©Brooks/Cole, 2003 Chapter 7 Operating Systems

©Brooks/Cole, 2003 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. After reading this chapter, the reader should be able to: O BJECTIVES List some of the characteristics of popular operating systems such as Windows 2000, UNIX, and Linux.

©Brooks/Cole, 2003 Figure 7-1 Computer System

©Brooks/Cole, 2003 DEFINITIONDEFINITION 7.1

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. Note:

©Brooks/Cole, 2003 EVOLUTIONEVOLUTION 7.2

COMPONENTSCOMPONENTS 7.3

Figure 7-2 Components of an operating system

©Brooks/Cole, 2003 Figure 7-3 Monoprogramming

©Brooks/Cole, 2003 Figure 7-4 Multiprogramming

©Brooks/Cole, 2003 Figure 7-5 Categories of multiprogramming

©Brooks/Cole, 2003 Figure 7-6 Partitioning

©Brooks/Cole, 2003 Figure 7-7 Paging

©Brooks/Cole, 2003 Figure 7-8 Virtual memory

©Brooks/Cole, 2003 Figure 7-9 State diagram with the boundaries between a program, a job, and a process

©Brooks/Cole, 2003 Figure 7-10 Job scheduler

©Brooks/Cole, 2003 Figure 7-11 Process scheduler

©Brooks/Cole, 2003 Figure 7-12 Queues for process management

©Brooks/Cole, 2003 Figure 7-13 Deadlock

©Brooks/Cole, 2003 Figure 7-14 Deadlock on a bridge

©Brooks/Cole, 2003 Deadlock occurs when the operating system does not put resource restrictions on processes. Note:

©Brooks/Cole, 2003 Figure 7-15.a Starvation

©Brooks/Cole, 2003 Figure 7-15.b Starvation

©Brooks/Cole, 2003 Figure 7-15.c Starvation