[Xcb] Interning multiple atoms w/ one function call (alla XInternAtoms)

[Barton C Massey]

Nice test!  Thanks much for writing, running, and sharing it.

	Bart

In message <Pine.LNX.4.51.0510010808040.30528 at cartan.iecn.u-nancy.fr> you wrote:
> 
> hey,
> 
> this morning, i wanted to code the 2 different methods and compute the
> time that each one takes. The code is here :
> 
> http://www.iecn.u-nancy.fr/~torri/files/xcb/test_speed.c
> 
> the correct use of xcb is 33 times faster to the bad use with most of the
> execution of the test (500 created atoms).
> 
> well, just FYI ;)
> 
> regards
> 
> Vincent
> 
> On Wed, 10 Aug 2005, Carl Worth wrote:
> 
> > On Wed, 10 Aug 2005 23:43:42 +0200 (CEST), Vincent Torri wrote:
> > > So, when the allocation fails, ok, I see why there are N
> > > round-trips.
> >
> > Here's a time-line for N==4 with a round-trip latency (T_round_trip)
> > that is 5 times as long as the time required to write or read a
> > request/reply (T_write/T_read) [*].
> >
> > 	W-----RW-----RW-----RW-----R
> >
> > W: Writing request
> > -: Stalled, waiting for data
> > R: Reading reply
> >
> > Total time: N * (T_write + T_round_trip + T_read)
> >
> > > But when it does not fail, there are N requests for the N atoms. Then we
> > > ask for N replies. So we always ask N times the server. So i don't
> > > understand the improvement.
> >
> > And here's the time-line for the two-loop version, again N==4 and the
> > same latency is in effect:
> >
> > 	WWWW--RRRR
> >
> > Total time: N * T_write
> > 	  + max (0, T_round_trip - ((N-1) * T_write))
> > 	  + N * T_read
> >
> > So, as you can (hopefully) see, the two-loop version takes a worst
> > case penalty of one round-trip latency over the time required to just
> > write and read as fast as possible.
> >
> > Does that help?
> >
> > And do let me know if I botched the figures or equations anywhere.
> >
> > -Carl
> >
> > [*] I won't claim the proportions here are realistic. A small integer
> > ratio just happens to be convenient for the ASCII artwork. I have no
> > idea what the actual timing proportions are likely to be in a
> > real-world scenario, but an interested party can measure them.
> >
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