Thank you all, in last few emails is answer!
--- On Sun, 4/18/10, Doriano Blengino <[email protected]> wrote: > From: Doriano Blengino <[email protected]> > Subject: Re: [Gambas-user] Did anybody try to run stepper motors through > paralel port > To: "mailing list for gambas users" <[email protected]> > Received: Sunday, April 18, 2010, 2:07 PM > 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 > ------------------------------------------------------------------------------ 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
