Operating Systems: Concurrent and Distributed Software Design

25.1. Introduction

In Chapter 24 we introduced UNIX as an archetypal kernel-based operating system, focusing on the design of Seventh Edition from 1978. That system provided a multiprogrammed environment, enforcing isolation between processes, the kernel and devices. The system exploited its initial target of uniprocessor machines to give a simple non-preemptable kernel invoked procedurally through a system call interface. We showed how the IPC mechanisms provided by classical UNIX are not very flexible: processes can exchange data through files held on disk, through pipes created in advance by a common parent and by simple asynchronous signals.

In this chapter we examine how UNIX and UNIX-derived systems have been developed to support more powerful ...