118 lines
3.5 KiB
C++
118 lines
3.5 KiB
C++
/****************************************************************************
|
|
**
|
|
** Copyright (C) 2016 The Qt Company Ltd.
|
|
** Contact: https://www.qt.io/licensing/
|
|
**
|
|
** This file is part of the QtCore module of the Qt Toolkit.
|
|
**
|
|
** $QT_BEGIN_LICENSE:LGPL$
|
|
** Commercial License Usage
|
|
** Licensees holding valid commercial Qt licenses may use this file in
|
|
** accordance with the commercial license agreement provided with the
|
|
** Software or, alternatively, in accordance with the terms contained in
|
|
** a written agreement between you and The Qt Company. For licensing terms
|
|
** and conditions see https://www.qt.io/terms-conditions. For further
|
|
** information use the contact form at https://www.qt.io/contact-us.
|
|
**
|
|
** GNU Lesser General Public License Usage
|
|
** Alternatively, this file may be used under the terms of the GNU Lesser
|
|
** General Public License version 3 as published by the Free Software
|
|
** Foundation and appearing in the file LICENSE.LGPL3 included in the
|
|
** packaging of this file. Please review the following information to
|
|
** ensure the GNU Lesser General Public License version 3 requirements
|
|
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
|
|
**
|
|
** GNU General Public License Usage
|
|
** Alternatively, this file may be used under the terms of the GNU
|
|
** General Public License version 2.0 or (at your option) the GNU General
|
|
** Public license version 3 or any later version approved by the KDE Free
|
|
** Qt Foundation. The licenses are as published by the Free Software
|
|
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
|
|
** included in the packaging of this file. Please review the following
|
|
** information to ensure the GNU General Public License requirements will
|
|
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
|
|
** https://www.gnu.org/licenses/gpl-3.0.html.
|
|
**
|
|
** $QT_END_LICENSE$
|
|
**
|
|
****************************************************************************/
|
|
|
|
#ifndef QREFCOUNT_H
|
|
#define QREFCOUNT_H
|
|
|
|
#include <QtCore/qatomic.h>
|
|
|
|
QT_BEGIN_NAMESPACE
|
|
|
|
|
|
namespace QtPrivate
|
|
{
|
|
|
|
class RefCount
|
|
{
|
|
public:
|
|
inline bool ref() noexcept {
|
|
int count = atomic.loadRelaxed();
|
|
#if !defined(QT_NO_UNSHARABLE_CONTAINERS)
|
|
if (count == 0) // !isSharable
|
|
return false;
|
|
#endif
|
|
if (count != -1) // !isStatic
|
|
atomic.ref();
|
|
return true;
|
|
}
|
|
|
|
inline bool deref() noexcept {
|
|
int count = atomic.loadRelaxed();
|
|
#if !defined(QT_NO_UNSHARABLE_CONTAINERS)
|
|
if (count == 0) // !isSharable
|
|
return false;
|
|
#endif
|
|
if (count == -1) // isStatic
|
|
return true;
|
|
return atomic.deref();
|
|
}
|
|
|
|
#if !defined(QT_NO_UNSHARABLE_CONTAINERS)
|
|
bool setSharable(bool sharable) noexcept
|
|
{
|
|
Q_ASSERT(!isShared());
|
|
if (sharable)
|
|
return atomic.testAndSetRelaxed(0, 1);
|
|
else
|
|
return atomic.testAndSetRelaxed(1, 0);
|
|
}
|
|
|
|
bool isSharable() const noexcept
|
|
{
|
|
// Sharable === Shared ownership.
|
|
return atomic.loadRelaxed() != 0;
|
|
}
|
|
#endif
|
|
|
|
bool isStatic() const noexcept
|
|
{
|
|
// Persistent object, never deleted
|
|
return atomic.loadRelaxed() == -1;
|
|
}
|
|
|
|
bool isShared() const noexcept
|
|
{
|
|
int count = atomic.loadRelaxed();
|
|
return (count != 1) && (count != 0);
|
|
}
|
|
|
|
void initializeOwned() noexcept { atomic.storeRelaxed(1); }
|
|
void initializeUnsharable() noexcept { atomic.storeRelaxed(0); }
|
|
|
|
QBasicAtomicInt atomic;
|
|
};
|
|
|
|
}
|
|
|
|
#define Q_REFCOUNT_INITIALIZE_STATIC { Q_BASIC_ATOMIC_INITIALIZER(-1) }
|
|
|
|
QT_END_NAMESPACE
|
|
|
|
#endif
|