Mercurial > hg > truffle
annotate src/share/vm/memory/referenceProcessor.hpp @ 17546:46fa2940e686 jdk8u5-b07
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author | asaha |
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date | Sun, 02 Feb 2014 22:45:03 -0800 |
parents | f2110083203d |
children | 836a62f43af9 fbc1677398c0 |
rev | line source |
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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 |
342
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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 BarrierSet* _bs; // Cached copy of BarrierSet. |
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239 bool _enqueuing_is_done; // true if all weak references enqueued |
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240 bool _processing_is_mt; // true during phases when |
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241 // reference processing is MT. |
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242 uint _next_id; // round-robin mod _num_q counter in |
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243 // support of work distribution |
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244 |
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245 // For collectors that do not keep GC liveness information |
0 | 246 // in the object header, this field holds a closure that |
247 // helps the reference processor determine the reachability | |
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248 // of an oop. It is currently initialized to NULL for all |
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249 // collectors except for CMS and G1. |
0 | 250 BoolObjectClosure* _is_alive_non_header; |
251 | |
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252 // Soft ref clearing policies |
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253 // . the default policy |
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254 static ReferencePolicy* _default_soft_ref_policy; |
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255 // . the "clear all" policy |
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256 static ReferencePolicy* _always_clear_soft_ref_policy; |
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257 // . the current policy below is either one of the above |
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258 ReferencePolicy* _current_soft_ref_policy; |
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259 |
0 | 260 // The discovered ref lists themselves |
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261 |
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262 // The active MT'ness degree of the queues below |
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263 uint _num_q; |
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264 // The maximum MT'ness degree of the queues below |
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265 uint _max_num_q; |
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266 |
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267 // Master array of discovered oops |
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268 DiscoveredList* _discovered_refs; |
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269 |
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270 // Arrays of lists of oops, one per thread (pointers into master array above) |
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271 DiscoveredList* _discoveredSoftRefs; |
0 | 272 DiscoveredList* _discoveredWeakRefs; |
273 DiscoveredList* _discoveredFinalRefs; | |
274 DiscoveredList* _discoveredPhantomRefs; | |
275 | |
276 public: | |
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277 static int number_of_subclasses_of_ref() { return (REF_PHANTOM - REF_OTHER); } |
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278 |
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279 uint num_q() { return _num_q; } |
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280 uint max_num_q() { return _max_num_q; } |
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281 void set_active_mt_degree(uint v) { _num_q = v; } |
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282 |
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283 DiscoveredList* discovered_refs() { return _discovered_refs; } |
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284 |
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285 ReferencePolicy* setup_policy(bool always_clear) { |
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286 _current_soft_ref_policy = always_clear ? |
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287 _always_clear_soft_ref_policy : _default_soft_ref_policy; |
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288 _current_soft_ref_policy->setup(); // snapshot the policy threshold |
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289 return _current_soft_ref_policy; |
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290 } |
