diff -r 000000000000 -r f90c822e73f8 src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.hpp	Wed Apr 27 01:25:04 2016 +0800
@@ -0,0 +1,172 @@
+/*
+ * Copyright (c) 2001, 2013, 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_IMPLEMENTATION_G1_G1SATBCARDTABLEMODREFBS_HPP
+#define SHARE_VM_GC_IMPLEMENTATION_G1_G1SATBCARDTABLEMODREFBS_HPP
+
+#include "memory/cardTableModRefBS.hpp"
+#include "memory/memRegion.hpp"
+#include "oops/oop.inline.hpp"
+#include "utilities/macros.hpp"
+
+#if INCLUDE_ALL_GCS
+
+class DirtyCardQueueSet;
+
+// This barrier is specialized to use a logging barrier to support
+// snapshot-at-the-beginning marking.
+
+class G1SATBCardTableModRefBS: public CardTableModRefBSForCTRS {
+protected:
+  enum G1CardValues {
+    g1_young_gen = CT_MR_BS_last_reserved << 1
+  };
+
+public:
+  static int g1_young_card_val()   { return g1_young_gen; }
+
+  // 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);
+
+  G1SATBCardTableModRefBS(MemRegion whole_heap,
+                          int max_covered_regions);
+
+  bool is_a(BarrierSet::Name bsn) {
+    return bsn == BarrierSet::G1SATBCT || CardTableModRefBS::is_a(bsn);
+  }
+
+  virtual bool has_write_ref_pre_barrier() { return true; }
+
+  // This notes that we don't need to access any BarrierSet data
+  // structures, so this can be called from a static context.
+  template <class T> static void write_ref_field_pre_static(T* field, oop newVal) {
+    T heap_oop = oopDesc::load_heap_oop(field);
+    if (!oopDesc::is_null(heap_oop)) {
+      enqueue(oopDesc::decode_heap_oop(heap_oop));
+    }
+  }
+
+  // We export this to make it available in cases where the static
+  // type of the barrier set is known.  Note that it is non-virtual.
+  template <class T> inline void inline_write_ref_field_pre(T* field, oop newVal) {
+    write_ref_field_pre_static(field, newVal);
+  }
+
+  // These are the more general virtual versions.
+  virtual void write_ref_field_pre_work(oop* field, oop new_val) {
+    inline_write_ref_field_pre(field, new_val);
+  }
+  virtual void write_ref_field_pre_work(narrowOop* field, oop new_val) {
+    inline_write_ref_field_pre(field, new_val);
+  }
+  virtual void write_ref_field_pre_work(void* field, oop new_val) {
+    guarantee(false, "Not needed");
+  }
+
+  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) {
+    if (!dest_uninitialized) {
+      write_ref_array_pre_work(dst, count);
+    }
+  }
+  virtual void write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized) {
+    if (!dest_uninitialized) {
+      write_ref_array_pre_work(dst, count);
+    }
+  }
+
+/*
+   Claimed and deferred bits are used together in G1 during the evacuation
+   pause. These bits can have the following state transitions:
+   1. The claimed bit can be put over any other card state. Except that
+      the "dirty -> dirty and claimed" transition is checked for in
+      G1 code and is not used.
+   2. Deferred bit can be set only if the previous state of the card
+      was either clean or claimed. mark_card_deferred() is wait-free.
+      We do not care if the operation is be successful because if
+      it does not it will only result in duplicate entry in the update
+      buffer because of the "cache-miss". So it's not worth spinning.
+ */
+
+  bool is_card_claimed(size_t card_index) {
+    jbyte val = _byte_map[card_index];
+    return (val & (clean_card_mask_val() | claimed_card_val())) == claimed_card_val();
+  }
+
+  void set_card_claimed(size_t card_index) {
+      jbyte val = _byte_map[card_index];
+      if (val == clean_card_val()) {
+        val = (jbyte)claimed_card_val();
+      } else {
+        val |= (jbyte)claimed_card_val();
+      }
+      _byte_map[card_index] = val;
+  }
+
+  void verify_g1_young_region(MemRegion mr) PRODUCT_RETURN;
+  void g1_mark_as_young(const MemRegion& mr);
+
+  bool mark_card_deferred(size_t card_index);
+
+  bool is_card_deferred(size_t card_index) {
+    jbyte val = _byte_map[card_index];
+    return (val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val();
+  }
+
+};
+
+// Adds card-table logging to the post-barrier.
+// Usual invariant: all dirty cards are logged in the DirtyCardQueueSet.
+class G1SATBCardTableLoggingModRefBS: public G1SATBCardTableModRefBS {
+ private:
+  DirtyCardQueueSet& _dcqs;
+ public:
+  G1SATBCardTableLoggingModRefBS(MemRegion whole_heap,
+                                 int max_covered_regions);
+
+  bool is_a(BarrierSet::Name bsn) {
+    return bsn == BarrierSet::G1SATBCTLogging ||
+      G1SATBCardTableModRefBS::is_a(bsn);
+  }
+
+  void write_ref_field_work(void* field, oop new_val, bool release = false);
+
+  // Can be called from static contexts.
+  static void write_ref_field_static(void* field, oop new_val);
+
+  // NB: if you do a whole-heap invalidation, the "usual invariant" defined
+  // above no longer applies.
+  void invalidate(MemRegion mr, bool whole_heap = false);
+
+  void write_region_work(MemRegion mr)    { invalidate(mr); }
+  void write_ref_array_work(MemRegion mr) { invalidate(mr); }
+
+
+};
+
+
+#endif // INCLUDE_ALL_GCS
+
+#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1SATBCARDTABLEMODREFBS_HPP