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1 /* |
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2 * Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. |
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8 * |
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9 * This code is distributed in the hope that it will be useful, but WITHOUT |
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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12 * version 2 for more details (a copy is included in the LICENSE file that |
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13 * accompanied this code). |
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14 * |
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15 * You should have received a copy of the GNU General Public License version |
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16 * 2 along with this work; if not, write to the Free Software Foundation, |
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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18 * |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
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22 * |
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23 */ |
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24 #ifndef SHARE_VM_MEMORY_METASPACE_HPP |
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25 #define SHARE_VM_MEMORY_METASPACE_HPP |
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26 |
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27 #include "memory/allocation.hpp" |
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28 #include "memory/memRegion.hpp" |
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29 #include "runtime/virtualspace.hpp" |
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30 #include "utilities/exceptions.hpp" |
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31 |
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32 // Metaspace |
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33 // |
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34 // Metaspaces are Arenas for the VM's metadata. |
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35 // They are allocated one per class loader object, and one for the null |
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36 // bootstrap class loader |
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37 // Eventually for bootstrap loader we'll have a read-only section and read-write |
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38 // to write for DumpSharedSpaces and read for UseSharedSpaces |
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39 // |
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40 // block X ---+ +-------------------+ |
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41 // | | Virtualspace | |
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42 // | | | |
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43 // | | | |
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44 // | |-------------------| |
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45 // | || Chunk | |
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46 // | || | |
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47 // | ||---------- | |
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48 // +------>||| block 0 | | |
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49 // ||---------- | |
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50 // ||| block 1 | | |
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51 // ||---------- | |
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52 // || | |
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53 // |-------------------| |
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54 // | | |
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55 // | | |
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56 // +-------------------+ |
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57 // |
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58 |
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59 class ClassLoaderData; |
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60 class MetaWord; |
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61 class Mutex; |
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62 class outputStream; |
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63 class FreeChunk; |
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64 template <class Chunk_t> class FreeList; |
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65 template <class Chunk_t> class BinaryTreeDictionary; |
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66 class SpaceManager; |
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67 |
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68 // Metaspaces each have a SpaceManager and allocations |
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69 // are done by the SpaceManager. Allocations are done |
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70 // out of the current Metachunk. When the current Metachunk |
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71 // is exhausted, the SpaceManager gets a new one from |
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72 // the current VirtualSpace. When the VirtualSpace is exhausted |
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73 // the SpaceManager gets a new one. The SpaceManager |
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74 // also manages freelists of available Chunks. |
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75 // |
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76 // Currently the space manager maintains the list of |
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77 // virtual spaces and the list of chunks in use. Its |
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78 // allocate() method returns a block for use as a |
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79 // quantum of metadata. |
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80 |
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81 class VirtualSpaceList; |
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82 |
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83 class Metaspace : public CHeapObj<mtClass> { |
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84 friend class VMStructs; |
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85 friend class SpaceManager; |
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86 friend class VM_CollectForMetadataAllocation; |
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87 friend class MetaspaceGC; |
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88 friend class MetaspaceAux; |
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89 |
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90 public: |
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91 enum MetadataType {ClassType, NonClassType}; |
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92 |
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93 private: |
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94 void initialize(Mutex* lock, size_t initial_size = 0); |
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95 |
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96 static size_t _first_chunk_word_size; |
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97 |
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98 SpaceManager* _vsm; |
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99 SpaceManager* vsm() const { return _vsm; } |
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100 |
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101 SpaceManager* _class_vsm; |
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102 SpaceManager* class_vsm() const { return _class_vsm; } |
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103 |
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104 MetaWord* allocate(size_t word_size, MetadataType mdtype); |
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105 |
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106 // Virtual Space lists for both classes and other metadata |
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107 static VirtualSpaceList* _space_list; |
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108 static VirtualSpaceList* _class_space_list; |
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109 |
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110 static VirtualSpaceList* space_list() { return _space_list; } |
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111 static VirtualSpaceList* class_space_list() { return _class_space_list; } |
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112 |
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113 public: |
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114 |
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115 Metaspace(Mutex* lock, size_t initial_size); |
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116 Metaspace(Mutex* lock); |
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117 ~Metaspace(); |
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118 |
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119 // Initialize globals for Metaspace |
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120 static void global_initialize(); |
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121 static void initialize_class_space(ReservedSpace rs); |
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122 |
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123 static size_t first_chunk_word_size() { return _first_chunk_word_size; } |
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124 |
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125 char* bottom() const; |
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126 size_t used_words(MetadataType mdtype) const; |
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127 size_t free_words(MetadataType mdtype) const; |
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128 size_t capacity_words(MetadataType mdtype) const; |
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129 size_t waste_words(MetadataType mdtype) const; |
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130 |
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131 static MetaWord* allocate(ClassLoaderData* loader_data, size_t size, |
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132 bool read_only, MetadataType mdtype, TRAPS); |
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133 |
