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

[Eli Zaretskii]

> 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, 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?