Mercurial > hg > truffle
annotate src/share/vm/memory/referenceProcessor.hpp @ 17746:a258f8cb530f
8029255: G1: Reference processing should not enqueue references on the shared SATB queue
Reviewed-by: brutisso, tschatzl
| author | pliden |
|---|---|
| date | Fri, 10 Jan 2014 09:53:53 +0100 |
| parents | f2110083203d |
| children | 63a4eb8bcd23 d60ecdb2773e |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 10405 | 2 * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved. |
| 0 | 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 * | |
| 5 * This code is free software; you can redistribute it and/or modify it | |
| 6 * under the terms of the GNU General Public License version 2 only, as | |
| 7 * published by the Free Software Foundation. | |
| 8 * | |
| 9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
| 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 12 * version 2 for more details (a copy is included in the LICENSE file that | |
| 13 * accompanied this code). | |
| 14 * | |
| 15 * You should have received a copy of the GNU General Public License version | |
| 16 * 2 along with this work; if not, write to the Free Software Foundation, | |
| 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| 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. |
| 0 | 22 * |
| 23 */ | |
| 24 | |
| 1972 | 25 #ifndef SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP |
| 26 #define SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP | |
| 27 | |
| 28 #include "memory/referencePolicy.hpp" | |
| 10405 | 29 #include "memory/referenceProcessorStats.hpp" |
| 30 #include "memory/referenceType.hpp" | |
| 1972 | 31 #include "oops/instanceRefKlass.hpp" |
| 32 | |
| 10405 | 33 class GCTimer; |
| 34 | |
| 0 | 35 // ReferenceProcessor class encapsulates the per-"collector" processing |
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36 // of java.lang.Reference objects for GC. The interface is useful for supporting |
| 0 | 37 // a generational abstraction, in particular when there are multiple |
| 38 // generations that are being independently collected -- possibly | |
| 39 // concurrently and/or incrementally. Note, however, that the | |
| 40 // ReferenceProcessor class abstracts away from a generational setting | |
| 41 // by using only a heap interval (called "span" below), thus allowing | |
| 42 // its use in a straightforward manner in a general, non-generational | |
| 43 // setting. | |
| 44 // | |
| 45 // The basic idea is that each ReferenceProcessor object concerns | |
| 46 // itself with ("weak") reference processing in a specific "span" | |
| 47 // of the heap of interest to a specific collector. Currently, | |
| 48 // the span is a convex interval of the heap, but, efficiency | |
| 49 // apart, there seems to be no reason it couldn't be extended | |
| 50 // (with appropriate modifications) to any "non-convex interval". | |
| 51 | |
| 52 // forward references | |
| 53 class ReferencePolicy; | |
| 54 class AbstractRefProcTaskExecutor; | |
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55 |
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56 // List of discovered references. |
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57 class DiscoveredList { |
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58 public: |
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59 DiscoveredList() : _len(0), _compressed_head(0), _oop_head(NULL) { } |
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60 oop head() const { |
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61 return UseCompressedOops ? oopDesc::decode_heap_oop(_compressed_head) : |
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62 _oop_head; |
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63 } |
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64 HeapWord* adr_head() { |
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65 return UseCompressedOops ? (HeapWord*)&_compressed_head : |
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66 (HeapWord*)&_oop_head; |
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67 } |
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68 void set_head(oop o) { |
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69 if (UseCompressedOops) { |
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70 // Must compress the head ptr. |
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71 _compressed_head = oopDesc::encode_heap_oop(o); |
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72 } else { |
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73 _oop_head = o; |
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74 } |
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75 } |
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76 bool is_empty() const { return head() == NULL; } |
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77 size_t length() { return _len; } |
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78 void set_length(size_t len) { _len = len; } |
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79 void inc_length(size_t inc) { _len += inc; assert(_len > 0, "Error"); } |
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80 void dec_length(size_t dec) { _len -= dec; } |
