referenced.h

/* Copyright (c) 2005-2014, 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_REFERENCED_H
#define LUNCHBOX_REFERENCED_H

#include <lunchbox/api.h>      // for LUNCHBOX_API
#include <lunchbox/atomic.h>   // member
#include <lunchbox/debug.h>    // for LBERROR

//#define LUNCHBOX_REFERENCED_DEBUG
#ifdef LUNCHBOX_REFERENCED_DEBUG
#  include <lunchbox/clock.h>
#  include <lunchbox/hash.h>
#  include <lunchbox/lockable.h>
#  include <lunchbox/scopedMutex.h>
#  include <lunchbox/spinLock.h>
#endif

namespace lunchbox
{
class Referenced
{
public:
    void ref( const void* holder LB_UNUSED = 0 ) const
    {
#ifndef NDEBUG
        LBASSERT( !_hasBeenDeleted );
#endif
        ++_refCount;

#ifdef LUNCHBOX_REFERENCED_DEBUG
        if( holder )
        {
            std::stringstream cs;
            cs << "Thread " << Log::instance().getThreadName() << " @ "
               << Log::instance().getClock().getTime64() << " rc " << _refCount
               << " from " << backtrace;
            ScopedFastWrite mutex( _holders );
            HolderHash::iterator i = _holders->find( holder );
            LBASSERTINFO( i == _holders->end(), i->second );
            _holders.data[ holder ] = cs.str();
        }
#endif
    }

    bool unref( const void* holder LB_UNUSED = 0 ) const
    {
#ifndef NDEBUG
        LBASSERT( !_hasBeenDeleted );
#endif
        LBASSERT( _refCount > 0 );
        const bool last = (--_refCount==0);

#ifdef LUNCHBOX_REFERENCED_DEBUG
        if( holder )
        {
            ScopedFastWrite mutex( _holders );
            HolderHash::iterator i = _holders->find( holder );
            LBASSERT( i != _holders->end( ));
            _holders->erase( i );
            LBASSERT( _holders->find( holder ) == _holders->end( ));
        }
#endif

        if( last )
            const_cast< Referenced* >( this )->notifyFree();
        return last;
    }

    int32_t getRefCount() const { return _refCount; }

#ifdef LUNCHBOX_REFERENCED_DEBUG
    void printHolders( std::ostream& os ) const
    {
        os << disableFlush << disableHeader << std::endl;
        {
            ScopedFastRead mutex( _holders );
            for( HolderHash::const_iterator i = _holders->begin();
                 i != _holders->end(); ++i )
            {
                os << "Holder " << i->first << ": " << i->second << std::endl;
            }
        }
        os << enableHeader << enableFlush;
    }
#else
    void printHolders( std::ostream& ) const {}
#endif

protected:
    LUNCHBOX_API Referenced();

    Referenced( const Referenced& )
        : _refCount( 0 )
        , _hasBeenDeleted( false )
#ifdef LUNCHBOX_REFERENCED_DEBUG
        , _holders()
#endif
    {}

    LUNCHBOX_API virtual ~Referenced();

    // cppcheck-suppress operatorEqVarError
    Referenced& operator = ( const Referenced& /*rhs*/ ) { return *this; }

    LUNCHBOX_API virtual void notifyFree();

private:
    mutable a_int32_t _refCount;
    bool _hasBeenDeleted;

#ifdef LUNCHBOX_REFERENCED_DEBUG
    typedef PtrHash< const void*, std::string > HolderHash;
    mutable Lockable< HolderHash, SpinLock > _holders;
#endif
};
}

namespace boost
{
inline void intrusive_ptr_add_ref( lunchbox::Referenced* referenced )
{
    referenced->ref();
}

inline void intrusive_ptr_release( lunchbox::Referenced* referenced )
{
    referenced->unref();
}
}

#endif //LUNCHBOX_REFERENCED_H