cis-410: operating systems spring 2008. organizational details class meeting: 7:00-9:45pm, monday,...
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CIS-410: Operating Systems
Spring 2008
Organizational Details
Class Meeting: 7:00-9:45pm, Monday, Room 252N
Instructor: Dr. Igor Aizenberg
Office: Aikin Building, 192Phone (903 223 3183)e-mail: [email protected]
Office hours:Tuesday, Thursday, Friday 12-30 – 2-00 pm
Text Book
A. Silberschatz, P. B. Galvin and G. Gagne "Operating System Concepts" 7th Edn., John Wiley & Sons,2005, ISBN 0-471-69466-5
Control
Exams (open book, open notes):
Midterm 1: March 3, 2007 Midterm 2: April 14, 2007 Final Exam: May 12, 2007
Homework
GradingGrading MethodHomework and preparation: 10%Midterm Exam 1: 25%Midterm Exam 2: 30%Final Exam: 35%
Grading Scale: 90%+ A 80%+ B 70%+ C 60%+ D less than 60% F
Chapter 1: IntroductionChapter 1: Introduction
1.7 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
What we will study?What we will study?
What Operating Systems Do
Computer-System Organization
Computer-System Architecture
Operating-System Structure
Operating-System Operations
Process Management
Memory Management
Storage Management
Protection and Security
Modern Operating Systems: Windows XP and Linux
1.8 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
ObjectivesObjectives
To provide a grand tour of the major operating systems components
To provide coverage of basic computer system organization
To learn basic ideas behind the modern operating systems.
To learn basic issues in operating system design and implementation.
To allow you to use an operating system to control your computer.
To give you the ability to quickly learn new operating systems.
1.9 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
What is an Operating System?What is an Operating System?
An Operating System is a program that acts as an intermediary between a user of a computer and the computer hardware.
Operating system goals:
Execute user programs and make solving user problems easier.
Make the computer system convenient to use.
Use the computer hardware in an efficient manner.
1.10 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
Computer System StructureComputer System Structure
Computer system can be divided into four components
Hardware – provides basic computing resources
CPU, memory, I/O devices
Operating system
Controls and coordinates use of hardware among various applications and users
Application programs – define the ways in which the system resources are used to solve the computing problems of the users
Word processors, compilers, web browsers, database systems, video games
Users
People, machines, other computers
1.11 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
Four Components of a Computer SystemFour Components of a Computer System
1.12 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
Operating System DefinitionOperating System Definition
OS is a resource allocator
Manages all resources
Decides between conflicting requests for efficient and fair resource use
OS is a control program
Controls execution of programs to prevent errors and improper use of the computer
1.13 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
Operating System Definition (Cont.)Operating System Definition (Cont.)
No universally accepted definition
“Everything a vendor ships when you order an operating system” is good approximation But varies wildly
“The one program running at all times on the computer” is the kernel. Everything else is either a
• system program (ships with the operating system) or
• an application program
1.14 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
Computer StartupComputer Startup
bootstrap program is loaded at power-up or reboot
Typically stored in ROM or EPROM, generally known as firmware
Initializates all aspects of system
Loads operating system kernel and starts execution
1.15 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
Historical OverviewHistorical Overview
•“The 1st Generation”: vacuum tube technology (1945-1955)
A few milliseconds per arithmetic operation
•“The 2nd Generation”: transistor technology (1955-1965)
High-level languages, compilers, separate I/O processors
Electronic Computers
•“The 3rd Generation”: integrated-circuit technology (1965-1975) Operating systems, Microprogramming, multiprogramming, pipelining, cache memories
•“The 4th Generation”: VLSI (Very Large Scale Integration) (1975- present) Microprocessors, virtual memories, concurrency, networks, high resolution graphics
•Beyond the 4th Generation: artificial intelligence, massively parallel machines, extensively distributed systems
1.16 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
11stst and 3 and 3rdrd Generations of Computers Generations of Computers
1st Generation Computer, 1954
3rd Generation Computer IBM-360, 1966
1.17 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
History of Operating Systems: PhasesHistory of Operating Systems: Phases
Phase 1: Hardware is expensive, humans are cheap (1945-1965)
User at console: single-user systems
Batching systems
Multi-programming systems
Phase 2: Hardware is cheap, humans are expensive (1965-1981)
Time sharing: Users use cheap terminals and share servers
Phase 3: Hardware is very cheap, humans are very expensive (1981-1990th)
Personal computing: One system per user
Distributed computing: lots of systems per user
Phase 4: Ubiquitous computing (1990th and beyond)
Computers everywhere:
Cell phone, mp3 player, DVD player, etc.
