On Thu, 2007-01-25 at 11:06 -0500, Melvin Newman wrote: > Paul: > > Once again thank you for your reply. In responce to your longer e-mail > I have several points. > > 1) Your e-mail has been most helpfull conceptually, and yes I am going > to have take a closer look at exactly what my program is doing. With > regards to my program, while people "should not" die when it > malfunctions, it is controlling a remote vehicle work probably 1500 > $... and it moves quite quickly, so if it where to hit a tree because > this program died, well things would not be pretty. So I would class > this program under mission critical. > > Basicaly what my backend thread does is precisely what you say it > should not do, it runs through a loop continousely reading from a file > descripter to a Joystick device. It then transmits these values to the > remote vehicle to command it to change direction or speed (via, > servos). Now I am not sure how to do things better such that I can > maintain as close to a 1:1 input to output timing without continousely > reading from this file descripter. > > 2) You are very correct in your reference to delays being relatively > insignificant in multi-ghz computers... unfortunately the laptop on > which this program must run is something like 700Mhz (actually it may > be 500Mhz, i cant remember and I cant check right now). > > In any event, thank you very much for your information, and if you > happen to have a better method for taking in user input from the > joystic, i would be glad to hear it. are you using poll/select to detect data from the joystick? many people will just write a tight non-blocking read(), which basically returns immediately saying "nothing to read". if you use select or poll (they are more or less 100% equivalent), your i/o thread will be asleep most of the time, except when there is data to read. --p _______________________________________________ gtk-list mailing list gtk-list@xxxxxxxxx http://mail.gnome.org/mailman/listinfo/gtk-list
