0
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1 /*
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2 * Copyright 2000-2007 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/_genCollectedHeap.cpp.incl"
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27
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28 GenCollectedHeap* GenCollectedHeap::_gch;
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29 NOT_PRODUCT(size_t GenCollectedHeap::_skip_header_HeapWords = 0;)
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30
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31 // The set of potentially parallel tasks in strong root scanning.
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32 enum GCH_process_strong_roots_tasks {
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33 // We probably want to parallelize both of these internally, but for now...
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34 GCH_PS_younger_gens,
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35 // Leave this one last.
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36 GCH_PS_NumElements
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37 };
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38
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39 GenCollectedHeap::GenCollectedHeap(GenCollectorPolicy *policy) :
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40 SharedHeap(policy),
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41 _gen_policy(policy),
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42 _gen_process_strong_tasks(new SubTasksDone(GCH_PS_NumElements)),
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43 _full_collections_completed(0)
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44 {
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45 if (_gen_process_strong_tasks == NULL ||
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46 !_gen_process_strong_tasks->valid()) {
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47 vm_exit_during_initialization("Failed necessary allocation.");
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48 }
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49 assert(policy != NULL, "Sanity check");
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50 _preloading_shared_classes = false;
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51 }
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52
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53 jint GenCollectedHeap::initialize() {
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54 int i;
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55 _n_gens = gen_policy()->number_of_generations();
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56
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57 // While there are no constraints in the GC code that HeapWordSize
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58 // be any particular value, there are multiple other areas in the
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59 // system which believe this to be true (e.g. oop->object_size in some
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60 // cases incorrectly returns the size in wordSize units rather than
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61 // HeapWordSize).
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62 guarantee(HeapWordSize == wordSize, "HeapWordSize must equal wordSize");
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63
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64 // The heap must be at least as aligned as generations.
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65 size_t alignment = Generation::GenGrain;
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66
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67 _gen_specs = gen_policy()->generations();
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68 PermanentGenerationSpec *perm_gen_spec =
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69 collector_policy()->permanent_generation();
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70
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71 // Make sure the sizes are all aligned.
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72 for (i = 0; i < _n_gens; i++) {
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73 _gen_specs[i]->align(alignment);
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74 }
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75 perm_gen_spec->align(alignment);
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76
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77 // If we are dumping the heap, then allocate a wasted block of address
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78 // space in order to push the heap to a lower address. This extra
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79 // address range allows for other (or larger) libraries to be loaded
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80 // without them occupying the space required for the shared spaces.
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81
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82 if (DumpSharedSpaces) {
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83 uintx reserved = 0;
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84 uintx block_size = 64*1024*1024;
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85 while (reserved < SharedDummyBlockSize) {
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86 char* dummy = os::reserve_memory(block_size);
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87 reserved += block_size;
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88 }
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89 }
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90
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91 // Allocate space for the heap.
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92
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93 char* heap_address;
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94 size_t total_reserved = 0;
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95 int n_covered_regions = 0;
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96 ReservedSpace heap_rs(0);
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97
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98 heap_address = allocate(alignment, perm_gen_spec, &total_reserved,
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99 &n_covered_regions, &heap_rs);
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100
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101 if (UseSharedSpaces) {
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102 if (!heap_rs.is_reserved() || heap_address != heap_rs.base()) {
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103 if (heap_rs.is_reserved()) {
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104 heap_rs.release();
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105 }
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106 FileMapInfo* mapinfo = FileMapInfo::current_info();
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107 mapinfo->fail_continue("Unable to reserve shared region.");
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108 allocate(alignment, perm_gen_spec, &total_reserved, &n_covered_regions,
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109 &heap_rs);
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110 }
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111 }
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112
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113 if (!heap_rs.is_reserved()) {
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114 vm_shutdown_during_initialization(
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115 "Could not reserve enough space for object heap");
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116 return JNI_ENOMEM;
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117 }
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118
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119 _reserved = MemRegion((HeapWord*)heap_rs.base(),
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120 (HeapWord*)(heap_rs.base() + heap_rs.size()));
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121
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122 // It is important to do this in a way such that concurrent readers can't
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123 // temporarily think somethings in the heap. (Seen this happen in asserts.)
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124 _reserved.set_word_size(0);
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125 _reserved.set_start((HeapWord*)heap_rs.base());
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126 size_t actual_heap_size = heap_rs.size() - perm_gen_spec->misc_data_size()
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127 - perm_gen_spec->misc_code_size();
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128 _reserved.set_end((HeapWord*)(heap_rs.base() + actual_heap_size));
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129
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130 _rem_set = collector_policy()->create_rem_set(_reserved, n_covered_regions);
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131 set_barrier_set(rem_set()->bs());
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132 _gch = this;
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133
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134 for (i = 0; i < _n_gens; i++) {
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135 ReservedSpace this_rs = heap_rs.first_part(_gen_specs[i]->max_size(),
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136 UseSharedSpaces, UseSharedSpaces);
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137 _gens[i] = _gen_specs[i]->init(this_rs, i, rem_set());
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138 heap_rs = heap_rs.last_part(_gen_specs[i]->max_size());
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139 }
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140 _perm_gen = perm_gen_spec->init(heap_rs, PermSize, rem_set());
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141
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142 clear_incremental_collection_will_fail();
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143 clear_last_incremental_collection_failed();
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144
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145 #ifndef SERIALGC
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146 // If we are running CMS, create the collector responsible
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147 // for collecting the CMS generations.
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148 if (collector_policy()->is_concurrent_mark_sweep_policy()) {
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149 bool success = create_cms_collector();
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150 if (!success) return JNI_ENOMEM;
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151 }
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152 #endif // SERIALGC
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153
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154 return JNI_OK;
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155 }
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156
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157
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158 char* GenCollectedHeap::allocate(size_t alignment,
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159 PermanentGenerationSpec* perm_gen_spec,
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160 size_t* _total_reserved,
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161 int* _n_covered_regions,
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162 ReservedSpace* heap_rs){
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163 const char overflow_msg[] = "The size of the object heap + VM data exceeds "
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164 "the maximum representable size";
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165
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166 // Now figure out the total size.
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167 size_t total_reserved = 0;
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168 int n_covered_regions = 0;
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169 const size_t pageSize = UseLargePages ?
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170 os::large_page_size() : os::vm_page_size();
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171
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172 for (int i = 0; i < _n_gens; i++) {
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173 total_reserved += _gen_specs[i]->max_size();
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174 if (total_reserved < _gen_specs[i]->max_size()) {
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175 vm_exit_during_initialization(overflow_msg);
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176 }
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177 n_covered_regions += _gen_specs[i]->n_covered_regions();
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178 }
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179 assert(total_reserved % pageSize == 0, "Gen size");
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180 total_reserved += perm_gen_spec->max_size();
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181 assert(total_reserved % pageSize == 0, "Perm Gen size");
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182
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183 if (total_reserved < perm_gen_spec->max_size()) {
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184 vm_exit_during_initialization(overflow_msg);
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185 }
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186 n_covered_regions += perm_gen_spec->n_covered_regions();
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187
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188 // Add the size of the data area which shares the same reserved area
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189 // as the heap, but which is not actually part of the heap.
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190 size_t s = perm_gen_spec->misc_data_size() + perm_gen_spec->misc_code_size();
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191
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192 total_reserved += s;
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193 if (total_reserved < s) {
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194 vm_exit_during_initialization(overflow_msg);
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195 }
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196
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197 if (UseLargePages) {
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198 assert(total_reserved != 0, "total_reserved cannot be 0");
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199 total_reserved = round_to(total_reserved, os::large_page_size());
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200 if (total_reserved < os::large_page_size()) {
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201 vm_exit_during_initialization(overflow_msg);
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202 }
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203 }
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204
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205 // Calculate the address at which the heap must reside in order for
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206 // the shared data to be at the required address.
