From 09fe4f9c7eb7721fc75eb30bd97de3cdd3e205e1 Mon Sep 17 00:00:00 2001 From: Stanley <46876382+slateny@users.noreply.github.com> Date: Sun, 16 Oct 2022 10:04:43 -0700 Subject: [PATCH] gh-85299: Add note warning about entry point guard for asyncio example (GH-93457) (cherry picked from commit 79fd6ccdbe00ec95e4d33fc24fe76076282a334e) Co-authored-by: Stanley <46876382+slateny@users.noreply.github.com> --- Doc/library/asyncio-eventloop.rst | 8 +++++++- Doc/library/multiprocessing.rst | 2 ++ 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/Doc/library/asyncio-eventloop.rst b/Doc/library/asyncio-eventloop.rst index 8125612de58a02..93bca96fff6f10 100644 --- a/Doc/library/asyncio-eventloop.rst +++ b/Doc/library/asyncio-eventloop.rst @@ -1232,7 +1232,13 @@ Executing code in thread or process pools pool, cpu_bound) print('custom process pool', result) - asyncio.run(main()) + if __name__ == '__main__': + asyncio.run(main()) + + Note that the entry point guard (``if __name__ == '__main__'``) + is required for option 3 due to the peculiarities of :mod:`multiprocessing`, + which is used by :class:`~concurrent.futures.ProcessPoolExecutor`. + See :ref:`Safe importing of main module `. This method returns a :class:`asyncio.Future` object. diff --git a/Doc/library/multiprocessing.rst b/Doc/library/multiprocessing.rst index dab115acdc207c..5516084780673f 100644 --- a/Doc/library/multiprocessing.rst +++ b/Doc/library/multiprocessing.rst @@ -2954,6 +2954,8 @@ Global variables However, global variables which are just module level constants cause no problems. +.. _multiprocessing-safe-main-import: + Safe importing of main module Make sure that the main module can be safely imported by a new Python