[PATCH 01/11] dix: split out window owner event delivery from DeliverEventsToWindow

[Peter Hutterer]

On Wed, May 11, 2011 at 01:36:49PM -0700, Jamey Sharp wrote:
> This looks good, but is there some strong reason not to just use early
> returns in DeliverToWindowOwner?
> 
> I'd re-write it this way:
> 
> On Wed, May 11, 2011 at 02:49:40PM +1000, Peter Hutterer wrote:
> > +static enum EventDeliveryState
> > +DeliverToWindowOwner(DeviceIntPtr dev, WindowPtr win,
> > +                     xEvent *events, int count, Mask filter,
> > +                     GrabPtr grab)
> > +{
> > +    int attempt;
> > +    enum EventDeliveryState rc = EVENT_SKIP;
> > +
> > +    /* if nobody ever wants to see this event, skip some work */
> > +    if (filter != CantBeFiltered &&
> > +            !((wOtherEventMasks(win)|win->eventMask) & filter))
> > +        goto out;
> > +
> > +    if (IsInterferingGrab(wClient(win), dev, events))
> > +        goto out;
> > +
> > +    rc = EVENT_NOT_DELIVERED;
> > +
> > +    if (XaceHook(XACE_RECEIVE_ACCESS, wClient(win), win, events, count))
> > +        /* do nothing */;
> > +    else if ((attempt = TryClientEvents(wClient(win), dev, events,
> > +                                        count, win->eventMask,
> > +                                        filter, grab)))
> > +        rc = (attempt > 0) ? EVENT_DELIVERED : EVENT_REJECTED;
> > +
> > +out:
> > +    return rc;
> > +}
> 
>     static enum EventDeliveryState
>     DeliverToWindowOwner(DeviceIntPtr dev, WindowPtr win,
>                          xEvent *events, int count, Mask filter,
>                          GrabPtr grab)
>     {
>         /* if nobody ever wants to see this event, skip some work */
>         if (filter != CantBeFiltered &&
>                 !((wOtherEventMasks(win)|win->eventMask) & filter))
>             return EVENT_SKIP;
> 
>         if (IsInterferingGrab(wClient(win), dev, events))
>             return EVENT_SKIP;
> 
>         if (!XaceHook(XACE_RECEIVE_ACCESS, wClient(win), win, events, count))
>         {
>             int attempt = TryClientEvents(wClient(win), dev, events,
>                                           count, win->eventMask,
>                                           filter, grab);
> 
>             if (attempt > 0)
>                 return EVENT_DELIVERED;
>             if (attempt < 0)
>                 return EVENT_REJECTED;
>         }
> 
>         return EVENT_NOT_DELIVERED;
>     }
> 

I'm a big fan of the goto out because it makes debugging so much easier.
setting a breakpoint or adding a printf at a single point is faster than
remembering to set 5 points. That's pretty much the only reason for me.

Cheers,
  Peter