--- /dev/null	2013-01-15 13:59:16.000000000 -0800
+++ new/src/share/vm/gc_implementation/g1/g1CardCounts.cpp	2013-01-15 13:59:16.091922693 -0800
@@ -0,0 +1,203 @@
+/*
+ * Copyright (c) 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.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "gc_implementation/g1/g1CardCounts.hpp"
+#include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
+#include "gc_implementation/g1/g1CollectorPolicy.hpp"
+#include "gc_implementation/g1/g1GCPhaseTimes.hpp"
+#include "memory/cardTableModRefBS.hpp"
+#include "services/memTracker.hpp"
+
+void G1CardCounts::clear_range(size_t from_card_num, size_t to_card_num) {
+  if (_committed_max_card_num > 0) {
+    check_card_num(from_card_num,
+                   err_msg("from card num out of range: "SIZE_FORMAT, from_card_num));
+    assert(from_card_num < to_card_num, "ordering?");
+    assert(to_card_num <= _committed_max_card_num,
+           err_msg("to card num out of range: "SIZE_FORMAT, to_card_num));
+
+    assert(_card_counts != NULL, "must be");
+    assert(G1ConcRSHotCardLimit > 0, "must be");
+
+    to_card_num = MIN2(_committed_max_card_num, to_card_num);
+
+    for (size_t card_num = from_card_num;
+         card_num < to_card_num; card_num += 1) {
+      _card_counts[card_num] = 0;
+    }
+  }
+}
+
+int G1CardCounts::add_card_count(jbyte* card_ptr) {
+  assert(_committed_max_card_num > 0, "sanity");
+  assert(_card_counts != NULL, "sanity");
+  assert(G1ConcRSHotCardLimit <= max_jubyte, "check");
+
+  size_t card_num = ptr_2_card_num(card_ptr);
+  int count = 0;
+  if (card_num < _committed_max_card_num) {
+    count = (int) _card_counts[card_num];
+    if (count < G1ConcRSHotCardLimit) {
+      _card_counts[card_num] += 1;
+    }
+    assert(_card_counts[card_num] <= G1ConcRSHotCardLimit, "overflow");
+  }
+  return count;
+}
+
+G1CardCounts::G1CardCounts(G1CollectedHeap *g1h):
+  _g1h(g1h), _card_counts(NULL),
+  _reserved_max_card_num(0), _committed_max_card_num(0),
+  _committed_size(0) {}
+
+void G1CardCounts::initialize() {
+  assert(_g1h->max_capacity() > 0, "initialization order");
+  assert(_g1h->capacity() == 0, "initialization order");
+
+  if (G1ConcRSHotCardLimit > 0) {
+    // The max value we can store in the counts table is
+    // max_jubyte. Guarantee the value of the hot
+    // threshold limit is no more than this.
+    guarantee(G1ConcRSHotCardLimit <= max_jubyte, "sanity");
+
+    ModRefBarrierSet* bs = _g1h->mr_bs();
+    guarantee(bs->is_a(BarrierSet::CardTableModRef), "Precondition");
+    _ct_bs = (CardTableModRefBS*)bs;  
+    _ct_bot = _ct_bs->byte_for_const(_g1h->reserved_region().start());
+
+    // Allocate/Reserve the counts table
+    size_t reserved_bytes = _g1h->max_capacity();
+    _reserved_max_card_num = reserved_bytes >> CardTableModRefBS::card_shift;
+
+    size_t reserved_size = _reserved_max_card_num * sizeof(jbyte);
+    ReservedSpace rs(ReservedSpace::allocation_align_size_up(reserved_size));
+    if (!rs.is_reserved()) {
+      warning("Could not reserve enough space for the card counts table");
+      guarantee(_card_counts == NULL, "should be NULL");
+      return;
+    }
+
+    MemTracker::record_virtual_memory_type((address)rs.base(), mtGC);
+
+    _card_counts_storage.initialize(rs, 0);
+    _card_counts = (jbyte*) _card_counts_storage.low();
+  }
+}
+
+void G1CardCounts::resize(size_t heap_capacity) {
+  // Expand the card counts table to handle a heap with the given capacity.
