rev 57223 : imported patch 8225484-changes-to-survivor-calculation
1 /*
2 * Copyright (c) 2001, 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.
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/g1SurvRateGroup.hpp"
29 #include "logging/log.hpp"
30 #include "memory/allocation.hpp"
31
32 G1SurvRateGroup::G1SurvRateGroup() :
33 _stats_arrays_length(0),
34 _accum_surv_rate_pred(NULL),
35 _last_pred(0.0),
36 _surv_rate_predictors(NULL),
37 _num_added_regions(0) {
38 reset();
39 start_adding_regions();
40 }
41
42 void G1SurvRateGroup::reset() {
43 _last_pred = 0.0;
44 // the following will set up the arrays with length 1
45 _num_added_regions = 1;
46
47 // The call to stop_adding_regions() will use "new" to refill
48 // the _surv_rate_pred array, so we need to make sure to call
49 // "delete".
50 for (size_t i = 0; i < _stats_arrays_length; ++i) {
51 delete _surv_rate_predictors[i];
52 }
53 _stats_arrays_length = 0;
54
55 stop_adding_regions();
56
57 // Seed initial _surv_rate_pred and _accum_surv_rate_pred values
58 guarantee(_stats_arrays_length == 1, "invariant" );
59 guarantee(_surv_rate_predictors[0] != NULL, "invariant" );
60 const double initial_surv_rate = 0.4;
61 _surv_rate_predictors[0]->add(initial_surv_rate);
62 _last_pred = _accum_surv_rate_pred[0] = initial_surv_rate;
63
64 _num_added_regions = 0;
65 }
66
67 void G1SurvRateGroup::start_adding_regions() {
68 _num_added_regions = 0;
69 }
70
71 void G1SurvRateGroup::stop_adding_regions() {
72 if (_num_added_regions > _stats_arrays_length) {
73 _accum_surv_rate_pred = REALLOC_C_HEAP_ARRAY(double, _accum_surv_rate_pred, _num_added_regions, mtGC);
74 _surv_rate_predictors = REALLOC_C_HEAP_ARRAY(TruncatedSeq*, _surv_rate_predictors, _num_added_regions, mtGC);
75
76 for (size_t i = _stats_arrays_length; i < _num_added_regions; ++i) {
77 _surv_rate_predictors[i] = new TruncatedSeq(10);
78 }
79
80 _stats_arrays_length = _num_added_regions;
81 }
82 }
83
84 void G1SurvRateGroup::record_surviving_words(int age_in_group, double surv_rate) {
85 guarantee(0 <= age_in_group && (size_t)age_in_group < _num_added_regions,
86 "age_in_group is %d not between 0 and " SIZE_FORMAT, age_in_group, _num_added_regions);
87 _surv_rate_predictors[age_in_group]->add(surv_rate);
88 }
89
90 void G1SurvRateGroup::all_surviving_words_recorded(const G1Predictions& predictor, bool update_predictors) {
91 if (update_predictors) {
92 fill_in_last_surv_rates();
93 }
94 finalize_predictions(predictor);
95 }
96
97 void G1SurvRateGroup::fill_in_last_surv_rates() {
98 if (_num_added_regions > 0) { // conservative
99 double surv_rate = _surv_rate_predictors[_num_added_regions-1]->last();
100 for (size_t i = _num_added_regions; i < _stats_arrays_length; ++i) {
101 _surv_rate_predictors[i]->add(surv_rate);
102 }
103 }
104 }
105
106 void G1SurvRateGroup::finalize_predictions(const G1Predictions& predictor) {
107 double accum = 0.0;
108 double pred = 0.0;
109 for (size_t i = 0; i < _stats_arrays_length; ++i) {
110 pred = predictor.predict_in_unit_interval(_surv_rate_predictors[i]);
111 accum += pred;
112 _accum_surv_rate_pred[i] = accum;
113 }
114 _last_pred = pred;
115 }
--- EOF ---