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207
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208 char* heap_address;
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209 if (UseSharedSpaces) {
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210
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211 // Calculate the address of the first word beyond the heap.
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212 FileMapInfo* mapinfo = FileMapInfo::current_info();
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213 int lr = CompactingPermGenGen::n_regions - 1;
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214 size_t capacity = align_size_up(mapinfo->space_capacity(lr), alignment);
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215 heap_address = mapinfo->region_base(lr) + capacity;
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216
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217 // Calculate the address of the first word of the heap.
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218 heap_address -= total_reserved;
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219 } else {
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220 heap_address = NULL; // any address will do.
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221 }
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222
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223 *_total_reserved = total_reserved;
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224 *_n_covered_regions = n_covered_regions;
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225 *heap_rs = ReservedSpace(total_reserved, alignment,
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226 UseLargePages, heap_address);
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227
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228 return heap_address;
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229 }
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230
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231
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232 void GenCollectedHeap::post_initialize() {
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233 SharedHeap::post_initialize();
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234 TwoGenerationCollectorPolicy *policy =
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235 (TwoGenerationCollectorPolicy *)collector_policy();
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236 guarantee(policy->is_two_generation_policy(), "Illegal policy type");
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237 DefNewGeneration* def_new_gen = (DefNewGeneration*) get_gen(0);
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238 assert(def_new_gen->kind() == Generation::DefNew ||
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239 def_new_gen->kind() == Generation::ParNew ||
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240 def_new_gen->kind() == Generation::ASParNew,
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241 "Wrong generation kind");
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242
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243 Generation* old_gen = get_gen(1);
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244 assert(old_gen->kind() == Generation::ConcurrentMarkSweep ||
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245 old_gen->kind() == Generation::ASConcurrentMarkSweep ||
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246 old_gen->kind() == Generation::MarkSweepCompact,
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247 "Wrong generation kind");
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248
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249 policy->initialize_size_policy(def_new_gen->eden()->capacity(),
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250 old_gen->capacity(),
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251 def_new_gen->from()->capacity());
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252 policy->initialize_gc_policy_counters();
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253 }
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254
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255 void GenCollectedHeap::ref_processing_init() {
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256 SharedHeap::ref_processing_init();
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257 for (int i = 0; i < _n_gens; i++) {
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258 _gens[i]->ref_processor_init();
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259 }
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260 }
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261
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262 size_t GenCollectedHeap::capacity() const {
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263 size_t res = 0;
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264 for (int i = 0; i < _n_gens; i++) {
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265 res += _gens[i]->capacity();
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266 }
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267 return res;
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268 }
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269
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270 size_t GenCollectedHeap::used() const {
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271 size_t res = 0;
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272 for (int i = 0; i < _n_gens; i++) {
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273 res += _gens[i]->used();
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274 }
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275 return res;
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276 }
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277
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278 // Save the "used_region" for generations level and lower,
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279 // and, if perm is true, for perm gen.
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280 void GenCollectedHeap::save_used_regions(int level, bool perm) {
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281 assert(level < _n_gens, "Illegal level parameter");
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282 for (int i = level; i >= 0; i--) {
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283 _gens[i]->save_used_region();
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284 }
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285 if (perm) {
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286 perm_gen()->save_used_region();
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287 }
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288 }
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289
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290 size_t GenCollectedHeap::max_capacity() const {
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291 size_t res = 0;
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292 for (int i = 0; i < _n_gens; i++) {
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293 res += _gens[i]->max_capacity();
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294 }
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295 return res;
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296 }
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297
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298 // Update the _full_collections_completed counter
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299 // at the end of a stop-world full GC.
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300 unsigned int GenCollectedHeap::update_full_collections_completed() {
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301 MonitorLockerEx ml(FullGCCount_lock, Mutex::_no_safepoint_check_flag);
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302 assert(_full_collections_completed <= _total_full_collections,
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303 "Can't complete more collections than were started");
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304 _full_collections_completed = _total_full_collections;
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305 ml.notify_all();
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306 return _full_collections_completed;
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307 }
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308
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309 // Update the _full_collections_completed counter, as appropriate,
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310 // at the end of a concurrent GC cycle. Note the conditional update
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311 // below to allow this method to be called by a concurrent collector
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312 // without synchronizing in any manner with the VM thread (which
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313 // may already have initiated a STW full collection "concurrently").
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314 unsigned int GenCollectedHeap::update_full_collections_completed(unsigned int count) {
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315 MonitorLockerEx ml(FullGCCount_lock, Mutex::_no_safepoint_check_flag);
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316 assert((_full_collections_completed <= _total_full_collections) &&
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317 (count <= _total_full_collections),
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318 "Can't complete more collections than were started");
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319 if (count > _full_collections_completed) {
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320 _full_collections_completed = count;
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321 ml.notify_all();
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322 }
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323 return _full_collections_completed;
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324 }
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325
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326
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327 #ifndef PRODUCT
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328 // Override of memory state checking method in CollectedHeap:
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329 // Some collectors (CMS for example) can't have badHeapWordVal written
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330 // in the first two words of an object. (For instance , in the case of
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331 // CMS these words hold state used to synchronize between certain
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332 // (concurrent) GC steps and direct allocating mutators.)
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333 // The skip_header_HeapWords() method below, allows us to skip
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334 // over the requisite number of HeapWord's. Note that (for
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335 // generational collectors) this means that those many words are
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336 // skipped in each object, irrespective of the generation in which
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337 // that object lives. The resultant loss of precision seems to be
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338 // harmless and the pain of avoiding that imprecision appears somewhat
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339 // higher than we are prepared to pay for such rudimentary debugging
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340 // support.
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341 void GenCollectedHeap::check_for_non_bad_heap_word_value(HeapWord* addr,
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342 size_t size) {
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343 if (CheckMemoryInitialization && ZapUnusedHeapArea) {
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344 // We are asked to check a size in HeapWords,
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345 // but the memory is mangled in juint words.
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346 juint* start = (juint*) (addr + skip_header_HeapWords());
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347 juint* end = (juint*) (addr + size);
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348 for (juint* slot = start; slot < end; slot += 1) {
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349 assert(*slot == badHeapWordVal,
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350 "Found non badHeapWordValue in pre-allocation check");
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351 }
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352 }
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353 }
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354 #endif
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355
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356 HeapWord* GenCollectedHeap::attempt_allocation(size_t size,
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357 bool is_tlab,
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358 bool first_only) {
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359 HeapWord* res;
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360 for (int i = 0; i < _n_gens; i++) {
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361 if (_gens[i]->should_allocate(size, is_tlab)) {
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362 res = _gens[i]->allocate(size, is_tlab);
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363 if (res != NULL) return res;
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364 else if (first_only) break;
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365 }
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366 }
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367 // Otherwise...
