Ideas to update module less when there are no changes (performance)

[tuurep]

Listening to ConfigureNotify has the effect that a lot of module updates are done when dragging and moving, or dragging and resizing a window, which allows to immediately sort the list by position, but is the biggest performance drawback of the entire program I think?

So let's add a config check, if sort_by is not "position", then we can omit SubStructureNotifyMask from this (if I recall correctly):

windowlist/main.c

Lines 413 to 417 in 27530c9

	// Ask X server to send ConfigureNotify and PropertyNotify events for root window
	// ConfigureNotify is sent when a window's size or position changes
	// PropertyNotify for changes in client list and active window
	Window root = DefaultRootWindow(d);
	XSelectInput(d, root, SubstructureNotifyMask | PropertyChangeMask);

Also see if solution in #6 causes a lot of events.

Thanks @Dupond:

I've carried out a few performance tests on my machine: in normal use, the impact of the module seems almost non-existent (at least, it's not very different from what it was with my previous script); but when moving a window, my 4 CPUs easily climb to 25 or 30% utilization each (tested with htop), whereas with my previous script, in this same scenario, they remained below 10%.

(from #25)

[tuurep]

Another idea to greatly reduce updating module even if sort_by == "position":

• It only makes sense to update when sort order changes
  • In the loop we already have prev_wlist and wlist, so:
    • first sort the lists, then see if they are 'different', and only output if they are 'different'
    • (but make sure to still indiscriminately output whenever active window changes)