ScopedLock

/* -*-c++-*- OpenThreads library, Copyright (C) 2002 - 2007  The Open Thread Group
 *
 * This library is open source and may be redistributed and/or modified under  
 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
 * (at your option) any later version.  The full license is in LICENSE file
 * included with this distribution, and on the openscenegraph.org website.
 * 
 * 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 
 * OpenSceneGraph Public License for more details.
*/


//
// ScopedLock and ReverseScopedLock templates
// ~~~~~~~
// 
#ifndef _ScopedLock_
#define _ScopedLock_

namespace OpenThreads{

template <class M> class ScopedLock
{
    private:
        M& m_lock;
        ScopedLock(const ScopedLock&); // prevent copy
        ScopedLock& operator=(const ScopedLock&); // prevent assign
    public:
        explicit ScopedLock(M& m):m_lock(m) {m_lock.lock();}
        ~ScopedLock(){m_lock.unlock();}
};

template <class M> class ReverseScopedLock
{
    private:
        M& m_lock;
        ReverseScopedLock(const ReverseScopedLock&); // prevent copy
        ReverseScopedLock& operator=(const ReverseScopedLock&); // prevent assign
    public:
        explicit ReverseScopedLock(M& m):m_lock(m) {m_lock.unlock();}
        ~ReverseScopedLock(){m_lock.lock();}
};


template <class M> class ScopedPointerLock
{
    private:
        M* m_lock;
        ScopedPointerLock(const ScopedPointerLock&); // prevent copy
        ScopedPointerLock& operator=(const ScopedPointerLock&); // prevent assign
    public:
        explicit ScopedPointerLock(M* m):m_lock(m) { if (m_lock) m_lock->lock();}
        ~ScopedPointerLock(){ if (m_lock) m_lock->unlock();}
};

template <class M> class ReverseScopedPointerLock
{
    private:
        M* m_lock;
        ReverseScopedPointerLock(const ReverseScopedPointerLock&); // prevent copy
        ReverseScopedPointerLock& operator=(const ReverseScopedPointerLock&); // prevent assign
    public:
        explicit ReverseScopedPointerLock(M* m):m_lock(m) { if (m_lock) m_lock->unlock();}
        ~ReverseScopedPointerLock(){ if (m_lock) m_lock->lock();}
};

}
#endif