1/*
2 * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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23 */
24
25#ifndef SHARE_GC_G1_G1HEAPSIZINGPOLICY_HPP
26#define SHARE_GC_G1_G1HEAPSIZINGPOLICY_HPP
27
28#include "memory/allocation.hpp"
29
30class G1Analytics;
31class G1CollectedHeap;
32
33class G1HeapSizingPolicy: public CHeapObj<mtGC> {
34 // MinOverThresholdForGrowth must be less than the number of recorded
35 // pause times in G1Analytics, representing the minimum number of pause
36 // time ratios that exceed GCTimeRatio before a heap expansion will be triggered.
37 const static uint MinOverThresholdForGrowth = 4;
38
39 const G1CollectedHeap* _g1h;
40 const G1Analytics* _analytics;
41
42 const uint _num_prev_pauses_for_heuristics;
43 // Ratio check data for determining if heap growth is necessary.
44 uint _ratio_over_threshold_count;
45 double _ratio_over_threshold_sum;
46 uint _pauses_since_start;
47
48
49protected:
50 G1HeapSizingPolicy(const G1CollectedHeap* g1h, const G1Analytics* analytics);
51public:
52
53 // If an expansion would be appropriate, because recent GC overhead had
54 // exceeded the desired limit, return an amount to expand by.
55 virtual size_t expansion_amount();
56
57 // Clear ratio tracking data used by expansion_amount().
58 void clear_ratio_check_data();
59
60 static G1HeapSizingPolicy* create(const G1CollectedHeap* g1h, const G1Analytics* analytics);
61};
62
63#endif // SHARE_GC_G1_G1HEAPSIZINGPOLICY_HPP
64