Why GIL? (was Re: what's the point of rpython?)

[Paul Rubin]

Bryan Olson <fakeaddress at nowhere.org> writes:
> The meaning of 'immutable' is well-established in the Python
> literature. Python's immutable types include tuple, frozenset, and
> various kinds of numbers and strings. Class instances, not so much.

But we are talking about objects as they live in the C implementation,
not at the level where Python code deals with them.