[xmonad] darcs patch: get rid of zombies in a more portable way

[Don Stewart]

Jan.Vornberger:
> On Sun, Apr 11, 2010 at 09:03:13PM +0200, Tomas Janousek wrote:
> > Sun Apr 11 20:55:10 CEST 2010  Tomas Janousek <tomi at nomi.cz>
> >   * get rid of zombies in a more portable way
> >   
> >   FreeBSD and OpenBSD don't support the signal(SIGCHLD, SIG_IGN) way of dealing
> >   with them. Wikipedia quote on the issue:
> >   
> >   "POSIX.1-2001 allows a parent process to elect for the kernel to automatically
> >   reap child processes that terminate by setting the disposition of SIGCHLD to
> >   SIG_IGN or by setting the SA_NOCLDWAIT flag for the SIGCHLD signal; Linux 2.6
> >   kernels adhere to this behavior while FreeBSD supports only the latter of
> >   these methods. Because of historical differences between System V and BSD
> >   behaviors with regard to ignoring SIGCHLD, calling wait remains the most
> >   portable paradigm for cleaning up after forked child processes."
> 
> A quick patch review: I played around with this and it seems to work
> fine in my testings and is a sound alternative to the current way of
> just ignoring the signal. If this solves issues for FreeBSD and OpenBSD
> I'm all for it. My thumbs up for applying this, Don and Spencer. :-)
> 

Interesting. Thanks for taking the time to check this.