Re: master 8dcb19f 4/4: Add a unit test testing interaction between threads and processes.

[Philipp Stephani <p.stephani2@gmail.com>]

Am Sa., 23. Jan. 2021 um 21:27 Uhr schrieb Eli Zaretskii <eliz@gnu.org>:
>
> > Date: Sat, 23 Jan 2021 21:49:18 +0200
> > From: Eli Zaretskii <eliz@gnu.org>
> > Cc: Philipp Stephani <phst@google.com>, emacs-devel@gnu.org
> >
> >   Test process-tests/multiple-threads-waiting condition:
> >       (ert-test-failed
> >        ((should
> >        (eql
> >         (process-exit-status process)
> >         0))
> >       :form
> >       (eql 1 0)
> >       :value nil))
> >      FAILED  21/26  process-tests/multiple-threads-waiting (8.859375 sec)
>
> And if I run just this one test (using SELECTOR=...), it hangs in the
> first call to thread-join.
>
> Can you describe the idea of the test,

This test essentially implements your request to verify the
interactions between the self-pipe for SIGCHLD and threads. Seems it
discovered some issues on Windows instead! The test works fine on
GNU/Linux and macOS.

> and in particular why did you
> expect the threads to start running?  IOW, which part of this test is
> supposed to force the main thread to yield so that one of the other
> threads starts running?

thread-join should yield.