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81 private: |
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82 // Set value depending on UseCompressedOops. This could be a template class |
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83 // but then we have to fix all the instantiations and declarations that use this class. |
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84 oop _oop_head; |
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85 narrowOop _compressed_head; |
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86 size_t _len; |
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87 }; |
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88 |
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89 // Iterator for the list of discovered references. |
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90 class DiscoveredListIterator { |
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91 private: |
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92 DiscoveredList& _refs_list; |
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93 HeapWord* _prev_next; |
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94 oop _prev; |
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95 oop _ref; |
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96 HeapWord* _discovered_addr; |
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97 oop _next; |
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98 HeapWord* _referent_addr; |
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99 oop _referent; |
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100 OopClosure* _keep_alive; |
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101 BoolObjectClosure* _is_alive; |
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102 |
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103 DEBUG_ONLY( |
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104 oop _first_seen; // cyclic linked list check |
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105 ) |
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106 |
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107 NOT_PRODUCT( |
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108 size_t _processed; |
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109 size_t _removed; |
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110 ) |
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111 |
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112 public: |
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113 inline DiscoveredListIterator(DiscoveredList& refs_list, |
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114 OopClosure* keep_alive, |
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115 BoolObjectClosure* is_alive): |
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116 _refs_list(refs_list), |
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117 _prev_next(refs_list.adr_head()), |
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118 _prev(NULL), |
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119 _ref(refs_list.head()), |
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120 #ifdef ASSERT |
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121 _first_seen(refs_list.head()), |
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122 #endif |
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123 #ifndef PRODUCT |
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124 _processed(0), |
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125 _removed(0), |
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126 #endif |
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127 _next(NULL), |
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128 _keep_alive(keep_alive), |
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129 _is_alive(is_alive) |
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130 { } |
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131 |
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132 // End Of List. |
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133 inline bool has_next() const { return _ref != NULL; } |
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134 |
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135 // Get oop to the Reference object. |
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136 inline oop obj() const { return _ref; } |
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137 |
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138 // Get oop to the referent object. |
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139 inline oop referent() const { return _referent; } |
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140 |
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141 // Returns true if referent is alive. |
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142 inline bool is_referent_alive() const { |
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143 return _is_alive->do_object_b(_referent); |
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144 } |
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145 |
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146 // Loads data for the current reference. |
