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1 /* |
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2 * Copyright 2002-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
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20 * CA 95054 USA or visit www.sun.com if you need additional information or |
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21 * have any questions. |
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22 * |
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23 */ |
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24 |
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25 #include "incls/_precompiled.incl" |
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26 #include "incls/_psPromotionManager.cpp.incl" |
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27 |
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28 PSPromotionManager** PSPromotionManager::_manager_array = NULL; |
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29 OopStarTaskQueueSet* PSPromotionManager::_stack_array_depth = NULL; |
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30 OopTaskQueueSet* PSPromotionManager::_stack_array_breadth = NULL; |
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31 PSOldGen* PSPromotionManager::_old_gen = NULL; |
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32 MutableSpace* PSPromotionManager::_young_space = NULL; |
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33 |
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34 void PSPromotionManager::initialize() { |
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35 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
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36 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
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37 |
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38 _old_gen = heap->old_gen(); |
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39 _young_space = heap->young_gen()->to_space(); |
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40 |
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41 assert(_manager_array == NULL, "Attempt to initialize twice"); |
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42 _manager_array = NEW_C_HEAP_ARRAY(PSPromotionManager*, ParallelGCThreads+1 ); |
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43 guarantee(_manager_array != NULL, "Could not initialize promotion manager"); |
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44 |
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45 if (UseDepthFirstScavengeOrder) { |
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46 _stack_array_depth = new OopStarTaskQueueSet(ParallelGCThreads); |
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47 guarantee(_stack_array_depth != NULL, "Count not initialize promotion manager"); |
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48 } else { |
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49 _stack_array_breadth = new OopTaskQueueSet(ParallelGCThreads); |
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50 guarantee(_stack_array_breadth != NULL, "Count not initialize promotion manager"); |
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51 } |
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52 |
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53 // Create and register the PSPromotionManager(s) for the worker threads. |
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54 for(uint i=0; i<ParallelGCThreads; i++) { |
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55 _manager_array[i] = new PSPromotionManager(); |
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56 guarantee(_manager_array[i] != NULL, "Could not create PSPromotionManager"); |
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57 if (UseDepthFirstScavengeOrder) { |
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58 stack_array_depth()->register_queue(i, _manager_array[i]->claimed_stack_depth()); |
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59 } else { |
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60 stack_array_breadth()->register_queue(i, _manager_array[i]->claimed_stack_breadth()); |
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61 } |
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62 } |
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63 |
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64 // The VMThread gets its own PSPromotionManager, which is not available |
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65 // for work stealing. |
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66 _manager_array[ParallelGCThreads] = new PSPromotionManager(); |
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67 guarantee(_manager_array[ParallelGCThreads] != NULL, "Could not create PSPromotionManager"); |
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68 } |
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69 |
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70 PSPromotionManager* PSPromotionManager::gc_thread_promotion_manager(int index) { |
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71 assert(index >= 0 && index < (int)ParallelGCThreads, "index out of range"); |
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72 assert(_manager_array != NULL, "Sanity"); |
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73 return _manager_array[index]; |
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74 } |
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75 |
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76 PSPromotionManager* PSPromotionManager::vm_thread_promotion_manager() { |
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77 assert(_manager_array != NULL, "Sanity"); |
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78 return _manager_array[ParallelGCThreads]; |
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79 } |
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80 |
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81 void PSPromotionManager::pre_scavenge() { |
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82 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
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83 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
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84 |
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85 _young_space = heap->young_gen()->to_space(); |
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86 |
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87 for(uint i=0; i<ParallelGCThreads+1; i++) { |
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88 manager_array(i)->reset(); |
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89 } |
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90 } |
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91 |
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92 void PSPromotionManager::post_scavenge() { |
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93 #if PS_PM_STATS |
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94 print_stats(); |
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95 #endif // PS_PM_STATS |
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96 |
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97 for(uint i=0; i<ParallelGCThreads+1; i++) { |
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98 PSPromotionManager* manager = manager_array(i); |
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99 |
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100 // the guarantees are a bit gratuitous but, if one fires, we'll |
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101 // have a better idea of what went wrong |
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102 if (i < ParallelGCThreads) { |
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103 guarantee((!UseDepthFirstScavengeOrder || |
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104 manager->overflow_stack_depth()->length() <= 0), |
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105 "promotion manager overflow stack must be empty"); |
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106 guarantee((UseDepthFirstScavengeOrder || |
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107 manager->overflow_stack_breadth()->length() <= 0), |
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108 "promotion manager overflow stack must be empty"); |
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109 |
