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/*
* Copyright (c) 2005, Eric Crahen
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is furnished
* to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* 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 AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
*/
#ifndef __ZTLOCKABLE_H__
#define __ZTLOCKABLE_H__
#include "zthread/Exceptions.h"
namespace ZThread {
/**
* @class Lockable
* @author Eric Crahen <http://www.code-foo.com>
* @date <2003-07-16T10:33:32-0400>
* @version 2.3.0
*
* The Lockable interface defines a common method of adding general <i>acquire-release</i>
* semantics to an object. An <i>acquire-release</i> protocol does not necessarily imply
* exclusive access.
*/
class Lockable {
public:
//! Destroy a Lockable object.
virtual ~Lockable() {}
/**
* Acquire the Lockable object.
*
* This method may or may not block the caller for an indefinite amount
* of time. Those details are defined by specializations of this class.
*
* @exception Interrupted_Exception thrown if the calling thread is interrupted before
* the operation completes.
*
* @post The Lockable is acquired only if no exception was thrown.
*/
virtual void acquire() = 0;
/**
* Attempt to acquire the Lockable object.
*
* This method may or may not block the caller for a definite amount
* of time. Those details are defined by specializations of this class;
* however, this method includes a timeout value that can be used to
* limit the maximum amount of time that a specialization <i>could</i> block.
*
* @param timeout - maximum amount of time (milliseconds) this method could block
*
* @return
* - <em>true</em> if the operation completes and the Lockable is acquired before
* the timeout expires.
* - <em>false</em> if the operation times out before the Lockable can be acquired.
*
* @exception Interrupted_Exception thrown if the calling thread is interrupted before
* the operation completes.
*
* @post The Lockable is acquired only if no exception was thrown.
*/
virtual bool tryAcquire(unsigned long timeout) = 0;
/**
* Release the Lockable object.
*
* This method may or may not block the caller for an indefinite amount
* of time. Those details are defined by specializations of this class.
*
* @post The Lockable is released only if no exception was thrown.
*/
virtual void release() = 0;
};
} // namespace ZThread
#endif // __ZTLOCKABLE_H__
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