org.freedesktop.PowerManagement

[Dan Winship]

Richard Hughes wrote:
> On Thu, 2007-03-29 at 18:31 -0400, David Zeuthen wrote:
>> Perhaps it's just easier to remove these from the org.fd.PM interface
>> then and tell ISV's to do... something else. I don't know. What's the
>> freedesktop.org story for this these days? How should an app reboot
>> the system? XMSP? Wasn't Dan Winship of Novell working on this?

XSMP lets an app request a logout, but not a reboot/shutdown. In GNOME,
reboots and shutdowns are really handled by gdm, so currently if you
want to shutdown/reboot directly from the desktop (like the panel and
gnome-power-manager do), you have to use a secret gdm protocol to tell
gdm to reboot/shutdown after the current session, and then use XSMP to
tell gnome-session to log out without presenting a dialog to the user
(and then once gnome-session exits, gdm does what you told it to).

XSMP is not really extensible, so if we want something better than this,
it would have to be via D-Bus anyway. I'd been thinking about eventually
having a standard D-Bus interface for the session manager, with Logout,
Reboot, and Shutdown commands. Putting those commands on a session
management interface would solve the objection some people had that
those commands should always be available even if you aren't running any
sort of power manager.

> Ick. So completely different ways to this. Doing this via XMSP also
> breaks the InhibitManual semantics also, as then we have to inhibit the
> session using XMSP (somehow) just to stop a shutdown half-way through a
> partition resize. Complexity central.

Well, but in that case you'd want to inhibit *logout* as well as
reboot/shutdown anyway, right? (Since logging out would kill X and
probably the partition-resizing app along with it.) So the session
manager needs to be involved somehow anyway. The easy way to do this
would be to have the power manager (or the partition-resizing app
itself) register as an XSMP client, and when it receives a logout
notification, cancel the logout and pop up a dialog explaining why. (Or
pop up an "are you sure blah blah blah" dialog and cancel or don't
cancel the logout accordingly.)

You're going to need the power manager to talk to the session manager
anyway, because if the power manager is handling o.f.PM.Shutdown, it's
probably going to want to implement it basically the same way g-p-m does
now (letting the session manager deal with the logout part), so that the
user gets logged out cleanly rather than just killing all his processes.

-- Dan