Chapter 7 Operating Systems

OBJECTIVES After reading this chapter, the reader should be able to: Define the purpose and functions of an operating system. Understand the components of an operating system. Understand the concept of virtual memory. Understand the concept of deadlock and starvation. List some of the characteristics of popular operating systems such as Windows 2000, UNIX, and Linux.

Figure 7-1 Computer System

7.1 DEFINITION

Note: An operating system is an interface between the hardware of a computer and the user (program or human) that facilitates the execution of the other programs and the access to hardware and software resources.

7.2 EVOLUTION

7.3 COMPONENTS

Components of an operating system Figure 7-2 Components of an operating system

Figure 7-3 Monoprogramming

Figure 7-4 Multiprogramming

Categories of multiprogramming Figure 7-5 Categories of multiprogramming

Figure 7-6 Partitioning

Figure 7-7 Paging

Figure 7-8 Virtual memory

State diagram with the boundaries between a program, a job, and a process Figure 7-9

Figure 7-10 Job scheduler

Figure 7-11 Process scheduler

Queues for process management Figure 7-12 Queues for process management

Figure 7-13 Deadlock

Figure 7-14 Deadlock on a bridge

Note: Deadlock occurs when the operating system does not put resource restrictions on processes.

Figure 7-15.a Starvation

Figure 7-15.b Starvation

Figure 7-15.c Starvation

Figure 7-16 Dining philosophers

7.4 POPULAR OPERATING SYSTEMS