Re: [Python-ideas] PEP 554: Stdlib Module to Support Multiple Interpreters in Python Code

On 8 Sep 2017, at 05:11, Eric Snow wrote:

On Thu, Sep 7, 2017 at 3:48 PM, Nathaniel Smith wrote:

...

Numpy is the one I'm most familiar with: when we get subinterpreter bugs we close them wontfix, because supporting subinterpreters properly would require non-trivial auditing, add overhead for non-subinterpreter use cases, and benefit a tiny tiny fraction of our users.

The main problem of which I'm aware is C globals in libraries and extension modules. PEPs 489 and 3121 are meant to help but I know that there is at least one major situation which is still a blocker for multi-interpreter-safe module state. Other than C globals, is there some other issue?

There’s also the PyGilState_* API that doesn't support multiple interpreters. The issue there is that callbacks from external libraries back into python need to use the correct subinterpreter. Ronald