[Q] Extension: Refcount for exception types
"Martin v. Löwis"
martin at v.loewis.de
Fri Apr 16 21:55:14 CEST 2004
Ames Andreas (MPA/DF) wrote:
> ^^^^^^^^^^^^^^^^^^^^^^^ I mean this one.
> PyModule_AddObject(m, "error", ErrorObject);
> I know that PyModule_AddObject steals a reference, but now
> ErrorObject's refcount should be 2, isn't it? I just fail to see
> how the refcount can return to 0. I'm sure this is simple to explain,
> so please enlighten me, why this isn't a leak.
It is a leak, but that is intentional. If the INCREF was not there,
and somebody would delete "error" from the dictionary, then the
error class would go away, and ErrorObject would be a dangling pointer.
Since the module C code refers to the exception through ErrorObject,
it must keep a reference that cannot go away. This is indeed a leak
because there is no module shutdown code which could decref ErrorObject,
and set it to NULL.
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