SUMMARY: XDM and cmd/shelltool problem

From: J. Theuerkauf (joerg@wp-470-1.fl.bs.dlr.de)
Date: Thu Jun 17 1993 - 01:59:10 CDT


Hello sun-managers,

my question was:
>
> We tried to set up xdm on a SS2 running 4.1.3 and OWN 3.0. We used the
> OpenWindows xdm and xlogin 2.01 rev.1.3. On a first look everthing
> seemed ok, but then we noticed that every cmdtool or shelltool that
> is started from openwin-init or from the olwm-menu is taking a lot of
> cpu time. A trace of such a cmdtool looks like this:
>
> Process 592 attached - interrupt to quit
> select (256, 0xf7fffa00, 0xf7fff9e0, 0xf7fff9c0, 0) = 1
> readv (4, 0xf779cd88, 2) = -1 EIO (I/O error)
> ioctl (3, 0x4004667f, 0xf7fff80c) = 0
> select (256, 0xf7fffa00, 0xf7fff9e0, 0xf7fff9c0, 0) = 1
> readv (4, 0xf779cd88, 2) = -1 EIO (I/O error)
> ioctl (3, 0x4004667f, 0xf7fff80c) = 0
>
> This is repeating endless. One way to stop this behavior is to do
> an [ echo "" >/dev/ttyp? ] to the pseudo device that belongs to the
> cmdtool. But if we do an [ stty sane ] or [ stty dec ] or an
> [ rlogin anywhere ] from this cmdtool, the strange behavior starts
> again.
>
> If we start a cmdtool from a remote machine with the display on the
> xdm-running machine this does not happen. Even if we do a remote login
> to this machine and start a cmdtool on :0 it works fine. Just the tools
> that are started from the xdm-controlled environment (openwin-init or olwm)
> seem to have this problem (with their ttyp??).
>

The solutions in short:

  - use xterm
  - use X11R5 xdm and 'stty sane' before xdm startup
  - start xdm with "-nodaemon" option

I will go with the last one, because many of our users like the "scrolling feature"
of cmdtool and I had some problems with X11R5 xdm and no time to deal with them now.

Fernando Dias (fdias@silvac.pt) said he posted a similar question about buggy
cmdtool some time ago. Maybe the workaround from Matt Cohen (Matt.Cohen@chron.com)
can help him too. I'll include his message at the end of this mail.

Thanks a lot to all who responded, you are really great!!!

---------------------------------------------------------------------
Joerg Theuerkauf /|
joerg@wp-470-1.fl.bs.dlr.de / |
                                  / |
Tel. (+49) 531 395 22 91 _____/___|_____
Fax (+49) 531 395 25 50 / / / /
                           / / / /
                         /____/____/____/
                              | / Deutsche Forschungsanstalt
                              | / fuer Luft- und Raumfahrt
     ___ | / Flughafen
    (o o) |/ D 3300 Braunschweig
---w--U--w-----------------------------------------------------------

P.S.: original messages:

> From: Matt.Cohen@chron.com (Matt Cohen)
>
> Joerg,
>
> This is a bug in shelltool/cmdtool.
>
> Whenever one is started without a controlling terminal,
> it goes into the loop you traced.
>
> There is no fix, but a workaround is to provide a controlling
> terminal. The best way I've found to do this is to arrange for one
> to be inherited from xdm. Normally, xdm disassociates itself from
> a controlling terminal to protect against a variety of basically unlikely
> potential problems.
>
> You can suppress this behavior by starting xdm in nodaemon mode -
> either use the "-nodaemon" option on the command line, or put the line:
> "DisplayManager.daemonMode: false" in your xdm-config file. Be sure to
> start xdm in the background, since it won't exit in nodaemon mode.
>
> Good luck - I hope this helps.
>
> -- Matt @8^1
>
> --
> Matt Cohen INET: sysnmc@chron.com
> Department of Technology Resources UUCP: ...!uunet!chron!sysnmc
> The Houston Chronicle AT&T: +1 713 220 7023
> 801 Texas Avenue, Houston, TX 77002 "Quidquid Latine dictum sit,
> "Houston's Leading Information Source" altum viditur."
>

---------------------------------------------------------------------------

> From ivan@fac.anu.edu.au Wed Jun 16 01:00:58 1993
>
> I solved this problem by placing a 'stty sane' in the script where I
> start up xdm. I am using the X11R5 xdm, as from all reports the OW 3.0
> one is not very good.
> -------------------------------------------------------------------
> Ivan Angus - ne Dean Here : x3261
> Faculties Computer Unit There : (06) 249 3261
> Australian National University Everywhere : +61 6 249 3261
>

---------------------------------------------------------------------------
> From Ian_MacPhedran@engr.usask.ca Tue Jun 15 21:40:45 1993
>
> Use xterm in place of {shell,command}tool. The tools are brain damaged.
> The problem seems to be that they have no controlling terminal. You could
> launch them from an xterm, once you have one on the screen.
>
> Ian.
> ----------------------------------------------------------------------------
> Ian MacPhedran, Engineering Computer Centre, University of Saskatchewan.
> 2B13 Engineering Building, U. of S. Campus, Saskatoon, Sask., CANADA S7N 0W0
> macphed@dvinci.USask.CA (306) 966-4832 Ian_MacPhedran@engr.USask.CA
>

Status: RO

Status: RO



This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:07:56 CDT