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1 /*
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2 * Copyright 2002-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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20 * CA 95054 USA or visit www.sun.com if you need additional information or
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21 * have any questions.
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22 *
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23 */
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24
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25 //
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26 // The GCTaskManager is a queue of GCTasks, and accessors
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27 // to allow the queue to be accessed from many threads.
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28 //
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29
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30 // Forward declarations of types defined in this file.
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31 class GCTask;
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32 class GCTaskQueue;
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33 class SynchronizedGCTaskQueue;
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34 class GCTaskManager;
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35 class NotifyDoneClosure;
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36 // Some useful subclasses of GCTask. You can also make up your own.
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37 class NoopGCTask;
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38 class BarrierGCTask;
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39 class ReleasingBarrierGCTask;
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40 class NotifyingBarrierGCTask;
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41 class WaitForBarrierGCTask;
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42 // A free list of Monitor*'s.
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43 class MonitorSupply;
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44
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45 // Forward declarations of classes referenced in this file via pointer.
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46 class GCTaskThread;
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47 class Mutex;
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48 class Monitor;
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49 class ThreadClosure;
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50
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51 // The abstract base GCTask.
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52 class GCTask : public ResourceObj {
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53 public:
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54 // Known kinds of GCTasks, for predicates.
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55 class Kind : AllStatic {
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56 public:
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57 enum kind {
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58 unknown_task,
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59 ordinary_task,
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60 barrier_task,
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61 noop_task
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62 };
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63 static const char* to_string(kind value);
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64 };
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65 private:
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66 // Instance state.
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67 const Kind::kind _kind; // For runtime type checking.
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68 const uint _affinity; // Which worker should run task.
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69 GCTask* _newer; // Tasks are on doubly-linked ...
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70 GCTask* _older; // ... lists.
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71 public:
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72 virtual char* name() { return (char *)"task"; }
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73
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74 // Abstract do_it method
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75 virtual void do_it(GCTaskManager* manager, uint which) = 0;
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76 // Accessors
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77 Kind::kind kind() const {
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78 return _kind;
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79 }
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80 uint affinity() const {
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81 return _affinity;
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82 }
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83 GCTask* newer() const {
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84 return _newer;
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85 }
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86 void set_newer(GCTask* n) {
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87 _newer = n;
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88 }
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89 GCTask* older() const {
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90 return _older;
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91 }
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92 void set_older(GCTask* p) {
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93 _older = p;
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94 }
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95 // Predicates.
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96 bool is_ordinary_task() const {
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97 return kind()==Kind::ordinary_task;
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98 }
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99 bool is_barrier_task() const {
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100 return kind()==Kind::barrier_task;
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101 }
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102 bool is_noop_task() const {
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103 return kind()==Kind::noop_task;
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104 }
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105 void print(const char* message) const PRODUCT_RETURN;
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106 protected:
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107 // Constructors: Only create subclasses.
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108 // An ordinary GCTask.
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109 GCTask();
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110 // A GCTask of a particular kind, usually barrier or noop.
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111 GCTask(Kind::kind kind);
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112 // An ordinary GCTask with an affinity.
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113 GCTask(uint affinity);
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114 // A GCTask of a particular kind, with and affinity.
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115 GCTask(Kind::kind kind, uint affinity);
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116 // We want a virtual destructor because virtual methods,
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117 // but since ResourceObj's don't have their destructors
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118 // called, we don't have one at all. Instead we have
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119 // this method, which gets called by subclasses to clean up.
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120 virtual void destruct();
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121 // Methods.
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122 void initialize();
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123 };
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124
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125 // A doubly-linked list of GCTasks.
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126 // The list is not synchronized, because sometimes we want to
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127 // build up a list and then make it available to other threads.
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128 // See also: SynchronizedGCTaskQueue.
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129 class GCTaskQueue : public ResourceObj {
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130 private:
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131 // Instance state.
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132 GCTask* _insert_end; // Tasks are enqueued at this end.
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133 GCTask* _remove_end; // Tasks are dequeued from this end.
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134 uint _length; // The current length of the queue.
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135 const bool _is_c_heap_obj; // Is this a CHeapObj?
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136 public:
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137 // Factory create and destroy methods.
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138 // Create as ResourceObj.
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139 static GCTaskQueue* create();
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140 // Create as CHeapObj.
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141 static GCTaskQueue* create_on_c_heap();
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142 // Destroyer.
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143 static void destroy(GCTaskQueue* that);
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144 // Accessors.
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145 // These just examine the state of the queue.
