Serious side effect of #6299 (silencing salut so gabble can connect)

[Dafydd Harries]

Ar 14/02/2008 am 12:19, ysgrifennodd John Watlington:
> 
> On Feb 14, 2008, at 11:52 AM, Jim Gettys wrote:
> 
> >
> > On Thu, 2008-02-14 at 16:58 +0200, Morgan Collett wrote:
> >> We're testing patches to Presence Service to not start salut (or stop
> >> it) for a while to give gabble a chance to connect to the  
> >> schoolserver.
> >>
> >> However, Daf came across what was a very minor problem which becomes
> >> more serious in light of this change.
> >>
> >> Many activities are calling PS get_preferred_connection() to interact
> >> directly with the appropriate Telepathy Connection Manager, which was
> >> required in the past before we expanded Presence Service's  
> >> management of
> >> setting up channels for activities.
> >>
> >> However, during the period when we stop salut to let gabble try to
> >> connect, this call fails as there is no running plugin in PS. If an
> >> activity is launched during this time (and there's no particular  
> >> UI to
> >> show this other than no buddies in mesh view) and it makes this  
> >> call in
> >> __init__ as most of them do, then it will crash with a gray screen.
> >>
> >> This affects: Calculate, Chat, Pippy, Record, Web and Write (of the
> >> activities we bundle) and potentially other non-bundled activities.
> >
> > Ouch...
> >
> > Seems like this is something we're going to have to fix pretty quickly
> > no matter what.
> >
> >>
> >> Our options are:
> >>
> >> (a) Touch all these activities now and port them to the newer cleaner
> >> API offered by PS/Sugar
> >
> > How big are the diffs?  Does this simplify the code?
> >
> >> (b) Don't do #6299 for Update.1, but do it and (a) for Update1.1
> >
> > This would be pretty much immediately, anyway.
> >
> >> (c) Find some way for the call to get_preferred_connection to fail
> >> gracefully (We can't think of one so far)
> >> (d) Make a UI change to let the children know not to launch  
> >> activities
> >> during this time period\
> 
> (d) might be the simplest to implement in the required time frame.
> 
> > Let me ask a different question: what happens to activities already
> > running which are running shared?  Are they going to fail?   
> > Presumably,
> > yes....
> 
> It sounds like any activity trying to share until either gable  
> connect to a server
> or gives up and starts salut is going to crash.  This either happens  
> on boot or
> when a user manually switches networks.

I don't think the activity will die: an exception will be raised, which will
get caught by the GObject main loop. The results of this depend on which code
path got prematurely aborted by the exception, but I would expect most
activities to run in an inconsistent state.

-- 
Dafydd