diff -r 34c2f89c8ebb -r 5451ff646f8e hotspot/src/share/vm/gc/g1/g1HeapVerifier.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc/g1/g1HeapVerifier.hpp	Tue Jan 26 15:28:31 2016 +0100
@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_GC_G1_G1HEAPVERIFIER_HPP
+#define SHARE_VM_GC_G1_G1HEAPVERIFIER_HPP
+
+#include "gc/g1/heapRegionSet.hpp"
+#include "memory/allocation.hpp"
+#include "memory/universe.hpp"
+
+class G1CollectedHeap;
+
+class G1HeapVerifier : public CHeapObj<mtGC> {
+private:
+  G1CollectedHeap* _g1h;
+
+  // verify_region_sets() performs verification over the region
+  // lists. It will be compiled in the product code to be used when
+  // necessary (i.e., during heap verification).
+  void verify_region_sets();
+
+public:
+
+  G1HeapVerifier(G1CollectedHeap* heap) : _g1h(heap) { }
+
+  // Perform verification.
+
+  // vo == UsePrevMarking  -> use "prev" marking information,
+  // vo == UseNextMarking -> use "next" marking information
+  // vo == UseMarkWord    -> use the mark word in the object header
+  //
+  // NOTE: Only the "prev" marking information is guaranteed to be
+  // consistent most of the time, so most calls to this should use
+  // vo == UsePrevMarking.
+  // Currently, there is only one case where this is called with
+  // vo == UseNextMarking, which is to verify the "next" marking
+  // information at the end of remark.
+  // Currently there is only one place where this is called with
+  // vo == UseMarkWord, which is to verify the marking during a
+  // full GC.
+  void verify(VerifyOption vo);
+
+  // verify_region_sets_optional() is planted in the code for
+  // list verification in non-product builds (and it can be enabled in
+  // product builds by defining HEAP_REGION_SET_FORCE_VERIFY to be 1).
+#if HEAP_REGION_SET_FORCE_VERIFY
+  void verify_region_sets_optional() {
+    verify_region_sets();
+  }
+#else // HEAP_REGION_SET_FORCE_VERIFY
+  void verify_region_sets_optional() { }
+#endif // HEAP_REGION_SET_FORCE_VERIFY
+
+  void prepare_for_verify();
+  double verify(bool guard, const char* msg);
+  void verify_before_gc();
+  void verify_after_gc();
+
+#ifndef PRODUCT
+  // Make sure that the given bitmap has no marked objects in the
+  // range [from,limit). If it does, print an error message and return
+  // false. Otherwise, just return true. bitmap_name should be "prev"
+  // or "next".
+  bool verify_no_bits_over_tams(const char* bitmap_name, CMBitMapRO* bitmap,
+                                HeapWord* from, HeapWord* limit);
+
+  // Verify that the prev / next bitmap range [tams,end) for the given
+  // region has no marks. Return true if all is well, false if errors
+  // are detected.
+  bool verify_bitmaps(const char* caller, HeapRegion* hr);
+#endif // PRODUCT
+
+  // If G1VerifyBitmaps is set, verify that the marking bitmaps for
+  // the given region do not have any spurious marks. If errors are
+  // detected, print appropriate error messages and crash.
+  void check_bitmaps(const char* caller, HeapRegion* hr) PRODUCT_RETURN;
+
+  // If G1VerifyBitmaps is set, verify that the marking bitmaps do not
+  // have any spurious marks. If errors are detected, print
+  // appropriate error messages and crash.
+  void check_bitmaps(const char* caller) PRODUCT_RETURN;
+
+  // Do sanity check on the contents of the in-cset fast test table.
+  bool check_cset_fast_test() PRODUCT_RETURN_( return true; );
+
+  void verify_card_table_cleanup() PRODUCT_RETURN;
+
+  void verify_not_dirty_region(HeapRegion* hr) PRODUCT_RETURN;
+  void verify_dirty_region(HeapRegion* hr) PRODUCT_RETURN;
+  void verify_dirty_young_list(HeapRegion* head) PRODUCT_RETURN;
+  void verify_dirty_young_regions() PRODUCT_RETURN;
+};
+
+#endif // SHARE_VM_GC_G1_G1HEAPVERIFIER_HPP