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110 guarantee((!UseDepthFirstScavengeOrder || |
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111 manager->claimed_stack_depth()->size() <= 0), |
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112 "promotion manager claimed stack must be empty"); |
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113 guarantee((UseDepthFirstScavengeOrder || |
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114 manager->claimed_stack_breadth()->size() <= 0), |
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115 "promotion manager claimed stack must be empty"); |
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116 } else { |
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117 guarantee((!UseDepthFirstScavengeOrder || |
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118 manager->overflow_stack_depth()->length() <= 0), |
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119 "VM Thread promotion manager overflow stack " |
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120 "must be empty"); |
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121 guarantee((UseDepthFirstScavengeOrder || |
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122 manager->overflow_stack_breadth()->length() <= 0), |
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123 "VM Thread promotion manager overflow stack " |
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124 "must be empty"); |
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125 |
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126 guarantee((!UseDepthFirstScavengeOrder || |
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127 manager->claimed_stack_depth()->size() <= 0), |
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128 "VM Thread promotion manager claimed stack " |
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129 "must be empty"); |
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130 guarantee((UseDepthFirstScavengeOrder || |
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131 manager->claimed_stack_breadth()->size() <= 0), |
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132 "VM Thread promotion manager claimed stack " |
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133 "must be empty"); |
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134 } |
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135 |
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136 manager->flush_labs(); |
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137 } |
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138 } |
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139 |
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140 #if PS_PM_STATS |
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141 |
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142 void |
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143 PSPromotionManager::print_stats(uint i) { |
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144 tty->print_cr("---- GC Worker %2d Stats", i); |
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145 tty->print_cr(" total pushes %8d", _total_pushes); |
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146 tty->print_cr(" masked pushes %8d", _masked_pushes); |
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147 tty->print_cr(" overflow pushes %8d", _overflow_pushes); |
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148 tty->print_cr(" max overflow length %8d", _max_overflow_length); |
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149 tty->print_cr(""); |
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150 tty->print_cr(" arrays chunked %8d", _arrays_chunked); |
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151 tty->print_cr(" array chunks processed %8d", _array_chunks_processed); |
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152 tty->print_cr(""); |
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153 tty->print_cr(" total steals %8d", _total_steals); |
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154 tty->print_cr(" masked steals %8d", _masked_steals); |
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155 tty->print_cr(""); |
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156 } |
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157 |
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158 void |
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159 PSPromotionManager::print_stats() { |
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160 tty->print_cr("== GC Tasks Stats (%s), GC %3d", |
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161 (UseDepthFirstScavengeOrder) ? "Depth-First" : "Breadth-First", |
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162 Universe::heap()->total_collections()); |
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163 |
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164 for (uint i = 0; i < ParallelGCThreads+1; ++i) { |
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165 PSPromotionManager* manager = manager_array(i); |
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166 manager->print_stats(i); |
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167 } |
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168 } |
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169 |
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170 #endif // PS_PM_STATS |
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171 |
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172 PSPromotionManager::PSPromotionManager() { |
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173 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
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174 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
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175 _depth_first = UseDepthFirstScavengeOrder; |
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176 |
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177 // We set the old lab's start array. |
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178 _old_lab.set_start_array(old_gen()->start_array()); |
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179 |
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180 uint queue_size; |
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181 if (depth_first()) { |
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182 claimed_stack_depth()->initialize(); |
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183 queue_size = claimed_stack_depth()->max_elems(); |
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184 // We want the overflow stack to be permanent |
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185 _overflow_stack_depth = new (ResourceObj::C_HEAP) GrowableArray<oop*>(10, true); |
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186 _overflow_stack_breadth = NULL; |
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187 } else { |
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188 claimed_stack_breadth()->initialize(); |
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189 queue_size = claimed_stack_breadth()->max_elems(); |
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190 // We want the overflow stack to be permanent |
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191 _overflow_stack_breadth = new (ResourceObj::C_HEAP) GrowableArray<oop>(10, true); |
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192 _overflow_stack_depth = NULL; |
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193 } |
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194 |
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195 _totally_drain = (ParallelGCThreads == 1) || (GCDrainStackTargetSize == 0); |
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196 if (_totally_drain) { |
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197 _target_stack_size = 0; |
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198 } else { |
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199 // don't let the target stack size to be more than 1/4 of the entries |
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200 _target_stack_size = (uint) MIN2((uint) GCDrainStackTargetSize, |
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201 (uint) (queue_size / 4)); |
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202 } |
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203 |
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204 _array_chunk_size = ParGCArrayScanChunk; |
