Re: long poll() delay

[Richard Frith-Macdonald]

On Wednesday, May 22, 2002, at 09:26 AM, Stefan Urbanek wrote:

> Hi,
>
> Still having problem with long delays each time I run an application or
> when I use a pasteboard for the first time in the app. I have traced
> down with gdb where the delay is and it is in poll() call in NSRunLoop.
> I have wrapped that call by NSLogs and here is the output of the
> application:
>
> > openapp Farmer.app
> 2002-05-22 10:09:29.621 Farmer[29584] Only one display per host fully
> supported.
> 2002-05-22 10:09:29.866 Farmer[29584] Poll start
> 2002-05-22 10:09:49.847 Farmer[29584] Poll end
> 2002-05-22 10:09:49.849 Farmer[29584] Poll start
> 2002-05-22 10:09:49.850 Farmer[29584] Poll end
> 2002-05-22 10:09:49.850 Farmer[29584] Poll start
> 2002-05-22 10:09:49.851 Farmer[29584] Poll end
> 2002-05-22 10:09:49.851 Farmer[29584] Poll start
> 2002-05-22 10:09:49.852 Farmer[29584] Poll end
> ...
> You may see that the first poll took 20 seconds. The gdnc server is
> already running. Subsequent poll calls are withot delay.
>
> And same happens when I use pateboard in the application for the first
> time:
> ...
> 2002-05-22 10:09:54.822 Farmer[29584] Initialize dragging
> 2002-05-22 10:09:54.850 Farmer[29584] Poll start
> 2002-05-22 10:10:14.857 Farmer[29584] Poll end
> ...
> The pasteboard server is also running. This is really annoying for
> example, when you select a text in a text field or start dragging.
>
> This is not happening when I am launching the application on localhost
> with local display. This is happening only when running on a remote
> display. The situation is, as I described last time, that I am running a
> XDM session on one host from another. Everthing is being run on the host
> 'altair': the application, two gdnc servers and two gpbs servers (one
> for localhost and one for the another with X server)
>
> Is anybody experiencing the same problem?

I'd suggest running the app under strace to log system calls, and see 
what
the poll is waiting for.

My guess is it's trying to contact gdomap on the remote host, and the
connection attempt is taking a while to time out rather than failing
instantly.

Only after failing to find the required server on the remote host will
it attempt to talk to an alternative on the local host.