test_values.py 文件源码

def test_frozentable(self):
        # Python exports a PyImport_FrozenModules symbol. This is a
        # pointer to an array of struct _frozen entries.  The end of the
        # array is marked by an entry containing a NULL name and zero
        # size.

        # In standard Python, this table contains a __hello__
        # module, and a __phello__ package containing a spam
        # module.
        class struct_frozen(Structure):
            _fields_ = [("name", c_char_p),
                        ("code", POINTER(c_ubyte)),
                        ("size", c_int)]
        FrozenTable = POINTER(struct_frozen)

        ft = FrozenTable.in_dll(pythonapi, "PyImport_FrozenModules")
        # ft is a pointer to the struct_frozen entries:
        items = []
        for entry in ft:
            # This is dangerous. We *can* iterate over a pointer, but
            # the loop will not terminate (maybe with an access
            # violation;-) because the pointer instance has no size.
            if entry.name is None:
                break
            items.append((entry.name, entry.size))

        expected = [("__hello__", 104),
                    ("__phello__", -104),
                    ("__phello__.spam", 104)]
        self.assertEqual(items, expected)

        from ctypes import _pointer_type_cache
        del _pointer_type_cache[struct_frozen]