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146 bool is_empty() const {
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147 assert(((insert_end() == NULL && remove_end() == NULL) ||
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148 (insert_end() != NULL && remove_end() != NULL)),
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149 "insert_end and remove_end don't match");
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150 return insert_end() == NULL;
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151 }
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152 uint length() const {
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153 return _length;
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154 }
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155 // Methods.
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156 // Enqueue one task.
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157 void enqueue(GCTask* task);
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158 // Enqueue a list of tasks. Empties the argument list.
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159 void enqueue(GCTaskQueue* list);
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160 // Dequeue one task.
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161 GCTask* dequeue();
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162 // Dequeue one task, preferring one with affinity.
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163 GCTask* dequeue(uint affinity);
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164 protected:
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165 // Constructor. Clients use factory, but there might be subclasses.
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166 GCTaskQueue(bool on_c_heap);
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167 // Destructor-like method.
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168 // Because ResourceMark doesn't call destructors.
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169 // This method cleans up like one.
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170 virtual void destruct();
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171 // Accessors.
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172 GCTask* insert_end() const {
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173 return _insert_end;
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174 }
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175 void set_insert_end(GCTask* value) {
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176 _insert_end = value;
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177 }
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178 GCTask* remove_end() const {
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179 return _remove_end;
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180 }
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181 void set_remove_end(GCTask* value) {
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182 _remove_end = value;
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183 }
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184 void increment_length() {
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185 _length += 1;
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186 }
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187 void decrement_length() {
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188 _length -= 1;
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189 }
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190 void set_length(uint value) {
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191 _length = value;
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192 }
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193 bool is_c_heap_obj() const {
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194 return _is_c_heap_obj;
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195 }
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196 // Methods.
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197 void initialize();
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198 GCTask* remove(); // Remove from remove end.
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199 GCTask* remove(GCTask* task); // Remove from the middle.
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200 void print(const char* message) const PRODUCT_RETURN;
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201 };
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202
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203 // A GCTaskQueue that can be synchronized.
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204 // This "has-a" GCTaskQueue and a mutex to do the exclusion.
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205 class SynchronizedGCTaskQueue : public CHeapObj {
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206 private:
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207 // Instance state.
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208 GCTaskQueue* _unsynchronized_queue; // Has-a unsynchronized queue.
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209 Monitor * _lock; // Lock to control access.
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210 public:
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211 // Factory create and destroy methods.
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212 static SynchronizedGCTaskQueue* create(GCTaskQueue* queue, Monitor * lock) {
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213 return new SynchronizedGCTaskQueue(queue, lock);
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214 }
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215 static void destroy(SynchronizedGCTaskQueue* that) {
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216 if (that != NULL) {
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217 delete that;
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218 }
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219 }
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220 // Accessors
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221 GCTaskQueue* unsynchronized_queue() const {
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222 return _unsynchronized_queue;
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223 }
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224 Monitor * lock() const {
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225 return _lock;
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226 }
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227 // GCTaskQueue wrapper methods.
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228 // These check that you hold the lock
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229 // and then call the method on the queue.
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230 bool is_empty() const {
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231 guarantee(own_lock(), "don't own the lock");
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232 return unsynchronized_queue()->is_empty();
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233 }
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234 void enqueue(GCTask* task) {
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235 guarantee(own_lock(), "don't own the lock");
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236 unsynchronized_queue()->enqueue(task);
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237 }
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238 void enqueue(GCTaskQueue* list) {
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239 guarantee(own_lock(), "don't own the lock");
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240 unsynchronized_queue()->enqueue(list);
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241 }
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242 GCTask* dequeue() {
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243 guarantee(own_lock(), "don't own the lock");
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244 return unsynchronized_queue()->dequeue();
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245 }
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246 GCTask* dequeue(uint affinity) {
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247 guarantee(own_lock(), "don't own the lock");
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248 return unsynchronized_queue()->dequeue(affinity);
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249 }
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250 uint length() const {
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251 guarantee(own_lock(), "don't own the lock");
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252 return unsynchronized_queue()->length();
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253 }
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254 // For guarantees.
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255 bool own_lock() const {
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256 return lock()->owned_by_self();
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257 }
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258 protected:
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259 // Constructor. Clients use factory, but there might be subclasses.
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260 SynchronizedGCTaskQueue(GCTaskQueue* queue, Monitor * lock);
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261 // Destructor. Not virtual because no virtuals.
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262 ~SynchronizedGCTaskQueue();
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263 };
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264
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265 // This is an abstract base class for getting notifications
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266 // when a GCTaskManager is done.
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267 class NotifyDoneClosure : public CHeapObj {
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268 public:
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269 // The notification callback method.
