Mercurial > hg > truffle
annotate src/share/vm/memory/referenceProcessor.hpp @ 3989:b9390528617c
7095236: G1: _markedRegions never contains NULL regions
Summary: Removed the code for skipping over NULL regions in _markedRegions, replacing it with an assertion that a NULL region is never encountered; removed dead methods, remove() and remove_region(), and inlined a simplified addRegion() directly into fillCache().
Reviewed-by: brutisso, tonyp
author | ysr |
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date | Thu, 06 Oct 2011 18:56:47 -0700 |
parents | 4dfb2df418f2 |
children | d1bdeef3e3e2 |
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0 | 1 /* |
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2 * Copyright (c) 2001, 2011, 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" | |
29 #include "oops/instanceRefKlass.hpp" | |
30 | |
0 | 31 // ReferenceProcessor class encapsulates the per-"collector" processing |
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32 // of java.lang.Reference objects for GC. The interface is useful for supporting |
0 | 33 // a generational abstraction, in particular when there are multiple |
34 // generations that are being independently collected -- possibly | |
35 // concurrently and/or incrementally. Note, however, that the | |
36 // ReferenceProcessor class abstracts away from a generational setting | |
37 // by using only a heap interval (called "span" below), thus allowing | |
38 // its use in a straightforward manner in a general, non-generational | |
39 // setting. | |
40 // | |
41 // The basic idea is that each ReferenceProcessor object concerns | |
42 // itself with ("weak") reference processing in a specific "span" | |
43 // of the heap of interest to a specific collector. Currently, | |
44 // the span is a convex interval of the heap, but, efficiency | |
45 // apart, there seems to be no reason it couldn't be extended | |
46 // (with appropriate modifications) to any "non-convex interval". | |
47 | |
48 // forward references | |
49 class ReferencePolicy; | |
50 class AbstractRefProcTaskExecutor; | |
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51 |
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52 // List of discovered references. |
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53 class DiscoveredList { |
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54 public: |
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55 DiscoveredList() : _len(0), _compressed_head(0), _oop_head(NULL) { } |
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56 oop head() const { |
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57 return UseCompressedOops ? oopDesc::decode_heap_oop(_compressed_head) : |
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58 _oop_head; |
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59 } |
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60 HeapWord* adr_head() { |
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61 return UseCompressedOops ? (HeapWord*)&_compressed_head : |
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62 (HeapWord*)&_oop_head; |
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63 } |
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64 void set_head(oop o) { |
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65 if (UseCompressedOops) { |
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66 // Must compress the head ptr. |
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67 _compressed_head = oopDesc::encode_heap_oop(o); |
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68 } else { |
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69 _oop_head = o; |
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70 } |
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71 } |
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72 bool is_empty() const { return head() == NULL; } |
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73 size_t length() { return _len; } |
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74 void set_length(size_t len) { _len = len; } |
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75 void inc_length(size_t inc) { _len += inc; assert(_len > 0, "Error"); } |
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76 void dec_length(size_t dec) { _len -= dec; } |
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77 private: |
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78 // Set value depending on UseCompressedOops. This could be a template class |
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79 // but then we have to fix all the instantiations and declarations that use this class. |
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80 oop _oop_head; |
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81 narrowOop _compressed_head; |
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82 size_t _len; |
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83 }; |
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84 |
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85 // Iterator for the list of discovered references. |
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86 class DiscoveredListIterator { |
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87 private: |
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88 DiscoveredList& _refs_list; |
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89 HeapWord* _prev_next; |
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90 oop _prev; |
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91 oop _ref; |
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92 HeapWord* _discovered_addr; |
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93 oop _next; |
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94 HeapWord* _referent_addr; |
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95 oop _referent; |
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96 OopClosure* _keep_alive; |
