Biyani's Think Tank
Concept based notes
Deptt. of IT
Biyani Girls College, Jaipur
Published by :
Biyani Group of Colleges
Concept & Copyright :
Biyani Shikshan Samiti
Sector-3, Vidhyadhar Nagar,
Jaipur-302 023 (Rajasthan)
Ph : 0141-2338371, 2338591-95 Fax : 0141-2338007
E-mail : [email protected]
Website :www.gurukpo.com; www.biyanicolleges.org
Edition : 2012
Leaser Type Setted by :
Biyani College Printing Department
While every effort is taken to avoid errors or omissions in this Publication, any mistake or
omission that may have crept in is not intentional. It may be taken note of that neither the
publisher nor the author will be responsible for any damage or loss of any kind arising to
anyone in any manner on account of such errors and omissions.
Operating System 3
I am glad to present this book, especially designed to serve the needs of the
students. The book has been written keeping in mind the general weakness in
understanding the fundamental concepts of the topics. The book is self-explanatory and
adopts the “Teach Yourself” style. It is based on question-answer pattern. The language
of book is quite easy and understandable based on scientific approach.
Any further improvement in the contents of the book by making corrections,
omission and inclusion is keen to be achieved based on suggestions from the readers
for which the author shall be obliged.
I acknowledge special thanks to Mr. Rajeev Biyani, Chairman & Dr. Sanjay Biyani,
Director (Acad.) Biyani Group of Colleges, who are the backbones and main concept
provider and also have been constant source of motivation throughout this endeavour.
They played an active role in coordinating the various stages of this endeavour and
spearheaded the publishing work.
I look forward to receiving valuable suggestions from professors of various
educational institutions, other faculty members and students for improvement of the
quality of the book. The reader may feel free to send in their comments and suggestions
to the under mentioned address.
OPERATING SYSTEM (MCA-204)
Introduction: Definition and types of operating systems, Batch Systems, multi
programming, time–sharing parallel, distributed and real-time systems, Operating
system structure, Operating system components and services, System calls, system
programs, Virtual machines.
Process Management: Process concept, Process scheduling, Cooperating processes,
Threads, Inter-process communication, CPU scheduling criteria, Scheduling algorithms,
Multiple processor scheduling, Real-time scheduling and Algorithm evaluation.
Process Synchronization and Deadlocks: The Critical-Section problem, synchronization
hardware, Semaphores, Classical problems of synchronization, Critical regions,
Monitors, Deadlocks-System model, Characterization, Deadlock prevention, Avoidance
and Detection, Recovery from deadlock, Combined approach to deadlock handling.
Storage management: Memory Management-Logical and Physical Address Space,
Swapping, Contiguous Allocation, Paging, Segmentation with paging, Virtual Memory,
Demand paging and its performance, Page replacement algorithms, Allocation of
frames, Thrashing, Page Size and other considerations, Demand segmentation,
File systems, secondary Storage Structure, File concept, access methods, directory
implementation, Efficiency and performance, recovery, Disk structure, Disk scheduling
methods, Disk management, Recovery, Disk structure, disk scheduling methods, Disk
management, Swap-Space management, Disk reliability.
Protection and Security-Goals of protection, Domain of protection, Access matrix,
Implementation of access Matrix, Revocation of Access Rights, language based
protection, The Security problem, Authentication, One Time passwords, Program
threats, System threats, Threat Monitoring, Encryption.
Case study: Windows NT-Design principles, System components, Environmental,
Environmental subsystems, File system, Networking and program interface.
Subsystems, File system, Networking and program interface.
□ □ □
Operating System 5
S.No. Name of Topic
1. Introduction to Operating System
1.1 Definition of Operating system
1.2 Types of operating system
1.3 Operating system structure
1.4 Operating system components and services
1.5 System calls, system programs
1.6 Virtual machines.
2. Process Management
2.1 Process concept, Process
2.2 Cooperating processes
2.4 Inter-process communication
2.5 scheduling CPU scheduling criteria
2.6 Scheduling algorithms & Algorithm evaluation.
2.7 Multiple processor scheduling
2.8 Real-time scheduling
3. Process synchronization and deadlocks
3.1 The Critical-Section problem, Critical regions
3.2 synchronization hardware
3.4 Classical problems of synchronization
3.6 Introduction to Deadlocks, System model
3.7 Necessary conditions for deadlock
3.8 Deadlock prevention, Avoidance
3.9 Detection, Recovery from deadlock
3.10 Combined approach to deadlock handling
S.No. Name of Topic Page No.
4. Primary memory management
4.1 Logical and Physical Address Space, Swapping
4.2 Contiguous Allocation
4.3 Paging, Segmentation with paging
4.4 Virtual Memory, Demand paging and its
4.5 Page replacement algorithms, Allocation of frames
4.6 Thrashing, Page Size and other considerations
4.7 Demand segmentation
5. Secondary storage management
5.1 File systems
5.2 secondary Storage Structure
5.3 File concept, access methods
5.4 directory implementation, Efficiency and
5.5 Disk structure
5.6 Disk scheduling methods
5.7 Disk management, Recovery, Disk reliability
5.8 Swap-Space management.
6. Protection and security
6.1 Goals of protection,
6.2 Access matrix, Implementation of access Matrix
Operating System 7
6.3 Revocation of Access Rights, language based
6.4 The Security problem
6.5 Authentication, One Time passwords
6.6 Program threats, System threats, Threat Monitoring
Introduction to Operating system
Q1 What do you mean by Operating System?
Ans: Operating System:- An operating system is a System software that acts as an
intermediary between a user of a computer and the computer hardware. The
purpose of an operating system is to provide an environment in which a user can
execute program. An operating system is an important part of almost every
computer system. It is basically a control program that controls the execution of
user programs to prevent errors and improper use of the computer. A computer
system can be divided roughly into four components: the hardware,
the operating system, the application programs, and the users
Q2 Write about various types of Operating systems.
Ans Evolution of Operating system:- The various types of operating systems evolved
can be briefly described as follows:-
1- Batch System:- This type of Operating systems was used in the earlier age. To
speed up processing, jobs with similar needs were batched together and were
run through the computer as a group. The definitive feature of a batch system is
the lack of interaction between the user and the job while that job is executing. In
this execution environment, the CPU is often idle.
Operating System 9
Memory layout for a batch system
In this execution environment, the CPU is often idle, because the speeds of
the mechanical I/O devices are intrinsically slower than are those of electronic
devices. The introduction of disk technology allowed the operating system to
keep all jobs on a disk, rather than in a serial card reader. With direct access to
several jobs, the operating system could perform job scheduling, to use resources
and perform tasks efficiently.
2- Multiprogramming Systems:- In this type of Operating systems, more than one
program will reside in to main memory. The operating system picks and begins
to execute one of the jobs in the memory. Eventually, the job may have to wait
for some task, the operating system simply switches to and executes another job.
When the first job finishes waiting and gets the CPU back. As long as there is
always some job to execute, the CPU will never be idle.
Memory layout for a multiprogramming system
3 Time Sharing Systems:- A time-shared operating system allows the many users to
share the computer simultaneously. A time-shared operating system uses CPU
scheduling and multiprogramming to provide each user with a small portion of a
time-shared computer. Time sharing (or multitasking) is