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134 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class); |
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135 |
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136 #ifndef PRODUCT |
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137 bool contains(const void *ptr) const; |
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138 bool contains_class(const void *ptr) const; |
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139 #endif |
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140 |
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141 void dump(outputStream* const out) const; |
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142 |
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143 void print_on(outputStream* st) const; |
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144 // Debugging support |
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145 void verify(); |
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146 }; |
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147 |
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148 class MetaspaceAux : AllStatic { |
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149 |
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150 // Statistics for class space and data space in metaspace. |
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151 static size_t used_in_bytes(Metaspace::MetadataType mdtype); |
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152 static size_t free_in_bytes(Metaspace::MetadataType mdtype); |
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153 static size_t capacity_in_bytes(Metaspace::MetadataType mdtype); |
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154 static size_t reserved_in_bytes(Metaspace::MetadataType mdtype); |
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155 |
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156 static size_t free_chunks_total(Metaspace::MetadataType mdtype); |
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157 static size_t free_chunks_total_in_bytes(Metaspace::MetadataType mdtype); |
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158 |
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159 public: |
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160 // Total of space allocated to metadata in all Metaspaces |
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161 static size_t used_in_bytes() { |
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162 return used_in_bytes(Metaspace::ClassType) + |
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163 used_in_bytes(Metaspace::NonClassType); |
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164 } |
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165 |
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166 // Total of available space in all Metaspaces |
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167 // Total of capacity allocated to all Metaspaces. This includes |
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168 // space in Metachunks not yet allocated and in the Metachunk |
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169 // freelist. |
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170 static size_t capacity_in_bytes() { |
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171 return capacity_in_bytes(Metaspace::ClassType) + |
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172 capacity_in_bytes(Metaspace::NonClassType); |
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173 } |
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174 |
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175 // Total space reserved in all Metaspaces |
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176 static size_t reserved_in_bytes() { |
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177 return reserved_in_bytes(Metaspace::ClassType) + |
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178 reserved_in_bytes(Metaspace::NonClassType); |
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179 } |
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180 |
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181 static size_t min_chunk_size(); |
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182 |
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183 // Print change in used metadata. |
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184 static void print_metaspace_change(size_t prev_metadata_used); |
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185 static void print_on(outputStream * out); |
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186 static void print_on(outputStream * out, Metaspace::MetadataType mdtype); |
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187 |
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188 static void print_waste(outputStream* out); |
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189 static void dump(outputStream* out); |
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190 }; |
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191 |
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192 // Metaspace are deallocated when their class loader are GC'ed. |
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193 // This class implements a policy for inducing GC's to recover |
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194 // Metaspaces. |
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195 |
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196 class MetaspaceGC : AllStatic { |
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197 |
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198 // The current high-water-mark for inducing a GC. When |
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199 // the capacity of all space in the virtual lists reaches this value, |
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200 // a GC is induced and the value is increased. This should be changed |
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201 // to the space actually used for allocations to avoid affects of |
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202 // fragmentation losses to partially used chunks. Size is in words. |
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203 static size_t _capacity_until_GC; |
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204 |
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205 // After a GC is done any allocation that fails should try to expand |
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206 // the capacity of the Metaspaces. This flag is set during attempts |
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207 // to allocate in the VMGCOperation that does the GC. |
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208 static bool _expand_after_GC; |
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209 |
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210 // For a CMS collection, signal that a concurrent collection should |
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211 // be started. |
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212 static bool _should_concurrent_collect; |
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213 |
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214 static uint _shrink_factor; |
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215 |
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216 static void set_capacity_until_GC(size_t v) { _capacity_until_GC = v; } |
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217 |
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218 static size_t shrink_factor() { return _shrink_factor; } |
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219 void set_shrink_factor(uint v) { _shrink_factor = v; } |
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220 |
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221 public: |
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222 |
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223 static size_t capacity_until_GC() { return _capacity_until_GC; } |
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224 static size_t capacity_until_GC_in_bytes() { return _capacity_until_GC * BytesPerWord; } |
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225 static void inc_capacity_until_GC(size_t v) { _capacity_until_GC += v; } |
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226 static void dec_capacity_until_GC(size_t v) { |
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227 _capacity_until_GC = _capacity_until_GC > v ? _capacity_until_GC - v : 0; |
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228 } |
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229 static bool expand_after_GC() { return _expand_after_GC; } |
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230 static void set_expand_after_GC(bool v) { _expand_after_GC = v; } |
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231 |
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232 static bool should_concurrent_collect() { return _should_concurrent_collect; } |
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233 static void set_should_concurrent_collect(bool v) { |
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234 _should_concurrent_collect = v; |
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235 } |
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236 |
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237 // The amount to increase the high-water-mark (_capacity_until_GC) |
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238 static size_t delta_capacity_until_GC(size_t word_size); |
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239 |
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240 // It is expected that this will be called when the current capacity |
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241 // has been used and a GC should be considered. |
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242 static bool should_expand(VirtualSpaceList* vsl, size_t word_size); |
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243 |
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244 // Calculate the new high-water mark at which to induce |
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245 // a GC. |
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246 static void compute_new_size(); |
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247 }; |
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248 |
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249 #endif // SHARE_VM_MEMORY_METASPACE_HPP |