This was -1, did it become 0 on purpose?

A value of-1 indicates to Python that the module has global state (PyModuleDef.m_size). It forbids any use of subinterpreters, re-initialisation, etc.

Changing to 0 was perhaps a gamble, seeing if tests passed. To be more conservative though, we could keepm_size to-1 and defer changing it to a non-negative number to a future PR. What would you suggest?

A

Yes, I think we should change it to 0 in a future PR. Please only change it in a single PR, lets get one of these in before the mass move of all the other ones. Does the change impact performance? I would suggest redoing this in#29030, or one of the others that touch a commonly used module, and then running the benchmarks to see if there is a regression when using multi-phase init.

Ok, I've updated#29030 to keepm_size = -1.

Is there infrastructure to benchmark a PR? My laptop isn't an ideal environment & I don't have a spare computer to run thelocal benchmarks.

Fromhttps://github.com/numpy/numpy/actions/runs/15179012580/job/42684537494?pr=29030

m_size may not be negative for multi-phase initialization

I'll get the Python documentation updated, this isn't very obvious! In the meantime, I'll revert the change to#29030.

I believe0 is the correct value to keep, as there is currently no per-module state and hence nothing to allocate memory for.