Re: Print plot error

[Ben Abbott]

On Aug 24, 2009, at 5:39 PM, Rob Mahurin wrote:

> On Aug 24, 2009, at 5:17 PM, Dmitri A. Sergatskov wrote:
> > On Sun, Aug 23, 2009 at 12:40 PM, Rob Mahurin<address@hidden> wrote:
> > > I think the solution is an occasional waitpid(-1,0,WNOHANG), but  
> > > I'm not
> >
> > I just added
> > waitpid(-1, 0)
> > to the end of print() function (in print.m) and that seems to solve  
> > the problem.
> >
> > Again, I am not sure if this is the solution, but at least can be a  
> > workaround
> > for now.
>
> Oh!  I didn't realize waitpid was also an Octave function.
>
> You probably want waitpid(-1,WNOHANG) so that print won't freeze if  
> there is actually no child.
>
> Attached as a patch (which is not a changeset, sorry).  This would  
> be good for 3.2.3.
>
> Rob

Regarding the patch, shouldn't WNOHANG be in quotes like below?

+  ## FIXME: we shouldn't leave zombie children, but clean them up if  
they happen
+  while (waitpid(-1,"WNOHANG"))
+    ## do nothing
+  endwhile

Also what about children that are not zombies? Will such produce an  
infinite loop?

Regarding the "zombies" does waitpid() kill them or just wait until  
the die?

Ben