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97 BoolObjectClosure* _is_alive; |
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98 |
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99 DEBUG_ONLY( |
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100 oop _first_seen; // cyclic linked list check |
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101 ) |
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102 |
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103 NOT_PRODUCT( |
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104 size_t _processed; |
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105 size_t _removed; |
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106 ) |
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107 |
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108 public: |
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109 inline DiscoveredListIterator(DiscoveredList& refs_list, |
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110 OopClosure* keep_alive, |
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111 BoolObjectClosure* is_alive): |
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112 _refs_list(refs_list), |
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113 _prev_next(refs_list.adr_head()), |
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114 _prev(NULL), |
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115 _ref(refs_list.head()), |
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116 #ifdef ASSERT |
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117 _first_seen(refs_list.head()), |
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118 #endif |
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119 #ifndef PRODUCT |
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120 _processed(0), |
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121 _removed(0), |
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122 #endif |
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123 _next(NULL), |
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124 _keep_alive(keep_alive), |
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125 _is_alive(is_alive) |
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126 { } |
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127 |
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128 // End Of List. |
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129 inline bool has_next() const { return _ref != NULL; } |
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130 |
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131 // Get oop to the Reference object. |
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132 inline oop obj() const { return _ref; } |
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133 |
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134 // Get oop to the referent object. |
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135 inline oop referent() const { return _referent; } |
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136 |
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137 // Returns true if referent is alive. |
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138 inline bool is_referent_alive() const { |
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139 return _is_alive->do_object_b(_referent); |
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140 } |
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141 |
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142 // Loads data for the current reference. |
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143 // The "allow_null_referent" argument tells us to allow for the possibility |
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144 // of a NULL referent in the discovered Reference object. This typically |
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145 // happens in the case of concurrent collectors that may have done the |
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146 // discovery concurrently, or interleaved, with mutator execution. |
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147 void load_ptrs(DEBUG_ONLY(bool allow_null_referent)); |
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148 |
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149 // Move to the next discovered reference. |
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150 inline void next() { |
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151 _prev_next = _discovered_addr; |
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152 _prev = _ref; |
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153 move_to_next(); |
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154 } |
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155 |
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156 // Remove the current reference from the list |
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157 void remove(); |
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158 |
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159 // Make the Reference object active again. |
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160 void make_active(); |
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161 |
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162 // Make the referent alive. |
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163 inline void make_referent_alive() { |
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164 if (UseCompressedOops) { |
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165 _keep_alive->do_oop((narrowOop*)_referent_addr); |
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166 } else { |
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167 _keep_alive->do_oop((oop*)_referent_addr); |
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168 } |
