Basic concepts

Abstract

Over the last few years, several algorithms and methodologies have been proposed in the literature to improve the predictability of real-time systems. In order to present these results we need to define some basic concepts that will be used throughout the book. We begin with the most important software entity treated by any operating system, the process. A process is a computation that is executed by the CPU in a sequential fashion. In this text, the terms process and task are used as synonyms. However, it is worth saying that some authors prefer to distinguish them and define a task as a sequential execution of code that does not suspend itself during execution, whereas a process is a more complex computational activity, that can be composed by many tasks.