test_weakref.py 文件源码

def test_ref_reuse(self):
        o = C()
        ref1 = weakref.ref(o)
        # create a proxy to make sure that there's an intervening creation
        # between these two; it should make no difference
        proxy = weakref.proxy(o)
        ref2 = weakref.ref(o)
        self.assertTrue(ref1 is ref2,
                     "reference object w/out callback should be re-used")

        o = C()
        proxy = weakref.proxy(o)
        ref1 = weakref.ref(o)
        ref2 = weakref.ref(o)
        self.assertTrue(ref1 is ref2,
                     "reference object w/out callback should be re-used")
        self.assertTrue(weakref.getweakrefcount(o) == 2,
                     "wrong weak ref count for object")
        del proxy
        self.assertTrue(weakref.getweakrefcount(o) == 1,
                     "wrong weak ref count for object after deleting proxy")