[3.7] bpo-33097: Fix submit accepting callable after executor shutdown by interpreter exit (GH-6144) by miss-islington · Pull Request #6445

[3.7] bpo-33097: Fix submit accepting callable after executor shutdown by interpreter exit (GH-6144) by miss-islington · Pull Request #6445 · python/cpython

…nterpreter exit (pythonGH-6144)

Executors in concurrent.futures accepted tasks after executor was shutdown by interpreter exit. Tasks were left in PENDING state forever. This fix changes submit to instead raise a RuntimeError.
(cherry picked from commit c4b695f)

Co-authored-by: Mark Nemec <mrknmc@me.com>