Re:Meta pledges Three-Year sponsorship for Python if GIL rem...
by dwaite on Sunday July 09, 2023 @12:04AM
(#36651403)
The most significant impact of this change is that python threads can run at the same time. Before, calls to C API were essentially cooperative multithreading yield points - even if you have 100 python threads, they can't run concurrently under the GIL. 99 are blocked waiting on the GIL.
C extensions have always been able to use real threading. But now there is no GIL to synchronize with the python interpreter on ingress/egress from the extension.
From a python perspective it wouldn't necessarily be a big change, but everything can branch out to c, and there you're going to get in trouble with shared memory.