--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/g1BarrierSet.hpp	Tue Mar 20 04:36:44 2018 +0100
@@ -0,0 +1,107 @@
+/*
+ * Copyright (c) 2001, 2018, 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_G1BARRIERSET_HPP
+#define SHARE_VM_GC_G1_G1BARRIERSET_HPP
+
+#include "gc/shared/cardTableModRefBS.hpp"
+
+class DirtyCardQueueSet;
+class CardTable;
+class G1CardTable;
+
+// This barrier is specialized to use a logging barrier to support
+// snapshot-at-the-beginning marking.
+
+class G1BarrierSet: public CardTableModRefBS {
+  friend class VMStructs;
+ private:
+  DirtyCardQueueSet& _dcqs;
+
+ public:
+  G1BarrierSet(G1CardTable* table);
+  ~G1BarrierSet() { }
+
+  // Add "pre_val" to a set of objects that may have been disconnected from the
+  // pre-marking object graph.
+  static void enqueue(oop pre_val);
+
+  static void enqueue_if_weak_or_archive(DecoratorSet decorators, oop value);
+
+  template <class T> void write_ref_array_pre_work(T* dst, int count);
+  virtual void write_ref_array_pre(oop* dst, int count, bool dest_uninitialized);
+  virtual void write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized);
+
+  template <DecoratorSet decorators, typename T>
+  void write_ref_field_pre(T* field);
+
+  // NB: if you do a whole-heap invalidation, the "usual invariant" defined
+  // above no longer applies.
+  void invalidate(MemRegion mr);
+
+  void write_region(MemRegion mr)         { invalidate(mr); }
+  void write_ref_array_work(MemRegion mr) { invalidate(mr); }
+
+  template <DecoratorSet decorators, typename T>
+  void write_ref_field_post(T* field, oop new_val);
+  void write_ref_field_post_slow(volatile jbyte* byte);
+
+  virtual void on_thread_attach(JavaThread* thread);
+  virtual void on_thread_detach(JavaThread* thread);
+
+  // Callbacks for runtime accesses.
+  template <DecoratorSet decorators, typename BarrierSetT = G1BarrierSet>
+  class AccessBarrier: public ModRefBarrierSet::AccessBarrier<decorators, BarrierSetT> {
+    typedef ModRefBarrierSet::AccessBarrier<decorators, BarrierSetT> ModRef;
+    typedef BarrierSet::AccessBarrier<decorators, BarrierSetT> Raw;
+
+  public:
+    // Needed for loads on non-heap weak references
+    template <typename T>
+    static oop oop_load_not_in_heap(T* addr);
+
+    // Needed for non-heap stores
+    template <typename T>
+    static void oop_store_not_in_heap(T* addr, oop new_value);
+
+    // Needed for weak references
+    static oop oop_load_in_heap_at(oop base, ptrdiff_t offset);
+
+    // Defensive: will catch weak oops at addresses in heap
+    template <typename T>
+    static oop oop_load_in_heap(T* addr);
+  };
+};
+
+template<>
+struct BarrierSet::GetName<G1BarrierSet> {
+  static const BarrierSet::Name value = BarrierSet::G1BarrierSet;
+};
+
+template<>
+struct BarrierSet::GetType<BarrierSet::G1BarrierSet> {
+  typedef ::G1BarrierSet type;
+};
+
+#endif // SHARE_VM_GC_G1_G1BARRIERSET_HPP