Chapter01-InClass.pdf - Chapter 1: Introduction Adapted...

Chapter 1: Introduction
Adapted from “Operating System Concepts”, 10th Edition; Abraham Silberschatz, Peter B. Galvin,Greg Gagne; 2018

Chapter 1: Introduction
What
Operating
Systems Do
Computer-
System
Organization
Computer-
System
Architecture
Operating-
System
Operations
Resource
Management
Security and
Protection
Virtualization
Computing
Environments
Kernel Data
Structures

Objectives
Describe the general organization of a computer system and
the role of interrupts
Describe
Describe the components in a modern, multiprocessor
computer system
Describe
Illustrate the transition from user mode to kernel mode
Illustrate
Discuss how operating systems are used in various computing
environments.
Discuss

What is an
Operating
System?
u
A program that acts as an
intermediary between a user
of a computer and the
computer hardware
u
Operating system goals:
u
Execute user programs and
make solving user problems
easier
u
Make the computer system
convenient to use
u
Use the computer hardware in
an efficient manner

Computer System Structure
u
Computer system can be divided into four components:
u
Hardware – provides basic computing resources
u
CPU, memory, I/O devices
u
Operating system
u
Controls and coordinates use of hardware among
various applications and users
u
Application programs – define the ways in which the
system resources are used to solve the computing
problems of the users
u
Word processors, compilers, web browsers, database
systems, video games
u
Users
u
People, machines, other computers

Abstract
View of
Components
of Computer

What Operating Systems Do?
u
Depends on the point of view
u
Users want convenience, ease of use and good
performance
u
Don’t care about resource utilization
u
But shared computer such as mainframe or minicomputer
must keep all users happy
u
Operating system is a resource allocator and control
program making efficient use of HW and managing
execution of user programs

What
Operating
Systems
Do?
u
Users of dedicate systems such
as workstations have dedicated
resources but frequently use
shared resources from servers
u
Mobile devices like smartphones
and tables are resource poor,
optimized for usability and
battery life
u
Mobile user interfaces such
as touch screens, voice
recognition
u
Some computers have little or
no user interface, such as
embedded computers in
devices and automobiles
u
Run primarily without user
intervention

Defining
Operating
Systems
u
Term OS covers many roles
u
Present in toasters through
ships, spacecraft, game
machines, TVs and industrial
control systems
u
Born when fixed use computers
for military became more
general purpose and needed
resource management and
program control

Operating System Definition
u
No universally accepted definition
u
“Everything a vendor ships when you order an operating
system” is a good approximation but varies wildly.