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270 virtual void notify(GCTaskManager* manager) = 0;
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271 protected:
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272 // Constructor.
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273 NotifyDoneClosure() {
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274 // Nothing to do.
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275 }
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276 // Virtual destructor because virtual methods.
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277 virtual ~NotifyDoneClosure() {
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278 // Nothing to do.
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279 }
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280 };
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281
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282 class GCTaskManager : public CHeapObj {
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283 friend class ParCompactionManager;
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284 friend class PSParallelCompact;
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285 friend class PSScavenge;
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286 friend class PSRefProcTaskExecutor;
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287 friend class RefProcTaskExecutor;
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288 private:
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289 // Instance state.
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290 NotifyDoneClosure* _ndc; // Notify on completion.
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291 const uint _workers; // Number of workers.
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292 Monitor* _monitor; // Notification of changes.
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293 SynchronizedGCTaskQueue* _queue; // Queue of tasks.
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294 GCTaskThread** _thread; // Array of worker threads.
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295 uint _busy_workers; // Number of busy workers.
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296 uint _blocking_worker; // The worker that's blocking.
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297 bool* _resource_flag; // Array of flag per threads.
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298 uint _delivered_tasks; // Count of delivered tasks.
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299 uint _completed_tasks; // Count of completed tasks.
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300 uint _barriers; // Count of barrier tasks.
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301 uint _emptied_queue; // Times we emptied the queue.
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302 NoopGCTask* _noop_task; // The NoopGCTask instance.
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303 uint _noop_tasks; // Count of noop tasks.
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304 public:
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305 // Factory create and destroy methods.
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306 static GCTaskManager* create(uint workers) {
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307 return new GCTaskManager(workers);
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308 }
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309 static GCTaskManager* create(uint workers, NotifyDoneClosure* ndc) {
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310 return new GCTaskManager(workers, ndc);
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311 }
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312 static void destroy(GCTaskManager* that) {
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313 if (that != NULL) {
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314 delete that;
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315 }
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316 }
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317 // Accessors.
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318 uint busy_workers() const {
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319 return _busy_workers;
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320 }
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321 // Pun between Monitor* and Mutex*
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322 Monitor* monitor() const {
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323 return _monitor;
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324 }
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325 Monitor * lock() const {
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326 return _monitor;
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327 }
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328 // Methods.
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329 // Add the argument task to be run.
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330 void add_task(GCTask* task);
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331 // Add a list of tasks. Removes task from the argument list.
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332 void add_list(GCTaskQueue* list);
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333 // Claim a task for argument worker.
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334 GCTask* get_task(uint which);
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335 // Note the completion of a task by the argument worker.
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336 void note_completion(uint which);
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337 // Is the queue blocked from handing out new tasks?
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338 bool is_blocked() const {
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339 return (blocking_worker() != sentinel_worker());
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340 }
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341 // Request that all workers release their resources.
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342 void release_all_resources();
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343 // Ask if a particular worker should release its resources.
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344 bool should_release_resources(uint which); // Predicate.
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345 // Note the release of resources by the argument worker.
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346 void note_release(uint which);
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347 // Constants.
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348 // A sentinel worker identifier.
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349 static uint sentinel_worker() {
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350 return (uint) -1; // Why isn't there a max_uint?
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351 }
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352
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353 // Execute the task queue and wait for the completion.
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354 void execute_and_wait(GCTaskQueue* list);
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355
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356 void print_task_time_stamps();
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357 void print_threads_on(outputStream* st);
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358 void threads_do(ThreadClosure* tc);
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359
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360 protected:
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361 // Constructors. Clients use factory, but there might be subclasses.
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362 // Create a GCTaskManager with the appropriate number of workers.
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363 GCTaskManager(uint workers);
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364 // Create a GCTaskManager that calls back when there's no more work.
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365 GCTaskManager(uint workers, NotifyDoneClosure* ndc);
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366 // Make virtual if necessary.
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367 ~GCTaskManager();
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368 // Accessors.
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369 uint workers() const {
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370 return _workers;
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371 }
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372 NotifyDoneClosure* notify_done_closure() const {
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373 return _ndc;
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374 }
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375 SynchronizedGCTaskQueue* queue() const {
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376 return _queue;
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377 }
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378 NoopGCTask* noop_task() const {
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379 return _noop_task;
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380 }
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381 // Bounds-checking per-thread data accessors.
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382 GCTaskThread* thread(uint which);
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383 void set_thread(uint which, GCTaskThread* value);
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384 bool resource_flag(uint which);
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385 void set_resource_flag(uint which, bool value);
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386 // Modifier methods with some semantics.