0 | 291 |
292 // Process references with a certain reachability level. | |
10405 | 293 size_t process_discovered_reflist(DiscoveredList refs_lists[], |
294 ReferencePolicy* policy, | |
295 bool clear_referent, | |
296 BoolObjectClosure* is_alive, | |
297 OopClosure* keep_alive, | |
298 VoidClosure* complete_gc, | |
299 AbstractRefProcTaskExecutor* task_executor); | |
0 | 300 |
301 void process_phaseJNI(BoolObjectClosure* is_alive, | |
302 OopClosure* keep_alive, | |
303 VoidClosure* complete_gc); | |
304 | |
305 // Work methods used by the method process_discovered_reflist | |
306 // Phase1: keep alive all those referents that are otherwise | |
307 // dead but which must be kept alive by policy (and their closure). | |
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308 void process_phase1(DiscoveredList& refs_list, |
0 | 309 ReferencePolicy* policy, |
310 BoolObjectClosure* is_alive, | |
311 OopClosure* keep_alive, | |
312 VoidClosure* complete_gc); | |
313 // Phase2: remove all those references whose referents are | |
314 // reachable. | |
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315 inline void process_phase2(DiscoveredList& refs_list, |
0 | 316 BoolObjectClosure* is_alive, |
317 OopClosure* keep_alive, | |
318 VoidClosure* complete_gc) { | |
319 if (discovery_is_atomic()) { | |
320 // complete_gc is ignored in this case for this phase | |
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321 pp2_work(refs_list, is_alive, keep_alive); |
0 | 322 } else { |
323 assert(complete_gc != NULL, "Error"); | |
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324 pp2_work_concurrent_discovery(refs_list, is_alive, |
0 | 325 keep_alive, complete_gc); |
326 } | |
327 } | |
328 // Work methods in support of process_phase2 | |
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329 void pp2_work(DiscoveredList& refs_list, |
0 | 330 BoolObjectClosure* is_alive, |
331 OopClosure* keep_alive); | |
332 void pp2_work_concurrent_discovery( | |
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333 DiscoveredList& refs_list, |
0 | 334 BoolObjectClosure* is_alive, |
335 OopClosure* keep_alive, | |
336 VoidClosure* complete_gc); | |
337 // Phase3: process the referents by either clearing them | |
338 // or keeping them alive (and their closure) | |
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339 void process_phase3(DiscoveredList& refs_list, |
0 | 340 bool clear_referent, |
341 BoolObjectClosure* is_alive, | |
342 OopClosure* keep_alive, | |
343 VoidClosure* complete_gc); | |
344 | |
345 // Enqueue references with a certain reachability level | |
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346 void enqueue_discovered_reflist(DiscoveredList& refs_list, HeapWord* pending_list_addr); |
0 | 347 |
348 // "Preclean" all the discovered reference lists | |
349 // by removing references with strongly reachable referents. | |
350 // The first argument is a predicate on an oop that indicates | |
351 // its (strong) reachability and the second is a closure that | |
352 // may be used to incrementalize or abort the precleaning process. | |
353 // The caller is responsible for taking care of potential | |
354 // interference with concurrent operations on these lists | |
355 // (or predicates involved) by other threads. Currently | |
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356 // only used by the CMS collector. |
0 | 357 void preclean_discovered_references(BoolObjectClosure* is_alive, |
358 OopClosure* keep_alive, | |
359 VoidClosure* complete_gc, | |
10405 | 360 YieldClosure* yield, |
361 GCTimer* gc_timer); | |
0 | 362 |
363 // Delete entries in the discovered lists that have | |
364 // either a null referent or are not active. Such | |
365 // Reference objects can result from the clearing | |
366 // or enqueueing of Reference objects concurrent | |
367 // with their discovery by a (concurrent) collector. | |
368 // For a definition of "active" see java.lang.ref.Reference; | |
369 // Refs are born active, become inactive when enqueued, | |
370 // and never become active again. The state of being | |
371 // active is encoded as follows: A Ref is active | |
372 // if and only if its "next" field is NULL. | |
373 void clean_up_discovered_references(); | |
374 void clean_up_discovered_reflist(DiscoveredList& refs_list); | |
375 | |
376 // Returns the name of the discovered reference list | |
377 // occupying the i / _num_q slot. | |
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378 const char* list_name(uint i); |
0 | 379 |
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380 void enqueue_discovered_reflists(HeapWord* pending_list_addr, AbstractRefProcTaskExecutor* task_executor); |
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381 |
0 | 382 protected: |
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383 // Set the 'discovered' field of the given reference to |
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384 // the given value - emitting barriers depending upon |
