I use Gambas for nearly real-time work and it performs remarkably well, actually quite impressed. Far better than VB I have a data stream at 13.5 Kbps coming in from a remote modem requiring immediate work and turn around output. It might not seem like a fast stream, but the remote end requires a response immediately otherwise there are resends. It works! Gambas 1.0.19 graphical, FC4, samba Longest running time was about 420 days sans error. Some rules to follow: multiple core if you have it: good! remove unneed cron jobs. reduce overhead. turn swap off. Very clean efficient programming as possible -Fernando
---------- Original Message ----------- From: Doriano Blengino <[email protected]> To: mailing list for gambas users <[email protected]> Sent: Sun, 18 Apr 2010 23:07:55 +0200 Subject: Re: [Gambas-user] Did anybody try to run stepper motors through paralel port > Zelimir Ikovic ha scritto: > > I wanted to know how predictable and reliable GAMBAS is when a reaction to > > real-world events is required. > > > > Let say that Java RealTimeSystem is intended only for suitable operating > > systems, which means that only a > > real-time operating system, such as QNX, is appropriate for implementing > > the JVM. > > So that means it depends on underlynig OS version ... > > > > Simply installing an RTS extension > > and renaming java.lang.Thread instances to > > javax.realtime.RealtimeThread will not turn the > > application into a real-time app. > > > > I just wanted to know what is Gamas reaction to real world compared under > > different underlyng OS. > > FreeBSD, OpenBSD and Linux are not he same. > > > I understand but, let me say, your sample code had nothing to do with > realtime... it was simply "fast as much as possible", without any > mechanism to ensure some kind of real-time response to some event. To > only read a counter is not enough. I can run 4 stepper motors directly > (no step+direction, but driving the phases directly instead) with a CPU > more than 100 times slower than a x86 CPU. But this is possible using > interrupts. Practically every OS can, in some way, use interrupts - > gambas can not. So, the only way in gambas to do precise timing is to > let it run alone, with maximum priority and privileges. Or, to delegate > high timing precision to some external piece of software (a libray or a > driver) which can take advantage of interrupts, or callbacks, or signals. > > On the other hand I think that gambas can, with tight loops, do delays > like you did in the original source. Surely it is predictable enough to > let you calculate in some way the correct amount of cycling to obtain > the needed delay - the fact is that gambas will never be the only thing > running on the system, and you have little control about that. The same > problem of windows xp - if you want precise timing, you must obtain > privileges, either for the program or using a driver. I must also add > that, without particular precautions, linux is more predictable about > sleep() than win2000 or xp. > > Regards, > > -- > Doriano Blengino > > "Listen twice before you speak. > This is why we have two ears, but only one mouth." > > ------------------------------------------------------------------------------ > Download Intel® Parallel Studio Eval > Try the new software tools for yourself. Speed compiling, find bugs > proactively, and fine-tune applications for parallel performance. > See why Intel Parallel Studio got high marks during beta. > http://p.sf.net/sfu/intel-sw-dev > _______________________________________________ > Gambas-user mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/gambas-user ------- End of Original Message ------- ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Gambas-user mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/gambas-user