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147 // The "allow_null_referent" argument tells us to allow for the possibility |
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148 // of a NULL referent in the discovered Reference object. This typically |
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149 // happens in the case of concurrent collectors that may have done the |
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150 // discovery concurrently, or interleaved, with mutator execution. |
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151 void load_ptrs(DEBUG_ONLY(bool allow_null_referent)); |
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152 |
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153 // Move to the next discovered reference. |
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154 inline void next() { |
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155 _prev_next = _discovered_addr; |
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156 _prev = _ref; |
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157 move_to_next(); |
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158 } |
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159 |
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160 // Remove the current reference from the list |
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161 void remove(); |
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162 |
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163 // Make the Reference object active again. |
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164 void make_active(); |
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165 |
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166 // Make the referent alive. |
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167 inline void make_referent_alive() { |
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168 if (UseCompressedOops) { |
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169 _keep_alive->do_oop((narrowOop*)_referent_addr); |
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170 } else { |
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171 _keep_alive->do_oop((oop*)_referent_addr); |
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172 } |
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173 } |
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174 |
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175 // Update the discovered field. |
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176 inline void update_discovered() { |
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177 // First _prev_next ref actually points into DiscoveredList (gross). |
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178 if (UseCompressedOops) { |
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179 if (!oopDesc::is_null(*(narrowOop*)_prev_next)) { |
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180 _keep_alive->do_oop((narrowOop*)_prev_next); |
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181 } |
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182 } else { |
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183 if (!oopDesc::is_null(*(oop*)_prev_next)) { |
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184 _keep_alive->do_oop((oop*)_prev_next); |
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185 } |
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186 } |
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187 } |
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188 |
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189 // NULL out referent pointer. |
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190 void clear_referent(); |
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191 |
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192 // Statistics |
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193 NOT_PRODUCT( |
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194 inline size_t processed() const { return _processed; } |
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195 inline size_t removed() const { return _removed; } |
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196 ) |
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197 |
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198 inline void move_to_next() { |
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199 if (_ref == _next) { |
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200 // End of the list. |
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201 _ref = NULL; |
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202 } else { |
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203 _ref = _next; |
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204 } |
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205 assert(_ref != _first_seen, "cyclic ref_list found"); |
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206 NOT_PRODUCT(_processed++); |
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207 } |
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208 }; |
| 0 | 209 |
| 6197 | 210 class ReferenceProcessor : public CHeapObj<mtGC> { |
| 10405 | 211 |
| 212 private: | |
| 213 size_t total_count(DiscoveredList lists[]); | |
