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1 /* |
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2 * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. |
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8 * |
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9 * This code is distributed in the hope that it will be useful, but WITHOUT |
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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12 * version 2 for more details (a copy is included in the LICENSE file that |
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13 * accompanied this code). |
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14 * |
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15 * You should have received a copy of the GNU General Public License version |
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16 * 2 along with this work; if not, write to the Free Software Foundation, |
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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18 * |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
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22 * |
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23 */ |
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24 |
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25 #ifndef SHARE_VM_OOPS_INSTANCEREFKLASS_HPP |
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26 #define SHARE_VM_OOPS_INSTANCEREFKLASS_HPP |
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27 |
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28 #include "gc/shared/specialized_oop_closures.hpp" |
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29 #include "oops/instanceKlass.hpp" |
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30 #include "utilities/macros.hpp" |
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31 |
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32 class ClassFileParser; |
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33 |
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34 // An InstanceRefKlass is a specialized InstanceKlass for Java |
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35 // classes that are subclasses of java/lang/ref/Reference. |
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36 // |
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37 // These classes are used to implement soft/weak/final/phantom |
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38 // references and finalization, and need special treatment by the |
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39 // garbage collector. |
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40 // |
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41 // During GC discovered reference objects are added (chained) to one |
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42 // of the four lists below, depending on the type of reference. |
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43 // The linked occurs through the next field in class java/lang/ref/Reference. |
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44 // |
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45 // Afterwards, the discovered references are processed in decreasing |
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46 // order of reachability. Reference objects eligible for notification |
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47 // are linked to the static pending_list in class java/lang/ref/Reference, |
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48 // and the pending list lock object in the same class is notified. |
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49 |
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50 |
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51 class InstanceRefKlass: public InstanceKlass { |
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52 friend class InstanceKlass; |
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53 private: |
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54 InstanceRefKlass(const ClassFileParser& parser) : InstanceKlass(parser, InstanceKlass::_misc_kind_reference) {} |
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55 |
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56 public: |
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57 InstanceRefKlass() { assert(DumpSharedSpaces || UseSharedSpaces, "only for CDS"); } |
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58 |
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59 // GC specific object visitors |
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60 // |
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61 #if INCLUDE_ALL_GCS |
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62 // Parallel Scavenge |
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63 void oop_ps_push_contents( oop obj, PSPromotionManager* pm); |
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64 // Parallel Compact |
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65 void oop_pc_follow_contents(oop obj, ParCompactionManager* cm); |
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66 void oop_pc_update_pointers(oop obj, ParCompactionManager* cm); |
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67 #endif |
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68 |
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69 // Oop fields (and metadata) iterators |
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70 // [nv = true] Use non-virtual calls to do_oop_nv. |
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71 // [nv = false] Use virtual calls to do_oop. |
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72 // |
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73 // The InstanceRefKlass iterators also support reference processing. |
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74 |
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75 |
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76 // Forward iteration |
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77 private: |
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78 // Iterate over all oop fields and metadata. |
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79 template <bool nv, class OopClosureType> |
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80 inline void oop_oop_iterate(oop obj, OopClosureType* closure); |
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81 |
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82 // Reverse iteration |
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83 #if INCLUDE_ALL_GCS |
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84 // Iterate over all oop fields and metadata. |
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85 template <bool nv, class OopClosureType> |
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86 inline void oop_oop_iterate_reverse(oop obj, OopClosureType* closure); |
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87 #endif // INCLUDE_ALL_GCS |
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88 |
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89 // Bounded range iteration |
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90 // Iterate over all oop fields and metadata. |
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91 template <bool nv, class OopClosureType> |
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92 inline void oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr); |
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93 |
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94 // Reference processing part of the iterators. |
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95 |
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96 // Specialized for [T = oop] or [T = narrowOop]. |
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97 template <bool nv, typename T, class OopClosureType, class Contains> |
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98 inline void oop_oop_iterate_ref_processing_specialized(oop obj, OopClosureType* closure, Contains& contains); |
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99 |
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100 // Only perform reference processing if the referent object is within mr. |
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101 template <bool nv, class OopClosureType> |
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102 inline void oop_oop_iterate_ref_processing_bounded(oop obj, OopClosureType* closure, MemRegion mr); |
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103 |
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104 // Reference processing |
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105 template <bool nv, class OopClosureType> |
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106 inline void oop_oop_iterate_ref_processing(oop obj, OopClosureType* closure); |
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107 |
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108 // Building blocks for specialized handling. |
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109 template <bool nv, typename T, class OopClosureType, class Contains> |
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110 static void do_referent(oop obj, OopClosureType* closure, Contains& contains); |
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111 |
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112 template <bool nv, typename T, class OopClosureType, class Contains> |
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113 static void do_next(oop obj, OopClosureType* closure, Contains& contains); |
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114 |
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115 template <bool nv, typename T, class OopClosureType, class Contains> |
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116 static void do_discovered(oop obj, OopClosureType* closure, Contains& contains); |
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117 |
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118 template <typename T, class OopClosureType> |
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119 static bool try_discover(oop obj, ReferenceType type, OopClosureType* closure); |
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120 |
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121 // Do discovery while handling InstanceRefKlasses. Reference discovery |
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122 // is only done if the closure provides a ReferenceProcessor. |
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123 template <bool nv, typename T, class OopClosureType, class Contains> |
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124 static void oop_oop_iterate_discovery(oop obj, ReferenceType type, OopClosureType* closure, Contains& contains); |
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125 |
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126 // Used for a special case in G1 where the closure needs to be applied |
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127 // to the discovered field. Reference discovery is also done if the |
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128 // closure provides a ReferenceProcessor. |
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129 template <bool nv, typename T, class OopClosureType, class Contains> |
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130 static void oop_oop_iterate_discovered_and_discovery(oop obj, ReferenceType type, OopClosureType* closure, Contains& contains); |
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131 |
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132 // Apply the closure to all fields. No reference discovery is done. |
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133 template <bool nv, typename T, class OopClosureType, class Contains> |
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134 static void oop_oop_iterate_fields(oop obj, OopClosureType* closure, Contains& contains); |
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135 |
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136 template <typename T> |
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137 static void trace_reference_gc(const char *s, oop obj) NOT_DEBUG_RETURN; |
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138 |
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139 public: |
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140 |
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141 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_OOP_ITERATE_DECL) |
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142 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_OOP_ITERATE_DECL) |
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143 |
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144 #if INCLUDE_ALL_GCS |
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145 ALL_OOP_OOP_ITERATE_CLOSURES_1(OOP_OOP_ITERATE_DECL_BACKWARDS) |
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146 ALL_OOP_OOP_ITERATE_CLOSURES_2(OOP_OOP_ITERATE_DECL_BACKWARDS) |
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147 #endif // INCLUDE_ALL_GCS |
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148 |
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149 // Update non-static oop maps so 'referent', 'nextPending' and |
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150 // 'discovered' will look like non-oops |
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151 static void update_nonstatic_oop_maps(Klass* k); |
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152 |
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153 public: |
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154 // Verification |
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155 void oop_verify_on(oop obj, outputStream* st); |
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156 }; |
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157 |
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158 #endif // SHARE_VM_OOPS_INSTANCEREFKLASS_HPP |