>"Robert G. Brown" <[EMAIL PROTECTED]> wrote: > Also you can do amazing things with C and actually > understand what the computer is doing when you do them.
I'd like to add that by "understand" you could read "debug with ease". Parallel debugging is miserable enough without having to wonder where the variable in question is actually stored, whether or not the language has bothered to create it yet, whether or not it has removed it yet, or for that matter, what mangled name corresponds to the nice one you used in the source code. For the original poster - parallel debugging is miserable because you need to keep track of messages flying back and forth, and the times and orders various logic is followed on N machines, and the bug you saw in node A in one run might show up on node B on another run, out of the 1000 nodes in play. So, for instance, even if you use the most accurate clock available and log debug events to separate files on each node, there may be enough jitter in the clocks (or not enough accuracy in the times) that from this post mortem information you still may not be able to discern the order in which key events transpired. Also if you try to send all of this information to a single node the act of doing so will generally perturb the timing of the run and may very well prevent you from ever finding the source of a bug. This is all worst case of course, in many instances parallel debugging just means following what happens on one compute node, and that's pretty much the same as normal debugging. > Nobody knows why CPS departments no longer teach students > to code in C (and instead teach a bizarre mix of C++, java, lisp, and > god-knows-what else first. I know, I know! The folks who teach computer science consider functional languages like C and Fortran to be both uninteresting and old fashioned. They also tend not to use those languages in their research, which is often on esoteric subjects having little to do with "crunching these numbers as fast as possible with as much accuracy as possible." They think these sorts of languages, along with God forbid, assembly language, should be taught in trade schools and not the CS department. This causes endless battles and the occasional undergraduate revolt, because all of those Engineering, Physics, and etc. students paying 35000 dollars a year to the University don't want to also attend a trade school, and they need and want to learn how to write fast efficient code in exactly those languages that the CS types don't want to teach. Regards, David Mathog [EMAIL PROTECTED] Manager, Sequence Analysis Facility, Biology Division, Caltech _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
