--- old/src/share/vm/gc/g1/heapRegionManager.cpp	2016-09-19 12:11:35.806310066 +0200
+++ new/src/share/vm/gc/g1/heapRegionManager.cpp	2016-09-19 12:11:35.702310061 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2016, 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
@@ -481,8 +481,9 @@
 HeapRegionClaimer::HeapRegionClaimer(uint n_workers) :
     _n_workers(n_workers), _n_regions(G1CollectedHeap::heap()->_hrm._allocated_heapregions_length), _claims(NULL) {
   assert(n_workers > 0, "Need at least one worker.");
-  _claims = NEW_C_HEAP_ARRAY(uint, _n_regions, mtGC);
-  memset(_claims, Unclaimed, sizeof(*_claims) * _n_regions);
+  uint* new_claims = NEW_C_HEAP_ARRAY(uint, _n_regions, mtGC);
+  memset(new_claims, Unclaimed, sizeof(*_claims) * _n_regions);
+  _claims = new_claims;
 }
 
 HeapRegionClaimer::~HeapRegionClaimer() {
--- old/src/share/vm/gc/g1/heapRegionManager.hpp	2016-09-19 12:11:36.566310099 +0200
+++ new/src/share/vm/gc/g1/heapRegionManager.hpp	2016-09-19 12:11:36.462310095 +0200
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2016, 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
@@ -258,9 +258,9 @@
 // The HeapRegionClaimer is used during parallel iteration over heap regions,
 // allowing workers to claim heap regions, gaining exclusive rights to these regions.
 class HeapRegionClaimer : public StackObj {
-  uint  _n_workers;
-  uint  _n_regions;
-  uint* _claims;
+  uint           _n_workers;
+  uint           _n_regions;
+  volatile uint* _claims;
 
   static const uint Unclaimed = 0;
   static const uint Claimed   = 1;
@@ -284,4 +284,3 @@
   bool claim_region(uint region_index);
 };
 #endif // SHARE_VM_GC_G1_HEAPREGIONMANAGER_HPP
-