--- a/hotspot/src/share/vm/gc_implementation/g1/g1MarkSweep.cpp	Fri Sep 05 12:36:37 2014 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1MarkSweep.cpp	Tue Sep 09 00:05:25 2014 +0200
@@ -193,76 +193,6 @@
   gc_tracer()->report_object_count_after_gc(&GenMarkSweep::is_alive);
 }
 
-class G1PrepareCompactClosure: public HeapRegionClosure {
-  G1CollectedHeap* _g1h;
-  ModRefBarrierSet* _mrbs;
-  CompactPoint _cp;
-  HeapRegionSetCount _humongous_regions_removed;
-
-  bool is_cp_initialized() const {
-    return _cp.space != NULL;
-  }
-
-  void prepare_for_compaction(HeapRegion* hr, HeapWord* end) {
-    // If this is the first live region that we came across which we can compact,
-    // initialize the CompactPoint.
-    if (!is_cp_initialized()) {
-      _cp.space = hr;
-      _cp.threshold = hr->initialize_threshold();
-    }
-    hr->prepare_for_compaction(&_cp);
-    // Also clear the part of the card table that will be unused after
-    // compaction.
-    _mrbs->clear(MemRegion(hr->compaction_top(), end));
-  }
-
-  void free_humongous_region(HeapRegion* hr) {
-    HeapWord* end = hr->end();
-    FreeRegionList dummy_free_list("Dummy Free List for G1MarkSweep");
-
-    assert(hr->startsHumongous(),
-           "Only the start of a humongous region should be freed.");
-
-    hr->set_containing_set(NULL);
-    _humongous_regions_removed.increment(1u, hr->capacity());
-
-    _g1h->free_humongous_region(hr, &dummy_free_list, false /* par */);
-    prepare_for_compaction(hr, end);
-    dummy_free_list.remove_all();
-  }
-
-public:
-  G1PrepareCompactClosure()
-  : _g1h(G1CollectedHeap::heap()),
-    _mrbs(_g1h->g1_barrier_set()),
-    _cp(NULL),
-    _humongous_regions_removed() { }
-
-  void update_sets() {
-    // We'll recalculate total used bytes and recreate the free list
-    // at the end of the GC, so no point in updating those values here.
-    HeapRegionSetCount empty_set;
-    _g1h->remove_from_old_sets(empty_set, _humongous_regions_removed);
-  }
-
-  bool doHeapRegion(HeapRegion* hr) {
-    if (hr->isHumongous()) {
-      if (hr->startsHumongous()) {
-        oop obj = oop(hr->bottom());
-        if (obj->is_gc_marked()) {
-          obj->forward_to(obj);
-        } else  {
-          free_humongous_region(hr);
-        }
-      } else {
-        assert(hr->continuesHumongous(), "Invalid humongous.");
-      }
-    } else {
-      prepare_for_compaction(hr, hr->end());
-    }
-    return false;
-  }
-};
 
 void G1MarkSweep::mark_sweep_phase2() {
   // Now all live objects are marked, compute the new object addresses.
@@ -271,14 +201,10 @@
   // phase2, phase3 and phase4, but the ValidateMarkSweep live oops
   // tracking expects us to do so. See comment under phase4.
 
-  G1CollectedHeap* g1h = G1CollectedHeap::heap();
-
   GCTraceTime tm("phase 2", G1Log::fine() && Verbose, true, gc_timer(), gc_tracer()->gc_id());
   GenMarkSweep::trace("2");
 
-  G1PrepareCompactClosure blk;
-  g1h->heap_region_iterate(&blk);
-  blk.update_sets();
+  prepare_compaction();
 }
 
 class G1AdjustPointersClosure: public HeapRegionClosure {
@@ -373,3 +299,68 @@
   g1h->heap_region_iterate(&blk);
 
 }
+
+void G1MarkSweep::prepare_compaction_work(G1PrepareCompactClosure* blk) {
+  G1CollectedHeap* g1h = G1CollectedHeap::heap();
+  g1h->heap_region_iterate(blk);
+  blk->update_sets();
+}
+
+void G1PrepareCompactClosure::free_humongous_region(HeapRegion* hr) {
+  HeapWord* end = hr->end();
+  FreeRegionList dummy_free_list("Dummy Free List for G1MarkSweep");
+
+  assert(hr->startsHumongous(),
+         "Only the start of a humongous region should be freed.");
+
+  hr->set_containing_set(NULL);
+  _humongous_regions_removed.increment(1u, hr->capacity());
+
+  _g1h->free_humongous_region(hr, &dummy_free_list, false /* par */);
+  prepare_for_compaction(hr, end);
+  dummy_free_list.remove_all();
+}
+
+void G1PrepareCompactClosure::prepare_for_compaction(HeapRegion* hr, HeapWord* end) {
+  // If this is the first live region that we came across which we can compact,
+  // initialize the CompactPoint.
+  if (!is_cp_initialized()) {
+    _cp.space = hr;
+    _cp.threshold = hr->initialize_threshold();
+  }
+  prepare_for_compaction_work(&_cp, hr, end);
+}
+
+void G1PrepareCompactClosure::prepare_for_compaction_work(CompactPoint* cp,
+                                                          HeapRegion* hr,
+                                                          HeapWord* end) {
+  hr->prepare_for_compaction(cp);
+  // Also clear the part of the card table that will be unused after
+  // compaction.
+  _mrbs->clear(MemRegion(hr->compaction_top(), end));
+}
+
+void G1PrepareCompactClosure::update_sets() {
+  // We'll recalculate total used bytes and recreate the free list
+  // at the end of the GC, so no point in updating those values here.
+  HeapRegionSetCount empty_set;
+  _g1h->remove_from_old_sets(empty_set, _humongous_regions_removed);
+}
+
+bool G1PrepareCompactClosure::doHeapRegion(HeapRegion* hr) {
+  if (hr->isHumongous()) {
+    if (hr->startsHumongous()) {
+      oop obj = oop(hr->bottom());
+      if (obj->is_gc_marked()) {
+        obj->forward_to(obj);
+      } else  {
+        free_humongous_region(hr);
+      }
+    } else {
+      assert(hr->continuesHumongous(), "Invalid humongous.");
+    }
+  } else {
+    prepare_for_compaction(hr, hr->end());
+  }
+  return false;
+}