Compiz DPMS Monitor

Overview

What?

A simple script that disables the "animations" Compiz plugin when the monitor is turned off.

Why?

I've found that if I leave my machine idle for any significant length of time it takes the first animation (i.e. effect handled by the animation Compiz plugin) a few seconds to display. Worse still, compiz ends up burning 100% CPU and the X session is effectively locked up until the animation does finally start.

The length of the freeze seems to be directly proportional to the length of time since the last animation played. That and the way that the very first frame of the animation is displayed before the freeze begins leads me to think that it's maybe caused by the plugin incrementing some internal time counter until it actually catches up with real time, or somesuch.

I have no idea why this affects me - my wife's machine with (almost) identical config is totally unaffected, for instance, and I've not found any other reports of it online. Furthermore, it's not the only Compiz weirdness that it seems that only my box suffers from, so I'm in no way laying the blame on Compiz here - it's just One Of Those Things(tm) as best I can tell.

Since I couldn't find a 'proper' solution and disabling animations by hand every time I was going to be away from the machine for a few hours was getting tedious, I knocked together a simple tool that would do it for me.

It's my hope that a future upgrade (I'm using Fedora 8 here, with no plans to upgrade until 10 is out) will 'magically' resolve this problem, but in the meantime this script at least allows me to avoid it.

How?

Once a second the script queries the X server to see if the monitor is turned on or off. If the script detects a change in monitor state it fires off a command (via Dbus) to compiz to enable/disable the "animation" plugin accordingly.

Naturally, this means that you must have Compiz's Dbus plugin active and the python dbus library (dbus-python package in Fedora) installed.

If compiz is not running, or dies, is restarted, etc. then the script will 'cope' (i.e. it basically ignores all errors, but tries to do things in a sensible way).

To use the script, simply start it with your session. It doesn't handle any sort of session management, daemonise, demand kibbles'n'bits, or anysuch. Simple, crude, effective.

Whirrr?

Use at your own risk. No warranty - see sections 11 & 12 of the GPLv2.

When?

Who?

Musus Umbra, aka Adny <musus.linux@verelanthe.co.uk>
http://www.verelanthe.co.uk/linux/