| 214 | |
| 0 | 215 protected: |
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216 // Compatibility with pre-4965777 JDK's |
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217 static bool _pending_list_uses_discovered_field; |
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218 |
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219 // The SoftReference master timestamp clock |
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220 static jlong _soft_ref_timestamp_clock; |
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221 |
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222 MemRegion _span; // (right-open) interval of heap |
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223 // subject to wkref discovery |
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224 |
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225 bool _discovering_refs; // true when discovery enabled |
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226 bool _discovery_is_atomic; // if discovery is atomic wrt |
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227 // other collectors in configuration |
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228 bool _discovery_is_mt; // true if reference discovery is MT. |
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229 |
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230 // If true, setting "next" field of a discovered refs list requires |
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231 // write barrier(s). (Must be true if used in a collector in which |
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232 // elements of a discovered list may be moved during discovery: for |
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233 // example, a collector like Garbage-First that moves objects during a |
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234 // long-term concurrent marking phase that does weak reference |
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235 // discovery.) |
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236 bool _discovered_list_needs_barrier; |
| 0 | 237 |
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238 bool _enqueuing_is_done; // true if all weak references enqueued |
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239 bool _processing_is_mt; // true during phases when |
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240 // reference processing is MT. |
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241 uint _next_id; // round-robin mod _num_q counter in |
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242 // support of work distribution |
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243 |
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244 // For collectors that do not keep GC liveness information |
| 0 | 245 // in the object header, this field holds a closure that |
| 246 // helps the reference processor determine the reachability | |
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247 // of an oop. It is currently initialized to NULL for all |
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248 // collectors except for CMS and G1. |
| 0 | 249 BoolObjectClosure* _is_alive_non_header; |
| 250 | |
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251 // Soft ref clearing policies |
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252 // . the default policy |
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253 static ReferencePolicy* _default_soft_ref_policy; |
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254 // . the "clear all" policy |
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255 static ReferencePolicy* _always_clear_soft_ref_policy; |
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256 // . the current policy below is either one of the above |
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257 ReferencePolicy* _current_soft_ref_policy; |
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258 |
| 0 | 259 // The discovered ref lists themselves |
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260 |
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261 // The active MT'ness degree of the queues below |
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262 uint _num_q; |
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263 // The maximum MT'ness degree of the queues below |
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264 uint _max_num_q; |
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265 |
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266 // Master array of discovered oops |
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267 DiscoveredList* _discovered_refs; |
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268 |
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269 // Arrays of lists of oops, one per thread (pointers into master array above) |
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270 DiscoveredList* _discoveredSoftRefs; |
| 0 | 271 DiscoveredList* _discoveredWeakRefs; |
| 272 DiscoveredList* _discoveredFinalRefs; | |
| 273 DiscoveredList* _discoveredPhantomRefs; | |
| 274 | |
| 275 public: | |
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276 static int number_of_subclasses_of_ref() { return (REF_PHANTOM - REF_OTHER); } |
