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RefBase

在头文件RefBase.h中实现RefBase类。

class RefBase                                                                      {                                                                                  public:    ..........    class weakref_type                                                              {                                                                               public:                                                                             RefBase*            refBase() const;                                            void                incWeak(const void* id);                                    void                decWeak(const void* id);                                                                                                                                // acquires a strong reference if there is already one.                         bool                attemptIncStrong(const void* id);                           // acquires a weak reference if there is already one.                           // This is not always safe. see ProcessState.cpp and BpBinder.cpp               // for proper use.                                                              bool                attemptIncWeak(const void* id);                             //! DEBUGGING ONLY: Get current weak ref count.                                 int32_t             getWeakCount() const;                                       //! DEBUGGING ONLY: Print references held on object.                            void                printRefs() const;          };                    weakref_type*   createWeak(const void* id) const;                               weakref_type*   getWeakRefs() const;              protected:                                                                                                  RefBase();                                              virtual                 ~RefBase(); private:         class weakref_impl; private:          weakref_impl* const mRefs;  }

可以看出在RefBase类中，有两个内部类weakref_type和weakref_impl。

类weakref_type中封装了函数。

weakref_impl类

在RefBase.cpp中实现weakref_impl类。

class RefBase::weakref_impl : public RefBase::weakref_type                         {                                                                                  public:                                                                                volatile int32_t    mStrong;                                                       volatile int32_t    mWeak;                                                         RefBase* const      mBase;                                                         volatile int32_t    mFlags;

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