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169 } |
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170 |
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171 // Update the discovered field. |
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172 inline void update_discovered() { |
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173 // First _prev_next ref actually points into DiscoveredList (gross). |
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174 if (UseCompressedOops) { |
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175 if (!oopDesc::is_null(*(narrowOop*)_prev_next)) { |
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176 _keep_alive->do_oop((narrowOop*)_prev_next); |
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177 } |
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178 } else { |
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179 if (!oopDesc::is_null(*(oop*)_prev_next)) { |
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180 _keep_alive->do_oop((oop*)_prev_next); |
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181 } |
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182 } |
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183 } |
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184 |
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185 // NULL out referent pointer. |
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186 void clear_referent(); |
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187 |
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188 // Statistics |
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189 NOT_PRODUCT( |
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190 inline size_t processed() const { return _processed; } |
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191 inline size_t removed() const { return _removed; } |
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192 ) |
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193 |
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194 inline void move_to_next() { |
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195 if (_ref == _next) { |
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196 // End of the list. |
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197 _ref = NULL; |
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198 } else { |
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199 _ref = _next; |
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200 } |
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201 assert(_ref != _first_seen, "cyclic ref_list found"); |
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202 NOT_PRODUCT(_processed++); |
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203 } |
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204 |
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205 }; |
0 | 206 |
207 class ReferenceProcessor : public CHeapObj { | |
208 protected: | |
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209 // Compatibility with pre-4965777 JDK's |
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210 static bool _pending_list_uses_discovered_field; |
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211 |
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212 MemRegion _span; // (right-open) interval of heap |
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213 // subject to wkref discovery |
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214 |
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215 bool _discovering_refs; // true when discovery enabled |
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216 bool _discovery_is_atomic; // if discovery is atomic wrt |
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217 // other collectors in configuration |
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218 bool _discovery_is_mt; // true if reference discovery is MT. |
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219 |
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220 // If true, setting "next" field of a discovered refs list requires |
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221 // write barrier(s). (Must be true if used in a collector in which |
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222 // elements of a discovered list may be moved during discovery: for |
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223 // example, a collector like Garbage-First that moves objects during a |
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224 // long-term concurrent marking phase that does weak reference |
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225 // discovery.) |
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226 bool _discovered_list_needs_barrier; |
0 | 227 |
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228 BarrierSet* _bs; // Cached copy of BarrierSet. |
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229 bool _enqueuing_is_done; // true if all weak references enqueued |
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230 bool _processing_is_mt; // true during phases when |
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231 // reference processing is MT. |
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232 int _next_id; // round-robin mod _num_q counter in |
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233 // support of work distribution |
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234 |
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235 // For collectors that do not keep GC liveness information |
0 | 236 // in the object header, this field holds a closure that |
237 // helps the reference processor determine the reachability | |
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238 // of an oop. It is currently initialized to NULL for all |
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239 // collectors except for CMS and G1. |
