Transcript ch1 OSs

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CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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“An
operating system (OS) is
software, consisting of programs
and data, that runs on computers
and manages the computer hardware
and provides common services for
efficient execution of various
application software
”
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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แนะนำรำยวิชำ
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เนื้ อหำวิชำครอบคลุมกำรศึกษำบทบำทและหน้ำที่ข อง
ระบบปฏิ บั ติ ก ำรที่ มี ค วำมส ำคั ญ ต่ อ ระบบคอมพิ ว เตอร์
องค์ป ระกอบของระบบปฏิ บัติ ก ำร กำรจัด กำรโพรเซส กำร
จัดกำรหน่วยควำมจำ กำรจัดกำรระบบแฟ้ มข้อมูล กำรจัด กำร
อุ ป กรณ์อิ น พุ ต และเอำท์พุ ต กำรควบคุ ม กำรเข้ำ ถึ ง ข้อ มู ล
รวมทั้งระบบปฏิบตั ิกำรสำหรับเครือข่ำย และระบบปฏิบตั ิกำร
สำหรับระบบมัลติโพรเซสเซอร์
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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ข้อตกลงในชั้นเรียน
• เวลำเข้ำเรียนไม่ต ่ำกว่ำร้อยละ 80
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– ขำดได้ไม่เกิน 3 ครั้ง
– มำสำยกว่ำเวลำเรียนครึ่งชั ่วโมง 2 ครั้ง ถือว่ำขำด 1 ครั้ง
• ส่งงำนที่ได้รบั มอบหมำยทั้งหมดครบและตรงตำม
ระยะเวลำที่กำหนด
• กำรแต่งกำย ให้เป็ นไปตำมระเบียบมหำวิทยำลัยกำหนด
หำกฝ่ ำฝื นจะไม่ได้รบั อนุญำตให้เข้ำชั้นเรียน
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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ข้อตกลงในกำรกำหนดคะแนน
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• ระหว่ำงภำค (50%) แบ่งเป็ น
–ควำมสนใจ
(กำรเข้ำเรียน จริยธรรม และ กำรแต่งกำย) 10%
–งำนที่ได้รบั มอบหมำย
20%
–สอบกลำงภำค
30%
• ปลำยภำค (50%)
–สอบปลำยภำค
50%
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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หนังสื อที่ใช้ในการทบทวน
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• TextBook Operating System 8th
Edition Silberschatz (Yale University ),
Peter B. Galvin (Corporate Technologies),
Greg Gagne (Westminster College) July 2008,
©2009
• E-Learning
htpp//ele.kbu.ac.th/Boonyong
• http://elc.kbu.ac.th/users/index.php
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Chapter 1
Introduction
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Objectives
• To describes the Operating system.
• To describes each Componets of an Operating System.
• To discuss Development of an Operating System.
• To explain the Operation of Different type of
Operating System.
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Topic Covered
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What is an Operating System?
What are the components of an OS?
What does an OS do?
Short History of OSs
Different types of OSs
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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What is an Operating System?
• 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.
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Computer System Components
1. Hardware – provides basic computing
resources (CPU, memory, I/O devices).
2. Operating system – controls and
coordinates the use of the hardware among
the various application programs for the
various users.
3. Applications programs – define the ways
in which the system resources are used to
solve the computing problems of the users
(compilers, database systems, video games,
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Abstract View of System Components
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CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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System Components
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Hides the complexity of machine
language from programmer
Instruction Set Architecture
Physical devices grouped together
to form functional units
Integrated circuit chips, power
supply, CRT
• The operating system run in kernel or supervisor mode
- protected from user tampering
• Compilers, editors and application programs run in
user mode
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Functions of an OS
• User Environment - OS layer transforms bare
hardware machine into higher level abstractions
– Execution environment - process management, file
manipulation, interrupt handling, I/O operations,
language.
– Error detection and handling
– Protection and security
– Fault tolerance and failure recovery
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Functions of an OS
• Resource Management
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– Time management
• CPU and disk transfer scheduling
– Space management
• main and secondary storage allocation
– Synchronization and deadlock handling
• IPC, critical section, coordination
– Accounting and status information
• resource usage tracking
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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History of Operating Systems
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• Pre-electronic
– Charles Babbage (1792-1871) “analytical machine”
– Purely mechanical, failed because technology could
not produce the required wheels, cog, gears to the
required precision
• First generation 1945 - 1955
– Aiken, von Neumann, Eckert, Mauchley and Zuse
– programming done via plugboards, no OS or language
– vacuum tubes
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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History of Operating Systems
• Second generation 1955 - 1965
– transistors more reliable than vacuum tubes
– jobs read in via punched cards
– batch systems introduced to reduce wasted time in setting
up and running jobs
•bring cards to 1401
•read cards to tape offline
•put tape on 7094 which does computing
•put tape on 1401 which prints output offline
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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History of Operating Systems
• Third generation 1965 – 1980
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IBM System/360: combine business and scientific computers into one machine
Computer will grow with client(memory, processor speed, number of I/O
devices etc.)
Forerunner of 370, 4300, 3080 and 3090
Use of integrated circuits provided major price/performance advantage over
2nd generation
OS/360 had to meet conflicting needs which resulted in enormous and
complex operating system
Introduced multiprogramming to make most efficient use of CPU
– Spooling: read jobs from cards to disk ready to load into memory and queue
output to disk for printing
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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History of Operating Systems
• In batch, total time from submitting a job to getting the output was a
few hours, very unproductive for programmers
• Timesharing (a variant of multiprogramming) provides for user
interaction with the computer system
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– On-line communication between the user and the system is provided; when the
operating system finishes the execution of one command, it seeks the next
“control statement” from the user’s keyboard.
