendible(suspendible)
   { }
 
   void work(uint worker_id) {
     SuspendibleThreadSetJoiner sts_join(_suspendible);
-    G1CollectedHeap::heap()->heap_region_par_iterate(&_cl, worker_id, &_hr_claimer, true);
+    all_heap_regions_work(&_cl, worker_id, true);
   }
 
   bool is_complete() {
@@ -1175,65 +1173,62 @@
   _gc_tracer_cm->report_object_count_after_gc(&is_alive);
 }
 
-class G1NoteEndOfConcMarkClosure : public HeapRegionClosure {
-  G1CollectedHeap* _g1;
-  size_t _freed_bytes;
-  FreeRegionList* _local_cleanup_list;
-  uint _old_regions_removed;
-  uint _humongous_regions_removed;
-  HRRSCleanupTask* _hrrs_cleanup_task;
+class G1ParNoteEndTask: public G1ParallelizeByRegionsTask {
+  class G1NoteEndOfConcMarkClosure : public HeapRegionClosure {
+    G1CollectedHeap* _g1;
+    size_t _freed_bytes;
+    FreeRegionList* _local_cleanup_list;
+    uint _old_regions_removed;
+    uint _humongous_regions_removed;
+    HRRSCleanupTask* _hrrs_cleanup_task;
 
-public:
-  G1NoteEndOfConcMarkClosure(G1CollectedHeap* g1,
-                             FreeRegionList* local_cleanup_list,
-                             HRRSCleanupTask* hrrs_cleanup_task) :
-    _g1(g1),
-    _freed_bytes(0),
-    _local_cleanup_list(local_cleanup_list),
-    _old_regions_removed(0),
-    _humongous_regions_removed(0),
-    _hrrs_cleanup_task(hrrs_cleanup_task) { }
-
-  size_t freed_bytes() { return _freed_bytes; }
-  const uint old_regions_removed() { return _old_regions_removed; }
-  const uint humongous_regions_removed() { return _humongous_regions_removed; }
-
-  bool doHeapRegion(HeapRegion *hr) {
-    if (hr->is_archive()) {
-      return false;
-    }
-    _g1->reset_gc_time_stamps(hr);
-    hr->note_end_of_marking();
+  public:
+    G1NoteEndOfConcMarkClosure(G1CollectedHeap* g1,
+                               FreeRegionList* local_cleanup_list,
+                               HRRSCleanupTask* hrrs_cleanup_task) :
+      _g1(g1),
+      _freed_bytes(0),
+      _local_cleanup_list(local_cleanup_list),
+      _old_regions_removed(0),
+      _humongous_regions_removed(0),
+      _hrrs_cleanup_task(hrrs_cleanup_task) { }
+
+    size_t freed_bytes() { return _freed_bytes; }
+    const uint old_regions_removed() { return _old_regions_removed; }
+    const uint humongous_regions_removed() { return _humongous_regions_removed; }
+
+    bool doHeapRegion(HeapRegion *hr) {
+      if (hr->is_archive()) {
+        return false;
+      }
+      _g1->reset_gc_time_stamps(hr);
+      hr->note_end_of_marking();
 
-    if (hr->used() > 0 && hr->max_live_bytes() == 0 && !hr->is_young()) {
-      _freed_bytes += hr->used();
-      hr->set_containing_set(NULL);
-      if (hr->is_humongous()) {
-        _humongous_regions_removed++;
-        _g1->free_humongous_region(hr, _local_cleanup_list, true /* skip_remset */);
+      if (hr->used() > 0 && hr->max_live_bytes() == 0 && !hr->is_young()) {
+        _freed_bytes += hr->used();
+        hr->set_containing_set(NULL);
+        if (hr->is_humongous()) {
+          _humongous_regions_removed++;
+          _g1->free_humongous_region(hr, _local_cleanup_list, true /* skip_remset */);
+        } else {
+          _old_regions_removed++;
+          _g1->free_region(hr, _local_cleanup_list, true /* skip_remset */);
+        }
       } else {
-        _old_regions_removed++;
-        _g1->free_region(hr, _local_cleanup_list, true /* skip_remset */);
+        hr->rem_set()->do_cleanup_work(_hrrs_cleanup_task);
       }
-    } else {
-      hr->rem_set()->do_cleanup_work(_hrrs_cleanup_task);
-    }
 
-    return false;
-  }
-};
-
-class G1ParNoteEndTask: public AbstractGangTask {
-  friend class G1NoteEndOfConcMarkClosure;
+      return false;
+    }
+  };
 
 protected:
   G1CollectedHeap* _g1h;
   FreeRegionList* _cleanup_list;
-  HeapRegionClaimer _hrclaimer;
 
 public:
   G1ParNoteEndTask(G1CollectedHeap* g1h, FreeRegionList* cleanup_list, uint n_workers) :
-      AbstractGangTask("G1 note end"), _g1h(g1h), _cleanup_list(cleanup_list), _hrclaimer(n_workers) {
+      G1ParallelizeByRegionsTask("G1 note end", n_workers), _g1h(g1h), _cleanup_list(cleanup_list) {
   }
 
   void work(uint worker_id) {
@@ -1241,7 +1236,7 @@
     HRRSCleanupTask hrrs_cleanup_task;
     G1NoteEndOfConcMarkClosure g1_note_end(_g1h, &local_cleanup_list,
                                            &hrrs_cleanup_task);
-    _g1h->heap_region_par_iterate(&g1_note_end, worker_id, &_hrclaimer);
+    all_heap_regions_work(&g1_note_end, worker_id );
     assert(g1_note_end.complete(), "Shouldn't have yielded!");
 
     // Now update the lists