1/*
2 * Copyright (c) 2001, 2015, 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.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25#include "precompiled.hpp"
26#include "gc/g1/g1CollectedHeap.inline.hpp"
27#include "gc/g1/g1Predictions.hpp"
28#include "gc/g1/heapRegion.hpp"
29#include "gc/g1/survRateGroup.hpp"
30#include "logging/log.hpp"
31#include "memory/allocation.hpp"
32
33SurvRateGroup::SurvRateGroup() :
34 _stats_arrays_length(0),
35 _accum_surv_rate_pred(NULL),
36 _last_pred(0.0),
37 _surv_rate_pred(NULL),
38 _all_regions_allocated(0),
39 _region_num(0),
40 _setup_seq_num(0)
41{
42 reset();
43 start_adding_regions();
44}
45
46void SurvRateGroup::reset() {
47 _all_regions_allocated = 0;
48 _setup_seq_num = 0;
49 _last_pred = 0.0;
50 // the following will set up the arrays with length 1
51 _region_num = 1;
52
53 // The call to stop_adding_regions() will use "new" to refill
54 // the _surv_rate_pred array, so we need to make sure to call
55 // "delete".
56 for (size_t i = 0; i < _stats_arrays_length; ++i) {
57 delete _surv_rate_pred[i];
58 }
59 _stats_arrays_length = 0;
60
61 stop_adding_regions();
62
63 // Seed initial _surv_rate_pred and _accum_surv_rate_pred values
64 guarantee( _stats_arrays_length == 1, "invariant" );
65 guarantee( _surv_rate_pred[0] != NULL, "invariant" );
66 const double initial_surv_rate = 0.4;
67 _surv_rate_pred[0]->add(initial_surv_rate);
68 _last_pred = _accum_surv_rate_pred[0] = initial_surv_rate;
69
70 _region_num = 0;
71}
72
73void SurvRateGroup::start_adding_regions() {
74 _setup_seq_num = _stats_arrays_length;
75 _region_num = 0;
76}
77
78void SurvRateGroup::stop_adding_regions() {
79 if (_region_num > _stats_arrays_length) {
80 _accum_surv_rate_pred = REALLOC_C_HEAP_ARRAY(double, _accum_surv_rate_pred, _region_num, mtGC);
81 _surv_rate_pred = REALLOC_C_HEAP_ARRAY(TruncatedSeq*, _surv_rate_pred, _region_num, mtGC);
82
83 for (size_t i = _stats_arrays_length; i < _region_num; ++i) {
84 _surv_rate_pred[i] = new TruncatedSeq(10);
85 }
86
87 _stats_arrays_length = _region_num;
88 }
89}
90
91void SurvRateGroup::record_surviving_words(int age_in_group, size_t surv_words) {
92 guarantee( 0 <= age_in_group && (size_t) age_in_group < _region_num,
93 "pre-condition" );
94
95 double surv_rate = (double) surv_words / (double) HeapRegion::GrainWords;
96 _surv_rate_pred[age_in_group]->add(surv_rate);
97}
98
99void SurvRateGroup::all_surviving_words_recorded(const G1Predictions& predictor, bool update_predictors) {
100 if (update_predictors) {
101 fill_in_last_surv_rates();
102 }
103 finalize_predictions(predictor);
104}
105
106void SurvRateGroup::fill_in_last_surv_rates() {
107 if (_region_num > 0) { // conservative
108 double surv_rate = _surv_rate_pred[_region_num-1]->last();
109 for (size_t i = _region_num; i < _stats_arrays_length; ++i) {
110 _surv_rate_pred[i]->add(surv_rate);
111 }
112 }
113}
114
115void SurvRateGroup::finalize_predictions(const G1Predictions& predictor) {
116 double accum = 0.0;
117 double pred = 0.0;
118 for (size_t i = 0; i < _stats_arrays_length; ++i) {
119 pred = predictor.get_new_prediction(_surv_rate_pred[i]);
120 if (pred > 1.0) pred = 1.0;
121 accum += pred;
122 _accum_surv_rate_pred[i] = accum;
123 }
124 _last_pred = pred;
125}
126