bug#28779: tests/workers.scm failure

[Eric Bavier <bavier@cray.com>]

Looks good to me.

Thanks,

Eric Bavier, Scientific Libraries, Cray Inc.

________________________________________
From: Ludovic Courtès <ludo@gnu.org>
Sent: Thursday, November 16, 2017 02:29
To: Eric Bavier
Cc: 28779@debbugs.gnu.org
Subject: Re: bug#28779: tests/workers.scm failure

Hi Eric,

Eric Bavier <bavier@cray.com> skribis:

> test-name: enqueue
> location: /home/users/bavier/src/guix/tests/workers.scm:26
> source:
> + (test-equal
> +   "enqueue"
> +   4242
> +   (let* ((pool (make-pool))
> +          (result 0)
> +          (#{1+!}# (let ((lock (make-mutex)))
> +                     (lambda ()
> +                       (with-mutex lock (set! result (+ result 1)))))))
> +     (let loop ((i 4242))
> +       (unless
> +         (zero? i)
> +         (pool-enqueue! pool #{1+!}#)
> +         (loop (- i 1))))
> +     (let poll ()
> +       (unless
> +         (pool-idle? pool)
> +         (pk 'busy result)
> +         (sleep 1)
> +         (poll)))
> +     result))
> expected-value: 4242
> actual-value: 4241
> result: FAIL
>
>
> To me the reason seems to be that the 'pool-idle? procedure indicates whether or not the task queue is empty, not whether all tasks have completed execution, so the poll loop exits before all 1+! updates are finished and the test fails.

Indeed, good catch.

The attached patch is a bit crude but it should fix the problem.

Thoughts?

Thanks,
Ludo’.