Mutex.cpp

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// ****************************************************************************
// This file is part of the Integrating Vision Toolkit (IVT).
//
// The IVT is maintained by the Karlsruhe Institute of Technology (KIT)
// (www.kit.edu) in cooperation with the company Keyetech (www.keyetech.de).
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// All rights reserved.
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// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
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//    notice, this list of conditions and the following disclaimer in the
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//    without specific prior written permission.
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// THIS SOFTWARE IS PROVIDED BY THE KIT AND CONTRIBUTORS “AS IS” AND ANY
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// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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// ****************************************************************************
// ****************************************************************************
// Filename:  Mutex.cpp
// Author:    Kai Welke
// Date:      13.01.2006
// ****************************************************************************


// ****************************************************************************
// Includes
// ****************************************************************************

#include <new> // for explicitly using correct new/delete operators on VC DSPs

#include "Mutex.h"



// ****************************************************************************
// Constructor / Destructor
// ****************************************************************************

CMutex::CMutex()
{
#ifdef WIN32
        InitializeCriticalSection(&m_CSWindowsMutex);
#else
        pthread_mutexattr_init(&m_MutexAttr);
        pthread_mutex_init(&m_PosixMutex ,&m_MutexAttr);
#endif
}

CMutex::~CMutex()
{
#ifdef WIN32
        DeleteCriticalSection(&m_CSWindowsMutex);
#else
        pthread_mutex_destroy(&m_PosixMutex);
        pthread_mutexattr_destroy(&m_MutexAttr);
#endif
}


// ****************************************************************************
// Methods
// ****************************************************************************

// try to lock the mutex. If another thread is owner of mutex, wait till mutex is unlocked
Threading::EMutexStatus CMutex::Lock()
{
#ifdef WIN32
        EnterCriticalSection(&m_CSWindowsMutex);
        return Threading::eMutexSuccess;
#else
        if (pthread_mutex_lock(&m_PosixMutex) == 0)
                return Threading::eMutexSuccess;
        else
                return Threading::eMutexError;
#endif
}

// try to lock the mutex. If another thread is owner of mutex, return EBusy, otherwise lock mutex
Threading::EMutexStatus CMutex::TryLock()
{
#ifdef WIN32
        if (TryEnterCriticalSection(&m_CSWindowsMutex) == 0)
        {
                return Threading::eMutexBusy;
        }
        else
        {
                return Threading::eMutexSuccess;
        }
#else
        const int nResult = pthread_mutex_trylock(&m_PosixMutex);
        
        if (nResult == 0)
        {
                return Threading::eMutexSuccess;
        }
        else if (nResult == EBUSY)
        {
                return Threading::eMutexBusy;
        }
        else
        {
                return Threading::eMutexError;
        }
#endif
}

// unlock mutex
Threading::EMutexStatus CMutex::UnLock()
{
#ifdef WIN32
        LeaveCriticalSection(&m_CSWindowsMutex);
        return Threading::eMutexSuccess;
#else
        if (pthread_mutex_unlock(&m_PosixMutex) == 0)
        {
                return Threading::eMutexSuccess;
        }
        else
        {
                return Threading::eMutexError;
        }
#endif
}