mtQueue.ipp

/* Copyright (c) 2005-2012, Stefan Eilemann <eile@equalizergraphics.com>
 *                    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.
 */

namespace lunchbox
{
template< typename T, size_t S >
MTQueue< T, S >& MTQueue< T, S >::operator = ( const MTQueue< T, S >& from )
{
    if( this != &from )
    {
        from._cond.lock();
        std::deque< T > copy = from._queue;
        const size_t maxSize = from._maxSize;
        from._cond.unlock();

        _cond.lock();
        _maxSize = maxSize;
        _queue.swap( copy );
        _cond.signal();
        _cond.unlock();
    }
    return *this;
}

template< typename T, size_t S >
const T& MTQueue< T, S >::operator[]( const size_t index ) const
{
    _cond.lock();
    while( _queue.size() <= index )
        _cond.wait();

    LBASSERT( _queue.size() > index );
    const T& element = _queue[index];
    _cond.unlock();
    return element;
}

template< typename T, size_t S >
void MTQueue< T, S >::setMaxSize( const size_t maxSize )
{
    _cond.lock();
    while( _queue.size() > maxSize )
        _cond.wait();
    _maxSize = maxSize;
    _cond.signal();
    _cond.unlock();
}

template< typename T, size_t S >
size_t MTQueue< T, S >::waitSize( const size_t minSize ) const
{
    LBASSERT( minSize <= _maxSize );
    _cond.lock();
    while( _queue.size() < minSize )
        _cond.wait();
    const size_t size = _queue.size();
    _cond.unlock();
    return size;
}

template< typename T, size_t S >
void MTQueue< T, S >::clear()
{
    _cond.lock();
    _queue.clear();
    _cond.signal();
    _cond.unlock();
}

template< typename T, size_t S >
T MTQueue< T, S >::pop()
{
    _cond.lock();
    while( _queue.empty( ))
        _cond.wait();

    LBASSERT( !_queue.empty( ));
    T element = _queue.front();
    _queue.pop_front();
    _cond.signal();
    _cond.unlock();
    return element;
}

template< typename T, size_t S >
bool MTQueue< T, S >::timedPop( const unsigned timeout, T& element )
{
    _cond.lock();
    while( _queue.empty( ))
    {
        if( !_cond.timedWait( timeout ))
        {
            _cond.unlock();
            return false;
        }
    }
    LBASSERT( !_queue.empty( ));
    element = _queue.front();
    _queue.pop_front();
    _cond.signal();
    _cond.unlock();
    return true;
}

template< typename T, size_t S > std::vector< T >
MTQueue< T, S >::timedPopRange( const unsigned timeout, const size_t minimum,
                                const size_t maximum )
{
    std::vector< T > result;

    _cond.lock();
    while( _queue.size() < minimum )
    {
        if( !_cond.timedWait( timeout ))
        {
            _cond.unlock();
            return result;
        }
    }

    const size_t size = LB_MIN( maximum, _queue.size( ));

    result.reserve( size );
    result.insert( result.end(), _queue.begin(), _queue.begin() + size );
    _queue.erase( _queue.begin(), _queue.begin() + size );

    _cond.unlock();
    return result;
}

template< typename T, size_t S >
bool MTQueue< T, S >::tryPop( T& result )
{
    _cond.lock();
    if( _queue.empty( ))
    {
        _cond.unlock();
        return false;
    }

    result = _queue.front();
    _queue.pop_front();
    _cond.signal();
    _cond.unlock();
    return true;
}

template< typename T, size_t S >
void MTQueue< T, S >::tryPop( const size_t num, std::vector< T >& result )
{
    _cond.lock();
    const size_t size = LB_MIN( num, _queue.size( ));
    if( size > 0 )
    {
        result.reserve( result.size() + size );
        for( size_t i = 0; i < size; ++i )
        {
            result.push_back( _queue.front( ));
            _queue.pop_front();
        }
        _cond.signal();
    }
    _cond.unlock();
}

template< typename T, size_t S > class MTQueue< T, S >::Group
{
    friend class MTQueue< T, S >;
    size_t height_;
    size_t waiting_;

public:
    explicit Group( const size_t height ) : height_( height ), waiting_( 0 ) {}

    void setHeight( const size_t height ) { height_ = height; }
};

template< typename T, size_t S >
bool MTQueue< T, S >::popBarrier( T& element, Group& barrier )
{
    LBASSERT( barrier.height_ > 0 )

    _cond.lock();
    ++barrier.waiting_;
    while( _queue.empty() && barrier.waiting_ < barrier.height_ )
        _cond.wait();

    if( _queue.empty( ))
    {
        LBASSERT( barrier.waiting_ == barrier.height_ );
        _cond.broadcast();
        _cond.unlock();
        return false;
    }

    element = _queue.front();
    _queue.pop_front();
    --barrier.waiting_;
    _cond.signal();
    _cond.unlock();
    return true;

}

template< typename T, size_t S >
bool MTQueue< T, S >::getFront( T& result ) const
{
    _cond.lock();
    if( _queue.empty( ))
    {
        _cond.unlock();
        return false;
    }
    // else
    result = _queue.front();
    _cond.unlock();
    return true;
}

template< typename T, size_t S >
bool MTQueue< T, S >::getBack( T& result ) const
{
    _cond.lock();
    if( _queue.empty( ))
    {
        _cond.unlock();
        return false;
    }
    // else
    result = _queue.back();
    _cond.unlock();
    return true;
}

template< typename T, size_t S >
void MTQueue< T, S >::push( const T& element )
{
    _cond.lock();
    while( _queue.size() >= _maxSize )
        _cond.wait();
    _queue.push_back( element );
    _cond.signal();
    _cond.unlock();
}

template< typename T, size_t S >
void MTQueue< T, S >::push( const std::vector< T >& elements )
{
    _cond.lock();
    LBASSERT( elements.size() <= _maxSize );
    while( (_maxSize - _queue.size( )) < elements.size( ))
        _cond.wait();
    _queue.insert( _queue.end(), elements.begin(), elements.end( ));
    _cond.signal();
    _cond.unlock();
}

template< typename T, size_t S >
void MTQueue< T, S >::pushFront( const T& element )
{
    _cond.lock();
    while( _queue.size() >= _maxSize )
        _cond.wait();
    _queue.push_front( element );
    _cond.signal();
    _cond.unlock();
}

template< typename T, size_t S >
void MTQueue< T, S >::pushFront( const std::vector< T >& elements )
{
    _cond.lock();
    LBASSERT( elements.size() <= _maxSize );
    while( (_maxSize - _queue.size( )) < elements.size( ))
        _cond.wait();
    _queue.insert(_queue.begin(), elements.begin(), elements.end());
    _cond.signal();
    _cond.unlock();
}
}