A detailed look at operating system processes

Abstract

An operating system provides, among other things, an operational definition of a process. The concept of a process is one of the fundamental concepts of Computer Science, and the designer of an operating system must strive to provide a definition that is simple to understand, does not violate the intuitive notions one has about processes, and is simple to implement efficiently on a wide range of computer systems. On the other hand, the definition should not fail to provide the functionality that existing operating systems have, by user demand, gradually evolved into providing. This paper presents a framework for discussing the operational definition of a process, and uses this framework to discuss systematically some of the more important decisions and trade-offs regarding processes, that the designer of a new operating system must make.