[maemo-developers] suspendprocess - poor man's power save

[From: Thomas Perl]

2010/9/20 Ville M. Vainio <vivainio at gmail.com>:
> I don't think real applications out there have a habit of
> unsubscribing from dbus signals when they don't need them either.

Yes, that's what listening for D-Bus signals is all about most of the
time (getting notified when something of interest happens, which can
happen at any time, hence there's no real possibility to unsubscribe).

IIRC D-Bus signal filter/receiver rules are checked in the D-Bus
daemon, so moving most of the checks into the rule instead of checking
for simple things in the callback reduces the wake-ups, right? It's
not something that we can do automated, but it would be nice to add
some info on how to write good, powerful match rules to the relevant
"power saving" Wiki pages. For example, is it possible to compare
parameters of D-Bus signals in the rule (say, the second parameter is
equal to "disconnected"), so we don't need to receive signals that we
won't process/need anyway?

Thanks,
Thomas