1 | // |
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2 | // Task.h |
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3 | // |
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4 | // $Id: //poco/1.3/Foundation/include/Poco/Task.h#1 $ |
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5 | // |
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6 | // Library: Foundation |
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7 | // Package: Tasks |
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8 | // Module: Tasks |
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9 | // |
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10 | // Definition of the Task class. |
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11 | // |
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12 | // Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH. |
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13 | // and Contributors. |
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14 | // |
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15 | // Permission is hereby granted, free of charge, to any person or organization |
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16 | // obtaining a copy of the software and accompanying documentation covered by |
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17 | // this license (the "Software") to use, reproduce, display, distribute, |
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18 | // execute, and transmit the Software, and to prepare derivative works of the |
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19 | // Software, and to permit third-parties to whom the Software is furnished to |
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20 | // do so, all subject to the following: |
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21 | // |
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22 | // The copyright notices in the Software and this entire statement, including |
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23 | // the above license grant, this restriction and the following disclaimer, |
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24 | // must be included in all copies of the Software, in whole or in part, and |
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25 | // all derivative works of the Software, unless such copies or derivative |
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26 | // works are solely in the form of machine-executable object code generated by |
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27 | // a source language processor. |
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28 | // |
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29 | // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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30 | // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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31 | // FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT |
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32 | // SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE |
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33 | // FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE, |
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34 | // ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
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35 | // DEALINGS IN THE SOFTWARE. |
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36 | // |
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37 | |
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38 | |
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39 | #ifndef Foundation_Task_INCLUDED |
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40 | #define Foundation_Task_INCLUDED |
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41 | |
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42 | |
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43 | #include "Poco/Foundation.h" |
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44 | #include "Poco/Runnable.h" |
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45 | #include "Poco/RefCountedObject.h" |
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46 | #include "Poco/Mutex.h" |
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47 | #include "Poco/Event.h" |
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48 | |
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49 | |
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50 | namespace Poco { |
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51 | |
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52 | |
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53 | class TaskManager; |
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54 | class Notification; |
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55 | class NotificationCenter; |
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56 | |
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57 | |
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58 | class Foundation_API Task: public Runnable, public RefCountedObject |
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59 | /// A Task is a subclass of Runnable that has a name |
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60 | /// and supports progress reporting and cancellation. |
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61 | /// |
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62 | /// A TaskManager object can be used to take care of the |
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63 | /// lifecycle of a Task. |
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64 | { |
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65 | public: |
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66 | enum TaskState |
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67 | { |
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68 | TASK_IDLE, |
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69 | TASK_STARTING, |
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70 | TASK_RUNNING, |
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71 | TASK_CANCELLING, |
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72 | TASK_FINISHED |
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73 | }; |
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74 | |
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75 | Task(const std::string& name); |
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76 | /// Creates the Task. |
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77 | |
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78 | const std::string& name() const; |
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79 | /// Returns the task's name. |
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80 | |
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81 | float progress() const; |
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82 | /// Returns the task's progress. |
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83 | /// The value will be between 0.0 (just started) |
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84 | /// and 1.0 (completed). |
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85 | |
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86 | void cancel(); |
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87 | /// Requests the task to cancel itself. For cancellation |
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88 | /// to work, the task's runTask() method must periodically |
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89 | /// call isCancelled() and react accordingly. |
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90 | |
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91 | bool isCancelled() const; |
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92 | /// Returns true if cancellation of the task has been |
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93 | /// requested. |
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94 | /// |
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95 | /// A Task's runTask() method should periodically |
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96 | /// call this method and stop whatever it is doing in an |
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97 | /// orderly way when this method returns true. |
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98 | |
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99 | TaskState state() const; |
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100 | /// Returns the task's current state. |
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101 | |
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102 | void reset(); |
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103 | /// Sets the task's progress to zero and clears the |
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104 | /// cancel flag. |
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105 | |
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106 | virtual void runTask() = 0; |
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107 | /// Do whatever the task needs to do. Must |
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108 | /// be overridden by subclasses. |
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109 | |
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110 | void run(); |
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111 | /// Calls the task's runTask() method and notifies the owner |
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112 | /// of the task's start and completion. |
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113 | |
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114 | protected: |
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115 | bool sleep(long milliseconds); |
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116 | /// Suspends the current thread for the specified |
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117 | /// amount of time. |
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118 | /// |
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119 | /// If the task is cancelled while it is sleeping, |
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120 | /// sleep() will return immediately and the return |
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121 | /// value will be true. If the time interval |
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122 | /// passes without the task being cancelled, the |
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123 | /// return value is false. |
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124 | /// |
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125 | /// A Task should use this method in favor of Thread::sleep(). |
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126 | |
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127 | void setProgress(float progress); |
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128 | /// Sets the task's progress. |
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129 | /// The value should be between 0.0 (just started) |
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130 | /// and 1.0 (completed). |
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131 | |
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132 | virtual void postNotification(Notification* pNf); |
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133 | /// Posts a notification to the task manager's |
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134 | /// notification center. |
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135 | /// |
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136 | /// A task can use this method to post custom |
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137 | /// notifications about its progress. |
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138 | |
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139 | void setOwner(TaskManager* pOwner); |
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140 | /// Sets the (optional) owner of the task. |
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141 | |
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142 | TaskManager* getOwner() const; |
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143 | /// Returns the owner of the task, which may be NULL. |
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144 | |
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145 | void setState(TaskState state); |
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146 | /// Sets the task's state. |
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147 | |
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148 | virtual ~Task(); |
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149 | /// Destroys the Task. |
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150 | |
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151 | private: |
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152 | Task(); |
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153 | Task(const Task&); |
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154 | Task& operator = (const Task&); |
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155 | |
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156 | std::string _name; |
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157 | TaskManager* _pOwner; |
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158 | float _progress; |
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159 | TaskState _state; |
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160 | Event _cancelEvent; |
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161 | mutable FastMutex _mutex; |
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162 | |
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163 | friend class TaskManager; |
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164 | }; |
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165 | |
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166 | |
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167 | // |
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168 | // inlines |
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169 | // |
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170 | inline const std::string& Task::name() const |
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171 | { |
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172 | return _name; |
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173 | } |
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174 | |
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175 | |
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176 | inline float Task::progress() const |
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177 | { |
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178 | FastMutex::ScopedLock lock(_mutex); |
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179 | |
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180 | return _progress; |
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181 | } |
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182 | |
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183 | |
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184 | inline bool Task::isCancelled() const |
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185 | { |
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186 | return _state == TASK_CANCELLING; |
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187 | } |
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188 | |
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189 | |
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190 | inline Task::TaskState Task::state() const |
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191 | { |
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192 | return _state; |
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193 | } |
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194 | |
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195 | |
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196 | inline TaskManager* Task::getOwner() const |
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197 | { |
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198 | FastMutex::ScopedLock lock(_mutex); |
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199 | |
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200 | return _pOwner; |
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201 | } |
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202 | |
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203 | |
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204 | } // namespace Poco |
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205 | |
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206 | |
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207 | #endif // Foundation_Task_INCLUDED |
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