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277 |
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278 uint num_q() { return _num_q; } |
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279 uint max_num_q() { return _max_num_q; } |
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280 void set_active_mt_degree(uint v) { _num_q = v; } |
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281 |
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282 DiscoveredList* discovered_refs() { return _discovered_refs; } |
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283 |
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284 ReferencePolicy* setup_policy(bool always_clear) { |
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285 _current_soft_ref_policy = always_clear ? |
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286 _always_clear_soft_ref_policy : _default_soft_ref_policy; |
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287 _current_soft_ref_policy->setup(); // snapshot the policy threshold |
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288 return _current_soft_ref_policy; |
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289 } |
| 0 | 290 |
| 291 // Process references with a certain reachability level. | |
| 10405 | 292 size_t process_discovered_reflist(DiscoveredList refs_lists[], |
| 293 ReferencePolicy* policy, | |
| 294 bool clear_referent, | |
| 295 BoolObjectClosure* is_alive, | |
| 296 OopClosure* keep_alive, | |
| 297 VoidClosure* complete_gc, | |
| 298 AbstractRefProcTaskExecutor* task_executor); | |
| 0 | 299 |
| 300 void process_phaseJNI(BoolObjectClosure* is_alive, | |
| 301 OopClosure* keep_alive, | |
| 302 VoidClosure* complete_gc); | |
| 303 | |
| 304 // Work methods used by the method process_discovered_reflist | |
| 305 // Phase1: keep alive all those referents that are otherwise | |
| 306 // dead but which must be kept alive by policy (and their closure). | |
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307 void process_phase1(DiscoveredList& refs_list, |
| 0 | 308 ReferencePolicy* policy, |
| 309 BoolObjectClosure* is_alive, | |
| 310 OopClosure* keep_alive, | |
| 311 VoidClosure* complete_gc); | |
| 312 // Phase2: remove all those references whose referents are | |
| 313 // reachable. | |
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314 inline void process_phase2(DiscoveredList& refs_list, |
| 0 | 315 BoolObjectClosure* is_alive, |
| 316 OopClosure* keep_alive, | |
| 317 VoidClosure* complete_gc) { | |
| 318 if (discovery_is_atomic()) { | |
| 319 // complete_gc is ignored in this case for this phase | |
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320 pp2_work(refs_list, is_alive, keep_alive); |
| 0 | 321 } else { |
| 322 assert(complete_gc != NULL, "Error"); | |
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323 pp2_work_concurrent_discovery(refs_list, is_alive, |
| 0 | 324 keep_alive, complete_gc); |
| 325 } | |
| 326 } | |
| 327 // Work methods in support of process_phase2 | |
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328 void pp2_work(DiscoveredList& refs_list, |
| 0 | 329 BoolObjectClosure* is_alive, |
| 330 OopClosure* keep_alive); | |
| 331 void pp2_work_concurrent_discovery( | |
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332 DiscoveredList& refs_list, |
| 0 | 333 BoolObjectClosure* is_alive, |
| 334 OopClosure* keep_alive, | |
| 335 VoidClosure* complete_gc); | |
| 336 // Phase3: process the referents by either clearing them | |
| 337 // or keeping them alive (and their closure) | |
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338 void process_phase3(DiscoveredList& refs_list, |
| 0 | 339 bool clear_referent, |
| 340 BoolObjectClosure* is_alive, | |
| 341 OopClosure* keep_alive, | |
| 342 VoidClosure* complete_gc); | |
| 343 | |
| 344 // Enqueue references with a certain reachability level | |
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345 void enqueue_discovered_reflist(DiscoveredList& refs_list, HeapWord* pending_list_addr); |
| 0 | 346 |
| 347 // "Preclean" all the discovered reference lists | |
| 348 // by removing references with strongly reachable referents. | |
| 349 // The first argument is a predicate on an oop that indicates | |
| 350 // its (strong) reachability and the second is a closure that | |
| 351 // may be used to incrementalize or abort the precleaning process. | |
| 352 // The caller is responsible for taking care of potential | |
| 353 // interference with concurrent operations on these lists | |
| 354 // (or predicates involved) by other threads. Currently | |
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355 // only used by the CMS collector. |
| 0 | 356 void preclean_discovered_references(BoolObjectClosure* is_alive, |
| 357 OopClosure* keep_alive, | |
| 358 VoidClosure* complete_gc, | |
| 10405 | 359 YieldClosure* yield, |
| 360 GCTimer* gc_timer); | |
| 0 | 361 |
| 362 // Delete entries in the discovered lists that have | |
| 363 // either a null referent or are not active. Such | |
| 364 // Reference objects can result from the clearing | |
| 365 // or enqueueing of Reference objects concurrent | |
| 366 // with their discovery by a (concurrent) collector. | |
