This document outlines the course structure and content for an Operating System Concepts lecture series. It discusses exams, assignments, course requirements, and how students can earn good marks. The lecture topics are then summarized, including operating system concepts and structures, processes, threads, CPU scheduling, synchronization, deadlocks, memory management, virtual memory, file systems, and mass storage. It defines the purpose of an operating system as a program that acts as an intermediary between the user and computer hardware to provide a simpler interface and efficiently manage system resources.

1. Operating System
Concepts
Lecture 1

2. Course Administration
• Exams and Assessment
– Basically 2 exams method Mid & Final
• 10 Sessional1
• 15 Sessional2
• 50 Final
• 25 Assignment/Quizes
– Eliminating one Exam suggests that there is a clear
room for more practical work (so you must start
getting worried about it !!!)
6 December 2021

3. Course Requirements
• Assignments/Quizes
– Written assignments (Small Tasks) (details in
coming lectures)
– Idea is to initiate research oriented writing not
“cut-copy-paste”
– Attendance, Presentations, Quiz & Class
Discussion & Participation (as a regular activity)
– Sessional’s loot sale
– Formal Presentations in groups
6 December 2021

4. How to get good marks?
• Requirements
– Overall Class Attitude
– Things to Avoid (Referencing, Cut-Copy-Paste
Culture, Carelessness, leg-pulling)
– Things to do (Innovation, Confidence, Work
Attitude)
– Sense of Maturity and continuous learning
6 December 2021

5. Examination
• I personally believe in “thorough studies” so usually no
choices given in the exam
• Every thing discussed, during the class or given as reading
material, could be part of the exams
• Questions will be formulated in a way to examine both
bookish as well as conceptual thinking
• Other details will be given close to Sessional
• I will try to follow my simple rule that is
– “ I’ll be very friendly in the lectures and very strict in
the exam hall (believe me no chance of misconduct…)”
6 December 2021

6. Text & References
• Focus will be on topics rather Chapters of any
text
• Many Text/books are available in market
– Operating System by H.M. Deitel
– Operating System concepts by Silberschatz
6 December 2021

7. 6 December 2021
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

8. Computer System
1. Hardware
2. Operating system
3. Applications programs
4. Users
6 December 2021

9. Layered View of a Computer
System
6 December 2021

10. 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 December 2021

11. 6 December 2021
Computer System Hardware
Keyboard Mouse
Printer
RAM/ROM
HD
Mem
Bus
System Bus
Monitor
CD
Processor
Floating Point
Unit
Integer
Unit
Cache
Control
Unit

12. 6 December 2021
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

13. 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
6 December 2021

14. 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
6 December 2021

15. Introduction to UNIX/Linux
• Directory structure
• Browsing directory structure
• Useful commands
6 December 2021

16. 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.)
6 December 2021

17. Processes (continued)
• Sample code for UNIX/Linux process
management
• Cooperating processes
• Interprocess communication (IPC)
• IPC in UNIX/Linux (pipe, FIFO, socket,
message queue, etc.)
6 December 2021

18. 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.)
6 December 2021

19. Threads
• Thread concept (thread, states,
attributes, etc.)
• User- and kernel-level threads
• POSIX threads (the pthread
library)
• Sample code
6 December 2021

20. CPU Scheduling
• Basic concepts
• Scheduling criteria
• Scheduling triggers
• Scheduling algorithms
• UNIX System V scheduling algorithm
• Optimal scheduling
• Algorithm evaluation
6 December 2021

21. 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
6 December 2021

22. 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
6 December 2021

23. Deadlocks
• Basic concept
• Deadlock characterization
• Deadlock handling (prevention, avoidance,
detection and recovery)
• Banker’s algorithm
6 December 2021

24. Memory Management
• Basic concepts
• Various techniques for memory
management
• Logical to physical address translation
• Swapping
• Contiguous memory allocation:
• External fragmentation
• Paging
• Hardware support for paging
• Internal fragmentation
6 December 2021

25. 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
6 December 2021

26. 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, …)
6 December 2021

27. 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.)
6 December 2021

28. 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)
6 December 2021

29. Mass Storage Structure and
Scheduling
• Disk structure and scheduling
• Disk management (formatting,
boot block, bad blocks, etc.)
• Course Recap
6 December 2021

30. 6 December 2021
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

31. 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.
6 December 2021

32. Available operating systems in the
market
• Popular modern operating system includes, Android
• BSD (Berkeley Software Distribution)
• iOS
• Linux
• MAC OS X
• Microsoft Windows
• Window phone
• IBM z/OS
• Symbian etc.
• All these except Windows and z/OS, share roots in UNIX
6 December 2021
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