0 | 240 BoolObjectClosure* _is_alive_non_header; |
241 | |
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242 // Soft ref clearing policies |
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243 // . the default policy |
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244 static ReferencePolicy* _default_soft_ref_policy; |
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245 // . the "clear all" policy |
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246 static ReferencePolicy* _always_clear_soft_ref_policy; |
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247 // . the current policy below is either one of the above |
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248 ReferencePolicy* _current_soft_ref_policy; |
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249 |
0 | 250 // The discovered ref lists themselves |
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251 |
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252 // The active MT'ness degree of the queues below |
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253 int _num_q; |
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254 // The maximum MT'ness degree of the queues below |
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255 int _max_num_q; |
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256 // Arrays of lists of oops, one per thread |
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257 DiscoveredList* _discoveredSoftRefs; |
0 | 258 DiscoveredList* _discoveredWeakRefs; |
259 DiscoveredList* _discoveredFinalRefs; | |
260 DiscoveredList* _discoveredPhantomRefs; | |
261 | |
262 public: | |
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263 static int number_of_subclasses_of_ref() { return (REF_PHANTOM - REF_OTHER); } |
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264 |
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265 int num_q() { return _num_q; } |
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266 int max_num_q() { return _max_num_q; } |
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267 void set_active_mt_degree(int v) { _num_q = v; } |
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268 DiscoveredList* discovered_soft_refs() { return _discoveredSoftRefs; } |
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269 |
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270 ReferencePolicy* setup_policy(bool always_clear) { |
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271 _current_soft_ref_policy = always_clear ? |
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272 _always_clear_soft_ref_policy : _default_soft_ref_policy; |
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273 _current_soft_ref_policy->setup(); // snapshot the policy threshold |
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274 return _current_soft_ref_policy; |
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275 } |
0 | 276 |
277 // Process references with a certain reachability level. | |
278 void process_discovered_reflist(DiscoveredList refs_lists[], | |
279 ReferencePolicy* policy, | |
280 bool clear_referent, | |
281 BoolObjectClosure* is_alive, | |
282 OopClosure* keep_alive, | |
283 VoidClosure* complete_gc, | |
284 AbstractRefProcTaskExecutor* task_executor); | |
285 | |
286 void process_phaseJNI(BoolObjectClosure* is_alive, | |
287 OopClosure* keep_alive, | |
288 VoidClosure* complete_gc); | |
289 | |
290 // Work methods used by the method process_discovered_reflist | |
291 // Phase1: keep alive all those referents that are otherwise | |
292 // dead but which must be kept alive by policy (and their closure). | |
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293 void process_phase1(DiscoveredList& refs_list, |
0 | 294 ReferencePolicy* policy, |
295 BoolObjectClosure* is_alive, | |
296 OopClosure* keep_alive, | |
297 VoidClosure* complete_gc); | |
298 // Phase2: remove all those references whose referents are | |
299 // reachable. | |
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300 inline void process_phase2(DiscoveredList& refs_list, |
0 | 301 BoolObjectClosure* is_alive, |
302 OopClosure* keep_alive, | |
303 VoidClosure* complete_gc) { | |
304 if (discovery_is_atomic()) { | |
305 // complete_gc is ignored in this case for this phase | |
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306 pp2_work(refs_list, is_alive, keep_alive); |
0 | 307 } else { |
308 assert(complete_gc != NULL, "Error"); | |
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309 pp2_work_concurrent_discovery(refs_list, is_alive, |
0 | 310 keep_alive, complete_gc); |
311 } | |
312 } | |
313 // Work methods in support of process_phase2 | |
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314 void pp2_work(DiscoveredList& refs_list, |
0 | 315 BoolObjectClosure* is_alive, |
316 OopClosure* keep_alive); | |
317 void pp2_work_concurrent_discovery( | |
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318 DiscoveredList& refs_list, |
0 | 319 BoolObjectClosure* is_alive, |
320 OopClosure* keep_alive, | |
321 VoidClosure* complete_gc); | |
322 // Phase3: process the referents by either clearing them | |
323 // or keeping them alive (and their closure) | |
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324 void process_phase3(DiscoveredList& refs_list, |
0 | 325 bool clear_referent, |
326 BoolObjectClosure* is_alive, | |
327 OopClosure* keep_alive, | |
328 VoidClosure* complete_gc); | |
329 | |
330 // Enqueue references with a certain reachability level | |
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331 void enqueue_discovered_reflist(DiscoveredList& refs_list, HeapWord* pending_list_addr); |
0 | 332 |
333 // "Preclean" all the discovered reference lists | |
334 // by removing references with strongly reachable referents. | |
335 // The first argument is a predicate on an oop that indicates | |
336 // its (strong) reachability and the second is a closure that | |
