약한 참조 객체

파이썬은 약한 참조를 1급 객체로 지원합니다. 약한 참조를 직접 구현하는 두 가지 구체적인 객체 형이 있습니다. 첫 번째는 간단한 참조 객체이며, 두 번째는 가능한 한 원래 객체의 프락시 역할을 합니다.

int PyWeakref_Check(PyObject *ob)

ob가 참조 객체나 프락시 객체면 참을 반환합니다. 이 함수는 항상 성공합니다.

int PyWeakref_CheckRef(PyObject *ob)

ob가 참조 객체면 참을 반환합니다. 이 함수는 항상 성공합니다.

int PyWeakref_CheckProxy(PyObject *ob)

ob가 프락시 객체면 참을 반환합니다. 이 함수는 항상 성공합니다.

PyObject *PyWeakref_NewRef(PyObject *ob, PyObject *callback)

Return value: New reference. Part of the Stable ABI.

Return a weak reference object for the object ob. This will always return a new reference, but is not guaranteed to create a new object; an existing reference object may be returned. The second parameter, callback, can be a callable object that receives notification when ob is garbage collected; it should accept a single parameter, which will be the weak reference object itself. callback may also be None or NULL. If ob is not a weakly referenceable object, or if callback is not callable, None, or NULL, this will return NULL and raise TypeError.

PyObject *PyWeakref_NewProxy(PyObject *ob, PyObject *callback)

Return value: New reference. Part of the Stable ABI.

Return a weak reference proxy object for the object ob. This will always return a new reference, but is not guaranteed to create a new object; an existing proxy object may be returned. The second parameter, callback, can be a callable object that receives notification when ob is garbage collected; it should accept a single parameter, which will be the weak reference object itself. callback may also be None or NULL. If ob is not a weakly referenceable object, or if callback is not callable, None, or NULL, this will return NULL and raise TypeError.

PyObject *PyWeakref_GetObject(PyObject *ref)

Return value: Borrowed reference. Part of the Stable ABI.

Return the referenced object from a weak reference, ref. If the referent is no longer live, returns Py_None.

참고

This function returns a borrowed reference to the referenced object. This means that you should always call Py_INCREF() on the object except when it cannot be destroyed before the last usage of the borrowed reference.

PyObject *PyWeakref_GET_OBJECT(PyObject *ref)

Return value: Borrowed reference.

Similar to PyWeakref_GetObject(), but does no error checking.

void PyObject_ClearWeakRefs(PyObject *object)

Part of the Stable ABI.

This function is called by the tp_dealloc handler to clear weak references.

This iterates through the weak references for object and calls callbacks for those references which have one. It returns when all callbacks have been attempted.