On Fri, Sep 08, 2017 at 04:04:27PM -0700, Eric Snow wrote: > * "stdlib support for subinterpreters adds extra burden > on C extension authors" > > In the ``Interpreter Isolation`` section below we identify ways in > which isolation in CPython's subinterpreters is incomplete. Most > notable is extension modules that use C globals to store internal > state. PEP 3121 and PEP 489 provide a solution for most of the > problem, but one still remains. [petr-c-ext]_ Until that is resolved, > C extension authors will face extra difficulty to support > subinterpreters.
It's a bit of a hassle, and the enormous slowdown in some of the existing solutions is really a no go [1]. In the case of _decimal, the tls-context is already subinterpreter safe and reasonable fast due to caching. The most promising model to me is to put *all* globals in a tls structure and cache the whole structure. Extrapolating from my experiences with the context, this might have a slowdown of "only" 4%. Still, the argument "who uses subinterpreters?" of course still remains. Stefan Krah [1] I'm referring to the slowdown of heaptypes + module state. _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
