[80] | 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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