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Table of Contents
Chapter 1 INTRODUCTION TO OPERATING SYSTEMS ....1-1
References .........................................................................................................................1-1
What is an Operating system? ...........................................................................................1-1
What is Multi-programming? ...........................................................................................1-2
Why were Multi-programming Systems Developed? ....................................................... 1-2
Definition of an Operating System ...................................................................................1-2
Types of Operating Systems .............................................................................................1-3
Some more definitions – Processors, Programs and Tasks ...............................................1-4
Hierarchical Structure of Operating Systems. ..................................................................1-5
A digression – the role of interrupts in Operating Systems. .............................................1-6
What is an interrupt? ....................................................................................................1-6
Why are interrupts crucial to Operating Systems? .......................................................1-6
Example: Producer-Consumer Problem .......................................................................1-8
Chapter 2 PRINCIPLES OF SOFTWARE DESIGN ...................2-1
Problems with Real Time Design .....................................................................................2-2
Some Suggestions on Program Structure .......................................................................... 2-3
The efficiency trap ............................................................................................................2-4
Chapter 3 OVERVIEW OF MULTI-TASKING ................................. 3-1
Coroutines .........................................................................................................................3-1
Tasks .................................................................................................................................3-3
Anatomy of an Operating System Kernel ......................................................................... 3-4
The Dispatcher .............................................................................................................3-4
Synchronization Primitives ..........................................................................................3-5
Protected and Non-protected Operating Systems .............................................................3-5
Brief Discussion of Memory Management .................................................................. 3-6
Brief Discussion of Supervisor Mode .......................................................................... 3-6
Chapter 4 SEMAPHORES ............................................................................4-1
Basic Concepts .................................................................................................................. 4-1
Wait and Signal .................................................................................................................4-2
Semaphores as Resource Counters ...................................................................................4-5
Task Synchronization ........................................................................................................4-6
Consumer-Producer Problem Revisited ............................................................................4-7
More Complex Synchronization Problems .....................................................................4-10
Multiple unit resource allocation ...............................................................................4-10
Dining philosophers problem .....................................................................................4-11
Readers and Writers problem .....................................................................................4-12
Variations on the semaphore ...........................................................................................4-15
Logic semaphores .......................................................................................................4-15
Timed semaphores, sleeping tasks and simulated task suspension ............................4-16