337 // may be used to incrementalize or abort the precleaning process. | |
338 // The caller is responsible for taking care of potential | |
339 // interference with concurrent operations on these lists | |
340 // (or predicates involved) by other threads. Currently | |
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341 // only used by the CMS collector. should_unload_classes is |
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342 // used to aid assertion checking when classes are collected. |
0 | 343 void preclean_discovered_references(BoolObjectClosure* is_alive, |
344 OopClosure* keep_alive, | |
345 VoidClosure* complete_gc, | |
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346 YieldClosure* yield, |
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347 bool should_unload_classes); |
0 | 348 |
349 // Delete entries in the discovered lists that have | |
350 // either a null referent or are not active. Such | |
351 // Reference objects can result from the clearing | |
352 // or enqueueing of Reference objects concurrent | |
353 // with their discovery by a (concurrent) collector. | |
354 // For a definition of "active" see java.lang.ref.Reference; | |
355 // Refs are born active, become inactive when enqueued, | |
356 // and never become active again. The state of being | |
357 // active is encoded as follows: A Ref is active | |
358 // if and only if its "next" field is NULL. | |
359 void clean_up_discovered_references(); | |
360 void clean_up_discovered_reflist(DiscoveredList& refs_list); | |
361 | |
362 // Returns the name of the discovered reference list | |
363 // occupying the i / _num_q slot. | |
364 const char* list_name(int i); | |
365 | |
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366 void enqueue_discovered_reflists(HeapWord* pending_list_addr, AbstractRefProcTaskExecutor* task_executor); |
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367 |
0 | 368 protected: |
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369 // Set the 'discovered' field of the given reference to |
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370 // the given value - emitting barriers depending upon |
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371 // the value of _discovered_list_needs_barrier. |
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372 void set_discovered(oop ref, oop value); |
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373 |
0 | 374 // "Preclean" the given discovered reference list |
375 // by removing references with strongly reachable referents. | |
376 // Currently used in support of CMS only. | |
377 void preclean_discovered_reflist(DiscoveredList& refs_list, | |
378 BoolObjectClosure* is_alive, | |
379 OopClosure* keep_alive, | |
380 VoidClosure* complete_gc, | |
381 YieldClosure* yield); | |
382 | |
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383 // round-robin mod _num_q (not: _not_ mode _max_num_q) |
0 | 384 int next_id() { |
385 int id = _next_id; | |
386 if (++_next_id == _num_q) { | |
387 _next_id = 0; | |
388 } | |
389 return id; | |
390 } | |
391 DiscoveredList* get_discovered_list(ReferenceType rt); | |
392 inline void add_to_discovered_list_mt(DiscoveredList& refs_list, oop obj, | |
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393 HeapWord* discovered_addr); |
0 | 394 void verify_ok_to_handle_reflists() PRODUCT_RETURN; |
395 | |
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396 void clear_discovered_references(DiscoveredList& refs_list); |
0 | 397 void abandon_partial_discovered_list(DiscoveredList& refs_list); |
398 | |
399 // Calculate the number of jni handles. | |
400 unsigned int count_jni_refs(); | |
401 | |
402 // Balances reference queues. | |
403 void balance_queues(DiscoveredList ref_lists[]); | |
404 | |
405 // Update (advance) the soft ref master clock field. | |
406 void update_soft_ref_master_clock(); | |
407 | |
408 public: | |
409 // constructor | |
410 ReferenceProcessor(): | |
411 _span((HeapWord*)NULL, (HeapWord*)NULL), | |
412 _discoveredSoftRefs(NULL), _discoveredWeakRefs(NULL), | |
413 _discoveredFinalRefs(NULL), _discoveredPhantomRefs(NULL), | |
414 _discovering_refs(false), | |
415 _discovery_is_atomic(true), | |
416 _enqueuing_is_done(false), | |
417 _discovery_is_mt(false), | |
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418 _discovered_list_needs_barrier(false), |
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419 _bs(NULL), |
0 | 420 _is_alive_non_header(NULL), |
421 _num_q(0), | |
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422 _max_num_q(0), |
0 | 423 _processing_is_mt(false), |
424 _next_id(0) | |
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425 { } |
0 | 426 |
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427 // Default parameters give you a vanilla reference processor. |
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428 ReferenceProcessor(MemRegion span, |
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429 bool mt_processing = false, int mt_processing_degree = 1, |
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430 bool mt_discovery = false, int mt_discovery_degree = 1, |
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431 bool atomic_discovery = true, |
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432 BoolObjectClosure* is_alive_non_header = NULL, |
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433 bool discovered_list_needs_barrier = false); |
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434 |
0 | 435 // RefDiscoveryPolicy values |
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436 enum DiscoveryPolicy { |
0 | 437 ReferenceBasedDiscovery = 0, |
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438 ReferentBasedDiscovery = 1, |
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439 DiscoveryPolicyMin = ReferenceBasedDiscovery, |
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440 DiscoveryPolicyMax = ReferentBasedDiscovery |