+
+  if (_card_counts == NULL) {
+    // Don't expand if we failed to reserve the card counts table.
+    return;
+  }
+
+  assert(_committed_size ==
+         ReservedSpace::allocation_align_size_up(_committed_size), "sanity");
+         
+  // Verify that the committed space for the card counts
+  // matches our committed max card num.
+  size_t prev_committed_size = _committed_size;
+  size_t prev_committed_card_num = prev_committed_size / sizeof(jbyte);
+  assert(prev_committed_card_num == _committed_max_card_num, "mismatch");
+
+  size_t new_size = (heap_capacity >> CardTableModRefBS::card_shift) * sizeof(jbyte);
+  size_t new_committed_size = ReservedSpace::allocation_align_size_up(new_size);
+  size_t new_committed_card_num =
+                MIN2(_reserved_max_card_num, new_committed_size / sizeof(jbyte));
+
+  if (_committed_max_card_num < new_committed_card_num) {
+    // we need to expand the backing store for the card counts
+    size_t expand_size = new_committed_size - prev_committed_size;
+
+    if (!_card_counts_storage.expand_by(expand_size)) {
+      warning("Card counts table backing store commit failure");
+      return;
+    }
+    assert(_card_counts_storage.committed_size() == new_committed_size,
+           "expansion commit failure");
+   
+    _committed_size = new_committed_size;
+    _committed_max_card_num = new_committed_card_num;
+
+    clear_range(prev_committed_card_num, _committed_max_card_num);
+  }
+}
+
+bool G1CardCounts::is_hot(jbyte* card_ptr) {
+  if (_committed_max_card_num > 0) {
+    assert(_card_counts != NULL, "must be");
+    assert(G1ConcRSHotCardLimit > 0, "must be");
+
+    int count = add_card_count(card_ptr);
+    if (count >= G1ConcRSHotCardLimit) {
+      return true;
+    }
+  }
+  // Failed to allocate the counts table (always cold), the card_ptr
+  // is beyond the committed end of the counts table (always cold),
+  // or the card is actually cold.
+  return false;
+}
+
+void G1CardCounts::clear_region(HeapRegion* hr) {
+  assert(!hr->isHumongous(), "unexpected");
+  HeapWord* bottom = hr->bottom();
+
+  // We use the last address in hr as hr could be the
+  // last region in the heap. In which case trying to find
+  // the card for hr->end() will be an OOB accesss to the
+  // card table.
+  HeapWord* last = hr->end() - 1;
+  assert(_g1h->g1_committed().contains(last), "not in committed");
+
+  const jbyte* from_card_ptr = _ct_bs->byte_for_const(bottom);
+  const jbyte* last_card_ptr = _ct_bs->byte_for_const(last);
+
+#ifdef ASSERT
+  HeapWord* start_addr = _ct_bs->addr_for(from_card_ptr);
+  assert(start_addr == hr->bottom(), "alignment");
+  HeapWord* last_addr = _ct_bs->addr_for(last_card_ptr);
+  assert((last_addr + CardTableModRefBS::card_size_in_words) == hr->end(), "alignment");
+#endif // ASSERT
+
+  // Clear the counts for the (exclusive) card range.
+  size_t from_card_num = ptr_2_card_num((jbyte*)from_card_ptr);
+  size_t to_card_num = ptr_2_card_num((jbyte*)last_card_ptr) + 1;
+  clear_range(from_card_num, to_card_num);
+}
+
+void G1CardCounts::clear_all() {
+  assert(SafepointSynchronize::is_at_safepoint(), "don't call this otherwise");
+  clear_range((size_t)0, _committed_max_card_num);
+}
+
+G1CardCounts::~G1CardCounts() {
+  if (_card_counts != NULL) {
+    assert(G1ConcRSHotCardLimit > 0, "must be");
+    _card_counts_storage.release();
+  }
+}
+