Operating Systems - CSEN 602 Lecture Slides PDF

German University in Cairo (GUC) Faculty of Media Engineering and Technology Operating Systems - CSEN 602 Module 1: Introduction to Oper...

German University in Cairo (GUC) Faculty of Media Engineering and Technology Operating Systems - CSEN 602 Module 1: Introduction to Operating Systems Lecture 01: Overview of OS © Dr. Eng. Catherine M. Elias and Dr. Aya Salama © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Outline What is an Operating System? What is Abstraction? What is Arbitration? Let’s Understand more the OS © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 2 Operating System What is an Operating System? Storage and Work Spaces Tools Let’s Visit our Toy Shop The Toy Shop Manager Toys This is our Operating Systems ☺ How!!! © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 3 Operating System What is an Operating System? The Simple Definition An Operating System is a special piece of software that Abstracts & Arbitrates The use of a computer system © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 4 Operating System What is Abstraction? In the context of computing, an abstraction is a representation that hides specifics from a consumer of services, making a system more generic and thus easily understood. Abstraction is the process of hiding the details and complexity of a system and presenting a simplified and consistent view to the users and applications. © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 5 Operating System What is Abstraction? Example An OS abstracts the details of disk drives, By using APIs, applications do not need to know keyboards, monitors, and other devices, and the specifics of the hardware or the OS and can provides a uniform way of accessing them run on different platforms and devices with through application programming interfaces minimal changes. (APIs). © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 6 Operating System Why Abstraction? The code Performs The operating Operation The operating Each running The operating needed to operations on system systems system program is system can control behalf of introduces introduce the transforms called a enforce peripheral programs. new functions file the computer process. security devices is not Example: as it abstracts abstraction so hardware into through standardized Input/Output the hardware. that programs multiple abstraction. don’t need to virtual have a disk to computers. operate. © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 7 Operating System What is Arbitration? Arbitration means the capability of the operating system in managing, overseeing, and controlling the underlying hardware use. The set of rules in a computer’s operating system for allocating the resources of the computer. It also means that the operating system manages access to shared hardware resources so that multiple applications can run on the same hardware at the same time without interfering with one another. © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 8 Operating System Why Arbitration? Allows its Must be able to peripheral handle the devices or potential access memory to be conflicts run by more between than one user. processors. Arbitration failure occurs when multiple Can result in request signals data corruption. arrive at the same location at the same time. © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 9 Operating System Abstraction Vs. Arbitration Let’s take a quick quiz … © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 10  Operating System Let’s Understand more the OS An Operating System is like a Toy Shop Direct Manager : Operational 1. Control Use of Employee time, parts, tools, etc. Resources 2. Fairness, Safety, Cleanup 3. Simplifies operations & optimizes performance Enforce Working Policies Mitigates Difficulty of Complex Tasks Let’s see how this relates to our Operating Systems ☺ © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 11 Operating System Let’s Understand more the OS An Operating System is like a Toy Shop Direct Manager : Operational 1. Control Use of CPU, memory, peripheral Resources devices, etc. 2. Fair resource access, limits to resource usage 3. Abstract hardware details (System calls) Enforce Working Policies Mitigates Difficulty of Complex Tasks © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 12 Operating System Why OS? Application Layer Hardware Layer © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 13 Operating System Why OS? Application Layer Memory Disk Hardware Layer Ethernet/Wifi Card © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 14 Operating System Why OS? What if applications ran directly on hardware? Problems: Portability Application Layer Resource sharing Memory Disk Hardware Layer Ethernet/Wifi Card © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 15 Operating System Why OS? Application Layer The operating system is the software layer between user applications and the hardware Operating System Layer The OS is “all the code that you Memory didn’t have to write” to implement your application Disk Hardware Layer Ethernet/Wifi Card © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 16  Operating System What does an OS do? Application Layer Beautician that hides all the ugly low- level details so that anyone can use Read/write to the storage Wizard that makes it appear to each Protection and Send/Receive Socket Network Isolation Operating System Layer program that it owns the machine and Memory Management CPU Scheduling shares resources while making them Memory seem better than they are Referee that arbitrates the available resources between the running programs efficiently, safely, fairly, and securely Managing a million crazy things happening at the same time is part of that Concurrency Disk Elephant that remembers all your data and makes it accessible to you -- persistence Hardware Layer Ethernet/Wifi Card © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 17 Operating System Understanding of OS Definition and Functionality Let’s take a quick quiz … © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 18 Thank you ☺ Thanks for your attention☺ Questions Please.. © Dr. Eng. Catherine M. Elias and Dr. Aya Salama Lecture 01: Overview of OS Monday, February 3, 2025 19