0 | 441 }; |
442 | |
443 static void init_statics(); | |
444 | |
445 public: | |
446 // get and set "is_alive_non_header" field | |
447 BoolObjectClosure* is_alive_non_header() { | |
448 return _is_alive_non_header; | |
449 } | |
450 void set_is_alive_non_header(BoolObjectClosure* is_alive_non_header) { | |
451 _is_alive_non_header = is_alive_non_header; | |
452 } | |
453 | |
454 // get and set span | |
455 MemRegion span() { return _span; } | |
456 void set_span(MemRegion span) { _span = span; } | |
457 | |
458 // start and stop weak ref discovery | |
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459 void enable_discovery(bool verify_disabled, bool check_no_refs) { |
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460 #ifdef ASSERT |
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461 // Verify that we're not currently discovering refs |
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462 assert(!verify_disabled || !_discovering_refs, "nested call?"); |
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463 |
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464 if (check_no_refs) { |
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465 // Verify that the discovered lists are empty |
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466 verify_no_references_recorded(); |
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467 } |
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468 #endif // ASSERT |
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469 _discovering_refs = true; |
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470 } |
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471 |
0 | 472 void disable_discovery() { _discovering_refs = false; } |
473 bool discovery_enabled() { return _discovering_refs; } | |
474 | |
475 // whether discovery is atomic wrt other collectors | |
476 bool discovery_is_atomic() const { return _discovery_is_atomic; } | |
477 void set_atomic_discovery(bool atomic) { _discovery_is_atomic = atomic; } | |
478 | |
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479 // whether the JDK in which we are embedded is a pre-4965777 JDK, |
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480 // and thus whether or not it uses the discovered field to chain |
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481 // the entries in the pending list. |
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482 static bool pending_list_uses_discovered_field() { |
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483 return _pending_list_uses_discovered_field; |
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484 } |
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485 |
0 | 486 // whether discovery is done by multiple threads same-old-timeously |
487 bool discovery_is_mt() const { return _discovery_is_mt; } | |
488 void set_mt_discovery(bool mt) { _discovery_is_mt = mt; } | |
489 | |
490 // Whether we are in a phase when _processing_ is MT. | |
491 bool processing_is_mt() const { return _processing_is_mt; } | |
492 void set_mt_processing(bool mt) { _processing_is_mt = mt; } | |
493 | |
494 // whether all enqueuing of weak references is complete | |
495 bool enqueuing_is_done() { return _enqueuing_is_done; } | |
496 void set_enqueuing_is_done(bool v) { _enqueuing_is_done = v; } | |
497 | |
498 // iterate over oops | |
499 void weak_oops_do(OopClosure* f); // weak roots | |
500 | |
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501 // Balance each of the discovered lists. |
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502 void balance_all_queues(); |
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503 |
0 | 504 // Discover a Reference object, using appropriate discovery criteria |
505 bool discover_reference(oop obj, ReferenceType rt); | |
506 | |
507 // Process references found during GC (called by the garbage collector) | |
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508 void process_discovered_references(BoolObjectClosure* is_alive, |
0 | 509 OopClosure* keep_alive, |
510 VoidClosure* complete_gc, | |
511 AbstractRefProcTaskExecutor* task_executor); | |
512 | |
513 public: | |
514 // Enqueue references at end of GC (called by the garbage collector) | |
515 bool enqueue_discovered_references(AbstractRefProcTaskExecutor* task_executor = NULL); | |
516 | |
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517 // If a discovery is in process that is being superceded, abandon it: all |
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518 // the discovered lists will be empty, and all the objects on them will |
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519 // have NULL discovered fields. Must be called only at a safepoint. |
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520 void abandon_partial_discovery(); |
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521 |
0 | 522 // debugging |
523 void verify_no_references_recorded() PRODUCT_RETURN; | |
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524 void verify_referent(oop obj) PRODUCT_RETURN; |
0 | 525 |
526 // clear the discovered lists (unlinking each entry). | |
527 void clear_discovered_references() PRODUCT_RETURN; | |
528 }; | |
529 | |
530 // A utility class to disable reference discovery in | |
531 // the scope which contains it, for given ReferenceProcessor. | |
532 class NoRefDiscovery: StackObj { | |
533 private: | |
534 ReferenceProcessor* _rp; | |
535 bool _was_discovering_refs; | |
536 public: | |
537 NoRefDiscovery(ReferenceProcessor* rp) : _rp(rp) { | |
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538 _was_discovering_refs = _rp->discovery_enabled(); |
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539 if (_was_discovering_refs) { |
0 | 540 _rp->disable_discovery(); |
541 } | |
542 } | |
543 | |
544 ~NoRefDiscovery() { | |
545 if (_was_discovering_refs) { | |