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385 // the value of _discovered_list_needs_barrier. |
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386 void set_discovered(oop ref, oop value); |
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387 |
0 | 388 // "Preclean" the given discovered reference list |
389 // by removing references with strongly reachable referents. | |
390 // Currently used in support of CMS only. | |
391 void preclean_discovered_reflist(DiscoveredList& refs_list, | |
392 BoolObjectClosure* is_alive, | |
393 OopClosure* keep_alive, | |
394 VoidClosure* complete_gc, | |
395 YieldClosure* yield); | |
396 | |
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397 // round-robin mod _num_q (not: _not_ mode _max_num_q) |
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398 uint next_id() { |
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399 uint id = _next_id; |
0 | 400 if (++_next_id == _num_q) { |
401 _next_id = 0; | |
402 } | |
403 return id; | |
404 } | |
405 DiscoveredList* get_discovered_list(ReferenceType rt); | |
406 inline void add_to_discovered_list_mt(DiscoveredList& refs_list, oop obj, | |
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407 HeapWord* discovered_addr); |
0 | 408 void verify_ok_to_handle_reflists() PRODUCT_RETURN; |
409 | |
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410 void clear_discovered_references(DiscoveredList& refs_list); |
0 | 411 void abandon_partial_discovered_list(DiscoveredList& refs_list); |
412 | |
413 // Calculate the number of jni handles. | |
414 unsigned int count_jni_refs(); | |
415 | |
416 // Balances reference queues. | |
417 void balance_queues(DiscoveredList ref_lists[]); | |
418 | |
419 // Update (advance) the soft ref master clock field. | |
420 void update_soft_ref_master_clock(); | |
421 | |
422 public: | |
423 // constructor | |
424 ReferenceProcessor(): | |
425 _span((HeapWord*)NULL, (HeapWord*)NULL), | |
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426 _discovered_refs(NULL), |
0 | 427 _discoveredSoftRefs(NULL), _discoveredWeakRefs(NULL), |
428 _discoveredFinalRefs(NULL), _discoveredPhantomRefs(NULL), | |
429 _discovering_refs(false), | |
430 _discovery_is_atomic(true), | |
431 _enqueuing_is_done(false), | |
432 _discovery_is_mt(false), | |
342
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433 _discovered_list_needs_barrier(false), |
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434 _bs(NULL), |
0 | 435 _is_alive_non_header(NULL), |
436 _num_q(0), | |
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437 _max_num_q(0), |
0 | 438 _processing_is_mt(false), |
439 _next_id(0) | |
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440 { } |
0 | 441 |
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442 // Default parameters give you a vanilla reference processor. |
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443 ReferenceProcessor(MemRegion span, |
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444 bool mt_processing = false, uint mt_processing_degree = 1, |
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445 bool mt_discovery = false, uint mt_discovery_degree = 1, |
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446 bool atomic_discovery = true, |
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447 BoolObjectClosure* is_alive_non_header = NULL, |
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448 bool discovered_list_needs_barrier = false); |
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449 |
0 | 450 // RefDiscoveryPolicy values |
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451 enum DiscoveryPolicy { |
0 | 452 ReferenceBasedDiscovery = 0, |
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453 ReferentBasedDiscovery = 1, |
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454 DiscoveryPolicyMin = ReferenceBasedDiscovery, |
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455 DiscoveryPolicyMax = ReferentBasedDiscovery |
0 | 456 }; |
457 | |
458 static void init_statics(); | |
459 | |
460 public: | |
461 // get and set "is_alive_non_header" field | |
462 BoolObjectClosure* is_alive_non_header() { | |
463 return _is_alive_non_header; | |
464 } | |
465 void set_is_alive_non_header(BoolObjectClosure* is_alive_non_header) { | |
466 _is_alive_non_header = is_alive_non_header; | |
467 } | |
468 | |
469 // get and set span | |
470 MemRegion span() { return _span; } | |
471 void set_span(MemRegion span) { _span = span; } | |
472 | |
473 // start and stop weak ref discovery | |
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474 void enable_discovery(bool verify_disabled, bool check_no_refs); |
0 | 475 void disable_discovery() { _discovering_refs = false; } |
476 bool discovery_enabled() { return _discovering_refs; } | |
477 | |
478 // whether discovery is atomic wrt other collectors | |
479 bool discovery_is_atomic() const { return _discovery_is_atomic; } | |
480 void set_atomic_discovery(bool atomic) { _discovery_is_atomic = atomic; } | |
