Computers as Components, 3rd Edition

6.2 Multiple Tasks and Multiple Processes

We studied the design of programs in Chapter 5. A real-time operating system allows us to run several programs concurrently. The RTOS helps build more complex systems using several programs that run concurrently. Processes and tasks are the building blocks of multitasking systems, much as C functions and code modules are the building blocks of programs.

6.2.1 Tasks and Processes

Many (if not most) embedded computing systems do more than one thing—that is, the environment can cause mode changes that in turn cause the embedded system to behave quite differently. For example, when designing a telephone answering machine, we can define recording a phone call and operating the user’s control panel as distinct ...