Introduction-1

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CGS 3763Operating System ConceptsSpring
2004Hal Stringer
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TODAYS AGENDA

• Go over course syllabus.
• What is an operating system?
• Class make up - whos enrolled
• Major or Minor?
• Computer Science, IT or MIS
• Other computer science courses
• CGS 1060 is minimum prerequisite
• CGS 3269 would be very helpful
• Programming experience will also be helpful
  although no programming projects required for
  this course

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SYLLABUS OVERVIEW

• Office Hours
• Hal Stringer CSB Rm 255
• Mon. 130 230, Wed. 130 330 or by
  appointment.
• Email
• stringer_at_cs.ucf.edu (include CGS3763 in subject
  line)
• Be professional in your correspondence
• Website
• http//www.cs.ucf.edu/courses/cgs3763/spring2004
• Be sure to take notes in class
• Text Book
• Operating System Concepts, Sixth Edition by
  Silberschatz, Galvin and Gagne
• http//cs-www.cs.yale.edu/homes/avi/os-book/osc

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SYLLABUS OVERVIEW (cont.)

• Class Times
• Mon, Wed Fri, 1130 - 1220, ENG2 Room 105
• Final Exam
• Wednesday April 21, 1000 - 1250
• It will be comprehensive
• Other Dates
• Jan. 9 End of Drop/Add (by 500)
• Jan. 19 Martin Luther King, Jr. Day, No classes.
• Feb. 27 Withdrawal Deadline
• Mar. 8-13 Spring Break, No classes.
• Apr. 19 Last Class

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SYLLABUS OVERVIEW (cont.)

• Attendance
• Not taken but strongly encouraged
• Homework exercises will be assigned
• Turned in during class.
• Answers given in class only.
• Tests Exams
• Closed book, closed notes
• T/F, Multi-Answer Multi-Choice, Problems, Essay
• Simple calculators only
• Academic Behavior
• Cheating or other forms of academic dishonesty
  will not be tolerated
• Please turn off all cell phones and pagers in
  class.

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SYLLABUS OVERVIEW (cont.)

• Grading Based on
• Homework 5 (20 pts)
• First Midterm 25 (100 pts)
• Second Midterm 30 (120 pts)
• Final Exam 40 (160 pts)
• Guaranteed Grading Scale
•   A 90 100 (360-400 pts)
• B 80 89 (320-359 pts)
• C 70 79 (280-319 pts)
• D 60 69 (240-279 pts)
• F Otherwise (lt 240 pts)
• May use /- or lower grading scale at my
  discretion.

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SYLLABUS OVERVIEW (cont.)

• Take advantage of multiple resources
• Classroom lectures
• Required text book
• Lecture slides and review exercises
• Publishers web site and slides
• Use the internet or other text books
• See me during office hours or email

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COURSE CONTENT

• Not a course in Windows, Mac or Unix.
• Not a point click, how to course.
• Instead well look at the basic concepts that
  underlie these and other operating systems.
• Processes threads,
• CPU scheduling,
• memory and secondary storage management,
• protection and security,
• distributed systems
• Why?
• Dispel some of the mystery - understand what
  happens when you point and click.
• Learn new algorithms - many OS concepts can be
  applied to other disciplines.

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TENTATIVE COURSE CALENDAR

• Chapter 1 - Introduction
• Chapter 2 - Computer System Structures
• Chapter 3 - Operating System Structures
• Chapter 4 - Processes
• Chapter 5 - Threads
• First Midterm (around Feb 6th)
• Chapter 6 - CPU Scheduling
• Chapter 7 - Process Synchronization
• Chapter 8 - Deadlocks
• Chapter 9 Basic Memory Management
• Second Midterm (in March)

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TENTATIVE COURSE CALENDAR (cont.)

• Chapter 10 - Virtual Memory
• Chapter 11/12 - File Systems
• Chapter 14 - Mass Storage Structures
• Chapter 15/16/17 - Distributed Systems
• Chapter 18/19 - Protection and Security
• Final Exam (April 21)

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WHAT IS AN OPERATING SYSTEM?

• Definition varies depending on who you ask
• resource allocator
• master control program
• everything vendor ships with the computer
• program that is always running (kernel)

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WHAT IS AN OPERATING SYSTEM?

• For purposes of our class an operating system
• 1) is the interface or intermediary between a
  user/application and the computer hardware
• 2) provides an environment in which the user can
  execute programs conveniently and
• application and/or system software
• 3) manages the computers resources efficiently
• memory, disk space, CPU time, I/O, software, etc.
• Often an OS is a tradeoff between convenience and
  efficiency
• Windows (GUI) vs. Unix (command interpreter)

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OS AS INTERMEDIARY

• Well discuss hardware later in Chapter 2.
• Whats an application?
• Software to accomplish a task
• Spread sheet, word processor, browser, email
• What about system software?
• Depending on who you ask, can be considered
  application programs, a computer resource, or
  part of the OS

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WHAT IS A PROCESS?
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WHAT IS A PROCESS (cont.)

• A process
• is a program in execution.
• has a process control block (PCB)
• has a program counter (PC)
• A process can have one or more threads.
• A thread is sometimes known as a lightweight
  process

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RUNNING MULTIPLE PROGRAMS

• Parallel/Simultaneous Execution
• Two or more processes performing the same
  activity at the same time
• Requires two or more of the same resource (e.g.,
  processors, printers, disk drives)
• Concurrent Execution
• Two or more processes executing at the same time
  but doing different activities
• Processes take turns using single shared resource
• Gives the illusion of parallel processing