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368 return NULL;
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369 }
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370
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371 HeapWord* GenCollectedHeap::mem_allocate(size_t size,
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372 bool is_large_noref,
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373 bool is_tlab,
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374 bool* gc_overhead_limit_was_exceeded) {
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375 return collector_policy()->mem_allocate_work(size,
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376 is_tlab,
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377 gc_overhead_limit_was_exceeded);
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378 }
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379
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380 bool GenCollectedHeap::must_clear_all_soft_refs() {
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381 return _gc_cause == GCCause::_last_ditch_collection;
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382 }
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383
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384 bool GenCollectedHeap::should_do_concurrent_full_gc(GCCause::Cause cause) {
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385 return (cause == GCCause::_java_lang_system_gc ||
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386 cause == GCCause::_gc_locker) &&
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387 UseConcMarkSweepGC && ExplicitGCInvokesConcurrent;
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388 }
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389
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390 void GenCollectedHeap::do_collection(bool full,
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391 bool clear_all_soft_refs,
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392 size_t size,
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393 bool is_tlab,
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394 int max_level) {
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395 bool prepared_for_verification = false;
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396 ResourceMark rm;
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397 DEBUG_ONLY(Thread* my_thread = Thread::current();)
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398
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399 assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
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400 assert(my_thread->is_VM_thread() ||
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401 my_thread->is_ConcurrentGC_thread(),
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402 "incorrect thread type capability");
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403 assert(Heap_lock->is_locked(), "the requesting thread should have the Heap_lock");
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404 guarantee(!is_gc_active(), "collection is not reentrant");
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405 assert(max_level < n_gens(), "sanity check");
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406
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407 if (GC_locker::check_active_before_gc()) {
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408 return; // GC is disabled (e.g. JNI GetXXXCritical operation)
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409 }
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410
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411 const size_t perm_prev_used = perm_gen()->used();
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412
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413 if (PrintHeapAtGC) {
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414 Universe::print_heap_before_gc();
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415 if (Verbose) {
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416 gclog_or_tty->print_cr("GC Cause: %s", GCCause::to_string(gc_cause()));
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417 }
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418 }
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419
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420 {
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421 FlagSetting fl(_is_gc_active, true);
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422
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423 bool complete = full && (max_level == (n_gens()-1));
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424 const char* gc_cause_str = "GC ";
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425 if (complete) {
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426 GCCause::Cause cause = gc_cause();
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427 if (cause == GCCause::_java_lang_system_gc) {
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428 gc_cause_str = "Full GC (System) ";
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429 } else {
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430 gc_cause_str = "Full GC ";
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431 }
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432 }
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433 gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
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434 TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
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435 TraceTime t(gc_cause_str, PrintGCDetails, false, gclog_or_tty);
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436
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437 gc_prologue(complete);
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438 increment_total_collections(complete);
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439
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440 size_t gch_prev_used = used();
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441
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442 int starting_level = 0;
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443 if (full) {
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444 // Search for the oldest generation which will collect all younger
|
|
445 // generations, and start collection loop there.
|
|
446 for (int i = max_level; i >= 0; i--) {
|
|
447 if (_gens[i]->full_collects_younger_generations()) {
|
|
448 starting_level = i;
|
|
449 break;
|
|
450 }
|
|
451 }
|
|
452 }
|
|
453
|
|
454 bool must_restore_marks_for_biased_locking = false;
|
|
455
|
|
456 int max_level_collected = starting_level;
|
|
457 for (int i = starting_level; i <= max_level; i++) {
|
|
458 if (_gens[i]->should_collect(full, size, is_tlab)) {
|
|
459 // Timer for individual generations. Last argument is false: no CR
|
|
460 TraceTime t1(_gens[i]->short_name(), PrintGCDetails, false, gclog_or_tty);
|
|
461 TraceCollectorStats tcs(_gens[i]->counters());
|
|
462 TraceMemoryManagerStats tmms(_gens[i]->kind());
|
|
463
|
|
464 size_t prev_used = _gens[i]->used();
|
|
465 _gens[i]->stat_record()->invocations++;
|
|
466 _gens[i]->stat_record()->accumulated_time.start();
|
|
467
|
|
468 if (PrintGC && Verbose) {
|
|
469 gclog_or_tty->print("level=%d invoke=%d size=" SIZE_FORMAT,
|
|
470 i,
|
|
471 _gens[i]->stat_record()->invocations,
|
|
472 size*HeapWordSize);
|
|
473 }
|
|
474
|
|
475 if (VerifyBeforeGC && i >= VerifyGCLevel &&
|
|
476 total_collections() >= VerifyGCStartAt) {
|
|
477 HandleMark hm; // Discard invalid handles created during verification
|
|
478 if (!prepared_for_verification) {
|
|
479 prepare_for_verify();
|
|
480 prepared_for_verification = true;
|
|
481 }
|
|
482 gclog_or_tty->print(" VerifyBeforeGC:");
|
|
483 Universe::verify(true);
|
|
484 }
|
|
485 COMPILER2_PRESENT(DerivedPointerTable::clear());
|
|
486
|
|
487 if (!must_restore_marks_for_biased_locking &&
|
|
488 _gens[i]->performs_in_place_marking()) {
|
|
489 // We perform this mark word preservation work lazily
|
|
490 // because it's only at this point that we know whether we
|
|
491 // absolutely have to do it; we want to avoid doing it for
|
|
492 // scavenge-only collections where it's unnecessary
|
|
493 must_restore_marks_for_biased_locking = true;
|
|
494 BiasedLocking::preserve_marks();
|
|
495 }
|
|
496
|
|
497 // Do collection work
|
|
498 {
|
|
499 // Note on ref discovery: For what appear to be historical reasons,
|
|
500 // GCH enables and disabled (by enqueing) refs discovery.
|
|
501 // In the future this should be moved into the generation's
|
|
502 // collect method so that ref discovery and enqueueing concerns
|
|
503 // are local to a generation. The collect method could return
|
|
504 // an appropriate indication in the case that notification on
|
|
505 // the ref lock was needed. This will make the treatment of
|
|
506 // weak refs more uniform (and indeed remove such concerns
|
|
507 // from GCH). XXX
|
|
508
|
|
509 HandleMark hm; // Discard invalid handles created during gc
|
|
510 save_marks(); // save marks for all gens
|
|
511 // We want to discover references, but not process them yet.
|
|
512 // This mode is disabled in process_discovered_references if the
|
|
513 // generation does some collection work, or in
|
|
514 // enqueue_discovered_references if the generation returns
|
|
515 // without doing any work.
|
|
516 ReferenceProcessor* rp = _gens[i]->ref_processor();
|
|
517 // If the discovery of ("weak") refs in this generation is
|
|
518 // atomic wrt other collectors in this configuration, we
|
|
519 // are guaranteed to have empty discovered ref lists.
|
|
520 if (rp->discovery_is_atomic()) {
|
|
521 rp->verify_no_references_recorded();
|
|
522 rp->enable_discovery();
|
|
523 } else {
|
|
524 // collect() will enable discovery as appropriate
|
|
525 }
|
|
526 _gens[i]->collect(full, clear_all_soft_refs, size, is_tlab);
|
|
527 if (!rp->enqueuing_is_done()) {
|
|
528 rp->enqueue_discovered_references();
|
|
529 } else {
|
|
530 rp->set_enqueuing_is_done(false);
|
|
531 }
|
|
532 rp->verify_no_references_recorded();
|
|
533 }
|
|
534 max_level_collected = i;
|
|
535
|
|
536 // Determine if allocation request was met.
|
|
537 if (size > 0) {
|
|
538 if (!is_tlab || _gens[i]->supports_tlab_allocation()) {
|
|
539 if (size*HeapWordSize <= _gens[i]->unsafe_max_alloc_nogc()) {
|
|
540 size = 0;
|
|
541 }
|
|
542 }
|
|
543 }
|
|
544
|
|
545 COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
|
|
546
|
|
547 _gens[i]->stat_record()->accumulated_time.stop();
|
|
548
|
|
549 update_gc_stats(i, full);
|
|
550
|
|
551 if (VerifyAfterGC && i >= VerifyGCLevel &&
|
|
552 total_collections() >= VerifyGCStartAt) {
|
|
553 HandleMark hm; // Discard invalid handles created during verification
|
|
554 gclog_or_tty->print(" VerifyAfterGC:");
|
|
555 Universe::verify(false);
|
|
556 }
|
|
557
|
|
558 if (PrintGCDetails) {
|
|
559 gclog_or_tty->print(":");
|
|
560 _gens[i]->print_heap_change(prev_used);
|
|
561 }
|
|
562 }
|
|
563 }
|
|
564
|
|
565 // Update "complete" boolean wrt what actually transpired --
|
|
566 // for instance, a promotion failure could have led to
|
|
567 // a whole heap collection.
