Download Operating Systems - University of Connecticut

Operating Systems
CSE 4300
Lecture 1
Wei Wei
University of Connecticut
Information
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Course web page:
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Use HuskyCT
Link will be on my web page
 http://www.engr.uconn.edu/~weiwei/
Instructor:
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Wei Wei
[email protected]
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Today’s Class
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Course organization & outline
Prerequisites & course sign-up
Introduction & History of Operating
Systems
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Course Organization
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Class: junior or senior-level
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Not for freshman or sophomores
Enrollment policy
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If space becomes an issue,
graduating seniors get preference
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Prerequisites
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Data Structures & Algorithms
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Computer Architecture
Programming skills:
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Dynamic memory management
Lists, Trees
Algorithm Analysis
C/C++
Textbook
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Operating system concepts: Silberschatz, Galvin and
Gagne, 7th Edition
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Course Grading
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In-class quizzes: +5%
Homework: 20%
Programming projects: 30%
Exams: exam I 15%, exam II 15%, final 20%
Strict late policy – not accepted
No incomplete
Cheaters will be found and punished
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Will use sophisticated software to detect plagiarized
programs
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Course Organization
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Accounts in C27
My office hours and location:
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Office hours:
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Tu, Th 3:30pm – 4:30pm
Wednesday 1:30pm – 4:30pm
Office ITE 331
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What is a class like?
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Brief announcements on homework, project, exam
Review of previous class
lecturing (questions & answers please!)
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mostly ppt slides (handwriting occasionally)
quiz (occasionally)
return homework, projects, exam; go over them
briefly
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Introduction to Operating Systems
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What’s an operating system (OS)?
Why learn OS?
Historical perspective on operating systems
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OS: More Traditional View
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Interface between user
and architecture
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Implements virtual machine:
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Hides architectural details
Easier to program than
raw hardware (hopefully)
Provides services and
coordinates machine
activities
User-level Applications
virtual machine interface
Operating System
physical machine interface
Hardware
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Operating Systems: Key Features
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Provides standard services (interface) that hardware
implements
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Coordinates multiple applications and users to
achieve safety, fairness and efficiency (high
throughput)
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File system, virtual memory, networking, scheduling,
time-sharing…
Concurrency, memory protection, networking, security
OS design challenges: convenient and efficient
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Software engineering & systems engineering problems
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Introduction to Operating Systems
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What’s an operating system? (OS)
Why learn OS?
Historical perspective on operating systems
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Importance of Operating Systems
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Key component of computer systems
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Meeting point of software & hardware
Understanding how computers work = understanding
operating systems
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OS provides key services required by all application
programs
Rich topic:
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OS = most complex software on your PC
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Windows XP kernel: 40 million lines of code
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New Developments in OS Design
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Operating systems: very active field of research
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Demands on OS’s growing
New application spaces (Web, Grid)
Rapidly evolving hardware
Advent of open-source operating systems – Linux
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You can contribute to and develop OS’s!
Excellent research platform
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Introduction to Operating Systems
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What’s an operating system? (OS)
Why learn OS?
Historical perspective on operating systems
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Generation I (1945-1955)
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Hardware technology
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Mechanical relays, then vacuum tubes
The Experience
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No O.S., no library calls
Programming in machine language (NOT
assembly)
Basic I/O
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E.g. punch cards
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ENIAC
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Generation II (1955-1965)
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Hardware Technology
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Transistors (smaller, more reliable, affordable)
Desktop (really)
The Experience
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Compilers, linkers, loaders are available!
Programming done in assembly and FORTRAN
I/O: magnetic tape
Batch processing
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Batch Processing
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Execute multiple “jobs” in batch:
Load program
 Run
 Print results, dump machine state
 Repeat
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Users submit jobs (on cards or tape)
 Human schedules jobs
 Operating system loads & runs jobs
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Examples (Generation II )
IBM 701
First machine with an OS
IBM 7094: Core memory, disk,
subroutine call instruction
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Generation III (1965-1980)
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Hardware technology
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The Experience
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Integrated Circuits
Multiprogramming
Unix is born
Examples:
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IBM 360,370,...
DEC PDP-1 to PDP-11, VAX
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Multiprogramming
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Allow several programs to run at same time
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Run one job until I/O
Run another job, etc.
OS manages interaction between programs:
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Which jobs to start
Protects program’s memory from others
Decides which to resume when CPU available
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The UNIX Era
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Multics
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Army of programmers, six years
Unix
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Three (four?) guys, two years
Integration of simple tools
“Shell”: composable commands
Written in C: easily portable
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Examples (Generation III)
IBM 360/30
First general purpose computer
PDP-11
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Generation IV (1979-1995)
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MAC (1980’s)
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Microsoft catches up (1985-1995)
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Steve Jobs discovers the Graphical User Interface
Pioneered at Xerox-PARC
GUI on top of MS-DOS.
win1.0[85],win2.0[87], win3.x[90], win95, win98
Meanwhile....
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MINIX is born (1987) followed by Linux (1992)
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Examples (Generation IV)
The Mac (1984)
X-windows
Windows 3.0 (1990)
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Generation V (1990’s-now)
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Different modalities:
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Parallel: Multiple processors, one machine
Distributed: Multiple networked processors
Real-time: Strict or loose deadlines
Sensor networks: Many small computers
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Moral of the Story
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The only constant: Change
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In 50 years, almost every computer component now
9 orders of magnitude faster, larger, cheaper
Example:
1983
1999
0.5
500
cost/MIP
$100,000
$500
memory
1 MB
1 GB
network
10 Mbit/s
1 GB/s
1 GB
1 Tbyte
MIPS
disk
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Moral of the Story, II
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No counterpart in any other sphere of
human existence!
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Transportation:
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Communication is closest:
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200 years to go from horseback (10 mph) to
Concorde (1000 mph) = 2 orders of magnitude
100 years to go from Pony Express (10 mph) to
nearly speed of light (600 million mph) = 7 orders
of magnitude
And operating systems must adapt…
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Course outline
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Introduction
Process management
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Memory management
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Multiprogramming, process/thread, CPU scheduling,
synchronization, deadlock
segmentation, paging, swapping
File system
I/O system
Advanced topics
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Protection, Security, etc.
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