diff options
| -rw-r--r-- | src/corelib/kernel/qpointer.h | 4 | ||||
| -rw-r--r-- | src/corelib/tools/qsharedpointer.cpp | 56 | ||||
| -rw-r--r-- | src/corelib/tools/qsharedpointer_impl.h | 20 |
3 files changed, 28 insertions, 52 deletions
diff --git a/src/corelib/kernel/qpointer.h b/src/corelib/kernel/qpointer.h index 5544a59705..88d8225621 100644 --- a/src/corelib/kernel/qpointer.h +++ b/src/corelib/kernel/qpointer.h @@ -57,7 +57,7 @@ class QPointerBase protected: inline QPointerBase() : wp() { } - inline QPointerBase(QObject *p) : wp(p) { } + inline QPointerBase(QObject *p) : wp(p, true) { } // compiler-generated copy/move ctor/assignment operators are fine! (even though public) inline ~QPointerBase() { } @@ -65,7 +65,7 @@ protected: { return wp.data(); } inline void assign(QObject *p) - { wp = p; } + { wp.assign(p); } inline bool isNull() const { return wp.isNull(); } diff --git a/src/corelib/tools/qsharedpointer.cpp b/src/corelib/tools/qsharedpointer.cpp index 50e555d968..ed8f5c9c0c 100644 --- a/src/corelib/tools/qsharedpointer.cpp +++ b/src/corelib/tools/qsharedpointer.cpp @@ -107,9 +107,8 @@ it makes no use of additional structure or reference counting. Finally, QPointer holds a pointer to a QObject-derived object, but it - does so weakly. QPointer can be replaced by QWeakPointer in almost all - cases, since they have the same functionality. See - \l{QWeakPointer#tracking-qobject} for more information. + does so weakly. QWeakPointer has the same functionality, but its use for + that function is deprecated. \section1 Optional pointer tracking @@ -181,8 +180,7 @@ (see below for information on custom deleters). The strong reference count can also exceptionally be -1, indicating that there are no QSharedPointers attached to an object, which is tracked too. The only - case where this is possible is that of - \l{QWeakPointer#tracking-qobject}{QWeakPointers tracking a QObject}. + case where this is possible is that of QWeakPointers tracking a QObject. The weak reference count controls the lifetime of the d-pointer itself. It can be thought of as an internal/intrusive reference count for @@ -369,8 +367,7 @@ deleted or not in another context. QWeakPointer objects can only be created by assignment from a - QSharedPointer. The exception is pointers derived from QObject: in that - case, QWeakPointer serves as a replacement to QPointer. + QSharedPointer. It's important to note that QWeakPointer provides no automatic casting operators to prevent mistakes from happening. Even though QWeakPointer @@ -389,45 +386,6 @@ not get deleted (or if you only need the pointer value) and the cost of creating a QSharedPointer using toStrongRef() is too high. - That function can also be used to obtain the tracked pointer for - QWeakPointers that cannot be promoted to QSharedPointer, such as those - created directly from a QObject pointer (not via QSharedPointer). - - \section1 Tracking QObject - - QWeakPointer can be used to track deletion of classes that derive from QObject, - even if they are not managed by QSharedPointer. When used in that role, - QWeakPointer replaces the older QPointer in all use-cases. QWeakPointer - is also more efficient than QPointer, so it should be preferred in all - new code. - - To do that, QWeakPointer provides a special constructor that is only - available if the template parameter \tt T is either QObject or a class - deriving from it. Trying to use that constructor if \tt T does not derive - from QObject will result in compilation errors. - - To obtain the QObject being tracked by QWeakPointer, you must use the - QWeakPointer::data() function, but only if you can guarantee that the - object cannot get deleted by another context. It should be noted that - QPointer had the same constraint, so use of QWeakPointer forces you to - consider whether the pointer is still valid. - - QObject-derived classes can only be deleted in the thread they have - affinity to (which is the thread they were created in or moved to, using - QObject::moveToThread()). In special, QWidget-derived classes cannot be - created in non-GUI threads nor moved there. Therefore, guaranteeing that - the tracked QObject has affinity to the current thread is enough to also - guarantee that it won't be deleted asynchronously. - - Note that QWeakPointer's size and data layout do not match QPointer, so - it cannot replace that class in a binary-compatible manner. - - Care must also be taken with QWeakPointers created directly from QObject - pointers when dealing with code that was compiled with Qt versions prior - to 4.6. Those versions may not track the reference counters correctly, so - QWeakPointers created from QObject should never be passed to code that - hasn't been recompiled. - \omit \secton1 QWeakPointer internals @@ -764,6 +722,7 @@ /*! \fn QWeakPointer::QWeakPointer(const QObject *obj) \since 4.6 + \deprecated Creates a QWeakPointer that holds a weak reference directly to the QObject \a obj. This constructor is only available if the template type @@ -776,18 +735,19 @@ Note that QWeakPointers created this way on arbitrary QObjects usually cannot be promoted to QSharedPointer. - \sa QSharedPointer, QWeakPointer#tracking-qobject + \sa QSharedPointer, QPointer */ /*! \fn QWeakPointer &QWeakPointer::operator=(const QObject *obj) \since 4.6 + \deprecated Makes this QWeakPointer hold a weak reference directly to the QObject \a obj. This function is only available if the template type \tt T is QObject or derives from it. - \sa QWeakPointer#tracking-qobject + \sa QPointer */ /*! diff --git a/src/corelib/tools/qsharedpointer_impl.h b/src/corelib/tools/qsharedpointer_impl.h index 4a9327fe81..d1d660dfc7 100644 --- a/src/corelib/tools/qsharedpointer_impl.h +++ b/src/corelib/tools/qsharedpointer_impl.h @@ -585,13 +585,18 @@ public: #ifndef QT_NO_QOBJECT // special constructor that is enabled only if X derives from QObject +#if QT_DEPRECATED_SINCE(5, 0) template <class X> - inline QWeakPointer(X *ptr) : d(ptr ? d->getAndRef(ptr) : 0), value(ptr) + QT_DEPRECATED inline QWeakPointer(X *ptr) : d(ptr ? d->getAndRef(ptr) : 0), value(ptr) { } #endif +#endif + +#if QT_DEPRECATED_SINCE(5, 0) template <class X> - inline QWeakPointer &operator=(X *ptr) + QT_DEPRECATED inline QWeakPointer &operator=(X *ptr) { return *this = QWeakPointer(ptr); } +#endif inline QWeakPointer(const QWeakPointer<T> &o) : d(o.d), value(o.value) { if (d) d->weakref.ref(); } @@ -664,6 +669,17 @@ private: public: #else template <class X> friend class QSharedPointer; + friend class QPointerBase; +#endif + + template <class X> + inline QWeakPointer &assign(X *ptr) + { return *this = QWeakPointer<X>(ptr, true); } + +#ifndef QT_NO_QOBJECT + template <class X> + inline QWeakPointer(X *ptr, bool) : d(ptr ? d->getAndRef(ptr) : 0), value(ptr) + { } #endif inline void internalSet(Data *o, T *actual) |