481 | |
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482 // whether the JDK in which we are embedded is a pre-4965777 JDK, |
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483 // and thus whether or not it uses the discovered field to chain |
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484 // the entries in the pending list. |
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485 static bool pending_list_uses_discovered_field() { |
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486 return _pending_list_uses_discovered_field; |
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487 } |
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488 |
0 | 489 // whether discovery is done by multiple threads same-old-timeously |
490 bool discovery_is_mt() const { return _discovery_is_mt; } | |
491 void set_mt_discovery(bool mt) { _discovery_is_mt = mt; } | |
492 | |
493 // Whether we are in a phase when _processing_ is MT. | |
494 bool processing_is_mt() const { return _processing_is_mt; } | |
495 void set_mt_processing(bool mt) { _processing_is_mt = mt; } | |
496 | |
497 // whether all enqueuing of weak references is complete | |
498 bool enqueuing_is_done() { return _enqueuing_is_done; } | |
499 void set_enqueuing_is_done(bool v) { _enqueuing_is_done = v; } | |
500 | |
501 // iterate over oops | |
502 void weak_oops_do(OopClosure* f); // weak roots | |
503 | |
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504 // Balance each of the discovered lists. |
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505 void balance_all_queues(); |
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506 void verify_list(DiscoveredList& ref_list); |
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507 |
0 | 508 // Discover a Reference object, using appropriate discovery criteria |
509 bool discover_reference(oop obj, ReferenceType rt); | |
510 | |
511 // Process references found during GC (called by the garbage collector) | |
10405 | 512 ReferenceProcessorStats |
513 process_discovered_references(BoolObjectClosure* is_alive, | |
514 OopClosure* keep_alive, | |
515 VoidClosure* complete_gc, | |
516 AbstractRefProcTaskExecutor* task_executor, | |
517 GCTimer *gc_timer); | |
0 | 518 |
519 // Enqueue references at end of GC (called by the garbage collector) | |
520 bool enqueue_discovered_references(AbstractRefProcTaskExecutor* task_executor = NULL); | |
521 | |
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522 // If a discovery is in process that is being superceded, abandon it: all |
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523 // the discovered lists will be empty, and all the objects on them will |
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524 // have NULL discovered fields. Must be called only at a safepoint. |
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525 void abandon_partial_discovery(); |
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526 |
0 | 527 // debugging |
528 void verify_no_references_recorded() PRODUCT_RETURN; | |
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529 void verify_referent(oop obj) PRODUCT_RETURN; |
0 | 530 |
531 // clear the discovered lists (unlinking each entry). | |
532 void clear_discovered_references() PRODUCT_RETURN; | |
533 }; | |
534 | |
535 // A utility class to disable reference discovery in | |
536 // the scope which contains it, for given ReferenceProcessor. | |
537 class NoRefDiscovery: StackObj { | |
538 private: | |
539 ReferenceProcessor* _rp; | |
540 bool _was_discovering_refs; | |
541 public: | |
542 NoRefDiscovery(ReferenceProcessor* rp) : _rp(rp) { | |
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543 _was_discovering_refs = _rp->discovery_enabled(); |
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544 if (_was_discovering_refs) { |
0 | 545 _rp->disable_discovery(); |
546 } | |
547 } | |
548 | |
549 ~NoRefDiscovery() { | |
550 if (_was_discovering_refs) { | |
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551 _rp->enable_discovery(true /*verify_disabled*/, false /*check_no_refs*/); |
0 | 552 } |
553 } | |
554 }; | |
555 | |
556 | |
557 // A utility class to temporarily mutate the span of the | |
558 // given ReferenceProcessor in the scope that contains it. | |
559 class ReferenceProcessorSpanMutator: StackObj { | |
560 private: | |
561 ReferenceProcessor* _rp; | |
562 MemRegion _saved_span; | |
563 | |
564 public: | |
565 ReferenceProcessorSpanMutator(ReferenceProcessor* rp, | |
566 MemRegion span): | |
567 _rp(rp) { | |
568 _saved_span = _rp->span(); | |
569 _rp->set_span(span); | |
570 } | |
571 | |
572 ~ReferenceProcessorSpanMutator() { | |
573 _rp->set_span(_saved_span); | |
574 } | |
575 }; | |
576 | |
577 // A utility class to temporarily change the MT'ness of | |
578 // reference discovery for the given ReferenceProcessor | |
579 // in the scope that contains it. | |
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580 class ReferenceProcessorMTDiscoveryMutator: StackObj { |