|
|
568 complete = complete || (max_level_collected == n_gens() - 1);
|
|
569
|
|
570 if (PrintGCDetails) {
|
|
571 print_heap_change(gch_prev_used);
|
|
572
|
|
573 // Print perm gen info for full GC with PrintGCDetails flag.
|
|
574 if (complete) {
|
|
575 print_perm_heap_change(perm_prev_used);
|
|
576 }
|
|
577 }
|
|
578
|
|
579 for (int j = max_level_collected; j >= 0; j -= 1) {
|
|
580 // Adjust generation sizes.
|
|
581 _gens[j]->compute_new_size();
|
|
582 }
|
|
583
|
|
584 if (complete) {
|
|
585 // Ask the permanent generation to adjust size for full collections
|
|
586 perm()->compute_new_size();
|
|
587 update_full_collections_completed();
|
|
588 }
|
|
589
|
|
590 // Track memory usage and detect low memory after GC finishes
|
|
591 MemoryService::track_memory_usage();
|
|
592
|
|
593 gc_epilogue(complete);
|
|
594
|
|
595 if (must_restore_marks_for_biased_locking) {
|
|
596 BiasedLocking::restore_marks();
|
|
597 }
|
|
598 }
|
|
599
|
|
600 AdaptiveSizePolicy* sp = gen_policy()->size_policy();
|
|
601 AdaptiveSizePolicyOutput(sp, total_collections());
|
|
602
|
|
603 if (PrintHeapAtGC) {
|
|
604 Universe::print_heap_after_gc();
|
|
605 }
|
|
606
|
|
607 if (ExitAfterGCNum > 0 && total_collections() == ExitAfterGCNum) {
|
|
608 tty->print_cr("Stopping after GC #%d", ExitAfterGCNum);
|
|
609 vm_exit(-1);
|
|
610 }
|
|
611 }
|
|
612
|
|
613 HeapWord* GenCollectedHeap::satisfy_failed_allocation(size_t size, bool is_tlab) {
|
|
614 return collector_policy()->satisfy_failed_allocation(size, is_tlab);
|
|
615 }
|
|
616
|
|
617 void GenCollectedHeap::set_par_threads(int t) {
|
|
618 SharedHeap::set_par_threads(t);
|
|
619 _gen_process_strong_tasks->set_par_threads(t);
|
|
620 }
|
|
621
|
|
622 class AssertIsPermClosure: public OopClosure {
|
|
623 public:
|
|
624 void do_oop(oop* p) {
|
|
625 assert((*p) == NULL || (*p)->is_perm(), "Referent should be perm.");
|
|
626 }
|
|
627 };
|
|
628 static AssertIsPermClosure assert_is_perm_closure;
|
|
629
|
|
630 void GenCollectedHeap::
|
|
631 gen_process_strong_roots(int level,
|
|
632 bool younger_gens_as_roots,
|
|
633 bool collecting_perm_gen,
|
|
634 SharedHeap::ScanningOption so,
|
|
635 OopsInGenClosure* older_gens,
|
|
636 OopsInGenClosure* not_older_gens) {
|
|
637 // General strong roots.
|
|
638 SharedHeap::process_strong_roots(collecting_perm_gen, so,
|
|
639 not_older_gens, older_gens);
|
|
640
|
|
641 if (younger_gens_as_roots) {
|
|
642 if (!_gen_process_strong_tasks->is_task_claimed(GCH_PS_younger_gens)) {
|
|
643 for (int i = 0; i < level; i++) {
|
|
644 not_older_gens->set_generation(_gens[i]);
|
|
645 _gens[i]->oop_iterate(not_older_gens);
|
|
646 }
|
|
647 not_older_gens->reset_generation();
|
|
648 }
|
|
649 }
|
|
650 // When collection is parallel, all threads get to cooperate to do
|
|
651 // older-gen scanning.
|
|
652 for (int i = level+1; i < _n_gens; i++) {
|
|
653 older_gens->set_generation(_gens[i]);
|
|
654 rem_set()->younger_refs_iterate(_gens[i], older_gens);
|
|
655 older_gens->reset_generation();
|
|
656 }
|
|
657
|
|
658 _gen_process_strong_tasks->all_tasks_completed();
|
|
659 }
|
|
660
|
|
661 void GenCollectedHeap::gen_process_weak_roots(OopClosure* root_closure,
|
|
662 OopClosure* non_root_closure) {
|
|
663 SharedHeap::process_weak_roots(root_closure, non_root_closure);
|
|
664 // "Local" "weak" refs
|
|
665 for (int i = 0; i < _n_gens; i++) {
|
|
666 _gens[i]->ref_processor()->weak_oops_do(root_closure);
|
|
667 }
|
|
668 }
|
|
669
|
|
670 #define GCH_SINCE_SAVE_MARKS_ITERATE_DEFN(OopClosureType, nv_suffix) \
|
|
671 void GenCollectedHeap:: \
|
|
672 oop_since_save_marks_iterate(int level, \
|
|
673 OopClosureType* cur, \
|
|
674 OopClosureType* older) { \
|
|
675 _gens[level]->oop_since_save_marks_iterate##nv_suffix(cur); \
|
|
676 for (int i = level+1; i < n_gens(); i++) { \
|
|
677 _gens[i]->oop_since_save_marks_iterate##nv_suffix(older); \
|
|
678 } \
|
|
679 perm_gen()->oop_since_save_marks_iterate##nv_suffix(older); \
|
|
680 }
|
|
681
|
|
682 ALL_SINCE_SAVE_MARKS_CLOSURES(GCH_SINCE_SAVE_MARKS_ITERATE_DEFN)
|
|
683
|
|
684 #undef GCH_SINCE_SAVE_MARKS_ITERATE_DEFN
|
|
685
|
|
686 bool GenCollectedHeap::no_allocs_since_save_marks(int level) {
|
|
687 for (int i = level; i < _n_gens; i++) {
|
|
688 if (!_gens[i]->no_allocs_since_save_marks()) return false;
|
|
689 }
|
|
690 return perm_gen()->no_allocs_since_save_marks();
|
|
691 }
|
|
692
|
|
693 bool GenCollectedHeap::supports_inline_contig_alloc() const {
|
|
694 return _gens[0]->supports_inline_contig_alloc();
|
|
695 }
|
|
696
|
|
697 HeapWord** GenCollectedHeap::top_addr() const {
|
|
698 return _gens[0]->top_addr();
|
|
699 }
|
|
700
|
|
701 HeapWord** GenCollectedHeap::end_addr() const {
|
|
702 return _gens[0]->end_addr();
|
|
703 }
|
|
704
|
|
705 size_t GenCollectedHeap::unsafe_max_alloc() {
|
|
706 return _gens[0]->unsafe_max_alloc_nogc();
|
|
707 }
|
|
708
|
|
709 // public collection interfaces
|
|
710
|
|
711 void GenCollectedHeap::collect(GCCause::Cause cause) {
|
|
712 if (should_do_concurrent_full_gc(cause)) {
|
|
713 #ifndef SERIALGC
|
|
714 // mostly concurrent full collection
|
|
715 collect_mostly_concurrent(cause);
|
|
716 #else // SERIALGC
|
|
717 ShouldNotReachHere();
|
|
718 #endif // SERIALGC
|
|
719 } else {
|
|
720 #ifdef ASSERT
|
|
721 if (cause == GCCause::_scavenge_alot) {
|
|
722 // minor collection only
|
|
723 collect(cause, 0);
|
|
724 } else {
|
|
725 // Stop-the-world full collection
|
|
726 collect(cause, n_gens() - 1);
|
|
727 }
|
|
728 #else
|
|
729 // Stop-the-world full collection
|
|
730 collect(cause, n_gens() - 1);
|
|
731 #endif
|
|
732 }
|
|
733 }
|
|
734
|
|
735 void GenCollectedHeap::collect(GCCause::Cause cause, int max_level) {
|
|
736 // The caller doesn't have the Heap_lock
|
|
737 assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
|
|
738 MutexLocker ml(Heap_lock);
|
|
739 collect_locked(cause, max_level);
|
|
740 }
|
|
741
|
|
742 // This interface assumes that it's being called by the
|
|
743 // vm thread. It collects the heap assuming that the
|
|
744 // heap lock is already held and that we are executing in
|
|
745 // the context of the vm thread.
