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Lectures On:

Functions & Goals of the Operating System

��Department of �Computer Science and Engineering�www.cse.ugv.edu.bd, 874/322, C&B Road, Barisal, Bangladesh.� 

University of Global Village (UGV)

Barishal, Bangladesh

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Lectures By��Md. Tariqul Islam�Lecturer & Coordinator

�Mobile: +880-1842733104 �Email: tariq.ugv@gmail.com

www.faculty.ugv.edu.bd/tariqul

www.sites.google.com/view/tariq-ugv

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Functions of the Operating System

To brief, Following are some of important functions of an operating System which we will look in more detail in upcoming chapters:

Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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Functions of the Operating System

  • Process Management
  • I/O Device Management
  • File Management
  • Network Management
  • Main Memory Management
  • Secondary Storage Management
  • Security Management
  • Command Interpreter System
  • Control over system performance
  • Job Accounting
  • Error Detection and Correction
  • Coordination between other software and users
  • Many more other important tasks

Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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Process Management

A process is program or a fraction of a program that is loaded in main memory. A process needs certain resources including CPU time, Memory, Files, and I/O devices to accomplish its task. The process management component manages the multiple processes running simultaneously on the Operating System.

A program in running state is called a process.

Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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Process Management

  • The operating system is responsible for the following activities in connection with process management:
  • Create, load, execute, suspend, resume, and terminate processes.
  • Switch system among multiple processes in main memory.
  • Provides communication mechanisms so that processes can communicate with each others
  • Provides synchronization mechanisms to control concurrent access to shared data to keep shared data consistent.
  • Allocate/de-allocate resources properly to prevent or avoid deadlock situation.

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Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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I/O Device Management

One of the purposes of an operating system is to hide the peculiarities of specific hardware devices from the user. I/O Device Management provides an abstract level of H/W devices and keep the details from applications to ensure proper use of devices, to prevent errors, and to provide users with convenient and efficient programming environment.

Following are the tasks of I/O Device Management component:

  • Hide the details of H/W devices
  • Manage main memory for the devices using cache, buffer, and spooling
  • Maintain and provide custom drivers for each device.

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Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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File Management

  • File management is one of the most visible services of an operating system. Computers can store information in several different physical forms; magnetic tape, disk, and drum are the most common forms.
  • A file is defined as a set of correlated information and it is defined by the creator of the file. Mostly files represent data, source and object forms, and programs. Data files can be of any type like alphabetic, numeric, and alphanumeric.

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A files is a sequence of bits, bytes, lines or records whose meaning is defined by its creator and user.

Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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File Management

The operating system implements the abstract concept of the file by managing mass storage device, such as types and disks. Also files are normally organized into directories to ease their use. These directories may contain files and other directories and so on.

The operating system is responsible for the following activities in connection with file management:

  • File creation and deletion
  • Directory creation and deletion
  • The support of primitives for manipulating files and directories
  • Mapping files onto secondary storage
  • File backup on stable (nonvolatile) storage media

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Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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Network Management

  • The definition of network management is often broad, as network management involves several different components. Network management is the process of managing and administering a computer network. A computer network is a collection of various types of computers connected with each other.
  • Network management comprises fault analysis, maintaining the quality of service, provisioning of networks, and performance management.

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Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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Network Management

Following are the features of network management:

  • Network administration
  • Network maintenance
  • Network operation
  • Network provisioning
  • Network security

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Network management is the process of keeping your network healthy for an efficient communication between different computers.

Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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Main Memory Management

  • Memory is a large array of words or bytes, each with its own address. It is a repository of quickly accessible data shared by the CPU and I/O devices.
  • Main memory is a volatile storage device which means it loses its contents in the case of system failure or as soon as system power goes down.

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Network management is the process of keeping your network healthy for an efficient communication between different computers.

Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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Main Memory Management

The operating system is responsible for the following activities in connections with memory management:

  • Keep track of which parts of memory are currently being used and by whom.
  • Decide which processes to load when memory space becomes available.
  • Allocate and deallocate memory space as needed.

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Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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Secondary Storage Management

  • The main purpose of a computer system is to execute programs. These programs, together with the data they access, must be in main memory during execution. Since the main memory is too small to permanently accommodate all data and program, the computer system must provide secondary storage to backup main memory.
  • Most modern computer systems use disks as the principle on-line storage medium, for both programs and data. Most programs, like compilers, assemblers, sort routines, editors, formatters, and so on, are stored on the disk until loaded into memory, and then use the disk as both the source and destination of their processing.

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Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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Secondary Storage Management

The operating system is responsible for the following activities in connection with disk management:

  • Free space management
  • Storage allocation
  • Disk scheduling

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Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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Security Management

The operating system is primarily responsible for all task and activities happen in the computer system. The various processes in an operating system must be protected from each others activities. For that purpose, various mechanisms which can be used to ensure that the files, memory segment, cpu and other resources can be operated on only by those processes that have gained proper authorization from the operating system.

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Security Management refers to a mechanism for controlling the access of programs, processes, or users to the resources defined by a computer controls to be imposed, together with some means of enforcement.

Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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Security Management

For example, memory addressing hardware ensure that a process can only execute within its own address space. The timer ensure that no process can gain control of the CPU without relinquishing it. Finally, no process is allowed to do its own I/O, to protect the integrity of the various peripheral devices.

Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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Command Interpreter System

  • One of the most important component of an operating system is its command interpreter. The command interpreter is the primary interface between the user and the rest of the system.
  • Command Interpreter System executes a user command by calling one or more number of underlying system programs or system calls.

Command Interpreter System allows human users to interact with the Operating System and provides convenient programming environment to the users.

Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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Command Interpreter System

Many commands are given to the operating system by control statements. A program which reads and interprets control statements is automatically executed. This program is called the shell and few examples are Windows DOS command window, Bash of Unix/Linux or C-Shell of Unix/Linux.

Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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Other Important Activities

An Operating System is a complex Software System. Apart from the above mentioned components and responsibilities, there are many other activities performed by the Operating System. Few of them are listed below:

  • Security − By means of password and similar other techniques, it prevents unauthorized access to programs and data.
  • Control over system performance − Recording delays between request for a service and response from the system.
  • Job accounting − Keeping track of time and resources used by various jobs and users.

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Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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Other Important Activities

  • Error detecting aids − Production of dumps, traces, error messages, and other debugging and error detecting aids.
  • Coordination between other software's and users − Coordination and assignment of compilers, interpreters, assemblers and other software to the various users of the computer systems.

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Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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Goals of Operating System

Primary Goals

  • The primary goals of an operating system (OS) are to provide a easy to use and convenient environment for executing user programs.
  • User Convenience : It should be easy to use, providing a user-friendly interface and making it simple to interact with the system.
  • Program Execution: It facilitates the execution of user programs, providing the necessary environment and services for them to run.
  • Resource Management: The OS manages and allocates the computer's resources, including the CPU, memory, disk storage, and input/output devices, to ensure fair utilization.
  • Security: The OS protects the system and user data from unauthorized access, ensuring the confidentiality, integrity, and availability of information.

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Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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Goals of Operating System

Secondary Goals

  • Efficient Resource Utilization: It should aim to maximize the performance and utilization of computer resources like CPU, Memory and IO devices, ensuring that the system runs smoothly and efficiently.
  • Reliability: It should be robust and reliable, able to handle errors and exceptions gracefully, ensuring that the system continues to operate smoothly. It should be modular in design and easy to debug.

Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv

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“Thank You”

Lectures By Md. Tariqul Islam, Lecturer & Coordinator, Dept. of CSE, UGV, Email: tariq.ugv@gmail.com, Web: www.sites.google.com/view/tariq-ugv