[Xcb] xlib versus xcb performance in Qt Applications?

[Jamey Sharp]

On 3/31/12, Rick Stockton <rickstockton at reno-computerhelp.com> wrote:
> On 03/30/2012 07:39 PM, Jeremy Huddleston wrote:
>>  On Mar 30, 2012, at 5:41 PM, Rick
>> Stockton<rickstockton at reno-computerhelp.com>   wrote:
>>
>>>  And BTW, we've removed xlib support in Qt5, switching to xcb on X11
>>> platforms. :)

I'm super excited to hear that. :-)

> So, what kinds of things would you like me to compare? I've got a
> example Apps with flying things; one which plays a short movie; and
> various other examples of "Painting Goodness". Can I assume that input
> (keyboard, mouse) doesn't need testing, because input events from xcb
> are 1:1 with events from Xlib? Or should I cover some input events too?

XCB has a 4kB receive buffer, but Xlib doesn't buffer input. So it's
possible that under very heavy event load, XCB might do better. My
guess is it won't make a measurable difference, but it would be
interesting to find out.

I look forward to seeing your results!

BTW, how did you guys handle keyboard input? We haven't provided very
good help for that yet, that I'm aware of.

Jamey