SeePEP 687.

Currently most stdlib extension have been ported to multi-phase init. There are still a number of them to be ported, almost entirely non-builtin modules. Also, some that have already been ported still have global state that needs to be fixed.

(This is part of the effort to finish isolating multiple interpreters from each other. Seegh-100227.)

High-Level Info

How to isolate modules:https://docs.python.org/3/howto/isolating-extensions.html (AKA PEP 630).

The full list of modules that need porting can be found with:...

The full list of remaining (unsupported) global variables is:

• builtin extensions:https://github.com/python/cpython/blob/main/Tools/c-analyzer/cpython/globals-to-fix.tsv#L308-L335
• non-builtin extensions:https://github.com/python/cpython/blob/main/Tools/c-analyzer/cpython/globals-to-fix.tsv#L338-L551

A full analysis of the modules may be found at the bottom of this post.

TODO

Here is the list of modules that need attention, in arough, best-effort priority order. Additional details (e.g. if there is an issue and/or PR) is found in the analysis table at the bottom.

• builtins (high priority)
  • Isolate the_io extension module #101819
  • isolate _collections
  • Isolate the tracemalloc Module Between Interpreters #101520
  • Isolate the faulthandler Module Between Interpreters #101509
• essential (higher priority)
  • port _socket
  • port readline (leave as is: only available in main interp)
  • isolate _ssl
  • port _pickle
  • Isolate the _datetime extension module #117398
  • isolate _asyncio
  • Isolate the_decimal extension module #106078
  • isolate array
  • port _ctypes
    • Convert _ctypes static types (and the "meta class") to heap types #114314
    • Convert _ctypes extension module to multi-phase init #117142
  • port _tkinter (leave as is: only available in main interp)
  • Isolate _multibytecodec #103583
  • Isolate the _curses extension module #101714
  • isolate _curses_panel (leave as is: only available in main interp)
  • isolate _elementtree
  • isolate pyexpat
  • port winreg (Windows)
  • port msvcrt (Windows)
• non-essential (lower priority)
  • port winsound (Windows)
  • isolate _lsprof

The above does not include test modules. They don't need to be ported/isolated (except for a few which already have been).

Modules Analysis

Linked PRs

• gh-103092: Isolate _collections #103093
• gh-103092: Isolate_pickle #102982
• gh-103092: Isolate socket #103094
• gh-103092: Isolate _tkinter (WIP) #103108
• gh-103092: Isolate msvcrt #103248
• gh-103092: Isolate winsound #103249
• gh-103092: Isolate winreg #103250
• gh-103092: Isolate_decimal #103381
• gh-103583: Add codecs and maps to _codecs_* module state #103540
• gh-103092: Isolate ctypes #103612
• gh-103092: Isolate _ctypes, part 1 #103893
• gh-103092: Adapt _ctypes's PyCStgDict type to heap type #103932
• gh-103092: Port _ctypes.COMError to heap type #104020
• GH-103092: port_asyncio freelist to module state #104196
• GH-103092: isolatepyexpat #104506
• GH-103092: isolate_elementtree #104561
• GH-103092: isolate_ssl #104725
• gh-103092: Make_elementtree module importable in sub-interpreters #113434
• gh-103092: Makepyexpat module importable in sub-interpreters #113555
• gh-103092: Convert some_ctypes metatypes to heap types #113620
• gh-103092: Port some_ctypes data types to heap types #113630
• gh-103092: Test_ctypes type hierarchy and features #113727
• gh-103092: Port some_ctypes data types to heap types (alt) #113774
• gh-103092: Ensure_ctypes.c static types are accessed via global state #113857
• gh-103092: isolate _lsprof #115130
• gh-103092: Adapt _lsprof methods to Argument Clinic #115242
• gh-103092: Add a mutex to make the random state of rotatingtree concurrent-safe #115301
• gh-103092: Prep curses module for multi-phase init #23091
• gh-103092: Support subinterpreters in _zstd #133674
• [3.14] gh-103092: Support subinterpreters in_zstd (GH-133674) #133695