1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/g1/g1CardCounts.hpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,130 @@
1.4 +/*
1.5 + * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1CARDCOUNTS_HPP
1.29 +#define SHARE_VM_GC_IMPLEMENTATION_G1_G1CARDCOUNTS_HPP
1.30 +
1.31 +#include "memory/allocation.hpp"
1.32 +#include "runtime/virtualspace.hpp"
1.33 +#include "utilities/globalDefinitions.hpp"
1.34 +
1.35 +class CardTableModRefBS;
1.36 +class G1CollectedHeap;
1.37 +class HeapRegion;
1.38 +
1.39 +// Table to track the number of times a card has been refined. Once
1.40 +// a card has been refined a certain number of times, it is
1.41 +// considered 'hot' and its refinement is delayed by inserting the
1.42 +// card into the hot card cache. The card will then be refined when
1.43 +// it is evicted from the hot card cache, or when the hot card cache
1.44 +// is 'drained' during the next evacuation pause.
1.45 +
1.46 +class G1CardCounts: public CHeapObj<mtGC> {
1.47 + G1CollectedHeap* _g1h;
1.48 +
1.49 + // The table of counts
1.50 + jubyte* _card_counts;
1.51 +
1.52 + // Max capacity of the reserved space for the counts table
1.53 + size_t _reserved_max_card_num;
1.54 +
1.55 + // Max capacity of the committed space for the counts table
1.56 + size_t _committed_max_card_num;
1.57 +
1.58 + // Size of committed space for the counts table
1.59 + size_t _committed_size;
1.60 +
1.61 + // CardTable bottom.
1.62 + const jbyte* _ct_bot;
1.63 +
1.64 + // Barrier set
1.65 + CardTableModRefBS* _ct_bs;
1.66 +
1.67 + // The virtual memory backing the counts table
1.68 + VirtualSpace _card_counts_storage;
1.69 +
1.70 + // Returns true if the card counts table has been reserved.
1.71 + bool has_reserved_count_table() { return _card_counts != NULL; }
1.72 +
1.73 + // Returns true if the card counts table has been reserved and committed.
1.74 + bool has_count_table() {
1.75 + return has_reserved_count_table() && _committed_max_card_num > 0;
1.76 + }
1.77 +
1.78 + size_t ptr_2_card_num(const jbyte* card_ptr) {
1.79 + assert(card_ptr >= _ct_bot,
1.80 + err_msg("Invalid card pointer: "
1.81 + "card_ptr: " PTR_FORMAT ", "
1.82 + "_ct_bot: " PTR_FORMAT,
1.83 + p2i(card_ptr), p2i(_ct_bot)));
1.84 + size_t card_num = pointer_delta(card_ptr, _ct_bot, sizeof(jbyte));
1.85 + assert(card_num >= 0 && card_num < _committed_max_card_num,
1.86 + err_msg("card pointer out of range: " PTR_FORMAT, p2i(card_ptr)));
1.87 + return card_num;
1.88 + }
1.89 +
1.90 + jbyte* card_num_2_ptr(size_t card_num) {
1.91 + assert(card_num >= 0 && card_num < _committed_max_card_num,
1.92 + err_msg("card num out of range: "SIZE_FORMAT, card_num));
1.93 + return (jbyte*) (_ct_bot + card_num);
1.94 + }
1.95 +
1.96 + // Helper routine.
1.97 + // Returns the number of cards that can be counted by the given committed
1.98 + // table size, with a maximum of the number of cards spanned by the max
1.99 + // capacity of the heap.
1.100 + size_t committed_to_card_num(size_t committed_size) {
1.101 + return MIN2(_reserved_max_card_num, committed_size / sizeof(jbyte));
1.102 + }
1.103 +
1.104 + // Clear the counts table for the given (exclusive) index range.
1.105 + void clear_range(size_t from_card_num, size_t to_card_num);
1.106 +
1.107 + public:
1.108 + G1CardCounts(G1CollectedHeap* g1h);
1.109 + ~G1CardCounts();
1.110 +
1.111 + void initialize();
1.112 +
1.113 + // Resize the committed space for the card counts table in
1.114 + // response to a resize of the committed space for the heap.
1.115 + void resize(size_t heap_capacity);
1.116 +
1.117 + // Increments the refinement count for the given card.
1.118 + // Returns the pre-increment count value.
1.119 + uint add_card_count(jbyte* card_ptr);
1.120 +
1.121 + // Returns true if the given count is high enough to be considered
1.122 + // 'hot'; false otherwise.
1.123 + bool is_hot(uint count);
1.124 +
1.125 + // Clears the card counts for the cards spanned by the region
1.126 + void clear_region(HeapRegion* hr);
1.127 +
1.128 + // Clear the entire card counts table during GC.
1.129 + // Updates the policy stats with the duration.
1.130 + void clear_all();
1.131 +};
1.132 +
1.133 +#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1CARDCOUNTS_HPP
