Re: [hackers] Re: [dwm][PATCH v2] Use sigaction(SA_NOCLDWAIT) for SIGCHLD handling

From: Hiltjo Posthuma <>
Date: Wed, 25 Jan 2023 21:17:53 +0100

On Wed, Jan 25, 2023 at 04:24:36PM +0600, NRK wrote:
> On Wed, Jan 25, 2023 at 09:37:58AM +0100, Hiltjo Posthuma wrote:
> > I don't think there can be any zombies since it is run in setup() before any
> > processes can spawn (via keybindings etc) or am I overlooking something
> > obvious?
> It was recently discussed here:
> And here's the original thread from 2009:
> - NRK

Thanks, yeah I'm also digging in the history now.

I just tried it on a Slackware 11 machine, because I'm curious what it might break etc.

Using the new patch it does not handle zombie/defunct processes anymore on this
machine. To reproduce it, in .xinitrc, on a dusty machine:

        sleep 10 &
        exec dwm

Run ps in the terminal, after the sleep process exits it is defunct. This used
to work without the patch.

I changed SIG_DFL to SIG_IGN and it seems to work.

Also, maybe it is better to not call sigprocmask? Since now it blocks all
signals, including SIGTERM in setup().

Kind regards,
Received on Wed Jan 25 2023 - 21:17:53 CET

This archive was generated by hypermail 2.3.0 : Wed Jan 25 2023 - 21:26:10 CET