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/****************************************************************************
**
** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** GNU Lesser General Public License Usage
** This file may be used under the terms of the GNU Lesser General Public
** License version 2.1 as published by the Free Software Foundation and
** appearing in the file LICENSE.LGPL included in the packaging of this
** file. Please review the following information to ensure the GNU Lesser
** General Public License version 2.1 requirements will be met:
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU General
** Public License version 3.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of this
** file. Please review the following information to ensure the GNU General
** Public License version 3.0 requirements will be met:
** http://www.gnu.org/copyleft/gpl.html.
**
** Other Usage
** Alternatively, this file may be used in accordance with the terms and
** conditions contained in a signed written agreement between you and Nokia.
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef QREFCOUNT_H
#define QREFCOUNT_H
#include <QtCore/qatomic.h>
QT_BEGIN_HEADER
QT_BEGIN_NAMESPACE
QT_MODULE(Core)
namespace QtPrivate
{
class RefCount
{
public:
inline bool ref() {
int count = atomic.load();
if (count == 0) // !isSharable
return false;
if (count != -1) // !isStatic
atomic.ref();
return true;
}
inline bool deref() {
int count = atomic.load();
if (count == 0) // !isSharable
return false;
if (count == -1) // isStatic
return true;
return atomic.deref();
}
bool setSharable(bool sharable)
{
Q_ASSERT(!isShared());
if (sharable)
return atomic.testAndSetRelaxed(0, 1);
else
return atomic.testAndSetRelaxed(1, 0);
}
bool isStatic() const
{
// Persistent object, never deleted
return atomic.load() == -1;
}
bool isSharable() const
{
// Sharable === Shared ownership.
return atomic.load() != 0;
}
bool isShared() const
{
int count = atomic.load();
return (count != 1) && (count != 0);
}
inline bool operator==(int value) const
{ return atomic.load() == value; }
inline bool operator!=(int value) const
{ return atomic.load() != value; }
inline bool operator!() const
{ return !atomic.load(); }
inline operator int() const
{ return atomic.load(); }
void initializeOwned() { atomic.store(1); }
void initializeUnsharable() { atomic.store(0); }
QBasicAtomicInt atomic;
};
}
#define Q_REFCOUNT_INITIALIZE_STATIC { Q_BASIC_ATOMIC_INITIALIZER(-1) }
QT_END_NAMESPACE
QT_END_HEADER
#endif
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