[systemd-devel] [PATCH 00/10] Device Management for systemd-logind

[David Herrmann]

Hi

On Mon, Aug 26, 2013 at 6:37 AM, Tom Gundersen <teg at jklm.no> wrote:
> On Sun, Aug 25, 2013 at 8:46 PM, David Herrmann <dh.herrmann at gmail.com> wrote:
>> logind itselfs takes care of revoking device access for inactive sessions
>> (synchronized with session-switches!). It also tries to resume every device
>> when a session is activated. But session-devices must not be used to watch
>> session state! A compositor has to use the PropertiesChanged() signal plus the
>> "Active" property of sessions for that! Session-devices do not replace this! On
>> sessions with VTs, this is obviously replaced by the VT_SETMODE interface as
>> usual.
>
> So essentially, all clients have to keep implementing the old
> VT_SETMODE interface in addition to the new logind one?
>
> Would it be possible to ship a wrapper around VT_SETMODE and friends
> so that new clients could only implement the logind interface, and
> logind would deal with the VT layer internally (or rather, I suppose,
> via some shim session daemon) when necessary?

It's an orthogonal problem. And you don't need to handle it at all.
The default for VT_SETMODE is a forced VT switch. So as long as no
process in a session opens the VT and modifies VT_SETMODE, VT switch
will "Just Work". And logind is notified via
/sys/class/tty/tty0/active

Thanks for looking over it, btw!
David