The _xxsubinterpreters module is essentially the low-level implementation of PEP 554. However, we added it a while back for testing purposes, especially to further exercise the runtime relative to subinterpreters. Since then, I've removed "channels" from PEP 554. So it may make sense to drop that part of the implementation. That part of Modules/_xxsubinterpretersmodule.c is much more code and certainly much more complex than the basic functionality the PEP now describes.

Linked PRs

• gh-101524: Split Up the _xxsubinterpreters Module #101526
• gh-101524: Fix the ChannelID tp_name #102655
• gh-101524: Only Use Public C-API in the _xxsubinterpreters Module #105258
• [3.12] gh-101524: Only Use Public C-API in the _xxsubinterpreters Module (gh-105258) #107303
• gh-101524: Only Use Public C-API in the _xxsubinterpreters Module #107359