| 367 // For a definition of "active" see java.lang.ref.Reference; | |
| 368 // Refs are born active, become inactive when enqueued, | |
| 369 // and never become active again. The state of being | |
| 370 // active is encoded as follows: A Ref is active | |
| 371 // if and only if its "next" field is NULL. | |
| 372 void clean_up_discovered_references(); | |
| 373 void clean_up_discovered_reflist(DiscoveredList& refs_list); | |
| 374 | |
| 375 // Returns the name of the discovered reference list | |
| 376 // occupying the i / _num_q slot. | |
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377 const char* list_name(uint i); |
| 0 | 378 |
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379 void enqueue_discovered_reflists(HeapWord* pending_list_addr, AbstractRefProcTaskExecutor* task_executor); |
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380 |
| 0 | 381 protected: |
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382 // Set the 'discovered' field of the given reference to |
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383 // the given value - emitting barriers depending upon |
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384 // the value of _discovered_list_needs_barrier. |
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385 void set_discovered(oop ref, oop value); |
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386 |
| 0 | 387 // "Preclean" the given discovered reference list |
| 388 // by removing references with strongly reachable referents. | |
| 389 // Currently used in support of CMS only. | |
| 390 void preclean_discovered_reflist(DiscoveredList& refs_list, | |
| 391 BoolObjectClosure* is_alive, | |
| 392 OopClosure* keep_alive, | |
| 393 VoidClosure* complete_gc, | |
| 394 YieldClosure* yield); | |
| 395 | |
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396 // round-robin mod _num_q (not: _not_ mode _max_num_q) |
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397 uint next_id() { |
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398 uint id = _next_id; |
| 0 | 399 if (++_next_id == _num_q) { |
| 400 _next_id = 0; | |
| 401 } | |
| 402 return id; | |
| 403 } | |
| 404 DiscoveredList* get_discovered_list(ReferenceType rt); | |
| 405 inline void add_to_discovered_list_mt(DiscoveredList& refs_list, oop obj, | |
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406 HeapWord* discovered_addr); |
| 0 | 407 void verify_ok_to_handle_reflists() PRODUCT_RETURN; |
| 408 | |
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409 void clear_discovered_references(DiscoveredList& refs_list); |
| 0 | 410 void abandon_partial_discovered_list(DiscoveredList& refs_list); |
| 411 | |
| 412 // Calculate the number of jni handles. | |
| 413 unsigned int count_jni_refs(); | |
| 414 | |
| 415 // Balances reference queues. | |
| 416 void balance_queues(DiscoveredList ref_lists[]); | |
| 417 | |
| 418 // Update (advance) the soft ref master clock field. | |
| 419 void update_soft_ref_master_clock(); | |
| 420 | |
| 421 public: | |
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422 // Default parameters give you a vanilla reference processor. |
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423 ReferenceProcessor(MemRegion span, |
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424 bool mt_processing = false, uint mt_processing_degree = 1, |
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425 bool mt_discovery = false, uint mt_discovery_degree = 1, |
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426 bool atomic_discovery = true, |
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427 BoolObjectClosure* is_alive_non_header = NULL, |
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428 bool discovered_list_needs_barrier = false); |
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429 |
| 0 | 430 // RefDiscoveryPolicy values |
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431 enum DiscoveryPolicy { |
| 0 | 432 ReferenceBasedDiscovery = 0, |
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433 ReferentBasedDiscovery = 1, |
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434 DiscoveryPolicyMin = ReferenceBasedDiscovery, |
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435 DiscoveryPolicyMax = ReferentBasedDiscovery |
| 0 | 436 }; |
| 437 | |
| 438 static void init_statics(); | |
| 439 | |
| 440 public: | |
| 441 // get and set "is_alive_non_header" field | |
| 442 BoolObjectClosure* is_alive_non_header() { | |
| 443 return _is_alive_non_header; | |
| 444 } | |
| 445 void set_is_alive_non_header(BoolObjectClosure* is_alive_non_header) { | |
| 446 _is_alive_non_header = is_alive_non_header; | |
| 447 } | |
| 448 | |
| 449 // get and set span | |
| 450 MemRegion span() { return _span; } | |
| 451 void set_span(MemRegion span) { _span = span; } | |
| 452 | |
| 453 // start and stop weak ref discovery | |
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454 void enable_discovery(bool verify_disabled, bool check_no_refs); |
| 0 | 455 void disable_discovery() { _discovering_refs = false; } |
| 456 bool discovery_enabled() { return _discovering_refs; } | |
| 457 | |
| 458 // whether discovery is atomic wrt other collectors | |
| 459 bool discovery_is_atomic() const { return _discovery_is_atomic; } | |