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205 // let's choose 1.5x the chunk size |
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206 _min_array_size_for_chunking = 3 * _array_chunk_size / 2; |
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207 |
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208 reset(); |
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209 } |
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210 |
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211 void PSPromotionManager::reset() { |
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212 assert(claimed_stack_empty(), "reset of non-empty claimed stack"); |
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213 assert(overflow_stack_empty(), "reset of non-empty overflow stack"); |
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214 |
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215 // We need to get an assert in here to make sure the labs are always flushed. |
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216 |
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217 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
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218 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
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219 |
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220 // Do not prefill the LAB's, save heap wastage! |
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221 HeapWord* lab_base = young_space()->top(); |
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222 _young_lab.initialize(MemRegion(lab_base, (size_t)0)); |
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223 _young_gen_is_full = false; |
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224 |
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225 lab_base = old_gen()->object_space()->top(); |
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226 _old_lab.initialize(MemRegion(lab_base, (size_t)0)); |
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227 _old_gen_is_full = false; |
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228 |
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229 _prefetch_queue.clear(); |
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230 |
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231 #if PS_PM_STATS |
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232 _total_pushes = 0; |
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233 _masked_pushes = 0; |
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234 _overflow_pushes = 0; |
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235 _max_overflow_length = 0; |
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236 _arrays_chunked = 0; |
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237 _array_chunks_processed = 0; |
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238 _total_steals = 0; |
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239 _masked_steals = 0; |
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240 #endif // PS_PM_STATS |
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241 } |
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242 |
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243 void PSPromotionManager::drain_stacks_depth(bool totally_drain) { |
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244 assert(depth_first(), "invariant"); |
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245 assert(overflow_stack_depth() != NULL, "invariant"); |
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246 totally_drain = totally_drain || _totally_drain; |
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247 |
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248 #ifdef ASSERT |
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249 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
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250 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
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251 MutableSpace* to_space = heap->young_gen()->to_space(); |
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252 MutableSpace* old_space = heap->old_gen()->object_space(); |
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253 MutableSpace* perm_space = heap->perm_gen()->object_space(); |
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254 #endif /* ASSERT */ |
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255 |
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256 do { |
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257 oop* p; |
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258 |
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259 // Drain overflow stack first, so other threads can steal from |
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260 // claimed stack while we work. |
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261 while(!overflow_stack_depth()->is_empty()) { |
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262 p = overflow_stack_depth()->pop(); |
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263 process_popped_location_depth(p); |
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264 } |
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265 |
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266 if (totally_drain) { |
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267 while (claimed_stack_depth()->pop_local(p)) { |
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268 process_popped_location_depth(p); |
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269 } |
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270 } else { |
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271 while (claimed_stack_depth()->size() > _target_stack_size && |
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272 claimed_stack_depth()->pop_local(p)) { |
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273 process_popped_location_depth(p); |
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274 } |
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275 } |
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276 } while( (totally_drain && claimed_stack_depth()->size() > 0) || |
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277 (overflow_stack_depth()->length() > 0) ); |
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278 |
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279 assert(!totally_drain || claimed_stack_empty(), "Sanity"); |
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280 assert(totally_drain || |
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281 claimed_stack_depth()->size() <= _target_stack_size, |
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282 "Sanity"); |
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283 assert(overflow_stack_empty(), "Sanity"); |
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284 } |
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285 |
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286 void PSPromotionManager::drain_stacks_breadth(bool totally_drain) { |
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287 assert(!depth_first(), "invariant"); |
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288 assert(overflow_stack_breadth() != NULL, "invariant"); |
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289 totally_drain = totally_drain || _totally_drain; |
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290 |
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291 #ifdef ASSERT |
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292 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
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293 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
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294 MutableSpace* to_space = heap->young_gen()->to_space(); |
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295 MutableSpace* old_space = heap->old_gen()->object_space(); |
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296 MutableSpace* perm_space = heap->perm_gen()->object_space(); |
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297 #endif /* ASSERT */ |
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298 |
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299 do { |
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300 oop obj; |
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301 |
