Re: interrupted system call when using named pipes on FreeBSD

[Roman Rakus]

On 01/29/2013 10:59 PM, Chet Ramey wrote:
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> On 1/18/13 1:30 AM, Mike Frysinger wrote:
> > this is somewhat a continuation of this thread:
> > http://lists.gnu.org/archive/html/bug-bash/2008-10/msg00091.html
> >
> > i've gotten more or less the same report in Gentoo:
> > http://bugs.gentoo.org/447810
> >
> > the simple test case is:
> > $ cat test.sh
> > #!/bin/bash
> > while :; do
> >         (:)& (:)& (:)& (:)& (:)& (:)& (:)& (:)& (:)& (:)&
> >         while read x ; do : ; done < <(echo foo)
> > done
> >
> > execute `./test.sh` and we see failures pretty much all the time.
>
> I did some looking around, and the script does result in open returning
> - -1/EINTR, even if SIGCHLD is installed with SA_RESTART, on FreeBSD and
> Mac OS X.  It doesn't happen on RHEL 5.  I may test Solaris 11 later.
>
> I did find a reference to the Linux kernel patch that makes this work:
>
> http://marc.info/?l=linux-kernel&m=134071285509470
>
> Chet
>
> - --
> ``The lyf so short, the craft so long to lerne.'' - Chaucer
>                  ``Ars longa, vita brevis'' - Hippocrates
> Chet Ramey, ITS, CWRU    chet@case.edu    http://cnswww.cns.cwru.edu/~chet/
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There is similar problem with ioctl() syscall in read.
Consider following script:
#!/bin/bash
( while :; do kill -CHLD $$ 2>&- || break; done ) &
while :; do
        read -p 1 -t 0.01 -d ' '
done

On my Fedora it is reporting many
/tmp/test.sh: line 4: read: error setting terminal attributes: 
Interrupted system call
Hold down Enter key and when you are lucky you'll end up with SIGABRT. 
Definitely it's a bug in kernel, but I'm not sure if there is also 
something wrong in bash.

RR