Comment by pflanze

> So AFAICT Embassy doesn't do this at all?

I haven't used Embassy, but the README mentions "Tasks on the same async executor run cooperatively, but you can create multiple executors with different priorities so that higher priority tasks preempt lower priority ones" and links to an example that shows how a higher priority task runs even though a lower priority one runs a long time job (does not yield), thus understanding and infrastructure seems to be there.

So, Embassy may in its entirety replace an RTOS / be one, but it's not the async mechanism that can provide the RT part (and I guess you're right to point out the dangerous sentence as it could mislead people to use only async and believe it's RT).

OTOH the sentence would be right if it were something like "async multitasking is an alternative to preemptive multitasking, and can replace the use of a preemptive OS if real-time guarantees are not needed (note that Embassy separately allows running multiple executors to allow to pre-empt tasks running in lower-priority executors)". They should probably also describe what the reason for not needing per-task stack size tuning is.