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302 // Drain overflow stack first, so other threads can steal from |
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303 // claimed stack while we work. |
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304 while(!overflow_stack_breadth()->is_empty()) { |
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305 obj = overflow_stack_breadth()->pop(); |
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306 obj->copy_contents(this); |
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307 } |
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308 |
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309 if (totally_drain) { |
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310 // obj is a reference!!! |
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311 while (claimed_stack_breadth()->pop_local(obj)) { |
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312 // It would be nice to assert about the type of objects we might |
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313 // pop, but they can come from anywhere, unfortunately. |
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314 obj->copy_contents(this); |
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315 } |
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316 } else { |
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317 // obj is a reference!!! |
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318 while (claimed_stack_breadth()->size() > _target_stack_size && |
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319 claimed_stack_breadth()->pop_local(obj)) { |
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320 // It would be nice to assert about the type of objects we might |
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321 // pop, but they can come from anywhere, unfortunately. |
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322 obj->copy_contents(this); |
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323 } |
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324 } |
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325 |
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326 // If we could not find any other work, flush the prefetch queue |
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327 if (claimed_stack_breadth()->size() == 0 && |
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328 (overflow_stack_breadth()->length() == 0)) { |
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329 flush_prefetch_queue(); |
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330 } |
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331 } while((totally_drain && claimed_stack_breadth()->size() > 0) || |
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332 (overflow_stack_breadth()->length() > 0)); |
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333 |
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334 assert(!totally_drain || claimed_stack_empty(), "Sanity"); |
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335 assert(totally_drain || |
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336 claimed_stack_breadth()->size() <= _target_stack_size, |
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337 "Sanity"); |
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338 assert(overflow_stack_empty(), "Sanity"); |
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339 } |
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340 |
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341 void PSPromotionManager::flush_labs() { |
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342 assert(claimed_stack_empty(), "Attempt to flush lab with live stack"); |
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343 assert(overflow_stack_empty(), "Attempt to flush lab with live overflow stack"); |
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344 |
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345 // If either promotion lab fills up, we can flush the |
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346 // lab but not refill it, so check first. |
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347 assert(!_young_lab.is_flushed() || _young_gen_is_full, "Sanity"); |
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348 if (!_young_lab.is_flushed()) |
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349 _young_lab.flush(); |
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350 |
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351 assert(!_old_lab.is_flushed() || _old_gen_is_full, "Sanity"); |
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352 if (!_old_lab.is_flushed()) |
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353 _old_lab.flush(); |
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354 |
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355 // Let PSScavenge know if we overflowed |
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356 if (_young_gen_is_full) { |
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357 PSScavenge::set_survivor_overflow(true); |
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358 } |
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359 } |
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360 |
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361 // |
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362 // This method is pretty bulky. It would be nice to split it up |
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363 // into smaller submethods, but we need to be careful not to hurt |
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364 // performance. |
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365 // |
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366 |
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367 oop PSPromotionManager::copy_to_survivor_space(oop o, bool depth_first) { |
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368 assert(PSScavenge::should_scavenge(o), "Sanity"); |
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369 |
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370 oop new_obj = NULL; |
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371 |
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372 // NOTE! We must be very careful with any methods that access the mark |
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373 // in o. There may be multiple threads racing on it, and it may be forwarded |
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374 // at any time. Do not use oop methods for accessing the mark! |
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375 markOop test_mark = o->mark(); |
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376 |
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377 // The same test as "o->is_forwarded()" |
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378 if (!test_mark->is_marked()) { |
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379 bool new_obj_is_tenured = false; |
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380 size_t new_obj_size = o->size(); |
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381 |
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382 // Find the objects age, MT safe. |
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383 int age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ? |
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384 test_mark->displaced_mark_helper()->age() : test_mark->age(); |
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385 |
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386 // Try allocating obj in to-space (unless too old) |
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387 if (age < PSScavenge::tenuring_threshold()) { |
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388 new_obj = (oop) _young_lab.allocate(new_obj_size); |
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389 if (new_obj == NULL && !_young_gen_is_full) { |
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390 // Do we allocate directly, or flush and refill? |
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391 if (new_obj_size > (YoungPLABSize / 2)) { |
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392 // Allocate this object directly |
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393 new_obj = (oop)young_space()->cas_allocate(new_obj_size); |
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394 } else { |
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395 // Flush and fill |
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396 _young_lab.flush(); |
