topical media & game development

topical media & game development

[] readme course(s) preface I 1 2 II 3 4 III 5 6 7 IV 8 9 10 V 11 12 afterthought(s) appendix reference(s) example(s) resource(s) _

lib-of-vs-libs-Poco-include-Poco-Task.h / h


  //
  // Task.h
  //
  //  $Id: //poco/1.3/Foundation/include/Poco/Task.h#1$ 
  //
  // Library: Foundation
  // Package: Tasks
  // Module:  Tasks
  //
  // Definition of the Task class.
  //
  // Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
  // and Contributors.
  //
  // Permission is hereby granted, free of charge, to any person or organization
  // obtaining a copy of the software and accompanying documentation covered by
  // this license (the "Software") to use, reproduce, display, distribute,
  // execute, and transmit the Software, and to prepare derivative works of the
  // Software, and to permit third-parties to whom the Software is furnished to
  // do so, all subject to the following:
  // 
  // The copyright notices in the Software and this entire statement, including
  // the above license grant, this restriction and the following disclaimer,
  // must be included in all copies of the Software, in whole or in part, and
  // all derivative works of the Software, unless such copies or derivative
  // works are solely in the form of machine-executable object code generated by
  // a source language processor.
  // 
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
  // SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
  // FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
  // ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  // DEALINGS IN THE SOFTWARE.
  //
  
  ifndef Foundation_Task_INCLUDED
  define Foundation_Task_INCLUDED
  
  include "Poco/Foundation.h"
  include "Poco/Runnable.h"
  include "Poco/RefCountedObject.h"
  include "Poco/Mutex.h"
  include "Poco/Event.h"
  
  namespace Poco {
  
  class TaskManager;
  class Notification;
  class NotificationCenter;
  
  class Foundation_API Task: public Runnable, public RefCountedObject

A Task is a subclass of Runnable that has a name and supports progress reporting and cancellation. A TaskManager object can be used to take care of the lifecycle of a Task. { public: enum TaskState { TASK_IDLE, TASK_STARTING, TASK_RUNNING, TASK_CANCELLING, TASK_FINISHED }; Task(const std::string& name); Creates the Task.


          const std::string& name() const;

Returns the task's name. float progress() const; Returns the task's progress. The value will be between 0.0 (just started) and 1.0 (completed).


          void cancel();

Requests the task to cancel itself. For cancellation to work, the task's runTask() method must periodically call isCancelled() and react accordingly.


          bool isCancelled() const;

Returns true if cancellation of the task has been requested. A Task's runTask() method should periodically call this method and stop whatever it is doing in an orderly way when this method returns true.


          TaskState state() const;

Returns the task's current state.


          void reset();

Sets the task's progress to zero and clears the cancel flag. virtual void runTask() = 0; Do whatever the task needs to do. Must be overridden by subclasses. void run(); Calls the task's runTask() method and notifies the owner of the task's start and completion.


  protected:
          bool sleep(long milliseconds);

Suspends the current thread for the specified amount of time. If the task is cancelled while it is sleeping, sleep() will return immediately and the return value will be true. If the time interval passes without the task being cancelled, the return value is false. A Task should use this method in favor of Thread::sleep().


          void setProgress(float progress);

Sets the task's progress. The value should be between 0.0 (just started) and 1.0 (completed).


          virtual void postNotification(Notification* pNf);

Posts a notification to the task manager's notification center. A task can use this method to post custom notifications about its progress.


          void setOwner(TaskManager* pOwner);

Sets the (optional) owner of the task. TaskManager* getOwner() const; Returns the owner of the task, which may be NULL.


          void setState(TaskState state);

Sets the task's state.


          virtual ~Task();

Destroys the Task. private: Task(); Task(const Task&); Task& operator = (const Task&); std::string _name; TaskManager* _pOwner; float _progress; TaskState _state; Event _cancelEvent; mutable FastMutex _mutex; friend class TaskManager; };


  //
  // inlines
  //
  inline const std::string& Task::name() const
  {
          return _name;
  }
  
  inline float Task::progress() const
  {
          FastMutex::ScopedLock lock(_mutex);
  
          return _progress;
  }
  
  inline bool Task::isCancelled() const
  {
          return _state == TASK_CANCELLING;
  }
  
  inline Task::TaskState Task::state() const
  {
          return _state;
  }
  
  inline TaskManager* Task::getOwner() const
  {
          FastMutex::ScopedLock lock(_mutex);
  
          return _pOwner;
  }
  
  } // namespace Poco
  
  endif // Foundation_Task_INCLUDED

[] readme course(s) preface I 1 2 II 3 4 III 5 6 7 IV 8 9 10 V 11 12 afterthought(s) appendix reference(s) example(s) resource(s) _

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