1.18 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
History of Operating Systems: PhasesHistory of Operating Systems: Phases
Phase 1: Hardware is expensive, humans are cheap
User at console: single-user systems
Batching systems
Multi-programming systems
Phase 2: Hardware is cheap, humans are expensive
Time sharing: Users use cheap terminals and share servers
Phase 3: Hardware is very cheap, humans are very expensive
Personal computing: One system per user
Distributed computing: lots of systems per user
Phase 4: Richer services
Real-time operating systems
1.19 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
A Brief History of Operating SystemsA Brief History of Operating SystemsHand programmed machines (‘45-‘55)Hand programmed machines (‘45-‘55)
Single user systems
OS = loader + libraries of common subroutines
Problem: low utilization of expensive components
= % utilization = % utilization Execution time
Execution time +Card reader time
1.20 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
Batch/Off-line processing (‘55-‘65)Batch/Off-line processing (‘55-‘65)
Batching v. sequential execution of jobs
Card Reader:
CPU:
Printer:
Read Batch 1Read Batch 1
Execute Batch 1 Batch 2Batch 2 Batch 3Batch 3
Batch 2Batch 2 Batch 3Batch 3
Print Batch 1Print Batch 1 Batch 2Batch 2 Batch 3Batch 3
Card Reader:
CPU:
Printer:
Read Job 1Read Job 1
Execute Job 1 Job 2Job 2 Job 3Job 3
Job 2Job 2 Job 3Job 3
Print Job 1Print Job 1 Job 2Job 2 Job 3Job 3
1.21 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
TapeTapeTapeTape
Batch processing (‘55-‘65)Batch processing (‘55-‘65)
Operating system = loader + sequencer + output processor
Input
Compute
Output
CardReader
CardReader PrinterPrinter
TapeTape TapeTape
Operating SystemOperating System
“System Software”“System Software”
User ProgramUser Program
User DataUser Data
1.22 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
Multiprogramming (‘65-‘80)Multiprogramming (‘65-‘80)
Keep several jobs in memory and multiplex CPU between jobs
Operating SystemOperating System
“System Software”“System Software”
User Program 1User Program 1
User Program 2User Program 2User Program 2User Program 2
User Program nUser Program n
...
program Pbegin : Read(var) :end P
program Pbegin : Read(var) :end P
system call Read()begin StartIO(input device) WaitIO(interrupt) EndIO(input device) :end Read
system call Read()begin StartIO(input device) WaitIO(interrupt) EndIO(input device) :end Read
Simple, “synchronous” input:
What to do while we wait for the I/O device?
1.23 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
Multiprogramming (‘65-‘80)Multiprogramming (‘65-‘80)
Keep several jobs in memory and multiplex CPU between jobs
Operating SystemOperating System
“System Software”“System Software”
User Program 1User Program 1
User Program 2User Program 2User Program 2User Program 2
User Program nUser Program n
...
Program 1I/O
Device
k: read()
k+1:
endio()interrupt
main{
}
}
OS
read{
startIO()waitIO()
1.24 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
Multiprogramming (‘65-‘80)Multiprogramming (‘65-‘80)
Keep several jobs in memory and multiplex CPU between jobs
Operating SystemOperating System
“System Software”“System Software”
User Program 1User Program 1
User Program 2User Program 2User Program 2User Program 2
User Program nUser Program n
...
Program 1 Program 2OSI/O
Device
k: read()
startIO()
interrupt
main{
read{
endio{
}schedule()
main{
k+1:
}
}schedule()
1.25 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
History of Operating Systems: PhasesHistory of Operating Systems: Phases
Phase 1: Hardware is expensive, humans are cheap
User at console: single-user systems
Batching systems
Multi-programming systems
Phase 2: Hardware is cheap, humans are expensive
Time sharing: Users use cheap terminals and share servers
Phase 3: Hardware is very cheap, humans are very expensive
Personal computing: One system per user
Distributed computing: lots of systems per user
Phase 4: Richer services
Real-time operating systems
1.26 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
Timesharing (‘70- )Timesharing (‘70- )
A timer interrupt is used to multiplex CPU among jobs
Operating SystemOperating System
“System Software”“System Software”
User Program 1User Program 1
User Program 2User Program 2User Program 2User Program 2
User Program nUser Program n
...Program 1 Program 2OS
k+1:
schedule{
timerinterrupt
schedule{
timerinterrupt
k:
main{
}main{
}
timerinterrupt
schedule{
1.27 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
History of Operating Systems: PhasesHistory of Operating Systems: Phases
Phase 1: Hardware is expensive, humans are cheap
User at console: single-user systems
Batching systems
Multi-programming systems
Phase 2: Hardware is cheap, humans are expensive
Time sharing: Users use cheap terminals and share servers
Phase 3: Hardware is very cheap, humans are very expensive
Personal computing: One system per user
Distributed computing: lots of systems per user
Phase 4: Richer services
Real-time operating systems
1.28 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
Operating Systems for PCsOperating Systems for PCs
Personal computing systems
Single user
Utilization is no longer a concern
Emphasis is on user interface and API
Many services & features not present
Evolution
Initially: OS as a simple service provider (simple libraries)
Now: Multi-application systems with support for coordination and communication
Growing security issues (e.g., online commerce, medical records)
1.29 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
Distributed Operating SystemsDistributed Operating Systems
Typically support distributed services
Sharing of data and coordination across multiple systems
Possibly employ multiple processors
Loosely coupled v. tightly coupled systems
High availability & reliability requirements
OSprocess
management
OSprocess
management
UserProgram
UserProgram
CPUCPU
LAN/WAN
OSprocess managementmemory management
OSprocess managementmemory management
UserProgram
UserProgram
CPUCPU
OSfile system
name servicesmail services
OSfile system
name servicesmail services
CPUCPU
Network
1.30 Silberschatz, Galvin and Gagne ©2005Operating System Concepts – 7th Edition, Jan 12, 2005
History of Operating Systems: PhasesHistory of Operating Systems: Phases
Phase 1: Hardware is expensive, humans are cheap User at console: single-user systems Batching systems Multi-programming systems
Phase 2: Hardware is cheap, humans are expensive Time sharing: Users use cheap terminals and share servers
Phase 3: Hardware is very cheap, humans are very expensive Personal computing: One system per user Distributed computing: lots of systems per user
Phase 4: Connecting people and their machines Intellectual property issues Information organization