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397 |
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398 HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize); |
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399 if (lab_base != NULL) { |
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400 _young_lab.initialize(MemRegion(lab_base, YoungPLABSize)); |
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401 // Try the young lab allocation again. |
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402 new_obj = (oop) _young_lab.allocate(new_obj_size); |
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403 } else { |
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404 _young_gen_is_full = true; |
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405 } |
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406 } |
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407 } |
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408 } |
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409 |
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410 // Otherwise try allocating obj tenured |
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411 if (new_obj == NULL) { |
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412 #ifndef PRODUCT |
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413 if (Universe::heap()->promotion_should_fail()) { |
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414 return oop_promotion_failed(o, test_mark); |
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415 } |
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416 #endif // #ifndef PRODUCT |
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417 |
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418 new_obj = (oop) _old_lab.allocate(new_obj_size); |
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419 new_obj_is_tenured = true; |
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420 |
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421 if (new_obj == NULL) { |
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422 if (!_old_gen_is_full) { |
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423 // Do we allocate directly, or flush and refill? |
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424 if (new_obj_size > (OldPLABSize / 2)) { |
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425 // Allocate this object directly |
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426 new_obj = (oop)old_gen()->cas_allocate(new_obj_size); |
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427 } else { |
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428 // Flush and fill |
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429 _old_lab.flush(); |
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430 |
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431 HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize); |
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432 if(lab_base != NULL) { |
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433 _old_lab.initialize(MemRegion(lab_base, OldPLABSize)); |
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434 // Try the old lab allocation again. |
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435 new_obj = (oop) _old_lab.allocate(new_obj_size); |
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436 } |
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437 } |
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438 } |
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439 |
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440 // This is the promotion failed test, and code handling. |
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441 // The code belongs here for two reasons. It is slightly |
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442 // different thatn the code below, and cannot share the |
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443 // CAS testing code. Keeping the code here also minimizes |
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444 // the impact on the common case fast path code. |
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445 |
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446 if (new_obj == NULL) { |
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447 _old_gen_is_full = true; |
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448 return oop_promotion_failed(o, test_mark); |
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449 } |
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450 } |
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451 } |
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452 |
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453 assert(new_obj != NULL, "allocation should have succeeded"); |
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454 |
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455 // Copy obj |
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456 Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size); |
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457 |
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458 // Now we have to CAS in the header. |
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459 if (o->cas_forward_to(new_obj, test_mark)) { |
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460 // We won any races, we "own" this object. |
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461 assert(new_obj == o->forwardee(), "Sanity"); |
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462 |
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463 // Increment age if obj still in new generation. Now that |
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464 // we're dealing with a markOop that cannot change, it is |
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465 // okay to use the non mt safe oop methods. |
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466 if (!new_obj_is_tenured) { |
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467 new_obj->incr_age(); |
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468 assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj"); |
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469 } |
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470 |
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471 if (depth_first) { |
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472 // Do the size comparison first with new_obj_size, which we |
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473 // already have. Hopefully, only a few objects are larger than |
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474 // _min_array_size_for_chunking, and most of them will be arrays. |
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475 // So, the is->objArray() test would be very infrequent. |
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476 if (new_obj_size > _min_array_size_for_chunking && |
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477 new_obj->is_objArray() && |
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478 PSChunkLargeArrays) { |
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479 // we'll chunk it |
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480 #if PS_PM_STATS |
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481 ++_arrays_chunked; |
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482 #endif // PS_PM_STATS |
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483 oop* const masked_o = mask_chunked_array_oop(o); |
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484 push_depth(masked_o); |
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485 #if PS_PM_STATS |
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486 ++_masked_pushes; |
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487 #endif // PS_PM_STATS |
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488 } else { |
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489 // we'll just push its contents |
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490 new_obj->push_contents(this); |
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491 } |
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492 } else { |
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493 push_breadth(new_obj); |
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494 } |
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495 } else { |
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496 // We lost, someone else "owns" this object |
