[haiku-appserver] Re: Scrolling (was Re: breakthrough)

  • From: "Axel Dörfler" <axeld@xxxxxxxxxxxxxxxx>
  • To: haiku-appserver@xxxxxxxxxxxxx
  • Date: Mon, 24 Oct 2005 12:40:46 +0200 CEST

Ingo Weinhold <bonefish@xxxxxxxxxxxxxxx> wrote:
> On Sun, 23 Oct 2005, Adi Oanca wrote:
> > Ingo Weinhold wrote:
> [...]
> >> BTW, since the number of messages in the looper port is actually 
> > > no 
> >> indicator of how busy the window thread is at the moment (only how 
> > > busy it 
> >> was since it last transferred the messages from the port to its 
> > > message 
> >> queue), it might be a good idea to let the app server know the 
> > > number of 
> >> messages in the queue (e.g. through shared memory), so that the 
> >> server-side queue could also be used when the port is not full but 
> > > there 
> >> are too many messages in the client side message queue already.
> >     I don't know... I don't think there's a strong reason for 
> > this...
> >     The messages in the port queue are fetched after any message is 
> > processed, and the MessageQueue object does its job very good. If 
> > processing 
> > a message takes so long that the port queue gets filled up, that's 
> > an example 
> > of bad programming - user should use a specialised thread.
> Sure, but the case I'm referring to is that the window manages to 
> process 
> the individual messages fast enough so that the looper port doesn't 
> fill 
> up, but slower than they arrive. E.g. if there are already a few 
> hundred 
> messages in the queue, it might be a good idea, if the app server 
> doesn't 
> send B_MOUSE_MOVED messages at the full rate anymore.

How about sending a message to the app_server in this case? Something 
like "argl, please slow down!"? That would be more expensive than 
shared memory, but also a lot easier to implement, and since it's 
assumed that the window is still somehow responsive, sounds like a good 
solution to me.


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