Understanding Operating Systems: Components, Types, and History, Slides of Operating Systems

Download Understanding Operating Systems: Components, Types, and History and more Slides Operating Systems in PDF only on Docsity! CS 362 Operating Systems Docsity.com INTRODUCTION What is an Operating System? Docsity.com Computer System Components 3. Applications programs – define the ways in which the system resources are used to solve the computing problems (compilers, database systems, video games, business programs). 4. Users – people, machines, other computers Docsity.com Abstract View of System Components system and application programs operating system computer hardware user user user user 1 2 3 vy compiler assembler text editor database system ity.com Operating 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). Docsity.com Mainframe Systems • Resident monitor – initial control in monitor – control transfers to job – when job completes control transfers back to monitor Docsity.com Memory Layout - Simple Batch System operating system user program area Docsity.com Multiprogrammed Batch Systems Several jobs are kept in main memory at the same time, and the CPU is multiplexed among them. Docsity.com Time-Sharing Systems • 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. • On-line system must be available for users to access data and code. Docsity.com Desktop Systems • Personal computers – computer system dedicated to a single user. • I/O devices – keyboards, mice, display screens, small printers. • User convenience and responsiveness. Docsity.com Desktop Systems OS • Can adopt technology developed for larger operating system • 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) Docsity.com Parallel Systems (Cont.) • Symmetric multiprocessing (SMP) – Each processor runs under a single copy of the operating system. – Many processes can run at once without performance deterioration. • This does not necessarily mean that there is any improvement… – Most modern operating systems support SMP Docsity.com Parallel Systems (Cont.) • Asymmetric multiprocessing – Each processor is assigned a specific task – Master processor schedules and allocated work to slave processors. – More common in extremely large systems Docsity.com Symmetric Multiprocessing Architecture CPU CPU CPU memory Docsity.com Distributed Systems (cont) • Requires networking infrastructure. • Local area networks (LAN) or Wide area networks (WAN) • May be either client-server or peer-to-peer systems in programming model. Docsity.com General Structure of Client-Server client client client client network server ® Docsity.com Clustered Systems • Clustering allows two or more systems to share storage. • Provides high reliability. • Asymmetric clustering: one server runs the application while other servers standby. • Symmetric clustering: all N hosts are running the application. Docsity.com Real-Time Systems (Cont.) • Soft real-time: “If you don’t meet your deadline, it’s not ideal, but we’ll live” – Limited utility in industrial control of robotics – Useful in applications (multimedia, virtual reality) requiring advanced operating-system features. Docsity.com Handheld Systems • Personal Digital Assistants (PDAs) • Cellular telephones • Issues: – Limited memory – Slow processors – Small display screens. Docsity.com