[logind] support multiple sessions multiplexed on one VT

[Chris Halse Rogers]

Here's the loginctl info for my session. To get here, I log in (which results in a working session), switch to a guest session, then switch back. You can also see the SSH session, which is correctly tracked.

chris@Swordfish ⮀ ~ ⮀ loginctl
   SESSION UID USER SEAT
         1 1000 chris
        c2 110 lightdm seat0
        c3 1000 chris seat0
        c5 123 guest-G8wccP seat0

chris@Swordfish ⮀ ~ ⮀ loginctl show-session 1 c2 c3 c5
Id=1
Timestamp=Thu 2013-06-20 16:37:23 EST
TimestampMonotonic=81475306
DefaultControlGroup=systemd:/user/1000.user/1.session
VTNr=0
Remote=yes
RemoteHost=ed.local
Service=sshd
Leader=1686
Audit=1
Type=tty
Class=user
Active=yes
State=active
KillProcesses=no
IdleHint=no
IdleSinceHint=1371710616567273
IdleSinceHintMonotonic=454924636
Name=chris

Id=c2
Timestamp=Thu 2013-06-20 16:39:22 EST
TimestampMonotonic=200767610
DefaultControlGroup=systemd:/user/110.user/c2.session
VTNr=7
Display=:0
Remote=no
Service=lightdm-greeter
Leader=2306
Audit=0
Type=x11
Class=user
Active=no
State=closing
KillProcesses=no
IdleHint=no
IdleSinceHint=0
IdleSinceHintMonotonic=0
Name=lightdm

Id=c3
Timestamp=Thu 2013-06-20 16:39:26 EST
TimestampMonotonic=205279819
DefaultControlGroup=systemd:/user/1000.user/c3.session
VTNr=7
Display=:0
Remote=no
Service=lightdm
Leader=2378
Audit=0
Type=x11
Class=user
Active=no
State=online
KillProcesses=no
IdleHint=no
IdleSinceHint=1371710549049829
IdleSinceHintMonotonic=387407192
Name=chris

Id=c5
Timestamp=Thu 2013-06-20 16:41:48 EST
TimestampMonotonic=347299084
DefaultControlGroup=systemd:/user/123.user/c5.session
VTNr=7
Display=:1
Remote=no
Service=lightdm-autologin
Leader=3439
Audit=0
Type=x11
Class=user
Active=no
State=online
KillProcesses=no
IdleHint=no
IdleSinceHint=0
IdleSinceHintMonotonic=0
Name=guest-G8wccP

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: systemd-services 204-0ubuntu4
ProcVersionSignature: Ubuntu 3.9.0-3.8-generic 3.9.4
Uname: Linux 3.9.0-3-generic x86_64
ApportVersion: 2.10.2-0ubuntu1
Architecture: amd64
Date: Thu Jun 20 16:31:42 2013
InstallationDate: Installed on 2013-04-24 (57 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release amd64 (20130423.1)
MarkForUpload: True
SourcePackage: systemd
UpgradeStatus: Upgraded to saucy on 2013-05-10 (41 days ago)

[Alexandre Magno (alexandre-mbm)]

See https://bugs.launchpad.net/lightdm/+bug/903194/comments/5 → https://bugs.launchpad.net/mir/+bug/1195762/comments/1. And the bug #1075125 (ConsoleKit?).

[Richard Hansen (rhansen)]

What do you mean by "losing track of sessions"?

[Alexandre Magno (alexandre-mbm)]

a7x, https://bugs.launchpad.net/mir/+bug/1195762/comments/1 ?

[Chris Halse Rogers (raof)]

a7x: You'll note in my loginctl output that logind does not think that there's an active local session, which is false.

[Alexandre Magno (alexandre-mbm)]

I use ck-list-sessions. I don't use loginctl. Do I am in the site right? I use Ubuntu 12.04.2 LTS.

[Richard Hansen (rhansen)]

> a7x: You'll note in my loginctl output that logind does not think
> that there's an active local session, which is false.

Ah, I see. It also shows c3 and c5 as being on the same VT; I would
expect them to be on different VTs (c3 on VT 7 and c5 on VT 8).

Does Ctrl-Alt-F7 and Ctrl-Alt-F8 switch between the two sessions?

[Richard Hansen (rhansen)]

> I use ck-list-sessions. I don't use loginctl. Do I am in the site
> right? I use Ubuntu 12.04.2 LTS.

You have an unrelated bug; this bug is specific to logind, which
doesn't exist in 12.04 (it was introduced to Ubuntu in 12.10).

[Chris Halse Rogers (raof)]

No, it's correct. All the sessions are on the same VT. The multiplexing is being done at the system-compositor level, rather than the VT level.

[Martin Pitt (pitti)]

Is this still a thing? This hasn't moved in two years, and this kind of massive redesign work isn't somethign which we should discuss at the distro level, but at upstream. I suggest discussing that on http://lists.freedesktop.org/mailman/listinfo/systemd-devel or providing issues/pull requests on https://github.com/systemd/systemd if you want to work on this.

I close this, as it's not going to be very useful here at the distro level. Thanks!