– The CPU is multiplexed among several jobs that are kept in memory and on
disk (the CPU is allocated to a job only if the job is in memory).
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takes advantage of the idle CPU
switch occurs so frequently that the user can interact with each program as it is running
each command is short so only a little CPU time is needed for each user
each user is given the impression that the entire system is dedicated to his use
Batch jobs could be running in background
CTSS (Compatible Time Sharing System - MIT) was first success
• Minicomputers and the development of UNIX
– UNIX was stripped down, one user version of MULTICS (extension of CTSS)
– Numerous variants : System V, BSD, POSIX (IEEE), MINIX, Linux
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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History of Operating Systems
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• Fourth generation 1980 – present
– Large Scale Integrated chips
– personal computers
– 1974: Intel developed 8080 chip (8 bit CPU), Gary Kildall wrote CP/M OS
(Intel gave him the rights) and formed Digital Research
– Early 1980s: IBM designed IBM PC. Bill Gates had BASIC interpreter and
recommended DR as an OS. Kildall sent subordinate to meeting and refused to
sign non-disclosure. Gates was asked for an OS, bought DOS from Seattle
Computer Products and offered IBM DOS/BASIC package. Renamed it MS -DOS
– Early Windows versions ran on top of DOS, Windows 95 and beyond and NT were
full fledged OSs
– Network Operating Systems (user sees multiple computers)
– Distributed Operating Systems (user sees one processor)
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Mainframe Systems
• First computers used to solve many commercial and
scientific applications
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– evolved from batch  time shared systems
• Reduce setup time by batching similar jobs
– serial card readers were initial input device then disks enabled
job scheduling by the operating system
• Automatic job sequencing – automatically transfers control
from one job to another.
– first rudimentary operating system.
– CPU often idle because of great differences in speed between
mechanical I/O vs. electronic devices
• Early OS called resident monitor
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initial control in monitor
control transfers to job
when job completes control transfers pack to monitor
eliminated intervention by programmer
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Memory Layout for a Simple Batch System
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CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Multiprogrammed Batch Systems
Several jobs from the pool of all submitted jobs are kept in main memory at
the same time, and the CPU is multiplexed among them.
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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OS Features Needed for Multiprogramming
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• Why multiprogramming?
– Increases CPU utilization by trying to always keep
the CPU busy processing some job
– I/O of one job causes switch to another job
• Memory management – the system must allocate the
memory to several jobs.
• CPU scheduling – the system must choose among
several jobs ready to run.
• Allocation of devices.
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Desktop Systems
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• Personal computers – computer system dedicated to a single
user.
• I/O devices – keyboards, mice, display screens, small
printers.
• User convenience and responsiveness.
• Can adopt technology developed for larger operating
systems. Often individuals have sole use of computer and
do not need advanced CPU utilization of protection
features.
• May run several different types of operating systems
(Windows, MacOS, UNIX, Linux)
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Parallel Systems
• Multiprocessor systems with more than on CPU in
close communication.
• Tightly coupled system – processors share memory
and a clock; communication usually takes place
through the shared memory.
• Advantages of parallel system:
– Increased throughput with more processors
– Economical – share peripherals, mass storage,
power etc. as opposed to individual PCs
– Increased reliability
• graceful degradation / fault tolerant
– failure of one processor will slow down but not halt the system
– other processors pick up the slack
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Parallel Systems (Cont.)
• Symmetric
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multiprocessing (SMP)
– Each processor runs and
identical copy of the
operating system.
– Many processes can run at
once without performance
deterioration.
– Most modern operating
systems support SMP
• Asymmetric multiprocessing
– Each processor is assigned a specific task; controlling processor
schedules and allocates work to other processors.
– More common in extremely large systems
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Distributed Systems
• Distribute the computation among several physical
processors.
• Loosely coupled system – each processor has its own
local memory; processors communicate with one another
through various communications lines, such as high-speed
buses or telephone lines.
• Advantages of distributed systems.
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Resource sharing
Computation speed up – load sharing
Reliability
Communications between processors and processes
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Distributed Systems (cont)
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• Requires networking infrastructure.
– TCP/IP is the most common network protocol
• Local area networks (LAN) or Wide area
networks (WAN)
• May be either client-server or peer-topeer systems.
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Real-Time Systems
• Often used as a control device in a dedicated application 30
such as controlling scientific experiments, medical imaging
systems, industrial control systems, and some display
systems.
• Well-defined, fixed time constraints.
• Hard real-time:
– Secondary storage limited or absent, data stored in short term
memory, or read-only memory (ROM)
– Not supported by general-purpose operating systems.
• Soft real-time
– Limited utility in industrial control of robotics
– Useful in applications (multimedia, virtual reality) requiring
advanced operating-system features.
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Handheld Systems
• Personal Digital Assistants (PDAs)
• Cellular telephones
• Issues:
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– Limited memory (512KB to 8MB) requires efficient
management
– Slow processors
– Small display screens.
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Migration of Operating-System Concepts and Features
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CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Assignment (1)
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• BOOTABLE DISK
• BOOTABLE CD
• BOOTABLE FLASH DRIVE
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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Assignment (2)
UNIX,MAC,SOLARY,SYMBIAN Operating System
• - History
• - Design Principles
• - System Components
• - Environmental Subsystems
• - File system
• - Networking
• - Programmer Interface
The
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Linux Operating System
History
Design Principles
Kernel Modules
Process Management
Scheduling
Memory Management
File Systems
Input and Output
Intercrosses Communication
Network Structure
Windows Operating System
• - History
• - Design Principles
• - System Components
• - Environmental Subsystems
• - File system
• - Networking
• - Programmer Interface
CS.217 Operating System By Ajarn..Sutapart Sappajak,METC,MSIT Chapter 1 Introduction
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