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/*
* Copyright (C) 2010 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef Task_h
#define Task_h
#include <wtf/Vector.h>
class TaskList;
// WebTask represents a task which can run by postTask() or postDelayedTask().
// it is named "WebTask", not "Task", to avoid conflist with base/task.h.
class WebTask {
public:
WebTask(TaskList*);
// The main code of this task.
// An implementation of run() should return immediately if cancel() was called.
virtual void run() = 0;
virtual void cancel() = 0;
virtual ~WebTask();
protected:
TaskList* m_taskList;
};
class TaskList {
public:
TaskList() {}
~TaskList() { revokeAll(); }
void registerTask(WebTask* task) { m_tasks.append(task); }
void unregisterTask(WebTask* task);
void revokeAll();
private:
Vector<WebTask*> m_tasks;
};
// A task containing an object pointer of class T. Is is supposed that
// runifValid() calls a member function of the object pointer.
// Class T must have "TaskList* taskList()".
template<class T> class MethodTask: public WebTask {
public:
MethodTask(T* object): WebTask(object->taskList()), m_object(object) {}
virtual void run()
{
if (m_object)
runIfValid();
}
virtual void cancel()
{
m_object = 0;
m_taskList->unregisterTask(this);
m_taskList = 0;
}
virtual void runIfValid() = 0;
protected:
T* m_object;
};
void postTask(WebTask* task);
void postDelayedTask(WebTask* task, int64_t ms);
#endif // Task_h
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