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546 _rp->enable_discovery(true /*verify_disabled*/, false /*check_no_refs*/); |
0 | 547 } |
548 } | |
549 }; | |
550 | |
551 | |
552 // A utility class to temporarily mutate the span of the | |
553 // given ReferenceProcessor in the scope that contains it. | |
554 class ReferenceProcessorSpanMutator: StackObj { | |
555 private: | |
556 ReferenceProcessor* _rp; | |
557 MemRegion _saved_span; | |
558 | |
559 public: | |
560 ReferenceProcessorSpanMutator(ReferenceProcessor* rp, | |
561 MemRegion span): | |
562 _rp(rp) { | |
563 _saved_span = _rp->span(); | |
564 _rp->set_span(span); | |
565 } | |
566 | |
567 ~ReferenceProcessorSpanMutator() { | |
568 _rp->set_span(_saved_span); | |
569 } | |
570 }; | |
571 | |
572 // A utility class to temporarily change the MT'ness of | |
573 // reference discovery for the given ReferenceProcessor | |
574 // in the scope that contains it. | |
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575 class ReferenceProcessorMTDiscoveryMutator: StackObj { |
0 | 576 private: |
577 ReferenceProcessor* _rp; | |
578 bool _saved_mt; | |
579 | |
580 public: | |
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581 ReferenceProcessorMTDiscoveryMutator(ReferenceProcessor* rp, |
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582 bool mt): |
0 | 583 _rp(rp) { |
584 _saved_mt = _rp->discovery_is_mt(); | |
585 _rp->set_mt_discovery(mt); | |
586 } | |
587 | |
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588 ~ReferenceProcessorMTDiscoveryMutator() { |
0 | 589 _rp->set_mt_discovery(_saved_mt); |
590 } | |
591 }; | |
592 | |
593 | |
594 // A utility class to temporarily change the disposition | |
595 // of the "is_alive_non_header" closure field of the | |
596 // given ReferenceProcessor in the scope that contains it. | |
597 class ReferenceProcessorIsAliveMutator: StackObj { | |
598 private: | |
599 ReferenceProcessor* _rp; | |
600 BoolObjectClosure* _saved_cl; | |
601 | |
602 public: | |
603 ReferenceProcessorIsAliveMutator(ReferenceProcessor* rp, | |
604 BoolObjectClosure* cl): | |
605 _rp(rp) { | |
606 _saved_cl = _rp->is_alive_non_header(); | |
607 _rp->set_is_alive_non_header(cl); | |
608 } | |
609 | |
610 ~ReferenceProcessorIsAliveMutator() { | |
611 _rp->set_is_alive_non_header(_saved_cl); | |
612 } | |
613 }; | |
614 | |
615 // A utility class to temporarily change the disposition | |
616 // of the "discovery_is_atomic" field of the | |
617 // given ReferenceProcessor in the scope that contains it. | |
618 class ReferenceProcessorAtomicMutator: StackObj { | |
619 private: | |
620 ReferenceProcessor* _rp; | |
621 bool _saved_atomic_discovery; | |
622 | |
623 public: | |
624 ReferenceProcessorAtomicMutator(ReferenceProcessor* rp, | |
625 bool atomic): | |
626 _rp(rp) { | |
627 _saved_atomic_discovery = _rp->discovery_is_atomic(); | |
628 _rp->set_atomic_discovery(atomic); | |
629 } | |
630 | |
631 ~ReferenceProcessorAtomicMutator() { | |
632 _rp->set_atomic_discovery(_saved_atomic_discovery); | |
633 } | |
634 }; | |
635 | |
636 | |
637 // A utility class to temporarily change the MT processing | |
638 // disposition of the given ReferenceProcessor instance | |
639 // in the scope that contains it. | |
640 class ReferenceProcessorMTProcMutator: StackObj { | |
641 private: | |
642 ReferenceProcessor* _rp; | |
643 bool _saved_mt; | |
644 | |
645 public: | |
646 ReferenceProcessorMTProcMutator(ReferenceProcessor* rp, | |
647 bool mt): | |
648 _rp(rp) { | |
649 _saved_mt = _rp->processing_is_mt(); | |
650 _rp->set_mt_processing(mt); | |
651 } | |
652 | |
653 ~ReferenceProcessorMTProcMutator() { | |
654 _rp->set_mt_processing(_saved_mt); | |
655 } | |
656 }; | |
657 | |
658 | |
659 // This class is an interface used to implement task execution for the | |
660 // reference processing. | |
661 class AbstractRefProcTaskExecutor { | |
662 public: | |
663 | |
664 // Abstract tasks to execute. | |
665 class ProcessTask; | |
666 class EnqueueTask; | |
667 | |
668 // Executes a task using worker threads. | |
669 virtual void execute(ProcessTask& task) = 0; | |
670 virtual void execute(EnqueueTask& task) = 0; | |
671 | |
672 // Switch to single threaded mode. | |
673 virtual void set_single_threaded_mode() { }; | |
674 }; | |
675 | |
676 // Abstract reference processing task to execute. | |
677 class AbstractRefProcTaskExecutor::ProcessTask { | |
678 protected: | |
679 ProcessTask(ReferenceProcessor& ref_processor, | |
680 DiscoveredList refs_lists[], | |
681 bool marks_oops_alive) | |
682 : _ref_processor(ref_processor), | |
683 _refs_lists(refs_lists), | |
684 _marks_oops_alive(marks_oops_alive) | |
685 { } | |
686 | |
687 public: | |
688 virtual void work(unsigned int work_id, BoolObjectClosure& is_alive, | |
689 OopClosure& keep_alive, | |
690 VoidClosure& complete_gc) = 0; | |
691 | |
692 // Returns true if a task marks some oops as alive. | |
693 bool marks_oops_alive() const | |
694 { return _marks_oops_alive; } | |
695 | |
696 protected: | |
697 ReferenceProcessor& _ref_processor; | |
698 DiscoveredList* _refs_lists; | |
699 const bool _marks_oops_alive; | |
700 }; | |
701 | |
702 // Abstract reference processing task to execute. | |
703 class AbstractRefProcTaskExecutor::EnqueueTask { | |
704 protected: | |
705 EnqueueTask(ReferenceProcessor& ref_processor, | |
706 DiscoveredList refs_lists[], | |
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707 HeapWord* pending_list_addr, |
0 | 708 int n_queues) |
709 : _ref_processor(ref_processor), | |
710 _refs_lists(refs_lists), | |
711 _pending_list_addr(pending_list_addr), | |
712 _n_queues(n_queues) | |
713 { } | |
714 | |
715 public: | |
716 virtual void work(unsigned int work_id) = 0; | |
717 | |
718 protected: | |
719 ReferenceProcessor& _ref_processor; | |
720 DiscoveredList* _refs_lists; | |
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721 HeapWord* _pending_list_addr; |
0 | 722 int _n_queues; |
723 }; | |
1972 | 724 |
725 #endif // SHARE_VM_MEMORY_REFERENCEPROCESSOR_HPP |