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1 /* |
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2 * Copyright (c) 2014, 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_implementation/g1/g1Allocator.hpp" |
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27 #include "gc_implementation/g1/g1CollectedHeap.hpp" |
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28 #include "gc_implementation/g1/g1CollectorPolicy.hpp" |
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29 #include "gc_implementation/g1/heapRegion.inline.hpp" |
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30 #include "gc_implementation/g1/heapRegionSet.inline.hpp" |
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31 |
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32 void G1DefaultAllocator::init_mutator_alloc_region() { |
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33 assert(_mutator_alloc_region.get() == NULL, "pre-condition"); |
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34 _mutator_alloc_region.init(); |
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35 } |
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36 |
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37 void G1DefaultAllocator::release_mutator_alloc_region() { |
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38 _mutator_alloc_region.release(); |
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39 assert(_mutator_alloc_region.get() == NULL, "post-condition"); |
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40 } |
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41 |
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42 void G1Allocator::reuse_retained_old_region(EvacuationInfo& evacuation_info, |
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43 OldGCAllocRegion* old, |
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44 HeapRegion** retained_old) { |
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45 HeapRegion* retained_region = *retained_old; |
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46 *retained_old = NULL; |
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47 |
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48 // We will discard the current GC alloc region if: |
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49 // a) it's in the collection set (it can happen!), |
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50 // b) it's already full (no point in using it), |
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51 // c) it's empty (this means that it was emptied during |
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52 // a cleanup and it should be on the free list now), or |
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53 // d) it's humongous (this means that it was emptied |
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54 // during a cleanup and was added to the free list, but |
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55 // has been subsequently used to allocate a humongous |
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56 // object that may be less than the region size). |
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57 if (retained_region != NULL && |
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58 !retained_region->in_collection_set() && |
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59 !(retained_region->top() == retained_region->end()) && |
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60 !retained_region->is_empty() && |
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61 !retained_region->isHumongous()) { |
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62 retained_region->record_top_and_timestamp(); |
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63 // The retained region was added to the old region set when it was |
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64 // retired. We have to remove it now, since we don't allow regions |
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65 // we allocate to in the region sets. We'll re-add it later, when |
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66 // it's retired again. |
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67 _g1h->_old_set.remove(retained_region); |
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68 bool during_im = _g1h->g1_policy()->during_initial_mark_pause(); |
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69 retained_region->note_start_of_copying(during_im); |
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70 old->set(retained_region); |
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71 _g1h->_hr_printer.reuse(retained_region); |
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72 evacuation_info.set_alloc_regions_used_before(retained_region->used()); |
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73 } |
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74 } |
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75 |
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76 void G1DefaultAllocator::init_gc_alloc_regions(EvacuationInfo& evacuation_info) { |
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77 assert_at_safepoint(true /* should_be_vm_thread */); |
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78 |
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79 _survivor_gc_alloc_region.init(); |
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80 _old_gc_alloc_region.init(); |
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81 reuse_retained_old_region(evacuation_info, |
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82 &_old_gc_alloc_region, |
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83 &_retained_old_gc_alloc_region); |
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84 } |
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85 |
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86 void G1DefaultAllocator::release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info) { |
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87 AllocationContext_t context = AllocationContext::current(); |
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88 evacuation_info.set_allocation_regions(survivor_gc_alloc_region(context)->count() + |
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89 old_gc_alloc_region(context)->count()); |
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90 survivor_gc_alloc_region(context)->release(); |
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91 // If we have an old GC alloc region to release, we'll save it in |
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92 // _retained_old_gc_alloc_region. If we don't |
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93 // _retained_old_gc_alloc_region will become NULL. This is what we |
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94 // want either way so no reason to check explicitly for either |
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95 // condition. |
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96 _retained_old_gc_alloc_region = old_gc_alloc_region(context)->release(); |
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97 |
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98 if (ResizePLAB) { |
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99 _g1h->_survivor_plab_stats.adjust_desired_plab_sz(no_of_gc_workers); |
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100 _g1h->_old_plab_stats.adjust_desired_plab_sz(no_of_gc_workers); |
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101 } |
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102 } |
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103 |
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104 void G1DefaultAllocator::abandon_gc_alloc_regions() { |
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105 assert(survivor_gc_alloc_region(AllocationContext::current())->get() == NULL, "pre-condition"); |
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106 assert(old_gc_alloc_region(AllocationContext::current())->get() == NULL, "pre-condition"); |
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107 _retained_old_gc_alloc_region = NULL; |
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108 } |
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109 |
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110 G1ParGCAllocBuffer::G1ParGCAllocBuffer(size_t gclab_word_size) : |
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111 ParGCAllocBuffer(gclab_word_size), _retired(true) { } |
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112 |
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113 HeapWord* G1ParGCAllocator::allocate_slow(GCAllocPurpose purpose, size_t word_sz, AllocationContext_t context) { |
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114 HeapWord* obj = NULL; |
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115 size_t gclab_word_size = _g1h->desired_plab_sz(purpose); |
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116 if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) { |
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117 G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose, context); |
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118 add_to_alloc_buffer_waste(alloc_buf->words_remaining()); |
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119 alloc_buf->retire(false /* end_of_gc */, false /* retain */); |
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120 |
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121 HeapWord* buf = _g1h->par_allocate_during_gc(purpose, gclab_word_size, context); |
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122 if (buf == NULL) { |
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123 return NULL; // Let caller handle allocation failure. |
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124 } |
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125 // Otherwise. |
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126 alloc_buf->set_word_size(gclab_word_size); |
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127 alloc_buf->set_buf(buf); |
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128 |
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129 obj = alloc_buf->allocate(word_sz); |
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130 assert(obj != NULL, "buffer was definitely big enough..."); |
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131 } else { |
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132 obj = _g1h->par_allocate_during_gc(purpose, word_sz, context); |
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133 } |
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134 return obj; |
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135 } |
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136 |
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137 G1DefaultParGCAllocator::G1DefaultParGCAllocator(G1CollectedHeap* g1h) : |
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138 G1ParGCAllocator(g1h), |
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139 _surviving_alloc_buffer(g1h->desired_plab_sz(GCAllocForSurvived)), |
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140 _tenured_alloc_buffer(g1h->desired_plab_sz(GCAllocForTenured)) { |
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141 |
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142 _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer; |
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143 _alloc_buffers[GCAllocForTenured] = &_tenured_alloc_buffer; |
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144 |
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145 } |
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146 |
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147 void G1DefaultParGCAllocator::retire_alloc_buffers() { |
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148 for (int ap = 0; ap < GCAllocPurposeCount; ++ap) { |
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149 size_t waste = _alloc_buffers[ap]->words_remaining(); |
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150 add_to_alloc_buffer_waste(waste); |
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151 _alloc_buffers[ap]->flush_stats_and_retire(_g1h->stats_for_purpose((GCAllocPurpose)ap), |
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152 true /* end_of_gc */, |
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153 false /* retain */); |
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154 } |
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155 } |