| 460 void set_atomic_discovery(bool atomic) { _discovery_is_atomic = atomic; } | |
| 461 | |
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462 // whether the JDK in which we are embedded is a pre-4965777 JDK, |
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463 // and thus whether or not it uses the discovered field to chain |
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464 // the entries in the pending list. |
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465 static bool pending_list_uses_discovered_field() { |
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466 return _pending_list_uses_discovered_field; |
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467 } |
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468 |
| 0 | 469 // whether discovery is done by multiple threads same-old-timeously |
| 470 bool discovery_is_mt() const { return _discovery_is_mt; } | |
| 471 void set_mt_discovery(bool mt) { _discovery_is_mt = mt; } | |
| 472 | |
| 473 // Whether we are in a phase when _processing_ is MT. | |
| 474 bool processing_is_mt() const { return _processing_is_mt; } | |
| 475 void set_mt_processing(bool mt) { _processing_is_mt = mt; } | |
| 476 | |
| 477 // whether all enqueuing of weak references is complete | |
| 478 bool enqueuing_is_done() { return _enqueuing_is_done; } | |
| 479 void set_enqueuing_is_done(bool v) { _enqueuing_is_done = v; } | |
| 480 | |
| 481 // iterate over oops | |
| 482 void weak_oops_do(OopClosure* f); // weak roots | |
| 483 | |
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484 // Balance each of the discovered lists. |
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485 void balance_all_queues(); |
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486 void verify_list(DiscoveredList& ref_list); |
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487 |
| 0 | 488 // Discover a Reference object, using appropriate discovery criteria |
| 489 bool discover_reference(oop obj, ReferenceType rt); | |
| 490 | |
| 491 // Process references found during GC (called by the garbage collector) | |
| 10405 | 492 ReferenceProcessorStats |
| 493 process_discovered_references(BoolObjectClosure* is_alive, | |
| 494 OopClosure* keep_alive, | |
| 495 VoidClosure* complete_gc, | |
| 496 AbstractRefProcTaskExecutor* task_executor, | |
| 497 GCTimer *gc_timer); | |
| 0 | 498 |
| 499 // Enqueue references at end of GC (called by the garbage collector) | |
| 500 bool enqueue_discovered_references(AbstractRefProcTaskExecutor* task_executor = NULL); | |
| 501 | |
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502 // If a discovery is in process that is being superceded, abandon it: all |
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503 // the discovered lists will be empty, and all the objects on them will |
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504 // have NULL discovered fields. Must be called only at a safepoint. |
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505 void abandon_partial_discovery(); |
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506 |
| 0 | 507 // debugging |
| 508 void verify_no_references_recorded() PRODUCT_RETURN; | |
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509 void verify_referent(oop obj) PRODUCT_RETURN; |
| 0 | 510 |
| 511 // clear the discovered lists (unlinking each entry). | |
| 512 void clear_discovered_references() PRODUCT_RETURN; | |
| 513 }; | |
| 514 | |
| 515 // A utility class to disable reference discovery in | |
| 516 // the scope which contains it, for given ReferenceProcessor. | |
| 517 class NoRefDiscovery: StackObj { | |
| 518 private: | |
| 519 ReferenceProcessor* _rp; | |
| 520 bool _was_discovering_refs; | |
| 521 public: | |
| 522 NoRefDiscovery(ReferenceProcessor* rp) : _rp(rp) { | |
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523 _was_discovering_refs = _rp->discovery_enabled(); |
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524 if (_was_discovering_refs) { |
| 0 | 525 _rp->disable_discovery(); |
| 526 } | |
| 527 } | |
| 528 | |
| 529 ~NoRefDiscovery() { | |
| 530 if (_was_discovering_refs) { | |
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531 _rp->enable_discovery(true /*verify_disabled*/, false /*check_no_refs*/); |
| 0 | 532 } |
| 533 } | |
| 534 }; | |
| 535 | |
| 536 | |
| 537 // A utility class to temporarily mutate the span of the | |
| 538 // given ReferenceProcessor in the scope that contains it. | |
| 539 class ReferenceProcessorSpanMutator: StackObj { | |
| 540 private: | |
| 541 ReferenceProcessor* _rp; | |
| 542 MemRegion _saved_span; | |
| 543 | |
| 544 public: | |
| 545 ReferenceProcessorSpanMutator(ReferenceProcessor* rp, | |
| 546 MemRegion span): | |
| 547 _rp(rp) { | |
| 548 _saved_span = _rp->span(); | |
| 549 _rp->set_span(span); | |
| 550 } | |
| 551 | |
| 552 ~ReferenceProcessorSpanMutator() { | |
| 553 _rp->set_span(_saved_span); | |
| 554 } | |
| 555 }; | |
| 556 | |
| 557 // A utility class to temporarily change the MT'ness of | |
| 558 // reference discovery for the given ReferenceProcessor | |
| 559 // in the scope that contains it. | |
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560 class ReferenceProcessorMTDiscoveryMutator: StackObj { |
