On Wed, 2008-10-29 at 21:11 +0100, Florian Echtler wrote: > Hello Jim, > > > I worry about the use of UDP, at least for networked input devices. > > Losing some of the event stream (e.g. up events) can be very confusing > > to applications (not to mention device drivers). Wireless is unreliable; > > UDP does not guarantee reliability. Latency with TCP is just as low > > (and bandwidth comparable) in the face of no packet loss (if TCP_NODELAY > > is set on the socket). > You are quite correct there. I simply chose UDP at first because in the > testing environment, everything runs on a single machine and UDP is the > fastest and easiest-to-implement cross-language message passing system. > In fact, all four daemons just expect classes derived from C++ iostream, > so in the single-machine scenario, you could just put all of them into > one multithreaded application and have them communicate internally.
Heh. I don't think we'd ever accept a C++ library dependency for the X server. > > > I've also been wondering about the relative merit its of an ad-hoc wire > > format (such as you've defined) for events versus something like XML, > > where parsers and extensibility is known. But it's time for me to > > perform some experiments to understand the performance trade-offs, > > rather than hand-waving; your existing code trumps my unproven > > hypothesis, so I better write some code. > I tried to keep the library core as simple and portable as possible, > which is why I decided against XML.. not for performance reasons in the > first place, but rather to keep the dependencies down. > After some quick investigation, I note that libxml2 is even more bloated than libxml1 was, weighing in at nearly 1.2 megabytes. expat is much lighter weighing in at 130K or so. We'll see.... - Jim -- Jim Gettys <[EMAIL PROTECTED]> One Laptop Per Child _______________________________________________ xorg mailing list xorg@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/xorg