|
|
746 void GenCollectedHeap::collect_as_vm_thread(GCCause::Cause cause) {
|
|
747 assert(Thread::current()->is_VM_thread(), "Precondition#1");
|
|
748 assert(Heap_lock->is_locked(), "Precondition#2");
|
|
749 GCCauseSetter gcs(this, cause);
|
|
750 switch (cause) {
|
|
751 case GCCause::_heap_inspection:
|
|
752 case GCCause::_heap_dump: {
|
|
753 HandleMark hm;
|
|
754 do_full_collection(false, // don't clear all soft refs
|
|
755 n_gens() - 1);
|
|
756 break;
|
|
757 }
|
|
758 default: // XXX FIX ME
|
|
759 ShouldNotReachHere(); // Unexpected use of this function
|
|
760 }
|
|
761 }
|
|
762
|
|
763 void GenCollectedHeap::collect_locked(GCCause::Cause cause) {
|
|
764 // The caller has the Heap_lock
|
|
765 assert(Heap_lock->owned_by_self(), "this thread should own the Heap_lock");
|
|
766 collect_locked(cause, n_gens() - 1);
|
|
767 }
|
|
768
|
|
769 // this is the private collection interface
|
|
770 // The Heap_lock is expected to be held on entry.
|
|
771
|
|
772 void GenCollectedHeap::collect_locked(GCCause::Cause cause, int max_level) {
|
|
773 if (_preloading_shared_classes) {
|
|
774 warning("\nThe permanent generation is not large enough to preload "
|
|
775 "requested classes.\nUse -XX:PermSize= to increase the initial "
|
|
776 "size of the permanent generation.\n");
|
|
777 vm_exit(2);
|
|
778 }
|
|
779 // Read the GC count while holding the Heap_lock
|
|
780 unsigned int gc_count_before = total_collections();
|
|
781 unsigned int full_gc_count_before = total_full_collections();
|
|
782 {
|
|
783 MutexUnlocker mu(Heap_lock); // give up heap lock, execute gets it back
|
|
784 VM_GenCollectFull op(gc_count_before, full_gc_count_before,
|
|
785 cause, max_level);
|
|
786 VMThread::execute(&op);
|
|
787 }
|
|
788 }
|
|
789
|
|
790 #ifndef SERIALGC
|
|
791 bool GenCollectedHeap::create_cms_collector() {
|
|
792
|
|
793 assert(((_gens[1]->kind() == Generation::ConcurrentMarkSweep) ||
|
|
794 (_gens[1]->kind() == Generation::ASConcurrentMarkSweep)) &&
|
|
795 _perm_gen->as_gen()->kind() == Generation::ConcurrentMarkSweep,
|
|
796 "Unexpected generation kinds");
|
|
797 // Skip two header words in the block content verification
|
|
798 NOT_PRODUCT(_skip_header_HeapWords = CMSCollector::skip_header_HeapWords();)
|
|
799 CMSCollector* collector = new CMSCollector(
|
|
800 (ConcurrentMarkSweepGeneration*)_gens[1],
|
|
801 (ConcurrentMarkSweepGeneration*)_perm_gen->as_gen(),
|
|
802 _rem_set->as_CardTableRS(),
|
|
803 (ConcurrentMarkSweepPolicy*) collector_policy());
|
|
804
|
|
805 if (collector == NULL || !collector->completed_initialization()) {
|
|
806 if (collector) {
|
|
807 delete collector; // Be nice in embedded situation
|
|
808 }
|
|
809 vm_shutdown_during_initialization("Could not create CMS collector");
|
|
810 return false;
|
|
811 }
|
|
812 return true; // success
|
|
813 }
|
|
814
|
|
815 void GenCollectedHeap::collect_mostly_concurrent(GCCause::Cause cause) {
|
|
816 assert(!Heap_lock->owned_by_self(), "Should not own Heap_lock");
|
|
817
|
|
818 MutexLocker ml(Heap_lock);
|
|
819 // Read the GC counts while holding the Heap_lock
|
|
820 unsigned int full_gc_count_before = total_full_collections();
|
|
821 unsigned int gc_count_before = total_collections();
|
|
822 {
|
|
823 MutexUnlocker mu(Heap_lock);
|
|
824 VM_GenCollectFullConcurrent op(gc_count_before, full_gc_count_before, cause);
|
|
825 VMThread::execute(&op);
|
|
826 }
|
|
827 }
|
|
828 #endif // SERIALGC
|
|
829
|
|
830
|
|
831 void GenCollectedHeap::do_full_collection(bool clear_all_soft_refs,
|
|
832 int max_level) {
|
|
833 int local_max_level;
|
|
834 if (!incremental_collection_will_fail() &&
|
|
835 gc_cause() == GCCause::_gc_locker) {
|
|
836 local_max_level = 0;
|
|
837 } else {
|
|
838 local_max_level = max_level;
|
|
839 }
|
|
840
|
|
841 do_collection(true /* full */,
|
|
842 clear_all_soft_refs /* clear_all_soft_refs */,
|
|
843 0 /* size */,
|
|
844 false /* is_tlab */,
|
|
845 local_max_level /* max_level */);
|
|
846 // Hack XXX FIX ME !!!
|
|
847 // A scavenge may not have been attempted, or may have
|
|
848 // been attempted and failed, because the old gen was too full
|
|
849 if (local_max_level == 0 && gc_cause() == GCCause::_gc_locker &&
|
|
850 incremental_collection_will_fail()) {
|
|
851 if (PrintGCDetails) {
|
|
852 gclog_or_tty->print_cr("GC locker: Trying a full collection "
|
|
853 "because scavenge failed");
|
|
854 }
|
|
855 // This time allow the old gen to be collected as well
|
|
856 do_collection(true /* full */,
|
|
857 clear_all_soft_refs /* clear_all_soft_refs */,
|
|
858 0 /* size */,
|
|
859 false /* is_tlab */,
|
|
860 n_gens() - 1 /* max_level */);
|
|
861 }
|
|
862 }
|
|
863
|
|
864 // Returns "TRUE" iff "p" points into the allocated area of the heap.
|
|
865 bool GenCollectedHeap::is_in(const void* p) const {
|
|
866 #ifndef ASSERT
|
|
867 guarantee(VerifyBeforeGC ||
|
|
868 VerifyDuringGC ||
|
|
869 VerifyBeforeExit ||
|
|
870 VerifyAfterGC, "too expensive");
|
|
871 #endif
|
|
872 // This might be sped up with a cache of the last generation that
|
|
873 // answered yes.
|
|
874 for (int i = 0; i < _n_gens; i++) {
|
|
875 if (_gens[i]->is_in(p)) return true;
|
|
876 }
|
|
877 if (_perm_gen->as_gen()->is_in(p)) return true;
|
|
878 // Otherwise...
|
|
879 return false;
|
|
880 }
|
|
881
|
|
882 // Returns "TRUE" iff "p" points into the allocated area of the heap.
