X event dropping with dbus

[retroj]

I noticed that my active-window-title widget was failing to update reliably, and with the help of folks in #xmonad (the window manager I use), traced the problem to some kind of timing issue related to the dbus event loop. I have only isolated it as far as follows:

Run mowedline with an active-window-title widget and some other widget that can be written to:

$ mowedline -q -flex 1 -active-window-title -text-widget foo

Switch windows a lot. The active-window-title widget should update reliably.

Cause dbus messages to be sent to mowedline:

$ while :; do sleep 0.25; echo a; done | mowedline-client read foo

While switching windows, watch for the active-window-title widget to occasionally fail to update.

This issue is probably not specific to the active-window-title widget - that is just the most convenient way to see the problem, since it responds to PropertyNotify events with an obvious change.

[retroj]

The problem seems not to occur if you have mowed-line client write to a non-existent widget. That means that widget lookup takes place, but widget-update, window-update-widget-dimensions, and window-expose do not get called. In the test case above, widget-update is only setting a variable. The other two are fairly complex procedures but not inordinately so.

[ryuslash]

I tried this and I'm unable to reproduce this in herbstluftwm with chicken 4.10.0 on Archlinux. I tried for several minutes to switch around normally, like a crazy person (as fast as my fingers can go) and I tried with shorter sleep times.

[ryuslash]

I tried this again, but this time on my 1.66Ghz single-core netbook, also with Archlinux, chicken 4.10.0 and herbstluftwm. I'm still unable to reproduce.