c/unix q

[Erez D]

On Thu, Jun 6, 2013 at 5:04 PM, E.S. Rosenberg <esr at g.jct.ac.il> wrote:

> 2013/6/6 Erez D <erez0001 at gmail.com>:
> >
> >
> >
> > On Tue, Jun 4, 2013 at 6:09 PM, Shachar Shemesh <shachar at shemesh.biz>
> wrote:
> >>
> >> On 04/06/13 15:28, Erez D wrote:
> >>
> >> thanks,
> >>
> >> so i guess if i use unidirectional connection, and the reader does not
> >> expect to get an EOF()
> >> thank i'm safe.
> >>
> >> Why are you so keen on doing it wrong?
> >>
> >> No, you are not safe. If the child process dies because of a
> segmentation
> >> fault (or whatever), the parent will notice this through the EOF
> received (I
> >> am assuming here, since you couldn't be bothered with closing a file
> >> descriptor, that you did not install a SIGCHLD handler to monitor for
> this
> >> possibility). This means that should one process die unexpectedly, the
> other
> >> will hang forever.
> >
> > it's not a matter of being bothered. closing a file has it's implications
> >
> > 1.  close the file for one thread closes for all
> thread and fork are 2 very different things, best practice for fork
> ('full' children, I think everyone understands fork() when you say
> child) is to close, when using threads that is I believe not the case.
> > 2. what if i want later children using the same pipe, as in all childs
> write
> > to same pipe read by parent...
> so the children are all closing the read end and the parent only
> closes write, where is the problem?
>
if the parent closes the "write" side, then new forked children have their
"write" side already closed.

> >
> >>
> >> Best practices are there for a reason, despite what others here might
> have
> >> you think.
> >>
> >> Shachar
> >
> >
> >
> > _______________________________________________
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> > http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
> >
>
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