--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/g1CardTable.cpp	Mon Feb 26 09:34:12 2018 +0100
@@ -0,0 +1,102 @@
+/*
+ * 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.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "gc/g1/g1CardTable.hpp"
+#include "gc/g1/g1CollectedHeap.inline.hpp"
+#include "gc/shared/memset_with_concurrent_readers.hpp"
+#include "logging/log.hpp"
+#include "runtime/atomic.hpp"
+#include "runtime/orderAccess.inline.hpp"
+
+bool G1CardTable::mark_card_deferred(size_t card_index) {
+  jbyte val = _byte_map[card_index];
+  // It's already processed
+  if ((val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val()) {
+    return false;
+  }
+
+  // Cached bit can be installed either on a clean card or on a claimed card.
+  jbyte new_val = val;
+  if (val == clean_card_val()) {
+    new_val = (jbyte)deferred_card_val();
+  } else {
+    if (val & claimed_card_val()) {
+      new_val = val | (jbyte)deferred_card_val();
+    }
+  }
+  if (new_val != val) {
+    Atomic::cmpxchg(new_val, &_byte_map[card_index], val);
+  }
+  return true;
+}
+
+void G1CardTable::g1_mark_as_young(const MemRegion& mr) {
+  jbyte *const first = byte_for(mr.start());
+  jbyte *const last = byte_after(mr.last());
+
+  memset_with_concurrent_readers(first, g1_young_gen, last - first);
+}
+
+#ifndef PRODUCT
+void G1CardTable::verify_g1_young_region(MemRegion mr) {
+  verify_region(mr, g1_young_gen,  true);
+}
+#endif
+
+void G1CardTableChangedListener::on_commit(uint start_idx, size_t num_regions, bool zero_filled) {
+  // Default value for a clean card on the card table is -1. So we cannot take advantage of the zero_filled parameter.
+  MemRegion mr(G1CollectedHeap::heap()->bottom_addr_for_region(start_idx), num_regions * HeapRegion::GrainWords);
+  _card_table->clear(mr);
+}
+
+void G1CardTable::initialize(G1RegionToSpaceMapper* mapper) {
+  mapper->set_mapping_changed_listener(&_listener);
+
+  _byte_map_size = mapper->reserved().byte_size();
+
+  _guard_index = cards_required(_whole_heap.word_size()) - 1;
+  _last_valid_index = _guard_index - 1;
+
+  HeapWord* low_bound  = _whole_heap.start();
+  HeapWord* high_bound = _whole_heap.end();
+
+  _cur_covered_regions = 1;
+  _covered[0] = _whole_heap;
+
+  _byte_map = (jbyte*) mapper->reserved().start();
+  _byte_map_base = _byte_map - (uintptr_t(low_bound) >> card_shift);
+  assert(byte_for(low_bound) == &_byte_map[0], "Checking start of map");
+  assert(byte_for(high_bound-1) <= &_byte_map[_last_valid_index], "Checking end of map");
+
+  log_trace(gc, barrier)("G1CardTable::G1CardTable: ");
+  log_trace(gc, barrier)("    &_byte_map[0]: " INTPTR_FORMAT "  &_byte_map[_last_valid_index]: " INTPTR_FORMAT,
+                         p2i(&_byte_map[0]), p2i(&_byte_map[_last_valid_index]));
+  log_trace(gc, barrier)("    _byte_map_base: " INTPTR_FORMAT,  p2i(_byte_map_base));
+}
+
+bool G1CardTable::is_in_young(oop obj) const {
+  volatile jbyte* p = byte_for(obj);
+  return *p == G1CardTable::g1_young_card_val();
+}