[systemd-devel] How soon after login can I rely on systemd --user having reached sockets.target?

[Lennart Poettering]

On Sun, 19.10.14 12:05, David Herrmann (dh.herrmann at gmail.com) wrote:

> Hi
> 
> On Fri, Oct 17, 2014 at 6:14 PM, Colin Guthrie <gmane at colin.guthr.ie> wrote:
> > Hi,
> >
> > How soon after login can I rely on systemd --user having reached
> > sockets.target?
> >
> > This feels a bit like a "you shouldn't rely on that point in time..."
> > type answer is warrented, and when e.g. GNOME or KDE sessions fully use
> > systemd to bring themselves up it won't be an issue, but right now,
> > systemd --user is started by (I think) PAM.
> >
> > I want to rely on systemd --user to handle PulseAudio's activation
> > (ditching the built in stuff) and but I'm worried that e.g. GNOME or KDE
> > might start up their own session stuff and spawn some PA consuming
> > process before systemd --user has reached it's sockets.target and is
> > thus ready and listening on PA's native socket.
> >
> > Doesn't seem to be a problem on my machine here (it's working really
> > nicely actually!) but figured I should ask here too.
> 
> Ordering of user units is (see /usr/lib/systemd/user/):
> default.target after basic.target after sockets.target
> 
> PAM creates sessions by calling into systemd's pam-module, which then
> uses CreateSession() (internal api!). This call does not return until
> the job of user at .service is done. `systemd --user` notifies READY=1
> only after "default.target" is ready.
> 
> Long story short: The PAM module blocks until the user-manager is
> ready. Therefore, sockets.target is loaded and ready.
> 
> (I'm no expert in sd job handling, so maybe Lennart can confirm this)

I hereby confirm this.

Lennart

-- 
Lennart Poettering, Red Hat