11.1Operating System ConceptsCSMC 412Operating SystemsProf. Ashok K Agrawala© 2004 Ashok Agrawala1.2Operating System ConceptsToday Review Syllabus) read the warning about the size of the project) make sure you get the 6thedition of the bookProgram #0 Handout (posted Aug 31)) its due in just over one week) purpose is to get familiar with the simulator/compiler/debuggerClass Grades Server) Grades.cs.umd.eduDiscussion Sections) will focus on the project and meet only once a week (W) Probably will have three times per week; you can attend the section of your choice. See web page for details.Reading) Chapter 1 ) Chapter 221.3Operating System ConceptsCyclone Based on C) Low-level control over memory management, data representation, and access to the machineBut type-safe !!) Rules out many hard-to-find bugs and security holes Buffer overflows Dangling pointers) These bugs have killed many projects1.4Operating System ConceptsCyclone in this class You are required to use it for project 0, to get familiar with it From then on it is optional) Could very well make your project more reliable, and prevent bugs) But, it’s a research compiler, and it will have bugs itself, and may have cryptic error messages. If a major problem in the compioler inhibits a good-faith attempt to complete the project, you will not be penalized.31.5Operating System ConceptsCyclone in this class Completing at least one project using Cyclone (from project 1to 6) will net you some extra credit) You must include a write up of your experience, including what features you used, what difficulties you ran into and suggestions for improvements) Seehttp://www.cs.umd.edu/projects/cyclone/1.6Operating System ConceptsClass Grades Serverhttp://grades.cs.umd.edu Get your LinuxLab account from here) CS computing cluster. Projects must work and be submitted on these machinesComplete grade information Interface for requesting regrades on exams and projects41.7Operating System ConceptsCatalog Description A hands-on introduction to operating systems, including topics in: multiprogramming, communication and synchronization, memory management, IO subsystems, and resource scheduling polices. The laboratory component consists of constructing a small kernel, including functions for device IO, multi-tasking, and memory management.1.8Operating System ConceptsPrerequisites CMSC 311 CMSC 33051.9Operating System ConceptsTopics Covered • Introduction to Operating Systems (1 week) • The Cyclone Programming Language (0.5 weeks) • Concurrent Processes (2 weeks) • Kernel implementation techniques (1 week) • CPU scheduling (1 week) • Memory Management (2 weeks) • File and I/O Systems (2 weeks) • Security and Protection (1 week) • Networking and Distributed Systems (2 weeks) • Objects and Naming (1 week) • Window and Display Services (0.5 weeks)1.10Operating System ConceptsText Required) Operating System Concepts 6th Edition, Siberschatz, Galvin and Gagne, John Wiley 2003.61.11Operating System ConceptsProgramming Projects: Understanding operating system concepts is a hands-on activity. This class will include several substantial programming projects that will require students to read and understand provided code, write new modules, and debug the resulting system. The programming assignments will be time consuming and students taking this class should plan their class schedules accordingly. The instructor reserves the right to fail, regardless of overall numeric score, students who do not submit a good faith attempt to complete all programming assignments. You will have the option to use Cyclone lannguage) Next lecture will be an introduction to Cyclone1.12Operating System ConceptsGrading Final Exam 30% Midterms (2 each worth 15%) 30% Programming Assignments 40%Exams: Midterm #1 - Midterm #2 - Final – Dec 16, 10:30 – 12:3071.13Operating System ConceptsIntroduction What is an Operating System? Mainframe Systems Desktop Systems Multiprocessor Systems Distributed Systems Clustered System Real -Time Systems Handheld Systems Computing Environments1.14Operating System ConceptsHardware Support Required Many of the functions carried out by the operating system require explicit hardware support) Privileged Instructions) Processor State) System Call) Memory Protection) …81.15Operating System ConceptsWhat 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.1.16Operating System ConceptsComputer System Components1. 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, business programs).4. Users (people, machines, other computers).91.17Operating System ConceptsAbstract View of System Components1.18Operating System ConceptsOperating System Definitions Resource allocator – manages and allocates resources. Control program – controls the execution of user programs and operations of I/O devices . Kernel – the one program running at all times (all else being application programs).101.19Operating System ConceptsMainframe Systems Reduce setup time by batching similar jobs Automatic job sequencing – automatically transfers control from one job to another. First rudimentary operating system. Resident monitor) initial control in monitor ) control transfers to job ) when job completes control transfers pack to monitor1.20Operating System ConceptsMemory Layout for a Simple Batch System111.21Operating System ConceptsMultiprogrammed Batch SystemsSeveral jobs are kept in main memory at the same time, and the CPU is multiplexed among them. 1.22Operating System ConceptsOS Features Needed for Multiprogramming I/O routine supplied by the system. Memory management – the system must allocate the memory to several jobs. CPU scheduling – the system must choose
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