monitor.h

/* Copyright (c) 2006-2013, Stefan Eilemann <eile@equalizergraphics.com>
 *                    2011, Cedric Stalder <cedric.stalder@gmail.com>
 *               2011-2012, Daniel Nachbaur <danielnachbaur@gmail.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_MONITOR_H
#define LUNCHBOX_MONITOR_H

#include <lunchbox/condition.h>   // member
#include <lunchbox/scopedMutex.h> // used inline
#include <lunchbox/types.h>

#include <errno.h>
#include <string.h>
#include <iostream>
#include <typeinfo>
#include <functional>
#include <boost/bind.hpp>

namespace lunchbox
{
template< class T > class Monitor
{
    typedef void (Monitor< T >::*bool_t)() const;
    void bool_true() const {}

public:
    Monitor() : _value( T( 0 )) {}

    explicit Monitor( const T& value ) : _value( value ) {}

    Monitor( const Monitor< T >& from ) : _value( from._value ) {}

    ~Monitor() {}

    Monitor& operator++ ()
    {
        ScopedCondition mutex( _cond );
        ++_value;
        _cond.broadcast();
        return *this;
    }

    Monitor& operator-- ()
    {
        ScopedCondition mutex( _cond );
        --_value;
        _cond.broadcast();
        return *this;
    }

    Monitor& operator = ( const T& value )
        { set( value ); return *this; }

    const Monitor& operator = ( const Monitor< T >& from )
        { set( from._value ); return *this; }

    Monitor& operator |= ( const T& value )
    {
        ScopedCondition mutex( _cond );
        _value |= value;
        _cond.broadcast();
        return *this;
    }

    Monitor& operator &= ( const T& value )
    {
        ScopedCondition mutex( _cond );
        _value &= value;
        _cond.broadcast();
        return *this;
    }

    T set( const T& value )
    {
        ScopedCondition mutex( _cond );
        const T old = _value;
        _value = value;
        _cond.broadcast();
        return old;
    }

    const T waitEQ( const T& value ) const
    {
        return _waitPredicate( boost::bind( std::equal_to<T>(), value, _1 ));
    }

    const T waitNE( const T& value ) const
    {
        return _waitPredicate( boost::bind( std::not_equal_to<T>(), value, _1));
    }

    const T waitNE( const T& v1, const T& v2 ) const
    {
        if( sizeof( T ) <= 8 ) // issue #1
        {
            const T current = _value;
            if( current != v1 && current != v2 )
                return current;
        }
        ScopedCondition mutex( _cond );
        while( _value == v1 || _value == v2 )
            _cond.wait();
        return _value;
    }

    const T waitGE( const T& value ) const
    {
        return _waitPredicate( boost::bind( std::greater_equal<T>(), _1,
                                            value ));
    }

    const T waitLE( const T& value ) const
     { return _waitPredicate( boost::bind( std::less_equal<T>(), _1, value )); }

    const T waitGT( const T& value ) const
        { return _waitPredicate( boost::bind( std::greater<T>(), _1, value )); }

    const T waitLT( const T& value ) const
        { return _waitPredicate( boost::bind( std::less<T>(), _1, value )); }

    bool timedWaitEQ( const T& value, const uint32_t timeout ) const
    {
        return _timedWaitPredicate( boost::bind( std::equal_to<T>(), _1,
                                                 value ), timeout );
    }

    bool timedWaitNE( const T& value, const uint32_t timeout ) const
    {
        return _timedWaitPredicate( boost::bind( std::not_equal_to<T>(), _1,
                                                 value ), timeout );
    }

    bool timedWaitGE( const T& value, const uint32_t timeout ) const
    {
        return _timedWaitPredicate( boost::bind( std::greater_equal<T>(), _1,
                                                 value ), timeout );
    }

    bool timedWaitLE( const T& value, const uint32_t timeout ) const
    {
        return _timedWaitPredicate( boost::bind( std::less_equal<T>(), _1,
                                                 value ), timeout );
    }

    bool timedWaitGT( const T& value, const uint32_t timeout ) const
    {
        return _timedWaitPredicate( boost::bind( std::greater<T>(), _1,
                                                 value ), timeout );
    }

    bool timedWaitLT( const T& value, const uint32_t timeout ) const
    {
        return _timedWaitPredicate( boost::bind( std::less<T>(), _1, value ),
                                    timeout );
    }