|
|
883 bool GenCollectedHeap::is_in_youngest(void* p) {
|
|
884 return _gens[0]->is_in(p);
|
|
885 }
|
|
886
|
|
887 void GenCollectedHeap::oop_iterate(OopClosure* cl) {
|
|
888 for (int i = 0; i < _n_gens; i++) {
|
|
889 _gens[i]->oop_iterate(cl);
|
|
890 }
|
|
891 }
|
|
892
|
|
893 void GenCollectedHeap::oop_iterate(MemRegion mr, OopClosure* cl) {
|
|
894 for (int i = 0; i < _n_gens; i++) {
|
|
895 _gens[i]->oop_iterate(mr, cl);
|
|
896 }
|
|
897 }
|
|
898
|
|
899 void GenCollectedHeap::object_iterate(ObjectClosure* cl) {
|
|
900 for (int i = 0; i < _n_gens; i++) {
|
|
901 _gens[i]->object_iterate(cl);
|
|
902 }
|
|
903 perm_gen()->object_iterate(cl);
|
|
904 }
|
|
905
|
|
906 void GenCollectedHeap::object_iterate_since_last_GC(ObjectClosure* cl) {
|
|
907 for (int i = 0; i < _n_gens; i++) {
|
|
908 _gens[i]->object_iterate_since_last_GC(cl);
|
|
909 }
|
|
910 }
|
|
911
|
|
912 Space* GenCollectedHeap::space_containing(const void* addr) const {
|
|
913 for (int i = 0; i < _n_gens; i++) {
|
|
914 Space* res = _gens[i]->space_containing(addr);
|
|
915 if (res != NULL) return res;
|
|
916 }
|
|
917 Space* res = perm_gen()->space_containing(addr);
|
|
918 if (res != NULL) return res;
|
|
919 // Otherwise...
|
|
920 assert(false, "Could not find containing space");
|
|
921 return NULL;
|
|
922 }
|
|
923
|
|
924
|
|
925 HeapWord* GenCollectedHeap::block_start(const void* addr) const {
|
|
926 assert(is_in_reserved(addr), "block_start of address outside of heap");
|
|
927 for (int i = 0; i < _n_gens; i++) {
|
|
928 if (_gens[i]->is_in_reserved(addr)) {
|
|
929 assert(_gens[i]->is_in(addr),
|
|
930 "addr should be in allocated part of generation");
|
|
931 return _gens[i]->block_start(addr);
|
|
932 }
|
|
933 }
|
|
934 if (perm_gen()->is_in_reserved(addr)) {
|
|
935 assert(perm_gen()->is_in(addr),
|
|
936 "addr should be in allocated part of perm gen");
|
|
937 return perm_gen()->block_start(addr);
|
|
938 }
|
|
939 assert(false, "Some generation should contain the address");
|
|
940 return NULL;
|
|
941 }
|
|
942
|
|
943 size_t GenCollectedHeap::block_size(const HeapWord* addr) const {
|
|
944 assert(is_in_reserved(addr), "block_size of address outside of heap");
|
|
945 for (int i = 0; i < _n_gens; i++) {
|
|
946 if (_gens[i]->is_in_reserved(addr)) {
|
|
947 assert(_gens[i]->is_in(addr),
|
|
948 "addr should be in allocated part of generation");
|
|
949 return _gens[i]->block_size(addr);
|
|
950 }
|
|
951 }
|
|
952 if (perm_gen()->is_in_reserved(addr)) {
|
|
953 assert(perm_gen()->is_in(addr),
|
|
954 "addr should be in allocated part of perm gen");
|
|
955 return perm_gen()->block_size(addr);
|
|
956 }
|
|
957 assert(false, "Some generation should contain the address");
|
|
958 return 0;
|
|
959 }
|
|
960
|
|
961 bool GenCollectedHeap::block_is_obj(const HeapWord* addr) const {
|
|
962 assert(is_in_reserved(addr), "block_is_obj of address outside of heap");
|
|
963 assert(block_start(addr) == addr, "addr must be a block start");
|
|
964 for (int i = 0; i < _n_gens; i++) {
|
|
965 if (_gens[i]->is_in_reserved(addr)) {
|
|
966 return _gens[i]->block_is_obj(addr);
|
|
967 }
|
|
968 }
|
|
969 if (perm_gen()->is_in_reserved(addr)) {
|
|
970 return perm_gen()->block_is_obj(addr);
|
|
971 }
|
|
972 assert(false, "Some generation should contain the address");
|
|
973 return false;
|
|
974 }
|
|
975
|
|
976 bool GenCollectedHeap::supports_tlab_allocation() const {
|
|
977 for (int i = 0; i < _n_gens; i += 1) {
|
|
978 if (_gens[i]->supports_tlab_allocation()) {
|
|
979 return true;
|
|
980 }
|
|
981 }
|
|
982 return false;
|
|
983 }
|
|
984
|
|
985 size_t GenCollectedHeap::tlab_capacity(Thread* thr) const {
|
|
986 size_t result = 0;
|
|
987 for (int i = 0; i < _n_gens; i += 1) {
|
|
988 if (_gens[i]->supports_tlab_allocation()) {
|
|
989 result += _gens[i]->tlab_capacity();
|
|
990 }
|
|
991 }
|
|
992 return result;
|
|
993 }
|
|
994
|
|
995 size_t GenCollectedHeap::unsafe_max_tlab_alloc(Thread* thr) const {
|
|
996 size_t result = 0;
|
|
997 for (int i = 0; i < _n_gens; i += 1) {
|
|
998 if (_gens[i]->supports_tlab_allocation()) {
|
|
999 result += _gens[i]->unsafe_max_tlab_alloc();
|
|
1000 }
|
|
1001 }
|
|
1002 return result;
|
|
1003 }
|
|
1004
|
|
1005 HeapWord* GenCollectedHeap::allocate_new_tlab(size_t size) {
|
|
1006 bool gc_overhead_limit_was_exceeded;
|
|
1007 HeapWord* result = mem_allocate(size /* size */,
|
|
1008 false /* is_large_noref */,
|
|
1009 true /* is_tlab */,
|
|
1010 &gc_overhead_limit_was_exceeded);
|
|
1011 return result;
|
|
1012 }
|
|
1013
|
|
1014 // Requires "*prev_ptr" to be non-NULL. Deletes and a block of minimal size
|
|
1015 // from the list headed by "*prev_ptr".
|
|
1016 static ScratchBlock *removeSmallestScratch(ScratchBlock **prev_ptr) {
|
|
1017 bool first = true;
|
|
1018 size_t min_size = 0; // "first" makes this conceptually infinite.
|
|
1019 ScratchBlock **smallest_ptr, *smallest;
|
|
1020 ScratchBlock *cur = *prev_ptr;
|
|
1021 while (cur) {
|
|
1022 assert(*prev_ptr == cur, "just checking");
|
|
1023 if (first || cur->num_words < min_size) {
|
|
1024 smallest_ptr = prev_ptr;
|
|
1025 smallest = cur;
|
|
1026 min_size = smallest->num_words;
|
|
1027 first = false;
|
|
1028 }
|
|
1029 prev_ptr = &cur->next;
|
|
1030 cur = cur->next;
|
|
1031 }
|
|
1032 smallest = *smallest_ptr;
|
|
1033 *smallest_ptr = smallest->next;
|
|
1034 return smallest;
|
|
1035 }
|
|
1036
|
|
1037 // Sort the scratch block list headed by res into decreasing size order,
|
|
1038 // and set "res" to the result.
