From mboxrd@z Thu Jan 1 00:00:00 1970 From: Samuel Thibault Subject: Re: [RFC] PVFB: Add refresh period to XenStore parameters? Date: Tue, 6 May 2008 18:29:59 +0100 Message-ID: <20080506172959.GR4430@implementation.uk.xensource.com> References: <20080304161220.GA9852@implementation.uk.xensource.com> <20080501175536.GV4797@implementation.uk.xensource.com> <20080502160638.GG4819@implementation.uk.xensource.com> <877ie917ix.fsf@pike.pond.sub.org> <20080505091808.GC4497@implementation.uk.xensource.com> <87ej8hysv6.fsf@pike.pond.sub.org> <20080505165008.GP4497@implementation.uk.xensource.com> <87ve1rv8xb.fsf@pike.pond.sub.org> <20080506163255.GP4430@implementation.uk.xensource.com> <87lk2ntm0z.fsf@pike.pond.sub.org> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <87lk2ntm0z.fsf@pike.pond.sub.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Markus Armbruster Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org 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