diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/hotspot/share/gc/shared/cardGeneration.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/shared/cardGeneration.hpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2014, 2015, 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_SHARED_CARDGENERATION_HPP
+#define SHARE_VM_GC_SHARED_CARDGENERATION_HPP
+
+// Class CardGeneration is a generation that is covered by a card table,
+// and uses a card-size block-offset array to implement block_start.
+
+#include "gc/shared/generation.hpp"
+
+class BlockOffsetSharedArray;
+class CompactibleSpace;
+
+class CardGeneration: public Generation {
+  friend class VMStructs;
+ protected:
+  // This is shared with other generations.
+  CardTableRS* _rs;
+  // This is local to this generation.
+  BlockOffsetSharedArray* _bts;
+
+  // Current shrinking effect: this damps shrinking when the heap gets empty.
+  size_t _shrink_factor;
+
+  size_t _min_heap_delta_bytes;   // Minimum amount to expand.
+
+  // Some statistics from before gc started.
+  // These are gathered in the gc_prologue (and should_collect)
+  // to control growing/shrinking policy in spite of promotions.
+  size_t _capacity_at_prologue;
+  size_t _used_at_prologue;
+
+  CardGeneration(ReservedSpace rs, size_t initial_byte_size, CardTableRS* remset);
+
+  virtual void assert_correct_size_change_locking() = 0;
+
+  virtual CompactibleSpace* space() const = 0;
+
+ public:
+
+  // Attempt to expand the generation by "bytes".  Expand by at a
+  // minimum "expand_bytes".  Return true if some amount (not
+  // necessarily the full "bytes") was done.
+  virtual bool expand(size_t bytes, size_t expand_bytes);
+
+  // Shrink generation with specified size
+  virtual void shrink(size_t bytes);
+
+  virtual void compute_new_size();
+
+  virtual void clear_remembered_set();
+
+  virtual void invalidate_remembered_set();
+
+  virtual void prepare_for_verify();
+
+  // Grow generation with specified size (returns false if unable to grow)
+  bool grow_by(size_t bytes);
+  // Grow generation to reserved size.
+  bool grow_to_reserved();
+
+  size_t capacity() const;
+  size_t used() const;
+  size_t free() const;
+  MemRegion used_region() const;
+
+  void space_iterate(SpaceClosure* blk, bool usedOnly = false);
+
+  void younger_refs_iterate(OopsInGenClosure* blk, uint n_threads);
+
+  bool is_in(const void* p) const;
+
+  CompactibleSpace* first_compaction_space() const;
+};
+
+#endif // SHARE_VM_GC_SHARED_CARDGENERATION_HPP