ResInsight/cafProjectDataModel/cafOmpMutex.h

//##################################################################################################
//
//   Custom Visualization Core library
//   Copyright (C) 2011-2012 Ceetron AS
//    
//   This library is free software: you can redistribute it and/or modify 
//   it under the terms of the GNU General Public License as published by 
//   the Free Software Foundation, either version 3 of the License, or 
//   (at your option) any later version. 
//    
//   This library is distributed in the hope that it will be useful, but WITHOUT ANY 
//   WARRANTY; without even the implied warranty of MERCHANTABILITY or 
//   FITNESS FOR A PARTICULAR PURPOSE.   
//    
//   See the GNU General Public License at <<http://www.gnu.org/licenses/gpl.html>> 
//   for more details. 
//
//##################################################################################################

#pragma once

#include <omp.h>

namespace caf
{

//==================================================================================================
/// OpenMP mutex definition
/// Taken from http://bisqwit.iki.fi/story/howto/openmp/
//==================================================================================================
class MutexType
{
public:
    MutexType()     { omp_init_lock(&m_lock); }
    ~MutexType()    { omp_destroy_lock(&m_lock); }
    void lock()     { omp_set_lock(&m_lock); }
    void unlock()   { omp_unset_lock(&m_lock); }
   
    MutexType(const MutexType& )                { omp_init_lock(&m_lock); }
    MutexType& operator= (const MutexType& )    { return *this; }

private:
    omp_lock_t m_lock;
};


//==================================================================================================
/// OpenMP scoped lock on a mutex
/// Taken from http://bisqwit.iki.fi/story/howto/openmp/
//==================================================================================================
class ScopedLock
{
public:
    explicit ScopedLock(MutexType& m) : m_mutex(m), m_locked(true)
    {
        m_mutex.lock();
    }

    ~ScopedLock()
    {
        unlock();
    }
    
    void unlock()
    {
        if(!m_locked) return;
        m_locked = false;
        m_mutex.unlock();
    }

    void lockAgain()
    {
        if (m_locked) return;
        m_mutex.lock();
        m_locked = true;
    }
    
private:
    MutexType&  m_mutex;
    bool        m_locked;
 
private: // prevent copying the scoped lock.
    void operator=(const ScopedLock&);
    ScopedLock(const ScopedLock&);
};

}