[Python-Dev] Python Interpreter Thread Safety?

[Michael Chermside]

Martin v. Löwis writes:
> Due to some
> unfortunate historical reasons, there is code which enters free()
> without holding the GIL - and that is what the allocator specifically
> deals with. Except for this single case, all callers of the allocator
> are required to hold the GIL.

Donovan Baarda writes:
> Just curious; is that "one case" a bug that needs fixing, or is the some
> reason this case can't be changed to use the GIL? Surely making it
> mandatory for all free() calls to hold the GIL is easier than making the
> allocator deal with the one case where this isn't done.

What Martin is trying to say here is that it _IS_ mandatory to hold
the GIL when calling free(). However, there is some very old code in
existance (written by other people) which calls free() without holding
the GIL. We work very hard to provide backward compatibility, so we
are jumping through hoops to ensure that even this old code which is
violating the rules doesn't get broken.

-- Michael Chermside