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