While trying to modify some code I found on an earlier post for
running N jobs in parallel I came across the interesting behavior
illustrated below. It appears that the wait command proceeds before
my SIGUSR's are all processed. Is this a bug or just a fact of life?
I understand that it isn't pos
Of course, this code probably also has a race condition around
--nrunning which makes it even less usable.
Thanks,
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Elliott ForneyE-Mail: id...@cs.colosetate.edu
On Mon, Nov 5, 2012 at 4:33 PM, Elliott Forney wrote:
> While trying to modify some code I found on an
Hi Elliott. The behavior of wait differs depending upon whether you are in
POSIX mode. Try this script, which I think does essentially what you're after
(also here: https://gist.github.com/3911059 ):
#!/usr/bin/env bash
${BASH_VERSION+shopt -s lastpipe extglob}
if [[ -v .sh.version ]]; then
OK, I see in POSIX mode that a trap on SIGCHLD will cause wait to
unblock. We are still maintaining a counter of running jobs though so
it seems to me that there could race condition in the following line
trap '((j--))' CHLD
if two processes quit in rapid succession and one trap gets preempted
i
On Monday, November 05, 2012 05:52:41 PM Elliott Forney wrote:
> OK, I see in POSIX mode that a trap on SIGCHLD will cause wait to
> unblock. We are still maintaining a counter of running jobs though so
> it seems to me that there could race condition in the following line
>
> trap '((j--))' CHLD
> I believe that Bash guarantees the trap will run once for every child that
> exits, so it shoud be impossible for the count to become off. See:
> https://lists.gnu.org/archive/html/bug-bash/2012-05/msg00055.html
I guess my question is "can more than one trap run simultaneously?"
The more I think
