Welcome to CS314 Operating Systems A Quick Tour for Introduction to OS Department of Computer Science Southern Illinois University Edwardsville Spring, 2016 Dr. Hiroshi Fujinoki CS 314 Operating Systems OS_Intro/001

OS_Intro/002 Presentation Agenda ( = Why not just application programming?) What kinds of Operating Systems exist? What is Operating System? Why do we need Operating Systems? What are we going to learn in this course? What are we NOT going to learn in this class? CS 314 Operating Systems

OS_Intro/003 What is Operating System? (1) A middleman between you (as a user) and computer hardware Computer Hardware You (or your program) command! You (yes, you) have to know how to directly control hardware Why not? CS 314 Operating Systems

OS_Intro/004 What is Operating System? (1) A middleman between you (as a user) and computer hardware Computer Hardware You need to manage: everything such as  Controller chips  Assembly language  and more... CS 314 Operating Systems

OS_Intro/005 What is Operating System? (1) A middleman between you (as a user) and computer hardware OS Computer Hardware You (or your program) command! Low-level commands As high-level commands (e.g. “READ My_File.txt”) “Read Sectors 1E to 4F” OS is the software that directly control hardware CS 314 Operating Systems

CPU Memory Disk Keyboard Network Etc. Request resources What is Operating System (continued)? (2) The government in your computer (the agent that allocate resources) A Computer Program A Program B Program C Program D OS_Intro/006 CS 314 Operating Systems

If you DO have an OS … OS CPU Memory Disk Keyboard Network Etc. Program AProgram BProgram C Program D OS_Intro/007 CS 314 Operating Systems

OS_Intro/008 Computer Hardware You (or your program) command! Computer hardware can not be shared by more than one user (or more than one program) (2) The government in your computer (the agent that allocate resources) Another User If the resource being used is printer, the output will be gibberish! What is Operating System (continued)? CS 314 Operating Systems

OS_Intro/009 OS Computer Hardware You (or your program) command! Manage (serialize) I/O requests from users Another User “print” (2) The government in your computer (the agent that allocate resources) What is Operating System (continued)? CS 314 Operating Systems

OS_Intro/010 You (as a user) The three-layer structure in a computer system Computer Hardware Operating System Application Programs High-level commands APIs (System Calls) Low-level Commands (Assembly Routines) CS 314 Operating Systems

OS_Intro/011 Summary for “What is Operating System” (1) OS is the software that directly control hardware (2) OS is a middleman between you (as a user) and computer hardware that hides details of hardware (3) OS is the government in your computer (the agent that allocate resources) OS provides “hardware abstraction” OS provides “resource management” in your computer CS 314 Operating Systems

› General Purpose OS: – UNIX, MS-DOS, Windows, Be-OS › Network OS: – Novell Netware, NFS, Windows-NT › Embedded OS: – TRON (I-TRON - Univ. of Tokyo) › Real-time OS: – RxDOS (Computer Wave) › Special Purpose (e.g., for super computers): – AIX (UNIX for Deep Blue, ASCI White) – IRIX (UNIX for Render Farm) › Research prototypes: – Amoebas (U. of Amsterdam), EROS (U. of Pennsylvania) What kinds of Operating Systems exist? OS_Intro/012 CS 314 Operating Systems

OS_Intro/013 What is this course about? What is this course NOT about? Identifying major components in modern operating systems Understand the purpose of each OS component Understand how each OS component works Performance analysis for different implementations of an OS component Survey for advanced operating systems How to use Windows XP (We may discuss it to compare to other operating systems) Develop an operating system CS 314 Operating Systems

OS_Intro/014 Major components in modern operating systems Inter-Process Communication (IPC) Process Synchronization Paging Segmentation Process and thread (light-weight process) (2) Memory management (1) Process management (= allocating CPU resource) (3) I/O resource management (4) User management Deadlock avoidance Security Virtual memory CS 314 Operating Systems

OS_Intro/015 Why do I need to learn OS? CS 314 Operating Systems Let’s talk about it before we start this course …..