[Python-Dev] PyWeakref_GetObject() borrows its reference from... whom?

[Devin Jeanpierre]

> It's my contention that this API is simply untenable under the Gilectomy

Yeah, I agree with your contention. The only circumstance PyWeakref_GetObject
would still be valid without a GIL is if you happened to know you had a
reference elsewhere that was keeping it alive. But if you did, you probably
wouldn't need to use the weakref. If you don't, then with GILectomy you
have no thread-safe options.

Trivial bikeshedding:  rather than change the existing API, wouldn't it be
better to add a new API, and not support the old one in GILectomized
CPython? Introducing memory leaks would be a little unfortunate, and it's
hard to audit C code for correct use of refcounted pointers even *before*
you change the ownership of returned pointers across versions.

w.r.t. the exact question:

> whose reference is it borrowing?

I think this is a red herring sort of question. "borrowed" only means
"unowned". But anyway, we borrowed from the weakref. (Borrowing from
somebody doesn't imply they own a reference -- we can borrow from a
borrowed reference, for example, and this is common.)

The term "borrowed" is supposed to imply a sensible scope during which
you're free to use the object, and weakrefs don't have that (except for
what is granted by the GIL), so this does sound wacky. I bet it was for
performance.

-- Devin
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