scopedMutex.h

/* Copyright (c) 2006-2013, Stefan Eilemann <eile@equalizergraphics.com>
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License version 2.1 as published
 * by the Free Software Foundation.
 *
 * 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 Lesser General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifndef LUNCHBOX_SCOPEDMUTEX_H
#define LUNCHBOX_SCOPEDMUTEX_H

#include <lunchbox/condition.h>   // used in inline method
#include <lunchbox/lock.h>        // used in inline method
#include <lunchbox/lockable.h>    // used in inline method
#include <lunchbox/types.h>

namespace lunchbox
{
class WriteOp;
class ReadOp;

template< class L, class T > struct ScopedMutexLocker {};
template< class L > struct ScopedMutexLocker< L, WriteOp >
{
    static inline void set( L& lock ) { lock.set(); }
    static inline void unset( L& lock ) { lock.unset(); }
};
template< class L > struct ScopedMutexLocker< L, ReadOp >
{
    static inline void set( L& lock ) { lock.setRead(); }
    static inline void unset( L& lock ) { lock.unsetRead(); }
};
template<> struct ScopedMutexLocker< Condition, WriteOp >
{
    static inline void set( Condition& cond ) { cond.lock(); }
    static inline void unset( Condition& cond ) { cond.unlock(); }
};
template< class L = Lock, class T = WriteOp >
class ScopedMutex
{
    typedef ScopedMutexLocker< L, T > LockTraits;

public:
    explicit ScopedMutex( L* lock ) : _lock( lock )
        { if( lock ) LockTraits::set( *lock ); }

    explicit ScopedMutex( L& lock ) : _lock( &lock )
        { LockTraits::set( lock ); }

    ScopedMutex( const ScopedMutex& rhs ) : _lock( rhs._lock )
    { const_cast< ScopedMutex& >( rhs )._lock = 0; }

    ScopedMutex& operator = ( ScopedMutex& rhs )
    {
        if( this != &rhs )
        {
            _lock = rhs._lock;
            rhs._lock = 0;
        }
        return *this;
    }

    template< typename LB > explicit ScopedMutex( const LB& lockable )
    : _lock( &lockable.lock ) { LockTraits::set( lockable.lock ); }

    ~ScopedMutex() { leave(); }

    void leave() { if( _lock ) LockTraits::unset( *_lock ); _lock = 0; }

private:
    ScopedMutex();
    L* _lock;
}; // LB_DEPRECATED;

typedef ScopedMutex< SpinLock, ReadOp > ScopedFastRead;

typedef ScopedMutex< SpinLock, WriteOp > ScopedFastWrite;

typedef ScopedMutex< Lock, ReadOp > ScopedRead;

typedef ScopedMutex< Lock, WriteOp > ScopedWrite;

typedef ScopedMutex< Condition, WriteOp > ScopedCondition;
}
#endif //LUNCHBOX_SCOPEDMUTEX_H