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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 __ZTFASTMUTEX_H__
#define __ZTFASTMUTEX_H__
#include "zthread/Lockable.h"
#include "zthread/NonCopyable.h"
namespace ZThread {
class FastLock;
/**
* @class FastMutex
* @author Eric Crahen <http://www.code-foo.com>
* @date <2003-07-19T18:45:39-0400>
* @version 2.2.0
*
* A FastMutex is a small fast implementation of a non-recursive, mutually exclusive
* Lockable object. This implementation is a bit faster than the other Mutex classes
* as it involved the least overhead. However, this slight increase in speed is
* gained by sacrificing the robustness provided by the other classes.
*
* A FastMutex has the useful property of not being interruptable; that is to say
* that acquire() and tryAcquire() will not throw Interrupted_Exceptions.
*
* @see Mutex
*
* <b>Scheduling</b>
*
* Scheduling is left to the operating systems and may vary.
*
* <b>Error Checking</b>
*
* No error checking is performed, this means there is the potential for deadlock.
*/
class ZTHREAD_API FastMutex : public Lockable, private NonCopyable {
FastLock* _lock;
public:
//! Create a FastMutex
FastMutex();
//! Destroy a FastMutex
virtual ~FastMutex();
/**
* Acquire exclusive access to the mutex. The calling thread will block until the
* lock can be acquired. No safety or state checks are performed.
*
* @pre The calling thread should <i>not</i> have previously acquired this lock.
* Deadlock will result if the same thread attempts to acquire the mutex more
* than once.
*
* @post The calling thread obtains the lock successfully if no exception is thrown.
* @exception Interrupted_Exception never thrown
*/
virtual void acquire();
/**
* Release exclusive access. No safety or state checks are performed.
*
* @pre the caller should have previously acquired this lock
*/
virtual void release();
/**
* Try to acquire exclusive access to the mutex. The calling thread will block until the
* lock can be acquired. No safety or state checks are performed.
*
* @pre The calling thread should <i>not</i> have previously acquired this lock.
* Deadlock will result if the same thread attempts to acquire the mutex more
* than once.
*
* @param timeout unused
* @return
* - <em>true</em> if the lock was acquired
* - <em>false</em> if the lock was acquired
*
* @post The calling thread obtains the lock successfully if no exception is thrown.
* @exception Interrupted_Exception never thrown
*/
virtual bool tryAcquire(unsigned long timeout);
}; /* FastMutex */
};
#endif // __ZTFASTMUTEX_H__
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