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 33 SurvRateGroup::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 46 void 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 73 void SurvRateGroup::start_adding_regions() { 74 _setup_seq_num = _stats_arrays_length; 75 _region_num = 0; 76 } 77 78 void 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 91 void 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 99 void 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 } 105 106 void 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 } 114 115 void 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 }