include/QtCore/qrefcount.h

0001 // Copyright (C) 2016 The Qt Company Ltd.
0002 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
0003 // Qt-Security score:significant reason:default
0004
0005 #ifndef QREFCOUNT_H
0006 #define QREFCOUNT_H
0007
0008 #include <QtCore/qatomic.h>
0009
0010 QT_BEGIN_NAMESPACE
0011
0012
0013 namespace QtPrivate
0014 {
0015
0016 class RefCount
0017 {
0018 public:
0019     inline bool ref() noexcept {
0020         int count = atomic.loadRelaxed();
0021         if (count != -1) // !isStatic
0022             atomic.ref();
0023         return true;
0024     }
0025
0026     inline bool deref() noexcept {
0027         int count = atomic.loadRelaxed();
0028         if (count == -1) // isStatic
0029             return true;
0030         return atomic.deref();
0031     }
0032
0033     bool isStatic() const noexcept
0034     {
0035         // Persistent object, never deleted
0036         return atomic.loadRelaxed() == -1;
0037     }
0038
0039     bool isShared() const noexcept
0040     {
0041         int count = atomic.loadRelaxed();
0042         return (count != 1) && (count != 0);
0043     }
0044
0045     void initializeOwned() noexcept { atomic.storeRelaxed(1); }
0046     void initializeUnsharable() noexcept { atomic.storeRelaxed(0); }
0047
0048     QBasicAtomicInt atomic;
0049 };
0050
0051 }
0052
0053 #define Q_REFCOUNT_INITIALIZE_STATIC { Q_BASIC_ATOMIC_INITIALIZER(-1) }
0054 #define Q_REFCOUNT_INITIALIZE_OWNED { Q_BASIC_ATOMIC_INITIALIZER(1) }
0055
0056 QT_END_NAMESPACE
0057
0058 #endif