|
|
1039 static void sort_scratch_list(ScratchBlock*& list) {
|
|
1040 ScratchBlock* sorted = NULL;
|
|
1041 ScratchBlock* unsorted = list;
|
|
1042 while (unsorted) {
|
|
1043 ScratchBlock *smallest = removeSmallestScratch(&unsorted);
|
|
1044 smallest->next = sorted;
|
|
1045 sorted = smallest;
|
|
1046 }
|
|
1047 list = sorted;
|
|
1048 }
|
|
1049
|
|
1050 ScratchBlock* GenCollectedHeap::gather_scratch(Generation* requestor,
|
|
1051 size_t max_alloc_words) {
|
|
1052 ScratchBlock* res = NULL;
|
|
1053 for (int i = 0; i < _n_gens; i++) {
|
|
1054 _gens[i]->contribute_scratch(res, requestor, max_alloc_words);
|
|
1055 }
|
|
1056 sort_scratch_list(res);
|
|
1057 return res;
|
|
1058 }
|
|
1059
|
|
1060 size_t GenCollectedHeap::large_typearray_limit() {
|
|
1061 return gen_policy()->large_typearray_limit();
|
|
1062 }
|
|
1063
|
|
1064 class GenPrepareForVerifyClosure: public GenCollectedHeap::GenClosure {
|
|
1065 void do_generation(Generation* gen) {
|
|
1066 gen->prepare_for_verify();
|
|
1067 }
|
|
1068 };
|
|
1069
|
|
1070 void GenCollectedHeap::prepare_for_verify() {
|
|
1071 ensure_parsability(false); // no need to retire TLABs
|
|
1072 GenPrepareForVerifyClosure blk;
|
|
1073 generation_iterate(&blk, false);
|
|
1074 perm_gen()->prepare_for_verify();
|
|
1075 }
|
|
1076
|
|
1077
|
|
1078 void GenCollectedHeap::generation_iterate(GenClosure* cl,
|
|
1079 bool old_to_young) {
|
|
1080 if (old_to_young) {
|
|
1081 for (int i = _n_gens-1; i >= 0; i--) {
|
|
1082 cl->do_generation(_gens[i]);
|
|
1083 }
|
|
1084 } else {
|
|
1085 for (int i = 0; i < _n_gens; i++) {
|
|
1086 cl->do_generation(_gens[i]);
|
|
1087 }
|
|
1088 }
|
|
1089 }
|
|
1090
|
|
1091 void GenCollectedHeap::space_iterate(SpaceClosure* cl) {
|
|
1092 for (int i = 0; i < _n_gens; i++) {
|
|
1093 _gens[i]->space_iterate(cl, true);
|
|
1094 }
|
|
1095 perm_gen()->space_iterate(cl, true);
|
|
1096 }
|
|
1097
|
|
1098 bool GenCollectedHeap::is_maximal_no_gc() const {
|
|
1099 for (int i = 0; i < _n_gens; i++) { // skip perm gen
|
|
1100 if (!_gens[i]->is_maximal_no_gc()) {
|
|
1101 return false;
|
|
1102 }
|
|
1103 }
|
|
1104 return true;
|
|
1105 }
|
|
1106
|
|
1107 void GenCollectedHeap::save_marks() {
|
|
1108 for (int i = 0; i < _n_gens; i++) {
|
|
1109 _gens[i]->save_marks();
|
|
1110 }
|
|
1111 perm_gen()->save_marks();
|
|
1112 }
|
|
1113
|
|
1114 void GenCollectedHeap::compute_new_generation_sizes(int collectedGen) {
|
|
1115 for (int i = 0; i <= collectedGen; i++) {
|
|
1116 _gens[i]->compute_new_size();
|
|
1117 }
|
|
1118 }
|
|
1119
|
|
1120 GenCollectedHeap* GenCollectedHeap::heap() {
|
|
1121 assert(_gch != NULL, "Uninitialized access to GenCollectedHeap::heap()");
|
|
1122 assert(_gch->kind() == CollectedHeap::GenCollectedHeap, "not a generational heap");
|
|
1123 return _gch;
|
|
1124 }
|
|
1125
|
|
1126
|
|
1127 void GenCollectedHeap::prepare_for_compaction() {
|
|
1128 Generation* scanning_gen = _gens[_n_gens-1];
|
|
1129 // Start by compacting into same gen.
|
|
1130 CompactPoint cp(scanning_gen, NULL, NULL);
|
|
1131 while (scanning_gen != NULL) {
|
|
1132 scanning_gen->prepare_for_compaction(&cp);
|
|
1133 scanning_gen = prev_gen(scanning_gen);
|
|
1134 }
|
|
1135 }
|
|
1136
|
|
1137 GCStats* GenCollectedHeap::gc_stats(int level) const {
|
|
1138 return _gens[level]->gc_stats();
|
|
1139 }
|
|
1140
|
|
1141 void GenCollectedHeap::verify(bool allow_dirty, bool silent) {
|
|
1142 if (!silent) {
|
|
1143 gclog_or_tty->print("permgen ");
|
|
1144 }
|
|
1145 perm_gen()->verify(allow_dirty);
|
|
1146 for (int i = _n_gens-1; i >= 0; i--) {
|
|
1147 Generation* g = _gens[i];
|
|
1148 if (!silent) {
|
|
1149 gclog_or_tty->print(g->name());
|
|
1150 gclog_or_tty->print(" ");
|
|
1151 }
|
|
1152 g->verify(allow_dirty);
|
|
1153 }
|
|
1154 if (!silent) {
|
|
1155 gclog_or_tty->print("remset ");
|
|
1156 }
|
|
1157 rem_set()->verify();
|
|
1158 if (!silent) {
|
|
1159 gclog_or_tty->print("ref_proc ");
|
|
1160 }
|
|
1161 ReferenceProcessor::verify();
|
|
1162 }
|
|
1163
|
|
1164 void GenCollectedHeap::print() const { print_on(tty); }
|
|
1165 void GenCollectedHeap::print_on(outputStream* st) const {
|
|
1166 for (int i = 0; i < _n_gens; i++) {
|
|
1167 _gens[i]->print_on(st);
|
|
1168 }
|
|
1169 perm_gen()->print_on(st);
|
|
1170 }
|
|
1171
|
|
1172 void GenCollectedHeap::gc_threads_do(ThreadClosure* tc) const {
|
|
1173 if (workers() != NULL) {
|
|
1174 workers()->threads_do(tc);
|
|
1175 }
|
|
1176 #ifndef SERIALGC
|
|
1177 if (UseConcMarkSweepGC) {
|
|
1178 ConcurrentMarkSweepThread::threads_do(tc);
|
|
1179 }
|
|
1180 #endif // SERIALGC
|
|
1181 }
|
|
1182
|
|
1183 void GenCollectedHeap::print_gc_threads_on(outputStream* st) const {
|
|
1184 #ifndef SERIALGC
|
|
1185 if (UseParNewGC) {
|
|
1186 workers()->print_worker_threads_on(st);
|
|
1187 }
|
|
1188 if (UseConcMarkSweepGC) {
|
|
1189 ConcurrentMarkSweepThread::print_all_on(st);
|
|
1190 }
|
|
1191 #endif // SERIALGC
|
|
1192 }
|
|
1193
|
|
1194 void GenCollectedHeap::print_tracing_info() const {
|
|
1195 if (TraceGen0Time) {
|
|
1196 get_gen(0)->print_summary_info();
|
|
1197 }
|
|
1198 if (TraceGen1Time) {
|
|
1199 get_gen(1)->print_summary_info();
|
|
1200 }
|
|
1201 }
|
|
1202
|
|
1203 void GenCollectedHeap::print_heap_change(size_t prev_used) const {
|
|
1204 if (PrintGCDetails && Verbose) {
|
|
1205 gclog_or_tty->print(" " SIZE_FORMAT
|
|
1206 "->" SIZE_FORMAT
|
|
1207 "(" SIZE_FORMAT ")",
|
|
1208 prev_used, used(), capacity());
|
|
1209 } else {
|
|
1210 gclog_or_tty->print(" " SIZE_FORMAT "K"
|
|
1211 "->" SIZE_FORMAT "K"
|
|
1212 "(" SIZE_FORMAT "K)",
|
|
1213 prev_used / K, used() / K, capacity() / K);
|
|
1214 }
|
|
1215 }
|
|
1216
|
|
1217 //New method to print perm gen info with PrintGCDetails flag
|
|
1218 void GenCollectedHeap::print_perm_heap_change(size_t perm_prev_used) const {
|
|
1219 gclog_or_tty->print(", [%s :", perm_gen()->short_name());
|
|
1220 perm_gen()->print_heap_change(perm_prev_used);
|
|
1221 gclog_or_tty->print("]");
|
|
1222 }
|
|
1223
|
|
1224 class GenGCPrologueClosure: public GenCollectedHeap::GenClosure {
|
|
1225 private:
|
|
1226 bool _full;
|
|
1227 public:
|
|
1228 void do_generation(Generation* gen) {
|
|
1229 gen->gc_prologue(_full);
|
|
1230 }
|
|
1231 GenGCPrologueClosure(bool full) : _full(full) {};
|
|
1232 };
|
|
1233
|
|
1234 void GenCollectedHeap::gc_prologue(bool full) {
|
|
1235 assert(InlineCacheBuffer::is_empty(), "should have cleaned up ICBuffer");
|
|
1236
|
|
1237 always_do_update_barrier = false;
|
|
1238 // Fill TLAB's and such
|
|
1239 CollectedHeap::accumulate_statistics_all_tlabs();
|
|
1240 ensure_parsability(true); // retire TLABs
|
|
1241
|
|
1242 // Call allocation profiler
|
|
1243 AllocationProfiler::iterate_since_last_gc();
|
|
1244 // Walk generations
|
|
1245 GenGCPrologueClosure blk(full);
|
|
1246 generation_iterate(&blk, false); // not old-to-young.
