DIT1353 Fundamentals Of Operating Systems PDF

DIT1353 FUNDAMENTALS OF OPERATING SYSTEMS TOPIC 1 – INTRODUCTION TO OPERATING SYSTEMS Course Objectives Introduces operating systems history and it’s changing roles in our current technological climate. The different types & designs of modern operating systems, and the general kinds...

DIT1353 FUNDAMENTALS OF OPERATING SYSTEMS TOPIC 1 – INTRODUCTION TO OPERATING SYSTEMS Course Objectives Introduces operating systems history and it’s changing roles in our current technological climate. The different types & designs of modern operating systems, and the general kinds of management & administration approaches that are taken in most architecture. Covered are the following types of architecture as reflected by their user market share, Windows, Android ( Mobile ), UNIX Based & Linux What is an Operating System (OS)? An operating system (OS) is a software that manages computer hardware and provides common services for computer programs. It acts as an intermediary between the hardware and the software applications, ensuring that programs can utilize hardware resources efficiently and securely. Types of Operating System (OS)? Window MacOS Linux Android IOS What Operating Systems Do? Operating System (OS) Anintermediary between software and the computer hardware. Software OS Hardware I’M THE MIDDLE MAN What is an Operating System (OS)? Users Compiler Assembler Text Editor Database System System and Applications Operating System Computer Hardware  What Operating Systems Do? Hide the complexity of hardware. Abstraction Provide a clean interface for using resources. What if you have to setup the hard disk to read a file? Manage all resources (memory, storage, etc). Resource Efficient and fair use of resources. Manager What if you are printing multiple documents? Abstraction for Software's ( allows developers to write software's faster and support more systems ) Resource Management for our hardware ( prevent unresponsiveness ) What is an Operating System (OS)? Users Compiler Assembler Text Editor Database System System and Applications Operating System Computer Hardware  Graphic Card C. Execute 3. the bootthe Execute loader to read program to the lookOS forinto thepartition. active memory. A. Check if all devices are responding correctly. CPU BIOS RAM 2. Load the first B. bootsector loaderoffrom the boot the active devicepartition into theinto memory. the memory. Hard Disk What is an Operating System (OS)? Users Compiler Assembler Text Editor Database System System and Applications Operating System Computer Hardware What is an Operating System? Generally: Users System and Applications Operating Commands / System Calls System Kernel Computer Hardware It's a collection of system programs and the main OS program called the kernel. And how most application interface with the kernel is through system calls or What is an Operating System? A more detail version: The kernel software of an operating systems are mainly a collection of system services that provide a lot of functionalities: Process/Program execution through allocation of CPU resources; I/O Operations ( mostly peripherals ) File System ( access through our storage devices, HDD, SSD, Thumbdrives ) Communication ( more than just what we know as networking, which is communication between multiple computers across a network but also communication between different processes or software in a system, communication between different processes is called IPC and is a heavily studied field in concurrent programming ) Accounting (consists of keeping track of the behavior of both users and processes in the computing system. For instance, the operating system analyzes which users require the execution of which processes. So, it can also investigate how many computing resources are requested by the processes executing on the computer. ) Three Essential Components Memory OS Process Storage Process Management How OSs manage them?  Process Management A program is only a set of instructions which defines what is it to do for us to get what we want. A process is a set of instructions is being executed, it means that we can have multiple processes of the same program. Or a program that does multiple process of executions. Toexecute the process requires resources which is where the OS comes in. OS Activities: Allocate resources (e.g. memory, files). Create and delete the process. Pause and resume the process. Provide mechanism for process communication. Process Management int x = 10; 0001 0110 0100 1010 int y = 12; 0001 0110 0101 1100 int z = x + y; Compiler 0010 0001 0010 0000 0011 0110 0110 0000 Memory Address Contents Remarks 100 10 Integer x 101 12 Integer y 102 22 Integer z 103 0 - 104 0001 0110 0100 1010 ADDI #10 100 105 0001 0110 0101 1100 ADDI #12 101 106 0010 0001 0010 0000 ADD 100 101 107 0011 0110 0110 0000 STORE 102 Process Management What we can notice is that there is a bunch of process being executed Which component executes all these ? Process Management Central Processing Unit (CPU) / Processor Process Scheduling Sequence of execution? Process Management (Process Scheduling) Determines the sequence of execution. Different types of algorithm. First-Come First-Serve ( FIFO ) Shortest Job First Priority Scheduling Round Robin Three Essential Components Memory OS Process Storage Memory Management Besides the process we can also see the amount of RAM being utilized. Though ideally, we would want everything in the RAM but this is usually limited. How OSs manage the use of memory?  Memory Management Microsoft Office Google Chrome Operating System Main Memory Memory management is the process of controlling and coordinating a computer's main memory. It ensures that blocks of memory space are properly managed and allocated so the operating system (OS), applications and other running processes have the memory they need to carry out their operations. Memory Management Determines what to be in the memory. Optimizing CPU utilization and computer response to users. OS Activities: Keeping track of which parts of memory are currently being used and by whom. Deciding which processes and data to move into and out of the memory. Allocating and de-allocating memory space as needed. Three Essential Components Memory OS Process Storage Storage-Device Hierarchy Faster access time, greater cost per bit Greater capacity, smaller cost per bit CPU Greater capacity, slower access time RAM Secondary Storage Cost Performance Storage Management Determines the storage of files. OS Activities: Manipulate files and directories. Free-space management. Allocation of free-space. Distributed System Collection of physically separated computer systems that are connected together. Distributed System What’re the advantages? Gain access to various resources. Increases: Computation Speed Functionality Data Availability Reliability Protection and Security Mechanisms necessary for the protection and security of computer systems. To control the authorization of accessing different resources. Asymmetric and symmetric encryption. Threats: Trojan Horse Logic Bomb Trap Door Denial-of-Service