User bus?

Thiago Macieira thiago at
Tue Mar 4 01:48:53 PST 2008

On Tuesday 04 March 2008 10:24:57 Patryk Zawadzki wrote:
> On Tue, Mar 4, 2008 at 8:35 AM, Thiago Macieira <thiago at> wrote:
> > Patryk Zawadzki wrote:
> > >Havoc, would you see that as a viable change?
> >
> >  I do have a question, though: what does registering the session bus
> >  address with CK buy you? What are the advantages over the storing in the
> >  X11 Window?
> The use case I mentioned earlier in the thread: beaing able to ask CK
> for all existing session buses and say try to send a critical message
> to all active notification-daemons (say, "machine will reboot it 2hrs"
> or "maintenance mode, some services will be down")

I don't agree with that use-case.

You'd want to emit that signal in the system bus and all notification daemons 
would get it from there and relay to the appropriate messaging system.

The root user has no business connecting to the users' session bus. In fact, 
it can't. You'd need to setuid() to each one before you attempt to connect. 
That means that it HAS to be done from root.

> or just those 
> belonging to members of some specific admin group ("warning, printing
> spool seems stuck").

That's a more intricate use-case. In general I'd think that messages should be 
subscribed to, instead of having them pushed down your throat.

It only gets problematic in case of sensitive messages. But that problem can 
be easily solved by making the content of the message not be broadcast, but 
have to be fetched via a call to CK (or another service), which then checks 
if the caller has enough privileges to retrieve the message.

> It would be more or less trivial to implement if 
> CK could provide such information (protected by some PolicyKit policy)
> and I believe such information really belongs to ConsoleKit as it is
> *the* session tracking service.

I don't agree. For me it seems the most natural place to store the session 
information is *in* the session. That's the X11 window. No need for reaping: 
if the session goes away (X11 connection closed), the information 
automatically goes to the limbo as well.

However, having a registry of all available sessions would bring back some 
functionality of DCOP we lost during the switch. Except you still can't 
connect to any other user's busses.

  Thiago Macieira  -  thiago (AT) - thiago (AT)
    PGP/GPG: 0x6EF45358; fingerprint:
    E067 918B B660 DBD1 105C  966C 33F5 F005 6EF4 5358
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part.
Url : 

More information about the xdg mailing list