Preemptive task on non RTOS

Question

It is correct that ideally preemption of task by other task is allowed by only RTOS systems, while in non RTOS system a task can be preempted by an Interrupt or ISR and not another task.

Also the below statement is correct for preemptive kernel, is it also applicable to preemptive tasks.

"most operating systems do not allow this but it is required for certain applications such as in real time systems"

You asked more-or-less the same question a few days ago and accepted the answer. What was not clear about that answer? If it was not clear why did you accept it? Your last paragraph is in quotes, but there is no citation. It is also not true, Windows, Linux, OSX (and other Unix OSs), are all preemptive operating systems that are not RTOSes (as explained in the accepted answer to your previous near identical question). — Clifford
Possible duplicate of Is interruption between task is possible in Non RTOS system — Clifford

sourav punoriyar sourav punoriyar · Accepted Answer · 2016-06-09T11:08:21

RTOS stands for Real Time Operating Systems.

You must compare various scheduling algorithms like FCFS,SJF,Priority Scheduling,Round-Robin Multiple queue, etc . Each have there pros and cons. Then you can figure out why we use priority preemptive in rtos. Because thats the need. Example Vxworks has priority preemtive but when two tasks of same priority comes it goes for round robin.

"most operating systems do not allow this but it is required for certain applications such as in real time systems". This isn't true as most modern operating systems are preemptive for better performance.

Check the comments. Informational link

Preemptive task on non RTOS

1 Answers