    bool operator == ( const T& value ) const
    {
        ScopedCondition mutex( sizeof(T)>8 ? &_cond : 0 ); // issue #1
        return _value == value;
    }
    bool operator != ( const T& value ) const
    {
        ScopedCondition mutex( sizeof(T)>8 ? &_cond : 0 ); // issue #1
        return _value != value;
    }
    bool operator < ( const T& value ) const
    {
        ScopedCondition mutex( sizeof(T)>8 ? &_cond : 0 ); // issue #1
        return _value < value;
    }
    bool operator > ( const T& value ) const
    {
        ScopedCondition mutex( sizeof(T)>8 ? &_cond : 0 ); // issue #1
        return _value > value;
    }
    bool operator <= ( const T& value ) const
    {
        ScopedCondition mutex( sizeof(T)>8 ? &_cond : 0 ); // issue #1
        return _value <= value;
    }
    bool operator >= ( const T& value ) const
    {
        ScopedCondition mutex( sizeof(T)>8 ? &_cond : 0 ); // issue #1
        return _value >= value;
    }

    bool operator == ( const Monitor<T>& rhs ) const
    {
        ScopedCondition mutex( sizeof(T)>8 ? &_cond : 0 ); // issue #1
        return _value == rhs._value;
    }
    bool operator != ( const Monitor<T>& rhs ) const
    {
        ScopedCondition mutex( sizeof(T)>8 ? &_cond : 0 ); // issue #1
        return _value != rhs._value;
    }
    bool operator < ( const Monitor<T>& rhs ) const
    {
        ScopedCondition mutex( sizeof(T)>8 ? &_cond : 0 ); // issue #1
        return _value < rhs._value;
    }
    bool operator > ( const Monitor<T>& rhs ) const
    {
        ScopedCondition mutex( sizeof(T)>8 ? &_cond : 0 ); // issue #1
        return _value > rhs._value;
    }
    bool operator <= ( const Monitor<T>& rhs ) const
    {
        ScopedCondition mutex( sizeof(T)>8 ? &_cond : 0 ); // issue #1
        return _value <= rhs._value;
    }
    bool operator >= ( const Monitor<T>& rhs ) const
    {
        ScopedCondition mutex( sizeof(T)>8 ? &_cond : 0 ); // issue #1
        return _value >= rhs._value;
    }
    operator bool_t()
    {
        ScopedCondition mutex( sizeof(T)>8 ? &_cond : 0 ); // issue #1
        return _value ? &Monitor< T >::bool_true : 0;
    }

    const T& operator->() const { return _value; }

    const T& get() const { return _value; }

    T operator + ( const T& value ) const
    {
        ScopedCondition mutex( sizeof(T)>8 ? &_cond : 0 ); // issue #1
        return _value + value;
    }

    T operator | ( const T& value ) const
    {
        ScopedCondition mutex( sizeof(T)>8 ? &_cond : 0 ); // issue #1
        return static_cast< T >( _value | value );
    }

    T operator & ( const T& value ) const
    {
        ScopedCondition mutex( sizeof(T)>8 ? &_cond : 0 ); // issue #1
        return static_cast< T >( _value & value );
    }

private:
    T _value;
    mutable Condition _cond;

    template< typename F >
    const T _waitPredicate( const F& predicate ) const
    {
        if( sizeof( T ) <= 8 ) // issue #1
        {
            const T current = _value;
            if( predicate( current ))
                return current;
        }
        ScopedCondition mutex( _cond );
        while( !predicate( _value ))
            _cond.wait();
        return _value;
    }

    template< typename F >
    bool _timedWaitPredicate( const F& predicate, const uint32_t timeout ) const
    {
        if( sizeof( T ) <= 8 ) // issue #1
        {
            const T current = _value;
            if( predicate( current ))
                return true;
        }
        ScopedCondition mutex( _cond );
        while( !predicate( _value ))
        {
            if( !_cond.timedWait( timeout ) )
            {
                return false;
            }
        }
        return true;
    }
};

typedef Monitor< bool >     Monitorb; 
typedef Monitor< uint32_t > Monitoru; 

template< typename T >
inline std::ostream& operator << ( std::ostream& os,
                                   const Monitor<T>& monitor )
{
    os << "Monitor< " << monitor.get() << " >";
    return os;
}

template<> inline Monitor< bool >& Monitor< bool >::operator++ ()
{
    ScopedCondition mutex( _cond );
    assert( !_value );
    _value = !_value;
    _cond.broadcast();
    return *this;
}

template<> inline Monitor< bool >& Monitor< bool >::operator-- ()
{
    ScopedCondition mutex( _cond );
    assert( !_value );
    _value = !_value;
    _cond.broadcast();
    return *this;
}

template<> inline
Monitor< bool >& Monitor< bool >::operator |= ( const bool& value )
{
    if( value )
    {
        ScopedCondition mutex( _cond );
        _value = value;
        _cond.broadcast();
    }
    return *this;
}
}

#include <servus/uint128_t.h>
namespace lunchbox
{
template<> inline Monitor< servus::uint128_t >::Monitor() {}
}

#endif //LUNCHBOX_MONITOR_H