Re: [PATCH] Futures: Avoid creating the worker pool more than once

[ludo@gnu.org (Ludovic Courtès)]

Hi Mark,

Mark H Weaver <mhw@netris.org> skribis:

> From b0d936a348b916e73e9071abeb7baae3d7c126d3 Mon Sep 17 00:00:00 2001
> From: Mark H Weaver <mhw@netris.org>
> Date: Wed, 7 Nov 2012 08:39:42 -0500
> Subject: [PATCH] Futures: Avoid creating the worker pool more than once.
>
> * module/ice-9/futures.scm (%create-workers!): Use 'with-mutex' in case
>   an exception is thrown.  Within the critical section, check to make
>   sure the worker pool hasn't already been created by another thread.
> ---
>  module/ice-9/futures.scm |   24 +++++++++++++++---------
>  1 file changed, 15 insertions(+), 9 deletions(-)
>
>
> diff --git a/module/ice-9/futures.scm b/module/ice-9/futures.scm
> index 0f64b5c..7fbccf6 100644
> --- a/module/ice-9/futures.scm
> +++ b/module/ice-9/futures.scm
> @@ -19,6 +19,7 @@
>  (define-module (ice-9 futures)
>    #:use-module (srfi srfi-1)
>    #:use-module (srfi srfi-9)
> +  #:use-module (ice-9 threads)
>    #:use-module (ice-9 q)
>    #:export (future make-future future? touch))

I just realized that this patch introduces a circular dependency between
the two modules.

Can you think of a way to avoid it?

Thanks,
Ludo’.