From mboxrd@z Thu Jan  1 00:00:00 1970
From: ludo@gnu.org (Ludovic =?utf-8?Q?Court=C3=A8s?=)
Subject: Re: Adding a TOR system test - confusing results
Date: Fri, 27 Jul 2018 10:41:05 +0200
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To: Chris Marusich <cmmarusich@gmail.com>
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Chris Marusich <cmmarusich@gmail.com> skribis:

> ludo@gnu.org (Ludovic Court=C3=A8s) writes:
>
>> Chris Marusich <cmmarusich@gmail.com> skribis:
>>
>>> Why does it pass?  The (sleep 999999) form appears to be totally
>>> ignored, and I don't understand why.  It's concerning to me that I can't
>>> understand how the code is being executed.  I expected the test to hang.
>>
>> According to the manual (info "(guile) Signals"):
>>
>>  -- Scheme Procedure: sleep secs
>>  -- Scheme Procedure: usleep usecs
>>  -- C Function: scm_sleep (secs)
>>  -- C Function: scm_usleep (usecs)
>>      Wait the given period SECS seconds or USECS microseconds (both
>>      integers).  If a signal arrives the wait stops and the return value
>>      is the time remaining, in seconds or microseconds respectively.  If
>>      the period elapses with no signal the return is zero.
>>
>> So I suspect that the marionette process got a signal, and thus =E2=80=
=98sleep=E2=80=99
>> returned quickly.  Could you print its return value?
>
> Thank you for the reply!  The return value is 999998.  Like you said,
> maybe it's possible that the marionette process got a signal.  But why
> would that happen?

I=E2=80=99m not sure!  It could be SIGPIPE or SIGCHLD, this is left as an
exercise to you.  :-)  Seriously, you could register signal handlers and
try to see what=E2=80=99s going on.

It doesn=E2=80=99t change the fact that the return value of =E2=80=98sleep=
=E2=80=99 must be
checked, though.

> I have a related question.  Is there a guarantee that the test case will
> begin after the TOR service has started up?

Most service tests start by waiting for the service to be up using
something like:

            (marionette-eval
             '(begin
                (use-modules (gnu services herd))
                (start-service 'mcron))
             marionette)

That blocks until =E2=80=98mcron=E2=80=99 is up or it has failed to start.

HTH!

Ludo=E2=80=99.