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387 // Is any worker blocking handing out new tasks?
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388 uint blocking_worker() const {
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389 return _blocking_worker;
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390 }
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391 void set_blocking_worker(uint value) {
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392 _blocking_worker = value;
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393 }
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394 void set_unblocked() {
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395 set_blocking_worker(sentinel_worker());
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396 }
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397 // Count of busy workers.
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398 void reset_busy_workers() {
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399 _busy_workers = 0;
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400 }
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401 uint increment_busy_workers();
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402 uint decrement_busy_workers();
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403 // Count of tasks delivered to workers.
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404 uint delivered_tasks() const {
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405 return _delivered_tasks;
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406 }
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407 void increment_delivered_tasks() {
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408 _delivered_tasks += 1;
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409 }
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410 void reset_delivered_tasks() {
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411 _delivered_tasks = 0;
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412 }
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413 // Count of tasks completed by workers.
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414 uint completed_tasks() const {
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415 return _completed_tasks;
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416 }
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417 void increment_completed_tasks() {
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418 _completed_tasks += 1;
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419 }
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420 void reset_completed_tasks() {
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421 _completed_tasks = 0;
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422 }
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423 // Count of barrier tasks completed.
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424 uint barriers() const {
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425 return _barriers;
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426 }
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427 void increment_barriers() {
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428 _barriers += 1;
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429 }
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430 void reset_barriers() {
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431 _barriers = 0;
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432 }
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433 // Count of how many times the queue has emptied.
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434 uint emptied_queue() const {
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435 return _emptied_queue;
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436 }
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437 void increment_emptied_queue() {
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438 _emptied_queue += 1;
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439 }
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440 void reset_emptied_queue() {
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441 _emptied_queue = 0;
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442 }
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443 // Count of the number of noop tasks we've handed out,
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444 // e.g., to handle resource release requests.
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445 uint noop_tasks() const {
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446 return _noop_tasks;
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447 }
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448 void increment_noop_tasks() {
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449 _noop_tasks += 1;
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450 }
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451 void reset_noop_tasks() {
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452 _noop_tasks = 0;
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453 }
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454 // Other methods.
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455 void initialize();
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456 };
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457
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458 //
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459 // Some exemplary GCTasks.
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460 //
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461
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462 // A noop task that does nothing,
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463 // except take us around the GCTaskThread loop.
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464 class NoopGCTask : public GCTask {
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465 private:
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466 const bool _is_c_heap_obj; // Is this a CHeapObj?
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467 public:
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468 // Factory create and destroy methods.
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469 static NoopGCTask* create();
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470 static NoopGCTask* create_on_c_heap();
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471 static void destroy(NoopGCTask* that);
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472 // Methods from GCTask.
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473 void do_it(GCTaskManager* manager, uint which) {
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474 // Nothing to do.
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475 }
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476 protected:
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477 // Constructor.
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478 NoopGCTask(bool on_c_heap) :
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479 GCTask(GCTask::Kind::noop_task),
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480 _is_c_heap_obj(on_c_heap) {
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481 // Nothing to do.
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482 }
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483 // Destructor-like method.
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484 void destruct();
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485 // Accessors.
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486 bool is_c_heap_obj() const {
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487 return _is_c_heap_obj;
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488 }
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489 };
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490
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491 // A BarrierGCTask blocks other tasks from starting,
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492 // and waits until it is the only task running.
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493 class BarrierGCTask : public GCTask {
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494 public:
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495 // Factory create and destroy methods.
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496 static BarrierGCTask* create() {
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497 return new BarrierGCTask();
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498 }
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499 static void destroy(BarrierGCTask* that) {
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500 if (that != NULL) {
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501 that->destruct();
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502 delete that;
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503 }
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504 }
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505 // Methods from GCTask.
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506 void do_it(GCTaskManager* manager, uint which);
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507 protected:
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508 // Constructor. Clients use factory, but there might be subclasses.
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509 BarrierGCTask() :
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510 GCTask(GCTask::Kind::barrier_task) {
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511 // Nothing to do.
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512 }
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513 // Destructor-like method.
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514 void destruct();
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515 // Methods.
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516 // Wait for this to be the only task running.
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517 void do_it_internal(GCTaskManager* manager, uint which);
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518 };
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519
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520 // A ReleasingBarrierGCTask is a BarrierGCTask
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521 // that tells all the tasks to release their resource areas.
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522 class ReleasingBarrierGCTask : public BarrierGCTask {
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523 public:
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524 // Factory create and destroy methods.
