dbus Activation

[John (J5) Palmieri]

On Thu, 2007-01-11 at 11:14 +0100, Frédéric DALLEAU wrote:
> John,
> 
> Thank you for answering.  Is there any standard dbus interface defined 
> that could be implemented to make sure the object is ready before 
> calling another method?

Not sure what you mean here.  If your object is currently busy messages
will be held in a queue.  Messages are guaranteed to come in in the
order they were sent.  If your call fails from the client, you need to
handle that there, either by resending, ignoring or exiting with an
error.

> Also, is there a way that a daemon could automatically exit when it's 
> methods are not used?

If you are talking about the dbus-daemon we are toying with the idea of
a timeout for autostarted session daemons going away on a timeout but
that is an edge case.  If you are talking about your dbus application it
is up to the app if it wants to go away but of course only applications
started on the session bus can be reactivated as of now.  You might also
run into some race conditions when you exit and someone is sending a
message at the same time.  That will most likely result in an error
being returned to the client but it is not a common code path.  Also
clients will have to be smart enough to reconnect to signals when your
object reappear, assuming they were listening before you went away.
   

-- 
John (J5) Palmieri <johnp at redhat.com>