1 /* |
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2 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. |
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8 * |
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9 * This code is distributed in the hope that it will be useful, but WITHOUT |
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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12 * version 2 for more details (a copy is included in the LICENSE file that |
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13 * accompanied this code). |
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14 * |
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15 * You should have received a copy of the GNU General Public License version |
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16 * 2 along with this work; if not, write to the Free Software Foundation, |
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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18 * |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
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22 * |
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23 */ |
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24 |
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25 #include "precompiled.hpp" |
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26 #include "gc/g1/g1CollectedHeap.inline.hpp" |
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27 #include "gc/g1/g1FullGCScope.hpp" |
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28 #include "gc/g1/g1MarkSweep.hpp" |
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29 #include "gc/g1/g1RemSet.inline.hpp" |
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30 #include "gc/g1/g1SerialFullCollector.hpp" |
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31 #include "gc/g1/heapRegionRemSet.hpp" |
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32 #include "gc/shared/referenceProcessor.hpp" |
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33 |
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34 G1SerialFullCollector::G1SerialFullCollector(G1FullGCScope* scope, |
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35 ReferenceProcessor* reference_processor) : |
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36 _scope(scope), |
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37 _reference_processor(reference_processor), |
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38 _is_alive_mutator(_reference_processor, NULL), |
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39 _mt_discovery_mutator(_reference_processor, false) { |
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40 // Temporarily make discovery by the STW ref processor single threaded (non-MT) |
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41 // and clear the STW ref processor's _is_alive_non_header field. |
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42 } |
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43 |
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44 void G1SerialFullCollector::prepare_collection() { |
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45 _reference_processor->enable_discovery(); |
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46 _reference_processor->setup_policy(_scope->should_clear_soft_refs()); |
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47 } |
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48 |
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49 void G1SerialFullCollector::complete_collection() { |
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50 // Enqueue any discovered reference objects that have |
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51 // not been removed from the discovered lists. |
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52 ReferenceProcessorPhaseTimes pt(NULL, _reference_processor->num_q()); |
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53 _reference_processor->enqueue_discovered_references(NULL, &pt); |
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54 pt.print_enqueue_phase(); |
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55 |
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56 // Iterate the heap and rebuild the remembered sets. |
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57 rebuild_remembered_sets(); |
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58 } |
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59 |
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60 void G1SerialFullCollector::collect() { |
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61 // Do the actual collection work. |
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62 G1MarkSweep::invoke_at_safepoint(_reference_processor, _scope->should_clear_soft_refs()); |
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63 } |
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64 |
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65 class PostMCRemSetClearClosure: public HeapRegionClosure { |
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66 G1CollectedHeap* _g1h; |
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67 ModRefBarrierSet* _mr_bs; |
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68 public: |
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69 PostMCRemSetClearClosure(G1CollectedHeap* g1h, ModRefBarrierSet* mr_bs) : |
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70 _g1h(g1h), _mr_bs(mr_bs) {} |
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71 |
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72 bool doHeapRegion(HeapRegion* r) { |
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73 HeapRegionRemSet* hrrs = r->rem_set(); |
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74 |
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75 _g1h->reset_gc_time_stamps(r); |
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76 |
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77 if (r->is_continues_humongous()) { |
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78 // We'll assert that the strong code root list and RSet is empty |
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79 assert(hrrs->strong_code_roots_list_length() == 0, "sanity"); |
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80 assert(hrrs->occupied() == 0, "RSet should be empty"); |
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81 } else { |
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82 hrrs->clear(); |
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83 } |
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84 // You might think here that we could clear just the cards |
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85 // corresponding to the used region. But no: if we leave a dirty card |
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86 // in a region we might allocate into, then it would prevent that card |
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87 // from being enqueued, and cause it to be missed. |
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88 // Re: the performance cost: we shouldn't be doing full GC anyway! |
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89 _mr_bs->clear(MemRegion(r->bottom(), r->end())); |
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90 |
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91 return false; |
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92 } |
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93 }; |
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94 |
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95 |
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96 class RebuildRSOutOfRegionClosure: public HeapRegionClosure { |
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97 G1CollectedHeap* _g1h; |
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98 RebuildRSOopClosure _cl; |
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99 public: |
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100 RebuildRSOutOfRegionClosure(G1CollectedHeap* g1, uint worker_i = 0) : |
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101 _cl(g1->g1_rem_set(), worker_i), |
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102 _g1h(g1) |
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103 { } |
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104 |
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105 bool doHeapRegion(HeapRegion* r) { |
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106 if (!r->is_continues_humongous()) { |
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107 _cl.set_from(r); |
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108 r->oop_iterate(&_cl); |
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109 } |
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110 return false; |
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111 } |
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112 }; |
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113 |
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114 class ParRebuildRSTask: public AbstractGangTask { |
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115 G1CollectedHeap* _g1; |
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116 HeapRegionClaimer _hrclaimer; |
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117 |
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118 public: |
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119 ParRebuildRSTask(G1CollectedHeap* g1) : |
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120 AbstractGangTask("ParRebuildRSTask"), _g1(g1), _hrclaimer(g1->workers()->active_workers()) {} |
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121 |
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122 void work(uint worker_id) { |
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123 RebuildRSOutOfRegionClosure rebuild_rs(_g1, worker_id); |
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124 _g1->heap_region_par_iterate(&rebuild_rs, worker_id, &_hrclaimer); |
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125 } |
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126 }; |
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127 |
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128 void G1SerialFullCollector::rebuild_remembered_sets() { |
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129 G1CollectedHeap* g1h = G1CollectedHeap::heap(); |
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130 // First clear the stale remembered sets. |
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131 PostMCRemSetClearClosure rs_clear(g1h, g1h->g1_barrier_set()); |
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132 g1h->heap_region_iterate(&rs_clear); |
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133 |
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134 // Rebuild remembered sets of all regions. |
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135 uint n_workers = AdaptiveSizePolicy::calc_active_workers(g1h->workers()->total_workers(), |
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136 g1h->workers()->active_workers(), |
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137 Threads::number_of_non_daemon_threads()); |
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138 g1h->workers()->update_active_workers(n_workers); |
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139 log_info(gc,task)("Using %u workers of %u to rebuild remembered set", n_workers, g1h->workers()->total_workers()); |
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140 |
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141 ParRebuildRSTask rebuild_rs_task(g1h); |
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142 g1h->workers()->run_task(&rebuild_rs_task); |
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143 } |
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