I tried to explain a little theory. There are different ways an RTOS can implemented. Not only how it works under the hood but how RT tasks are presented to the user. Are they special tasks using a separate API or are they POSIX tasks? One version of this simply replaces the scheduler and nothing else, other versions. Which is best? It depends on what yu need to do.
It gets hard if you want to do "everything", that means genera steps in software and runs a smooth and responsive 3D user interface. And then different kind of system fail in different ways. Does this matter? likely not for a machine tool it can simply stop ad ring an alarm. Aircraft flight controllers can't do that so you might care about how performance degrades of not. There are a lot of use cases for real time so that is why the half dozen or some solutions But note that none of then are as good as simply putting there RT task unit's own hardware and doing the task scheduling with a hardware timer that is divided down from a crystal oscilator. If you care about sub-microseconds that is the only way. but many people work at the 1/100 second level. RTLinux uses a kind of virtual machine, RTAI is simpler and only captures interrupts. the Wiki article has a "see also" with links to other RT Linuxes https://en.wikipedia.org/wiki/RTLinux#See_also -- Chris Albertson Redondo Beach, California ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
