source: vscpl/src/hu/varadiistvan/scpl/_posix/Mutex.h@ 5:55892b4e7748

// Copyright (c) 2013 by István Váradi

// This file is part of VSCPL, a simple cross-platform utility library

// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:

// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.
// 2. 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.

// 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.

// The views and conclusions contained in the software and documentation are those
// of the authors and should not be interpreted as representing official policies,
// either expressed or implied, of the FreeBSD Project.

#ifndef HU_VARADIISTVAN_SCPL_MUTEX_H
#define HU_VARADIISTVAN_SCPL_MUTEX_H
//------------------------------------------------------------------------------

#include <pthread.h>

//------------------------------------------------------------------------------

namespace hu { namespace varadiistvan { namespace scpl {

//------------------------------------------------------------------------------

/**
 * Mutual exclusion device for POSIX threads.
 */
class Mutex
{
private:
    /**
     * The mutex structure.
     */
    pthread_mutex_t mutex;

public:
    /**
     * Construct the mutex.
     */
    Mutex();

    /**
     * Destroy the mutex.
     */
    ~Mutex();

    /**
     * Lock the mutex. If the mutex is locked by another thread, the
     * caller one waits until the other thread releases the mutex.
     */
    void lock();

    /**
     * Try to lock the mutex. If the mutex is locked by another
     * thread, this function returns false immediately. Otherwise it
     * locks the mutex and returns true.
     */
    bool tryLock();

    /**
     * Unlock the mutex.
     */
    void unlock();

    friend class CondVar;
};

//------------------------------------------------------------------------------
// Inline definitions
//------------------------------------------------------------------------------

inline Mutex::Mutex()
{
    pthread_mutex_init(&mutex, 0);
}

//------------------------------------------------------------------------------

inline Mutex::~Mutex()
{
    pthread_mutex_destroy(&mutex);
}

//------------------------------------------------------------------------------

inline void Mutex::lock()
{
    pthread_mutex_lock(&mutex);
}

//------------------------------------------------------------------------------

inline bool Mutex::tryLock()
{
    return pthread_mutex_trylock(&mutex)==0;
}

//------------------------------------------------------------------------------

inline void Mutex::unlock()
{
    pthread_mutex_unlock(&mutex);
}

//------------------------------------------------------------------------------

} /* namespace hu::varadiistvan::scpl */ } /* namespace hu::varadiistvan */ } /* namespace hu */

//------------------------------------------------------------------------------
#endif // HU_VARADIISTVAN_SCPL_MUTEX_H

// Local Variables:
// mode: C++
// c-basic-offset: 4
// indent-tabs-mode: nil
// End: