startup time: autostart

[Matthias Ettrich]

When klauncher performs autostart, it reads all items from the "autostart" 
folder, sorts them according to X-KDE-autostart-after and launches them at 
the same time.

On slow machines with little memory, starting those ~9 applications at the 
same time (including bigger ones like kicker and kdesktop) causes significant 
activity, hence the modified startkde scripts.

Most applications, at least the big ones like kicker, kdesktop or even kwrited 
and khotkeys register with dcop. Thus we could use the dcop bus to figure out 
when the application has been started.

Say we add a field

    X-KDE-autostart-wait-DCOP=appname

to the desktop files which makes klauncher wait for the 
DCOPClient::applicationRegistered(appname) signal.

This would serialize the startup to a large degree and could result in a 
faster and more straightforward startup without adding arbitrary waits or 
sleeps.

Waldo, any thoughts on this?


Matthias