Hi, ----- Original Message ----- > No. gdm uses a single Xserver for the login-screen and for the > session. But once you log in multiple times, I think it starts a new > Xserver for each. But I am not that familiar with gdm.. > > > * Can gdm pass in the session id, or the pid of the session leader > > to X when starting X ? > > Just use sd_pid_get_session(). It's in systemd/sd-login.h. It returns > the session ID of a given process. Don't pass session-ids around. We don't actually run the X server in a session at the moment.
> Start one Xserver for each session. Yes, blending and other transition > effects will get very hard to implement then, but still better than > sharing an xserver between sessions.. I think it might be better to wait on that until we have wayland and a system compositor. > Why undesirable? That's the way to go. 1) It will cause flicker 2) It will mean there's always an X server with a login screen running in the background, even on single user systems. I mean it's something we can consider, we even used to have code to do it (called "factory mode"), but I don't it's a absolute given that we should do it at this point. > systemd-consoled is an example how graphics applications work with > TakeControl()/TakeDevice(). It expects to be run inside a session, so > the session has to be setup by the parent beforehand. > systemd-welcomed is an example how login-screens can work. It spawns a > separate process for the greeter and one for each session. Note that > the greeter runs as user "nobody" *inside* of a systemd-logind > session. So it's the same as any other session. Not like gdm which > treats the greeter special. gdm runs the greeter inside a logind session as a "gdm" user, too. It does this by invoking a minimal pam stack to open the session which runs pam_systemd. The X server doesn't run inside the session at the moment though. --Ray _______________________________________________ xorg-devel@lists.x.org: X.Org development Archives: http://lists.x.org/archives/xorg-devel Info: http://lists.x.org/mailman/listinfo/xorg-devel