Re: [RFC] PVFB: Add refresh period to XenStore parameters?

[Samuel Thibault <samuel.thibault@eu.citrix.com>]

Markus Armbruster, le Tue 06 May 2008 18:50:04 +0200, a écrit :
> > Instead of expressing idleness or "status", maybe we could rather
> > express whether periodic update notifications are wanted or not, and let
> > the backend request an explicit update notification when it feels the
> > need for one (low-frequency thumbnail update). It has the advantage of
> > only talking about the PVFB protocol itself and not something around it
> > (idleness of the actual output).  That is also backward compatible in
> > that a frontend which doesn't know these two events will just continue
> > sending periodic update notifications, which is fine for the backend.
> 
> I think that's a better way to define this feature.

More precisely, we could have an UPDATE_PERIOD event which carries
an advice from the backend about how often the frontend should sent
update notifications (0 if periodic notification is not useful), and a
REQUEST_UPDATE event that requests a one-time update notification?  The
latter could even contain the requested area? (not sure whether it'd be
really useful considering the added complexity, though).

Samuel