<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN" "http://www.w3.org/TR/REC-html40/strict.dtd"><html><head><meta name="qrichtext" content="1" /><style type="text/css">p, li { white-space: pre-wrap; }</style></head><body style=" font-family:'Liberation Sans'; font-size:9pt; font-weight:400; font-style:normal;">On Saturday 17 January 2009 15:10:58 Peter Clifton wrote: > Ok, it looks like I was off-base on my diagnosis of an infinite loop. > > It seems that gnome-power-manager may have been emitting a series of > very small changes in backlight brightness to cause a fading effect. The > fact that each triggered one (or more!) output probes meant that the > process took a very long time indeed! > > Each change caused a notification from Xrandr, which all GDK using > applications then translated to a "monitors-changed" signal. > > Interestingly, some people seeing the looping behaviour have reported it > as only occurring after an upgrade from libXrandr 1.2.3 to 1.2.99.2. > I've not had a lot of luck figuring out why this might be, but wonder if > the bug fixed during that period relating to a corrupt / unset "window" > property on the wire for some events, might have caused GTK to drop some > of those events in the past without handling them. (Just an untested > idea). > > gnome-power-manager handles the "monitors-changed" signal by retrieving > information from Xrandr, causing a re-probe of outputs. > > Patching GDK not to emit "monitors-changed" for output property > notifications causes the problem to go away as far as I can tell. > > Now Xrandr 1.3 is available, on systems which have it, > gnome-power-manager should probably be calling > XRRGetScreenResourcesCurrent () in retaliation to notified events - at > the very least. (Not XRRGetScreenResources () as it currently uses) > > Arguably, GDK shouldn't be generating a "monitors-changed" signal for an > output property change. The description of that signal states: > > "The ::monitors-changed signal is emitted when the number, size or > position of the monitors attached to the screen change." > > I presume output properties don't reflect any of the above changes? Using XRRGetScreenResourcesCurrent instead of XRRGetScreenResources in both gnome-desktop and gnome-power-manager solves the problem here (without having to patch GDK). Regards, Alberto Milone</body></html>