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

[Ronald Oussoren]

> On 8 Sep 2017, at 05:11, Eric Snow <ericsnowcurrently at gmail.com> wrote:

> On Thu, Sep 7, 2017 at 3:48 PM, Nathaniel Smith <njs at pobox.com> 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