Repository navigation
Support for Python 3.13 freethreading #744
Description
In #711 we added support for Python 3.13. More work is needed to add support for freethreading (and build wheels supporting it).
- Add CI support
- Synchronize around caches
- Synchronize around critical sections (I believe these mostly exist in serialization)
- Ensure type parsing logic and caching is threadsafe
- Expand tests to add threading tests
Reacted by Edgar Ramírez Mondragón, Michael, Martin Námešný, Shlomo Zalman Rabinowitz, 叶子, Ralf Gommers, owocado, Matt Smith, Dan Kuester, Luca | Serenita and 1 more
Reacted by Ofek Lev, Jack McIvor, 93578237, euri10, Michael H, Jacopo Farina, Burton DeWilde, Michael Feil, georgy, Cem Karagozlu and 9 more
Reacted by Gökhan Mete ERTÜRK
Activity
gokhanmeteerturk commentedon Sep 22, 2025
I don’t have enough C expertise to contribute directly to this, but I’m really interested to know if the support for freethreading is expected to be implemented in the future. Would be nice to start a discussion around this. Is there anyone who could share some guidance on the approach, or perhaps whether this might be planned for 3.14 instead?
rgommers commentedon Sep 22, 2025
@kumaraditya303 has been working on this, and I believe is close to ready to open a PR with all necessary thread-safety changes.
ofek commentedon Oct 19, 2025
The aforementioned PR is open but there will be no support for 3.13 as there are several CPython issues with it that won't be fixed.
jacopoabramo commentedon Oct 20, 2025
@ofek just out of curiosity, what are the specific problems with support for 3.13t? Thanks in advance!
ofek commentedon Oct 20, 2025
No idea cc @kumaraditya303
kumaraditya303 commentedon Oct 20, 2025
3.13 has very experimental support for free-threading and the critical section implementation has weaker guarantees, specifically 3.14 implements python/cpython#114203 which makes critical section more like recursive locks.