[Python-ideas] Ideas towards GIL removal

[Josiah Carlson]

Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
> Josiah Carlson wrote:
> 
> > Certainly, but thread B isn't the owning thread, thread A was the owning
> > thread, and by virtue of decrefing its thread count to zero, acquiring
> > the GIL, and checking the global refcount to make sure that either
> > someone else is responsible for its deallocation (global refcount > 0),
> > or that thread A is responsible for its deallocation (global refcount ==
> > 0).
> 
> Thread B holding the GIL doesn't help, because the
> local refcount is not covered by the GIL. Thread A
> must be able to assume it has total ownership of the
> local refcount, otherwise there's no benefit in
> the scheme.

I seem to not be explaining myself well enough.  What you describe is
precisely what I described earlier.  I don't believe we have a
disagreement about the execution semantics of threads on an object with
a local thread count.

I was only mentioning A acquiring the GIL if/when it becomes finished
with the object, to determine if the object could be sent to the
standard Python deallocation rutines, and/or if thread A should send it
(as opposed to thread B in the case if thread B was passed the object
and was using it beyond the time that A did).


 - Josiah