|
|
1247 perm_gen()->gc_prologue(full);
|
|
1248 };
|
|
1249
|
|
1250 class GenGCEpilogueClosure: public GenCollectedHeap::GenClosure {
|
|
1251 private:
|
|
1252 bool _full;
|
|
1253 public:
|
|
1254 void do_generation(Generation* gen) {
|
|
1255 gen->gc_epilogue(_full);
|
|
1256 }
|
|
1257 GenGCEpilogueClosure(bool full) : _full(full) {};
|
|
1258 };
|
|
1259
|
|
1260 void GenCollectedHeap::gc_epilogue(bool full) {
|
|
1261 // Remember if a partial collection of the heap failed, and
|
|
1262 // we did a complete collection.
|
|
1263 if (full && incremental_collection_will_fail()) {
|
|
1264 set_last_incremental_collection_failed();
|
|
1265 } else {
|
|
1266 clear_last_incremental_collection_failed();
|
|
1267 }
|
|
1268 // Clear the flag, if set; the generation gc_epilogues will set the
|
|
1269 // flag again if the condition persists despite the collection.
|
|
1270 clear_incremental_collection_will_fail();
|
|
1271
|
|
1272 #ifdef COMPILER2
|
|
1273 assert(DerivedPointerTable::is_empty(), "derived pointer present");
|
|
1274 size_t actual_gap = pointer_delta((HeapWord*) (max_uintx-3), *(end_addr()));
|
|
1275 guarantee(actual_gap > (size_t)FastAllocateSizeLimit, "inline allocation wraps");
|
|
1276 #endif /* COMPILER2 */
|
|
1277
|
|
1278 resize_all_tlabs();
|
|
1279
|
|
1280 GenGCEpilogueClosure blk(full);
|
|
1281 generation_iterate(&blk, false); // not old-to-young.
|
|
1282 perm_gen()->gc_epilogue(full);
|
|
1283
|
|
1284 always_do_update_barrier = UseConcMarkSweepGC;
|
|
1285 };
|
|
1286
|
|
1287 class GenEnsureParsabilityClosure: public GenCollectedHeap::GenClosure {
|
|
1288 public:
|
|
1289 void do_generation(Generation* gen) {
|
|
1290 gen->ensure_parsability();
|
|
1291 }
|
|
1292 };
|
|
1293
|
|
1294 void GenCollectedHeap::ensure_parsability(bool retire_tlabs) {
|
|
1295 CollectedHeap::ensure_parsability(retire_tlabs);
|
|
1296 GenEnsureParsabilityClosure ep_cl;
|
|
1297 generation_iterate(&ep_cl, false);
|
|
1298 perm_gen()->ensure_parsability();
|
|
1299 }
|
|
1300
|
|
1301 oop GenCollectedHeap::handle_failed_promotion(Generation* gen,
|
|
1302 oop obj,
|
|
1303 size_t obj_size,
|
|
1304 oop* ref) {
|
|
1305 assert(obj_size == (size_t)obj->size(), "bad obj_size passed in");
|
|
1306 HeapWord* result = NULL;
|
|
1307
|
|
1308 // First give each higher generation a chance to allocate the promoted object.
|
|
1309 Generation* allocator = next_gen(gen);
|
|
1310 if (allocator != NULL) {
|
|
1311 do {
|
|
1312 result = allocator->allocate(obj_size, false);
|
|
1313 } while (result == NULL && (allocator = next_gen(allocator)) != NULL);
|
|
1314 }
|
|
1315
|
|
1316 if (result == NULL) {
|
|
1317 // Then give gen and higher generations a chance to expand and allocate the
|
|
1318 // object.
|
|
1319 do {
|
|
1320 result = gen->expand_and_allocate(obj_size, false);
|
|
1321 } while (result == NULL && (gen = next_gen(gen)) != NULL);
|
|
1322 }
|
|
1323
|
|
1324 if (result != NULL) {
|
|
1325 Copy::aligned_disjoint_words((HeapWord*)obj, result, obj_size);
|
|
1326 }
|
|
1327 return oop(result);
|
|
1328 }
|
|
1329
|
|
1330 class GenTimeOfLastGCClosure: public GenCollectedHeap::GenClosure {
|
|
1331 jlong _time; // in ms
|
|
1332 jlong _now; // in ms
|
|
1333
|
|
1334 public:
|
|
1335 GenTimeOfLastGCClosure(jlong now) : _time(now), _now(now) { }
|
|
1336
|
|
1337 jlong time() { return _time; }
|
|
1338
|
|
1339 void do_generation(Generation* gen) {
|
|
1340 _time = MIN2(_time, gen->time_of_last_gc(_now));
|
|
1341 }
|
|
1342 };
|
|
1343
|
|
1344 jlong GenCollectedHeap::millis_since_last_gc() {
|
|
1345 jlong now = os::javaTimeMillis();
|
|
1346 GenTimeOfLastGCClosure tolgc_cl(now);
|
|
1347 // iterate over generations getting the oldest
|
|
1348 // time that a generation was collected
|
|
1349 generation_iterate(&tolgc_cl, false);
|
|
1350 tolgc_cl.do_generation(perm_gen());
|
|
1351 // XXX Despite the assert above, since javaTimeMillis()
|
|
1352 // doesnot guarantee monotonically increasing return
|
|
1353 // values (note, i didn't say "strictly monotonic"),
|
|
1354 // we need to guard against getting back a time
|
|
1355 // later than now. This should be fixed by basing
|
|
1356 // on someting like gethrtime() which guarantees
|
|
1357 // monotonicity. Note that cond_wait() is susceptible
|
|
1358 // to a similar problem, because its interface is
|
|
1359 // based on absolute time in the form of the
|
|
1360 // system time's notion of UCT. See also 4506635
|
|
1361 // for yet another problem of similar nature. XXX
|
|
1362 jlong retVal = now - tolgc_cl.time();
|
|
1363 if (retVal < 0) {
|
|
1364 NOT_PRODUCT(warning("time warp: %d", retVal);)
|
|
1365 return 0;
|
|
1366 }
|
|
1367 return retVal;
|
|
1368 }
|