On Fri, Feb 24, 2012 at 6:21 PM, Andy Wingo <wi...@pobox.com> wrote:
> On Fri 24 Feb 2012 04:00, Nala Ginrut <nalagin...@gmail.com> writes:
>
> > I think I could use pipes to handle some sub-process rather than do it
> > with fork manually. But I must create a daemon, it can't avoid to use
> > fork, will this circumstance cause problems if I use threads after it?
>
> I just pushed a patch like this:
>
> --- a/libguile/posix.c
> +++ b/libguile/posix.c
> @@ -1,4 +1,4 @@
> -/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2003, 2004,
> 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
> +/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2003, 2004,
> 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc
> *
> * This library is free software; you can redistribute it and/or
> * modify it under the terms of the GNU Lesser General Public License
> @@ -1248,6 +1248,18 @@ SCM_DEFINE (scm_fork, "primitive-fork", 0, 0, 0,
> #define FUNC_NAME s_scm_fork
> {
> int pid;
> + if (scm_ilength (scm_all_threads ()) != 1)
> + /* Other threads may be holding on to resources that Guile needs --
> + it is not safe to permit one thread to fork while others are
> + running.
> +
> + In addition, POSIX clearly specifies that if a multi-threaded
> + program forks, the child must only call functions that are
> + async-signal-safe. We can't guarantee that in general. The
> best
> + we can do is to allow forking only very early, before any call
> to
> + sigaction spawns the signal-handling thread. */
> + SCM_MISC_ERROR ("attempt to fork while multiple threads are
> running",
> + SCM_EOL);
>
Well, at least it support to create a daemon.
Considering the new 'open-process' hasn't been done, the issues left
suspending.
And I'm glad to see the skills you deal with this problem soon. ;-)
> pid = fork ();
> if (pid == -1)
> SCM_SYSERROR;
>
> What do you think?
>
> Andy
> --
> http://wingolog.org/
>
