Session Management Proposal

[George]

On Mon, Dec 29, 2003 at 02:46:35PM +0100, Oswald Buddenhagen wrote:
> another thing i'm wondering about is "Suspend" mode. considerations:
> - like reboot/halt it might need authorization - after all it makes the
>   box unresponsive to network activity (apart from WOL, etc.)
> - but it doesn't need to end the session

Suspend is kind of icky.  I doubt this needs to be done at the session
manager level at all.  There is no session management stuff that happens at
suspend really.  So I think with something like consolehelper this problem is
already solved.

> - still, it could be useful to tell all interested applications that
>   they should enter some passive state. i'm not sure this should be done
>   over xsmp, though - maybe some generic d-bus based system would be
>   more useful

Likely.  I can't think of any apps that would need to know this though
offhand.  Perhaps the screensaver should note this to avoid flickering
on unsuspend and such.

> the next point is communicating the system shutdown request to the
> desktop manager, as that's the place it belongs to. currently kdm has a
> one-way command fifo and gdm has some fancy command socket. i'd like to
> replace that with something common, possibly based on d-bus - dunno.

A common thing would be nice, but really so far there are 2 different
implementations GDM (only in the CVS version though) and KDM and so I don't
think it's a huge issue anyway - just implement both so far.  GDM allows
querying which actions are available and that's really the only thing where
it differs from KDM.  That's the only difference.

> yet another option to system shutdown ... kdm supports three "shutdown
> timings": "force now" (the usual thing), "try now" (shut down only if no
> user session is open) and "schedule" (shut down when last user session
> exits). "schedule" could be generalized to take a timeout - "try now"
> would be the special case 0 then. "force now" could be coalesced into
> the generic "schedule" mode by adding a timeout action: "cancel" and
> "force shutdown".
> as these scheduling modes are way too complicated for normal users
> (believe me, i tried it :), the usual course of action should be to pop
> up a warning box "sessions are still open. what now? [cancel] [schedule]
> [kill 'em all!]" on demand. i.e., the shutdown request needs a
> "fast/slow" "sub-option" for "fine-grained options" (the defaults would
> be to hide this feature entirely unless explicitly enabled it in the
> control center).

Well, yeah, this is the other difference.  GDM only supports scheduling a
shutdown/reboot after the session from which it was requested ends.
Scheduling a shutdown would also be useful in GDM I suppose.  Other then that
it's then really up to the session manager to figure out what DM is running
and what are it's capabilities.  And if consolehelper is available it can
fall back on that is the current gnome-session does (it doesn't use gdm sup
protocol yet I don't think).

George

-- 
George <jirka at 5z.com>
   There is nothing so useless as doing efficiently that
   which should not be done at all.
                       -- Peter Drucker