[raphui]

As ab71e5 said, "Real time" in the context of OSes, means the operating system is optimized for determinism. The OS guarantees that events will be handle in a particular time-window and that high priority task will always run first.

[araes]

Cool, thanks for the reply. Why does a dirtbike anti-theft tracker care about time-windows and that high priority tasks?

Actually, what kind of stuff other than the stock market actually cares that much about strict determinism and task priority? Only, other that really suggests itself is schedulers for multiple groups running big iron tasks, rather than micro-controllers.

Not familiar enough, just doesn't seem like there would be a lot of groups fighting about priority on micro-controllers. Usually seem very focused and single task specific anyways.

[raphui]

In my use case (dirtbike anti theft tracker), it is useful to use an RTOS, not specifically for hard time constraints, as I don't have those, but more to have all the other functionality: task synchronisation mechanisms, driver abstraction, etc. That allows to better design the application. For example, having separate tasks for GPS updates, cellular communication, and motion detection with proper prioritization makes the code much cleaner than a giant main loop with interrupts. About other industries, I would say highly critical medical systems, avionics and automotive find it useful to use RTOSes because they have use cases where time constraints are really hard.