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525 static ReleasingBarrierGCTask* create() {
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526 return new ReleasingBarrierGCTask();
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527 }
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528 static void destroy(ReleasingBarrierGCTask* that) {
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529 if (that != NULL) {
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530 that->destruct();
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531 delete that;
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532 }
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533 }
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534 // Methods from GCTask.
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535 void do_it(GCTaskManager* manager, uint which);
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536 protected:
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537 // Constructor. Clients use factory, but there might be subclasses.
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538 ReleasingBarrierGCTask() :
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539 BarrierGCTask() {
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540 // Nothing to do.
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541 }
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542 // Destructor-like method.
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543 void destruct();
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544 };
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545
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546 // A NotifyingBarrierGCTask is a BarrierGCTask
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547 // that calls a notification method when it is the only task running.
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548 class NotifyingBarrierGCTask : public BarrierGCTask {
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549 private:
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550 // Instance state.
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551 NotifyDoneClosure* _ndc; // The callback object.
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552 public:
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553 // Factory create and destroy methods.
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554 static NotifyingBarrierGCTask* create(NotifyDoneClosure* ndc) {
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555 return new NotifyingBarrierGCTask(ndc);
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556 }
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557 static void destroy(NotifyingBarrierGCTask* that) {
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558 if (that != NULL) {
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559 that->destruct();
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560 delete that;
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561 }
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562 }
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563 // Methods from GCTask.
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564 void do_it(GCTaskManager* manager, uint which);
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565 protected:
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566 // Constructor. Clients use factory, but there might be subclasses.
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567 NotifyingBarrierGCTask(NotifyDoneClosure* ndc) :
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568 BarrierGCTask(),
|
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569 _ndc(ndc) {
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570 assert(notify_done_closure() != NULL, "can't notify on NULL");
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571 }
|
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572 // Destructor-like method.
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573 void destruct();
|
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574 // Accessor.
|
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575 NotifyDoneClosure* notify_done_closure() const { return _ndc; }
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576 };
|
|
577
|
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578 // A WaitForBarrierGCTask is a BarrierGCTask
|
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579 // with a method you can call to wait until
|
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580 // the BarrierGCTask is done.
|
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581 // This may cover many of the uses of NotifyingBarrierGCTasks.
|
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582 class WaitForBarrierGCTask : public BarrierGCTask {
|
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583 private:
|
|
584 // Instance state.
|
|
585 Monitor* _monitor; // Guard and notify changes.
|
|
586 bool _should_wait; // true=>wait, false=>proceed.
|
|
587 const bool _is_c_heap_obj; // Was allocated on the heap.
|
|
588 public:
|
|
589 virtual char* name() { return (char *) "waitfor-barrier-task"; }
|
|
590
|
|
591 // Factory create and destroy methods.
|
|
592 static WaitForBarrierGCTask* create();
|
|
593 static WaitForBarrierGCTask* create_on_c_heap();
|
|
594 static void destroy(WaitForBarrierGCTask* that);
|
|
595 // Methods.
|
|
596 void do_it(GCTaskManager* manager, uint which);
|
|
597 void wait_for();
|
|
598 protected:
|
|
599 // Constructor. Clients use factory, but there might be subclasses.
|
|
600 WaitForBarrierGCTask(bool on_c_heap);
|
|
601 // Destructor-like method.
|
|
602 void destruct();
|
|
603 // Accessors.
|
|
604 Monitor* monitor() const {
|
|
605 return _monitor;
|
|
606 }
|
|
607 bool should_wait() const {
|
|
608 return _should_wait;
|
|
609 }
|
|
610 void set_should_wait(bool value) {
|
|
611 _should_wait = value;
|
|
612 }
|
|
613 bool is_c_heap_obj() {
|
|
614 return _is_c_heap_obj;
|
|
615 }
|
|
616 };
|
|
617
|
|
618 class MonitorSupply : public AllStatic {
|
|
619 private:
|
|
620 // State.
|
|
621 // Control multi-threaded access.
|
|
622 static Mutex* _lock;
|
|
623 // The list of available Monitor*'s.
|
|
624 static GrowableArray<Monitor*>* _freelist;
|
|
625 public:
|
|
626 // Reserve a Monitor*.
|
|
627 static Monitor* reserve();
|
|
628 // Release a Monitor*.
|
|
629 static void release(Monitor* instance);
|
|
630 private:
|
|
631 // Accessors.
|
|
632 static Mutex* lock() {
|
|
633 return _lock;
|
|
634 }
|
|
635 static GrowableArray<Monitor*>* freelist() {
|
|
636 return _freelist;
|
|
637 }
|
|
638 };
|