--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/g1ConcurrentMarkBitMap.hpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,128 @@
+/*
+ * Copyright (c) 2017, 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_G1CONCURRENTMARKBITMAP_HPP
+#define SHARE_VM_GC_G1_G1CONCURRENTMARKBITMAP_HPP
+
+#include "gc/g1/g1RegionToSpaceMapper.hpp"
+#include "memory/allocation.hpp"
+#include "memory/memRegion.hpp"
+#include "utilities/bitMap.hpp"
+#include "utilities/globalDefinitions.hpp"
+#include "utilities/macros.hpp"
+
+class G1CMBitMap;
+class G1CMTask;
+class G1ConcurrentMark;
+
+// Closure for iteration over bitmaps
+class G1CMBitMapClosure VALUE_OBJ_CLASS_SPEC {
+private:
+  G1ConcurrentMark* const _cm;
+  G1CMTask* const _task;
+public:
+  G1CMBitMapClosure(G1CMTask *task, G1ConcurrentMark* cm) : _task(task), _cm(cm) { }
+
+  bool do_addr(HeapWord* const addr);
+};
+
+class G1CMBitMapMappingChangedListener : public G1MappingChangedListener {
+ private:
+  G1CMBitMap* _bm;
+ public:
+  G1CMBitMapMappingChangedListener() : _bm(NULL) {}
+
+  void set_bitmap(G1CMBitMap* bm) { _bm = bm; }
+
+  virtual void on_commit(uint start_idx, size_t num_regions, bool zero_filled);
+};
+
+// A generic mark bitmap for concurrent marking.  This is essentially a wrapper
+// around the BitMap class that is based on HeapWords, with one bit per (1 << _shifter) HeapWords.
+class G1CMBitMap VALUE_OBJ_CLASS_SPEC {
+private:
+  MemRegion _covered;    // The heap area covered by this bitmap.
+
+  const int _shifter;    // Shift amount from heap index to bit index in the bitmap.
+
+  BitMapView _bm;        // The actual bitmap.
+
+  G1CMBitMapMappingChangedListener _listener;
+
+  inline void check_mark(HeapWord* addr) NOT_DEBUG_RETURN;
+
+  // Convert from bit offset to address.
+  HeapWord* offset_to_addr(size_t offset) const {
+    return _covered.start() + (offset << _shifter);
+  }
+  // Convert from address to bit offset.
+  size_t addr_to_offset(const HeapWord* addr) const {
+    return pointer_delta(addr, _covered.start()) >> _shifter;
+  }
+public:
+  static size_t compute_size(size_t heap_size);
+  // Returns the amount of bytes on the heap between two marks in the bitmap.
+  static size_t mark_distance();
+  // Returns how many bytes (or bits) of the heap a single byte (or bit) of the
+  // mark bitmap corresponds to. This is the same as the mark distance above.
+  static size_t heap_map_factor() {
+    return mark_distance();
+  }
+
+  G1CMBitMap() : _covered(), _bm(), _shifter(LogMinObjAlignment), _listener() { _listener.set_bitmap(this); }
+
+  // Initializes the underlying BitMap to cover the given area.
+  void initialize(MemRegion heap, G1RegionToSpaceMapper* storage);
+
+  // Read marks
+  bool is_marked(HeapWord* addr) const {
+    assert(_covered.contains(addr),
+           "Address " PTR_FORMAT " is outside underlying space from " PTR_FORMAT " to " PTR_FORMAT,
+           p2i(addr), p2i(_covered.start()), p2i(_covered.end()));
+    return _bm.at(addr_to_offset(addr));
+  }
+
+  // Apply the closure to the addresses that correspond to marked bits in the bitmap.
+  inline bool iterate(G1CMBitMapClosure* cl, MemRegion mr);
+
+  // Return the address corresponding to the next marked bit at or after
+  // "addr", and before "limit", if "limit" is non-NULL.  If there is no
+  // such bit, returns "limit" if that is non-NULL, or else "endWord()".
+  inline HeapWord* get_next_marked_addr(const HeapWord* addr,
+                                        const HeapWord* limit) const;
+
+  // The argument addr should be the start address of a valid object
+  inline HeapWord* addr_after_obj(HeapWord* addr);
+
+  void print_on_error(outputStream* st, const char* prefix) const;
+
+  // Write marks.
+  inline void mark(HeapWord* addr);
+  inline void clear(HeapWord* addr);
+  inline bool par_mark(HeapWord* addr);
+
+  void clear_range(MemRegion mr);
+};
+
+#endif // SHARE_VM_GC_G1_G1CONCURRENTMARKBITMAP_HPP