<div dir="ltr">I'm sorry for the late reply. I've realized I made a mistake in the initial post, the server is actually running motif windows manager.<div><br></div><div>The output of xlsclients is:</div><div><br></div><div># xlsclients -al<br>Window 0x60005b:<br>Â Machine: Â localhost.localdomain<br>Â Name: Â mwm<br>Â Icon Name: Â mwm<br>Â Command: Â /usr/bin/mwm<br>Â Instance/Class: Â mwm/Mwm<br></div><div><br></div><div>The output of xwininfo is:<div><br></div><div># xwininfo -root -tree<br><br>xwininfo: Window id: 0xde (the root window) (has no name)<br><br>Â Root window id: 0xde (the root window) (has no name)<br>Â Parent window id: 0x0 (none)<br>Â Â Â 13 children:<br>Â Â Â 0x600088 (has no name): () Â 800x600+0+0 Â +0+0<br>Â Â Â Â 1 child:<br>Â Â Â Â 0x600089 (has no name): () Â 800x600+0+0 Â +0+0<br>Â Â Â Â Â Â 1 child:<br>Â Â Â Â Â Â 0x800005 "CTM - tc3": ("
CTM
" "
CTM
") Â 800x600+0+0 Â +0+0<br>Â Â Â 0x60008a (has no name): () Â 62x79+0+0 Â +0+0<br>Â Â Â 0x800007 (has no name): () Â 1x1+0+0 Â +0+0<br>Â Â Â 0x800003 (has no name): () Â 3x3+0+0 Â +0+0<br>Â Â Â 0x60005e (has no name): () Â 5x5+0+0 Â +0+0<br>Â Â Â Â 1 child:<br>Â Â Â Â 0x60005f (has no name): () Â 117x153+0+0 Â +0+0<br>Â Â Â 0xa00001 (has no name): () Â 10x10+-20+-20 Â +-20+-20<br>Â Â Â 0x60005b "mwm": ("mwm" "Mwm") Â 10x10+10000+0 Â +10000+0<br>Â Â Â 0x600055 (has no name): () Â 5x5+0+0 Â +0+0<br>Â Â Â Â 1 child:<br>Â Â Â Â 0x600056 (has no name): () Â 84x175+0+0 Â +0+0<br>Â Â Â 0x600054 (has no name): () Â 1x1+0+0 Â +0+0<br>Â Â Â 0x600023 (has no name): () Â 10x10+-100+-100 Â +-100+-100<br>Â Â Â 0x600015 (has no name): () Â 10x10+10000+10000 Â +10000+10000<br>Â Â Â Â 1 child:<br>Â Â Â Â 0x600016 (has no name): () Â 10x10+0+0 Â +10000+10000<br>Â Â Â 0x600007 (has no name): () Â 1x1+0+0 Â +0+0<br>Â Â Â 0x600006 "mwm": ("mwm" "Mwm") Â 1x1+0+0 Â +0+0<br><div><br></div><div>Where "
CTM
" is an executable running in a separate computer on the same network, showing its content on the local X server using "export DISPLAY=...". When that machine dies, the screen does not go black, instead the last image of the
CTM executable stays on screen. </div><div><br></div><div>Then if I try to do a netstat, I can see that the TCP connections from the machine (that is now powered off) are still ESTABLISHED. </div><div><br></div><div>I guess there should be a way of activating a KEEPALIVE mechanism on the connection to the Xorg, but I'm not quite sure how to do that. The application is using Qt by the way, if it matters.</div><div><br></div><div>Regards.</div></div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">El mié, 24 feb 2021 a las 10:18, Ilya Anfimov (<<a href="mailto:ilan@tzirechnoy.com">ilan@tzirechnoy.com</a>>) escribió:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">On Wed, Feb 17, 2021 at 05:13:45PM +0100, Jos?? Tom??s Tocino Garc??a wrote:<br>
>Â Â Hello.<br>
>Â Â I have an xorg server running in a Linux box with no wm, and a separate<br>
>Â Â machine running an application exporting to the X server in the first<br>
>Â Â machine.<br>
> <br>
>Â Â The problem arises when the connection is lost between the two machines or<br>
>Â Â the application exporting the display fails. The X111 server keeps a stale<br>
>Â Â image on screen that is obviously unresponsive. I'd rather it turn black<br>
>Â Â the moment the connection is lost.<br>
> <br>
>Â Â Is there a way of forcing the X server to stop showing that stale image<br>
>Â Â when the connection is lost? Not sure if it has something to do with it<br>
>Â Â not having a wm.<br>
>Â Â Thanks!<br>
>Â Â Regards.<br>
<br>
 This looks rather strange. Usually connection failures<br>
closes tcp socket, then windows, created by the<br>
app should be destroyed be the server.<br>
 What does xlsclients -al and xwininfo -root -tree show<br>
before and after failure?<br>
 Does the client still connected? Does it's window(s) still exists?<br>
<br>
>Â Â --<br>
>Â Â Jose Tomas Tocino<br>
>Â Â <a href="http://josetomastocino.com" rel="noreferrer" target="_blank">http://josetomastocino.com</a><br>
>Â Â <a href="http://cadizenmoto.com" rel="noreferrer" target="_blank">http://cadizenmoto.com</a><br>
<br>
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</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="gmail_signature"><div dir="ltr"><div><div style="font-size:small">José Tomás Tocino</div><div style="font-size:small"><a href="http://josetomastocino.com" target="_blank">http://josetomastocino.com</a></div><div style="font-size:small"><a href="http://cadizenmoto.com" target="_blank">http://cadizenmoto.com</a></div></div></div></div>