diff options
| -rw-r--r-- | src/corelib/tools/qsharedpointer_impl.h | 53 |
1 files changed, 27 insertions, 26 deletions
diff --git a/src/corelib/tools/qsharedpointer_impl.h b/src/corelib/tools/qsharedpointer_impl.h index 98f225b..2c9cd95 100644 --- a/src/corelib/tools/qsharedpointer_impl.h +++ b/src/corelib/tools/qsharedpointer_impl.h @@ -232,31 +232,31 @@ namespace QtSharedPointer { }; template <class T> - struct ExternalRefCountWithContiguousData: public ExternalRefCountData + struct ExternalRefCountWithContiguousData: public ExternalRefCountWithDestroyFn { -#ifdef Q_DECL_ALIGN -# ifdef Q_ALIGNOF -# define QSP_ALIGNOF(T) Q_ALIGNOF(T) -# else -# define QSP_ALIGNOF(T) (sizeof(T) >= 16 ? 16 : sizeof(T) >= 8 ? 8 : sizeof(T) >= 4 ? 4 : sizeof(T) >= 2 ? 2 : 1) -# endif + typedef ExternalRefCountWithDestroyFn Parent; + typedef ExternalRefCountWithContiguousData Self; + T data; - char data[sizeof(T)] Q_DECL_ALIGN(QSP_ALIGNOF(T)); - inline T *pointer() { return reinterpret_cast<T *>(data); } + static void deleter(ExternalRefCountData *self) + { + ExternalRefCountWithContiguousData *that = + static_cast<ExternalRefCountWithContiguousData *>(self); + that->data.~T(); + } -# undef QSP_ALIGNOF -#else - union { - char data[sizeof(T) + 16]; - double dummy1; -# ifndef Q_OS_DARWIN - long double dummy2; -# endif - }; - inline T *pointer() { return reinterpret_cast<T *>(data + 16 - (quintptr(data) & 0xf)); } -#endif + static inline ExternalRefCountData *create(T **ptr) + { + DestroyerFn destroy = &deleter; + Self *d = static_cast<Self *>(::operator new(sizeof(Self))); + + // initialize the d-pointer sub-object + // leave d->data uninitialized + new (d) Parent(destroy); // can't throw - inline bool destroy() { this->pointer()->~T(); return true; } + *ptr = &d->data; + return d; + } }; template <class T> @@ -292,12 +292,10 @@ namespace QtSharedPointer { inline void internalCreate() { - ExternalRefCountWithContiguousData<T> *dd = new ExternalRefCountWithContiguousData<T>; - T *ptr = dd->pointer(); - new (ptr) T(); // create + T *ptr; + d = ExternalRefCountWithContiguousData<T>::create(&ptr); Basic<T>::internalConstruct(ptr); - d = dd; } inline ExternalRefCount() : d(0) { } @@ -429,10 +427,13 @@ public: QWeakPointer<T> toWeakRef() const; public: - static QSharedPointer<T> create() + static inline QSharedPointer<T> create() { QSharedPointer<T> result; result.internalCreate(); + + // now initialize the data + new (result.data()) T(); return result; } }; |