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497 guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed."); |
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498 |
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499 // Unallocate the space used. NOTE! We may have directly allocated |
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500 // the object. If so, we cannot deallocate it, so we have to test! |
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501 if (new_obj_is_tenured) { |
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502 if (!_old_lab.unallocate_object(new_obj)) { |
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503 // The promotion lab failed to unallocate the object. |
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504 // We need to overwrite the object with a filler that |
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505 // contains no interior pointers. |
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506 MemRegion mr((HeapWord*)new_obj, new_obj_size); |
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507 // Clean this up and move to oopFactory (see bug 4718422) |
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508 SharedHeap::fill_region_with_object(mr); |
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509 } |
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510 } else { |
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511 if (!_young_lab.unallocate_object(new_obj)) { |
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512 // The promotion lab failed to unallocate the object. |
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513 // We need to overwrite the object with a filler that |
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514 // contains no interior pointers. |
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515 MemRegion mr((HeapWord*)new_obj, new_obj_size); |
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516 // Clean this up and move to oopFactory (see bug 4718422) |
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517 SharedHeap::fill_region_with_object(mr); |
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518 } |
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519 } |
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520 |
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521 // don't update this before the unallocation! |
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522 new_obj = o->forwardee(); |
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523 } |
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524 } else { |
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525 assert(o->is_forwarded(), "Sanity"); |
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526 new_obj = o->forwardee(); |
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527 } |
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528 |
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529 #ifdef DEBUG |
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530 // This code must come after the CAS test, or it will print incorrect |
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531 // information. |
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532 if (TraceScavenge) { |
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533 gclog_or_tty->print_cr("{%s %s 0x%x -> 0x%x (%d)}", |
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534 PSScavenge::should_scavenge(new_obj) ? "copying" : "tenuring", |
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535 new_obj->blueprint()->internal_name(), o, new_obj, new_obj->size()); |
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536 |
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537 } |
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538 #endif |
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539 |
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540 return new_obj; |
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541 } |
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542 |
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543 void PSPromotionManager::process_array_chunk(oop old) { |
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544 assert(PSChunkLargeArrays, "invariant"); |
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545 assert(old->is_objArray(), "invariant"); |
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546 assert(old->is_forwarded(), "invariant"); |
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547 |
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548 #if PS_PM_STATS |
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549 ++_array_chunks_processed; |
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550 #endif // PS_PM_STATS |
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551 |
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552 oop const obj = old->forwardee(); |
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553 |
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554 int start; |
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555 int const end = arrayOop(old)->length(); |
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556 if (end > (int) _min_array_size_for_chunking) { |
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557 // we'll chunk more |
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558 start = end - _array_chunk_size; |
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559 assert(start > 0, "invariant"); |
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560 arrayOop(old)->set_length(start); |
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561 push_depth(mask_chunked_array_oop(old)); |
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562 #if PS_PM_STATS |
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563 ++_masked_pushes; |
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564 #endif // PS_PM_STATS |
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565 } else { |
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566 // this is the final chunk for this array |
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567 start = 0; |
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568 int const actual_length = arrayOop(obj)->length(); |
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569 arrayOop(old)->set_length(actual_length); |
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570 } |
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571 |
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572 assert(start < end, "invariant"); |
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573 oop* const base = objArrayOop(obj)->base(); |
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574 oop* p = base + start; |
|
575 oop* const chunk_end = base + end; |
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576 while (p < chunk_end) { |
|
577 if (PSScavenge::should_scavenge(*p)) { |
|
578 claim_or_forward_depth(p); |
|
579 } |
|
580 ++p; |
|
581 } |
|
582 } |
|
583 |
|
584 oop PSPromotionManager::oop_promotion_failed(oop obj, markOop obj_mark) { |
|
585 assert(_old_gen_is_full || PromotionFailureALot, "Sanity"); |
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586 |
|
587 // Attempt to CAS in the header. |
|
588 // This tests if the header is still the same as when |
|
589 // this started. If it is the same (i.e., no forwarding |
|
590 // pointer has been installed), then this thread owns |
|
591 // it. |
|
592 if (obj->cas_forward_to(obj, obj_mark)) { |
|
593 // We won any races, we "own" this object. |
|
594 assert(obj == obj->forwardee(), "Sanity"); |
|
595 |
|
596 if (depth_first()) { |
|
597 obj->push_contents(this); |
|
598 } else { |
|
599 // Don't bother incrementing the age, just push |
|
600 // onto the claimed_stack.. |
|
601 push_breadth(obj); |
|
602 } |
|
603 |
|
604 // Save the mark if needed |
|
605 PSScavenge::oop_promotion_failed(obj, obj_mark); |
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606 } else { |
|
607 // We lost, someone else "owns" this object |
|
608 guarantee(obj->is_forwarded(), "Object must be forwarded if the cas failed."); |
|
609 |
|
610 // No unallocation to worry about. |
|
611 obj = obj->forwardee(); |
|
612 } |
|
613 |
|
614 #ifdef DEBUG |
|
615 if (TraceScavenge) { |
|
616 gclog_or_tty->print_cr("{%s %s 0x%x (%d)}", |
|
617 "promotion-failure", |
|
618 obj->blueprint()->internal_name(), |
|
619 obj, obj->size()); |
|
620 |
|
621 } |
|
622 #endif |
|
623 |
|
624 return obj; |
|
625 } |