bpo-34679: ProactorEventLoop only uses set_wakeup_fd() in main thread (GH-16901)


bpo-34679, bpo-38563: asyncio.ProactorEventLoop.close() now only calls
signal.set_wakeup_fd() in the main thread.
(cherry picked from commit 1b53a24fb4417c764dd5933bce505f5c94249ca6)

Co-authored-by: Victor Stinner <vstinner@python.org>
3 files changed