0 | 581 private: |
582 ReferenceProcessor* _rp; | |
583 bool _saved_mt; | |
584 | |
585 public: | |
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586 ReferenceProcessorMTDiscoveryMutator(ReferenceProcessor* rp, |
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587 bool mt): |
0 | 588 _rp(rp) { |
589 _saved_mt = _rp->discovery_is_mt(); | |
590 _rp->set_mt_discovery(mt); | |
591 } | |
592 | |
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593 ~ReferenceProcessorMTDiscoveryMutator() { |
0 | 594 _rp->set_mt_discovery(_saved_mt); |
595 } | |
596 }; | |
597 | |
598 | |
599 // A utility class to temporarily change the disposition | |
600 // of the "is_alive_non_header" closure field of the | |
601 // given ReferenceProcessor in the scope that contains it. | |
602 class ReferenceProcessorIsAliveMutator: StackObj { | |
603 private: | |
604 ReferenceProcessor* _rp; | |
605 BoolObjectClosure* _saved_cl; | |
606 | |
607 public: | |
608 ReferenceProcessorIsAliveMutator(ReferenceProcessor* rp, | |
609 BoolObjectClosure* cl): | |
610 _rp(rp) { | |
611 _saved_cl = _rp->is_alive_non_header(); | |
612 _rp->set_is_alive_non_header(cl); | |
613 } | |
614 | |
615 ~ReferenceProcessorIsAliveMutator() { | |
616 _rp->set_is_alive_non_header(_saved_cl); | |
617 } | |
618 }; | |
619 | |
620 // A utility class to temporarily change the disposition | |
621 // of the "discovery_is_atomic" field of the | |
622 // given ReferenceProcessor in the scope that contains it. | |
623 class ReferenceProcessorAtomicMutator: StackObj { | |
624 private: | |
625 ReferenceProcessor* _rp; | |
626 bool _saved_atomic_discovery; | |
627 | |
628 public: | |
629 ReferenceProcessorAtomicMutator(ReferenceProcessor* rp, | |
630 bool atomic): | |
631 _rp(rp) { | |
632 _saved_atomic_discovery = _rp->discovery_is_atomic(); | |
633 _rp->set_atomic_discovery(atomic); | |
634 } | |
635 | |
636 ~ReferenceProcessorAtomicMutator() { | |
637 _rp->set_atomic_discovery(_saved_atomic_discovery); | |
638 } | |
639 }; | |
640 | |
641 | |
642 // A utility class to temporarily change the MT processing | |
643 // disposition of the given ReferenceProcessor instance | |
644 // in the scope that contains it. | |
645 class ReferenceProcessorMTProcMutator: StackObj { | |
646 private: | |
647 ReferenceProcessor* _rp; | |
648 bool _saved_mt; | |
649 | |
650 public: | |
651 ReferenceProcessorMTProcMutator(ReferenceProcessor* rp, | |
652 bool mt): | |
653 _rp(rp) { | |
654 _saved_mt = _rp->processing_is_mt(); | |
655 _rp->set_mt_processing(mt); | |
656 } | |
657 | |
658 ~ReferenceProcessorMTProcMutator() { | |
659 _rp->set_mt_processing(_saved_mt); | |
660 } | |
661 }; | |
662 | |
663 | |
664 // This class is an interface used to implement task execution for the | |
665 // reference processing. | |
666 class AbstractRefProcTaskExecutor { | |
667 public: | |
668 | |
669 // Abstract tasks to execute. | |
670 class ProcessTask; | |
671 class EnqueueTask; | |
672 | |
673 // Executes a task using worker threads. | |
674 virtual void execute(ProcessTask& task) = 0; | |
675 virtual void execute(EnqueueTask& task) = 0; | |
676 | |
677 // Switch to single threaded mode. | |
678 virtual void set_single_threaded_mode() { }; | |
679 }; | |
680 | |
681 // Abstract reference processing task to execute. | |
682 class AbstractRefProcTaskExecutor::ProcessTask { | |
683 protected: | |
684 ProcessTask(ReferenceProcessor& ref_processor, | |
685 DiscoveredList refs_lists[], | |
686 bool marks_oops_alive) | |
687 : _ref_processor(ref_processor), | |
688 _refs_lists(refs_lists), | |
689 _marks_oops_alive(marks_oops_alive) | |
690 { } | |
691 | |
692 public: | |
693 virtual void work(unsigned int work_id, BoolObjectClosure& is_alive, | |
694 OopClosure& keep_alive, | |
695 VoidClosure& complete_gc) = 0; | |
696 | |
697 // Returns true if a task marks some oops as alive. | |
698 bool marks_oops_alive() const | |
699 { return _marks_oops_alive; } | |
700 | |
701 protected: | |
702 ReferenceProcessor& _ref_processor; | |
703 DiscoveredList* _refs_lists; | |
704 const bool _marks_oops_alive; | |
705 }; | |
706 | |
707 // Abstract reference processing task to execute. | |
708 class AbstractRefProcTaskExecutor::EnqueueTask { | |
709 protected: | |
710 EnqueueTask(ReferenceProcessor& ref_processor, | |
711 DiscoveredList refs_lists[], | |
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712 HeapWord* pending_list_addr, |
0 | 713 int n_queues) |
714 : _ref_processor(ref_processor), | |
715 _refs_lists(refs_lists), | |
716 _pending_list_addr(pending_list_addr), | |
717 _n_queues(n_queues) | |
718 { } | |
719 | |
720 public: | |
721 virtual void work(unsigned int work_id) = 0; | |
722 | |
723 protected: | |
724 ReferenceProcessor& _ref_processor; | |
725 DiscoveredList* _refs_lists; | |
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726 HeapWord* _pending_list_addr; |
0 | 727 int _n_queues; |
728 }; | |
1972 | 729 |
730 #endif // SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP |