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/* refcounted.h
*
* $Id$
*
* Reference counted objects.
*
* This file is part of the OpenLink Software Virtuoso Open-Source (VOS)
* project.
*
* Copyright (C) 1998-2018 OpenLink Software
*
* This project is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; only version 2 of the License, dated June 1991.
*
* This program 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*
*/
#ifndef REFCOUNTED_H
#define REFCOUNTED_H
class RefCountedImpl
{
public:
RefCountedImpl(const char *identity);
virtual ~RefCountedImpl();
void AddRef();
void Release();
/**
* This function is called when the reference count
* goes from 0 to 1.
*/
virtual void Referenced();
/**
* This function is called when the reference count
* goes from 1 to 0.
*/
virtual void Unreferenced();
private:
long ref_count;
const char *object_identity;
};
// ``Impl'' must be a subclass of the ``RefCountedImpl'' class.
template <class Impl>
class RefCounted
{
public:
RefCounted()
{
impl = NULL;
}
~RefCounted()
{
Release();
}
bool
IsInitialized()
{
return impl != NULL;
}
/**
* An utility method for implementing copy constructors.
*/
void
CopyCtor(const RefCounted<Impl>& other)
{
impl = other.impl;
if (impl != NULL)
impl->AddRef();
}
/**
* An utility method for implementing copy operators.
*/
void
CopyOp(const RefCounted<Impl>& other)
{
if (impl != NULL)
impl->Release();
impl = other.impl;
if (impl != NULL)
impl->AddRef();
}
void
Release()
{
if (impl != NULL)
{
((RefCountedImpl*) impl)->Release();
impl = NULL;
}
}
protected:
Impl *impl;
};
#endif
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