| 0 | 561 private: |
| 562 ReferenceProcessor* _rp; | |
| 563 bool _saved_mt; | |
| 564 | |
| 565 public: | |
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566 ReferenceProcessorMTDiscoveryMutator(ReferenceProcessor* rp, |
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567 bool mt): |
| 0 | 568 _rp(rp) { |
| 569 _saved_mt = _rp->discovery_is_mt(); | |
| 570 _rp->set_mt_discovery(mt); | |
| 571 } | |
| 572 | |
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573 ~ReferenceProcessorMTDiscoveryMutator() { |
| 0 | 574 _rp->set_mt_discovery(_saved_mt); |
| 575 } | |
| 576 }; | |
| 577 | |
| 578 | |
| 579 // A utility class to temporarily change the disposition | |
| 580 // of the "is_alive_non_header" closure field of the | |
| 581 // given ReferenceProcessor in the scope that contains it. | |
| 582 class ReferenceProcessorIsAliveMutator: StackObj { | |
| 583 private: | |
| 584 ReferenceProcessor* _rp; | |
| 585 BoolObjectClosure* _saved_cl; | |
| 586 | |
| 587 public: | |
| 588 ReferenceProcessorIsAliveMutator(ReferenceProcessor* rp, | |
| 589 BoolObjectClosure* cl): | |
| 590 _rp(rp) { | |
| 591 _saved_cl = _rp->is_alive_non_header(); | |
| 592 _rp->set_is_alive_non_header(cl); | |
| 593 } | |
| 594 | |
| 595 ~ReferenceProcessorIsAliveMutator() { | |
| 596 _rp->set_is_alive_non_header(_saved_cl); | |
| 597 } | |
| 598 }; | |
| 599 | |
| 600 // A utility class to temporarily change the disposition | |
| 601 // of the "discovery_is_atomic" field of the | |
| 602 // given ReferenceProcessor in the scope that contains it. | |
| 603 class ReferenceProcessorAtomicMutator: StackObj { | |
| 604 private: | |
| 605 ReferenceProcessor* _rp; | |
| 606 bool _saved_atomic_discovery; | |
| 607 | |
| 608 public: | |
| 609 ReferenceProcessorAtomicMutator(ReferenceProcessor* rp, | |
| 610 bool atomic): | |
| 611 _rp(rp) { | |
| 612 _saved_atomic_discovery = _rp->discovery_is_atomic(); | |
| 613 _rp->set_atomic_discovery(atomic); | |
| 614 } | |
| 615 | |
| 616 ~ReferenceProcessorAtomicMutator() { | |
| 617 _rp->set_atomic_discovery(_saved_atomic_discovery); | |
| 618 } | |
| 619 }; | |
| 620 | |
| 621 | |
| 622 // A utility class to temporarily change the MT processing | |
| 623 // disposition of the given ReferenceProcessor instance | |
| 624 // in the scope that contains it. | |
| 625 class ReferenceProcessorMTProcMutator: StackObj { | |
| 626 private: | |
| 627 ReferenceProcessor* _rp; | |
| 628 bool _saved_mt; | |
| 629 | |
| 630 public: | |
| 631 ReferenceProcessorMTProcMutator(ReferenceProcessor* rp, | |
| 632 bool mt): | |
| 633 _rp(rp) { | |
| 634 _saved_mt = _rp->processing_is_mt(); | |
| 635 _rp->set_mt_processing(mt); | |
| 636 } | |
| 637 | |
| 638 ~ReferenceProcessorMTProcMutator() { | |
| 639 _rp->set_mt_processing(_saved_mt); | |
| 640 } | |
| 641 }; | |
| 642 | |
| 643 | |
| 644 // This class is an interface used to implement task execution for the | |
| 645 // reference processing. | |
| 646 class AbstractRefProcTaskExecutor { | |
| 647 public: | |
| 648 | |
| 649 // Abstract tasks to execute. | |
| 650 class ProcessTask; | |
| 651 class EnqueueTask; | |
| 652 | |
| 653 // Executes a task using worker threads. | |
| 654 virtual void execute(ProcessTask& task) = 0; | |
| 655 virtual void execute(EnqueueTask& task) = 0; | |
| 656 | |
| 657 // Switch to single threaded mode. | |
| 658 virtual void set_single_threaded_mode() { }; | |
| 659 }; | |
| 660 | |
| 661 // Abstract reference processing task to execute. | |
| 662 class AbstractRefProcTaskExecutor::ProcessTask { | |
| 663 protected: | |
| 664 ProcessTask(ReferenceProcessor& ref_processor, | |
| 665 DiscoveredList refs_lists[], | |
| 666 bool marks_oops_alive) | |
| 667 : _ref_processor(ref_processor), | |
| 668 _refs_lists(refs_lists), | |
| 669 _marks_oops_alive(marks_oops_alive) | |
| 670 { } | |
| 671 | |
| 672 public: | |
| 673 virtual void work(unsigned int work_id, BoolObjectClosure& is_alive, | |
| 674 OopClosure& keep_alive, | |
| 675 VoidClosure& complete_gc) = 0; | |
| 676 | |
| 677 // Returns true if a task marks some oops as alive. | |
| 678 bool marks_oops_alive() const | |
| 679 { return _marks_oops_alive; } | |
| 680 | |
| 681 protected: | |
| 682 ReferenceProcessor& _ref_processor; | |
| 683 DiscoveredList* _refs_lists; | |
| 684 const bool _marks_oops_alive; | |
| 685 }; | |
| 686 | |
| 687 // Abstract reference processing task to execute. | |
| 688 class AbstractRefProcTaskExecutor::EnqueueTask { | |
| 689 protected: | |
| 690 EnqueueTask(ReferenceProcessor& ref_processor, | |
| 691 DiscoveredList refs_lists[], | |
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692 HeapWord* pending_list_addr, |
| 0 | 693 int n_queues) |
| 694 : _ref_processor(ref_processor), | |
| 695 _refs_lists(refs_lists), | |
| 696 _pending_list_addr(pending_list_addr), | |
| 697 _n_queues(n_queues) | |
| 698 { } | |
| 699 | |
| 700 public: | |
| 701 virtual void work(unsigned int work_id) = 0; | |
| 702 | |
| 703 protected: | |
| 704 ReferenceProcessor& _ref_processor; | |
| 705 DiscoveredList* _refs_lists; | |
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706 HeapWord* _pending_list_addr; |
| 0 | 707 int _n_queues; |
| 708 }; | |
| 1972 | 709 |
| 710 #endif // SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP |