Lec1.CS604.ppt
- 1. Click to add Text Operating Systems Lecture 1
- 2. July 12, 2023 © Copyright Virtual University of Pakistan Agenda for Today Introduction and purpose of the course Organization of a computer system Purpose of a computer system—setting the stage for OS concepts and principles Outline of topics to be discussed in the course What is an operating system? Recap of the lecture
- 3. July 12, 2023 © Copyright Virtual University of Pakistan Computer System 1. Hardware 2. Operating system 3. Applications programs 4. Users
- 4. July 12, 2023 © Copyright Virtual University of Pakistan Layered View of a Computer System
- 5. July 12, 2023 © Copyright Virtual University of Pakistan Purpose of a Computer System Computer systems consist of software and hardware that are combined to provide a tool to solve specific problems in an efficient manner Execute programs
- 6. July 12, 2023 © Copyright Virtual University of Pakistan Computer System Hardware Keyboard Mouse Printer RAM/ROM HD Mem Bus System Bus Monitor CD Processor Floating Point Unit Integer Unit Cache Control Unit
- 7. July 12, 2023 © Copyright Virtual University of Pakistan Course Outline Operating system concepts Operating system structures Introduction to UNIX/Linux user interface Processes and threads—scheduling, concurrency, synchronization, etc. Deadlocks Memory management Virtual memory File system Secondary storage management
- 8. July 12, 2023 © Copyright Virtual University of Pakistan Operating System Concepts Single-user systems Batch systems Multiprogrammed systems Time-sharing systems Real-time systems Interrupts, traps, and software interrupts (UNIX signals) Hardware protection
- 9. July 12, 2023 © Copyright Virtual University of Pakistan Operating System Structures Operating system services System calls Semantics of system call execution Operating system structures (monolithic, microkernel-based, layered, virtual machines, DOS-Windows, UNIX) System design and implementation
- 10. July 12, 2023 © Copyright Virtual University of Pakistan Introduction to UNIX/Linux Directory structure Browsing directory structure Useful commands
- 11. July 12, 2023 © Copyright Virtual University of Pakistan Processes Process concept (process, states, attributes, etc.) Process scheduling (scheduler) Context switching (dispatcher) Operations on processes (creation, termination, signaling, suspend, foreground, background, etc.) Process management in UNIX (fork, wait, exec, exit, etc.)
- 12. July 12, 2023 © Copyright Virtual University of Pakistan Processes (continued) Sample code for UNIX/Linux process management Cooperating processes Interprocess communication (IPC) IPC in UNIX/Linux (pipe, FIFO, socket, message queue, etc.)
- 13. July 12, 2023 © Copyright Virtual University of Pakistan Processes (continued) Communication between UNIX/Linux processes (pipe, mkfifo, read, write, close, etc.) Sample code UNIX/Linux processes (process images, control structures, etc. explained with sample code) Managing UNIX/Linux processes (ps, top, fg, bg, <Ctrl-Z>, <Ctrl-C>, etc.)
- 14. July 12, 2023 © Copyright Virtual University of Pakistan Threads Thread concept (thread, states, attributes, etc.) User- and kernel-level threads POSIX threads (the pthread library) Sample code
- 15. July 12, 2023 © Copyright Virtual University of Pakistan CPU Scheduling Basic concepts Scheduling criteria Scheduling triggers Scheduling algorithms UNIX System V scheduling algorithm Optimal scheduling Algorithm evaluation
- 16. July 12, 2023 © Copyright Virtual University of Pakistan Process Synchronization Basic concept The Critical Section Problem Solutions for the Critical Section Problem Software-based solutions—the Bakery Algorithm Hardware-based solutions Semaphores Binary and counting semaphores
- 17. July 12, 2023 © Copyright Virtual University of Pakistan Process Synchronization … Classic problems of synchronization Deadlocks and starvation Critical regions Monitors Synchronization tools used in Solaris, Linux, and Windows Deadlocks and starvation Pthread library functions
- 18. July 12, 2023 © Copyright Virtual University of Pakistan Deadlocks Basic concept Deadlock characterization Deadlock handling (prevention, avoidance, detection and recovery) Banker’s algorithm
- 19. July 12, 2023 © Copyright Virtual University of Pakistan Memory Management Basic concepts Various techniques for memory management Logical to physical address translation Swapping Contiguous memory allocation: MFT, MVT External fragmentation Paging Hardware support for paging Internal fragmentation
- 20. July 12, 2023 © Copyright Virtual University of Pakistan Memory Management … Performance of paging Protection and sharing Page table issues: Multi-level paging, Hashed page tables, Inverted page tables Segmentation Protection and sharing Segmentation with paging Intel P4 example
- 21. July 12, 2023 © Copyright Virtual University of Pakistan Virtual Memory Basic concept Demand paging Page fault Performance of demand paging Page replacement Allocation of frames Thrashing Operating-system examples Other considerations (I/O locking, page size, …)
- 22. July 12, 2023 © Copyright Virtual University of Pakistan File System Interface Basic concepts (file attributes, operations, types, structure, etc.) Access methods (sequential, random, etc.) Directory structure UNIX/Linux directory structure (links in UNIX) File system mounting, sharing, and protection UNIX/Linux examples for sharing and protection, and relevant commands (chmod, ln, ln –s, etc.)
- 23. July 12, 2023 © Copyright Virtual University of Pakistan File System Implementation Basic concepts (overview of disk structure, file structure, boot control block, super block, inode, per process file descriptor table, system-wide open-file table, etc.) Directory implementation Free space management methods Space Allocation Methods Time and space performance of allocation methods Brief introduction to Network File System (NFS)
- 24. July 12, 2023 © Copyright Virtual University of Pakistan Mass Storage Structure and Scheduling Disk structure and scheduling Disk management (formatting, boot block, bad blocks, etc.) Course Recap
- 25. July 12, 2023 © Copyright Virtual University of Pakistan What is an Operating System? A program that acts as an intermediary between a user of a computer and the computer hardware—provides the user a simpler (virtual) machine to work with A program that allocates and deallocates computer system resources in an efficient, fair, and secure manner—a resource manager
- 26. July 12, 2023 © Copyright Virtual University of Pakistan 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.
- 27. Click to add Text Operating Systems Lecture 1