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39
40#ifndef QQMLREFCOUNT_P_H
41#define QQMLREFCOUNT_P_H
42
43//
44// W A R N I N G
45// -------------
46//
47// This file is not part of the Qt API. It exists purely as an
48// implementation detail. This header file may change from version to
49// version without notice, or even be removed.
50//
51// We mean it.
52//
53
54#include <QtCore/qglobal.h>
55#include <QtCore/qatomic.h>
56#include <private/qv4global_p.h>
57
58QT_BEGIN_NAMESPACE
59
60
61class Q_QML_PRIVATE_EXPORT QQmlRefCount
62{
63 Q_DISABLE_COPY_MOVE(QQmlRefCount)
64public:
65 inline QQmlRefCount();
66 inline void addref() const;
67 inline void release() const;
68 inline int count() const;
69
70protected:
71 inline virtual ~QQmlRefCount();
72
73private:
74 mutable QAtomicInt refCount;
75};
76
77template<class T>
78class QQmlRefPointer
79{
80public:
81 enum Mode {
82 AddRef,
83 Adopt
84 };
85 inline QQmlRefPointer();
86 inline QQmlRefPointer(T *, Mode m = AddRef);
87 inline QQmlRefPointer(const QQmlRefPointer<T> &);
88 inline QQmlRefPointer(QQmlRefPointer<T> &&);
89 inline ~QQmlRefPointer();
90
91 inline QQmlRefPointer<T> &operator=(const QQmlRefPointer<T> &o);
92 inline QQmlRefPointer<T> &operator=(QQmlRefPointer<T> &&o);
93
94 inline bool isNull() const { return !o; }
95
96 inline T* operator->() const { return o; }
97 inline T& operator*() const { return *o; }
98 explicit inline operator bool() const { return o != nullptr; }
99 inline T* data() const { return o; }
100
101 inline QQmlRefPointer<T> &adopt(T *);
102
103 inline T* take() { T *res = o; o = nullptr; return res; }
104
105private:
106 T *o;
107};
108
109QQmlRefCount::QQmlRefCount()
110: refCount(1)
111{
112}
113
114QQmlRefCount::~QQmlRefCount()
115{
116 Q_ASSERT(refCount.loadRelaxed() == 0);
117}
118
119void QQmlRefCount::addref() const
120{
121 Q_ASSERT(refCount.loadRelaxed() > 0);
122 refCount.ref();
123}
124
125void QQmlRefCount::release() const
126{
127 Q_ASSERT(refCount.loadRelaxed() > 0);
128 if (!refCount.deref())
129 delete this;
130}
131
132int QQmlRefCount::count() const
133{
134 return refCount.loadRelaxed();
135}
136
137template<class T>
138QQmlRefPointer<T>::QQmlRefPointer()
139: o(nullptr)
140{
141}
142
143template<class T>
144QQmlRefPointer<T>::QQmlRefPointer(T *o, Mode m)
145: o(o)
146{
147 if (m == AddRef && o)
148 o->addref();
149}
150
151template<class T>
152QQmlRefPointer<T>::QQmlRefPointer(const QQmlRefPointer<T> &other)
153: o(other.o)
154{
155 if (o) o->addref();
156}
157
158template <class T>
159QQmlRefPointer<T>::QQmlRefPointer(QQmlRefPointer<T> &&other)
160 : o(other.take())
161{
162}
163
164template<class T>
165QQmlRefPointer<T>::~QQmlRefPointer()
166{
167 if (o) o->release();
168}
169
170template<class T>
171QQmlRefPointer<T> &QQmlRefPointer<T>::operator=(const QQmlRefPointer<T> &other)
172{
173 if (other.o) other.o->addref();
174 if (o) o->release();
175 o = other.o;
176 return *this;
177}
178
179template <class T>
180QQmlRefPointer<T> &QQmlRefPointer<T>::operator=(QQmlRefPointer<T> &&other)
181{
182 QQmlRefPointer<T> m(std::move(other));
183 qSwap(o, m.o);
184 return *this;
185}
186
187/*!
188Takes ownership of \a other. take() does *not* add a reference, as it assumes ownership
189of the callers reference of other.
190*/
191template<class T>
192QQmlRefPointer<T> &QQmlRefPointer<T>::adopt(T *other)
193{
194 if (o) o->release();
195 o = other;
196 return *this;
197}
198
199QT_END_NAMESPACE
200
201#endif // QQMLREFCOUNT_P_H
202

source code of qtdeclarative/src/qml/qml/ftw/qqmlrefcount_p.h