Operating System definitions and about system calls
Operating System Services
User and Operating System-Interface
System Calls
Types of system calls
System Programs
Operating System definitions and about system calls
Operating System Services
User and Operating System-Interface
System Calls
Types of system calls
System Programs
An operating system acts as an intermediary between the user of a computer and computer hardware. The purpose of an operating system is to provide an environment in which a user can execute programs in a convenient and efficient manner.
OS | Functions of OS | Operations of OS | Operations of a process | Scheduling algorithms | FCFS scheduling | SJF scheduling | RR scheduling | Paging | File system implementation | Cryptography as a security tool
An operating system acts as an intermediary between the user of a computer and computer hardware. The purpose of an operating system is to provide an environment in which a user can execute programs in a convenient and efficient manner.
OS | Functions of OS | Operations of OS | Operations of a process | Scheduling algorithms | FCFS scheduling | SJF scheduling | RR scheduling | Paging | File system implementation | Cryptography as a security tool
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
Online blood donation management system project.pdfKamal Acharya
Blood Donation Management System is a web database application that enables the public to make online session reservation, to view nationwide blood donation events online and at the same time provides centralized donor and blood stock database. This application is developed
by using ASP.NET technology from Visual Studio with the MySQL 5.0 as the database management system. The methodology used to develop this system as a whole is Object Oriented Analysis and Design; whilst, the database for BDMS is developed by following the steps in Database Life Cycle. The targeted users for this application are the public who is eligible to donate blood ,'system moderator, administrator from National Blood Center and the staffs who are working in the blood banks of the participating hospitals. The main objective of the development of this application is to overcome the problems that exist in the current system, which are the lack of facilities for online session reservation and online advertising on the nationwide blood donation events, and also decentralized donor and blood stock database. Besides, extra features in the system such as security protection by using password, generating reports, reminders of blood stock shortage and workflow tracking can even enhance the efficiency of the management in the blood banks. The final result of this project is the development of web database application, which is the BDMS.
This document is by explosives industry in which document discussed manufacturing process and flow charts details by nitric acid and sulfuric acid and tetra benzene and step by step details of explosive industry explosives industry is produced raw materials and manufacture it by manufacturing process
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Toll tax management system project report..pdfKamal Acharya
Toll Tax Management System is a web based application that can provide all the information related to toll plazas and the passenger checks in and pays the amount, then he/she will be provided by a receipt. With this receipt he/she can leave the toll booth without waiting for any verification call.
The information would also cover registration of staff, toll plaza collection, toll plaza collection entry for vehicles, date wise report entry, Vehicle passes and passes reports b/w dates.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Welcome to WIPAC Monthly the magazine brought to you by the LinkedIn Group Water Industry Process Automation & Control.
In this month's edition, along with this month's industry news to celebrate the 13 years since the group was created we have articles including
A case study of the used of Advanced Process Control at the Wastewater Treatment works at Lleida in Spain
A look back on an article on smart wastewater networks in order to see how the industry has measured up in the interim around the adoption of Digital Transformation in the Water Industry.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
2. Chapter 2: Operating-System Structures
2.2
● Operating System Services
● User Operating System Interface
● System Calls
● Types of System Calls
● System Programs
● Operating System Design and Implementation
● Operating System Structure
● Operating System Debugging
● Operating System Generation
● System Boot
3. Operating System Services
2.3
● User interface
● Program Execution
● I/O Operations
● File System manipulation
● Communications
● Error detection
● Resource Allocation
● Accounting
● Protection and Security
4. Operating System Services
2.4
● Operating systems provide an environment for execution of programs
and services to programs and users
● One set of operating-system services provides functions that are
helpful to the user:
● User interface - Almost all operating systems have a user
interface (UI).
4 Varies between Command-Line (CLI), Graphics User
Interface (GUI), Batch
● Program execution - The system must be able to load a
program into memory and to run that program, end execution,
either normally or abnormally (indicating error)
● I/Ooperations - A running program may require I/O, which may
involve a file or an I/O device
5. Operating System Services (Cont.)
2.5
● One set of operating-system services provides functions that are helpful to
the user (Cont.):
● File-system manipulation - The file system is of particular interest.
Programs need to read and write files and directories, create and delete
them, search them, list file Information, permission management.
● Communications – Processes may exchange information, on the same
computer or between computers over a network
4 Communications may be via shared memory or through message
passing (packets moved by the OS)
● Error detection – OS needs to be constantly aware of possible errors
4 May occur in the CPU and memory hardware, in I/O devices, in user
program
4 For each type of error, OS should take the appropriate action to
ensure correct and consistent computing
4 Debugging facilities can greatly enhance the user’s and
programmer’s abilities to efficiently use the system
6. Operating System Services (Cont.)
2.6
● Another set of OS functions exists for ensuring the efficient operation of the
system itself via resource sharing
● Resource allocation - When multiple users or multiple jobs running
concurrently, resources must be allocated to each of them
4 Many types of resources - CPU cycles, main memory, file storage,
I/O devices.
● Accounting - To keep track of which users use how much and what
kinds of computer resources
● Protection and security - The owners of information stored in a
multiuser or networked computer system may want to control use of
that information, concurrent processes should not interfere with each
other
4 Protection involves ensuring that all access to system resources is
controlled
4 Security of the system from outsiders requires user authentication,
extends to defending external I/O devices from invalid access
attempts
8. User Operating System Interface - CLI
2.8
CLI or command interpreter allows direct command entry
● Sometimes implemented in kernel, sometimes by systems program
● Sometimes multiple flavors implemented – shells
● Primarily fetches a command from user and executes it
● Sometimes commands built-in, sometimes just names of programs
9. User Operating System Interface - GUI
2.9
● User-friendly desktop metaphor interface
● Usually mouse, keyboard, and monitor
● Icons represent files, programs, actions, etc
● Various mouse buttons over objects in the interface cause various actions
(provide information, options, execute function, open directory (known as a
folder)
● Many systems now include both CLI and GUI interfaces
● Microsoft Windows is GUI with CLI “command” shell
● Apple Mac OS X is “Aqua” GUI interface with UNIX kernel underneath
and shells available
● Unix and Linux have CLI with optional GUI interfaces (CDE, KDE, GNOME)
10. Touchscreen Interfaces
2.10
● Touchscreen devices require new
interfaces
● Mouse not possible or not desired
● Actions and selection based on
gestures
● Virtual keyboard for text entry
● Voice commands.
12. Operating System Mode
The User Mode is concerned with the
actual interface between the user and the
system.
It controls things like running applications
and accessing files.
The Kernel Mode is concerned with everything
running in the background.
It controls things like accessing system
resources, controlling hardware functions and
processing program instructions.
System calls are used to change mode
from User to Kernel.
13. Kernel
Kernel is a software code that reside in central core of OS. It has complete
control over system.
When operation system boots, kernel is first part of OS to load in main memory.
Kernel remains in main memory for entire duration of computer session. The
kernel code is usually loaded in to protected area of memory.
Kernel performs it’s task like executing processes and handling interrupts in
kernel space.
User performs it’s task in user area of memory.
This memory separation is made in order to prevent user data and kernel data
from interfering with each other.
Kernel does not interact directly with user, but it interacts using SHELL and other
programs and hardware.
14. Kernel cont…
Kernel includes:-
1. Scheduler: It allocates the Kernel’s processing time to various
processes.
2. Supervisor: It grants permission to use computer system resources to
each process.
3. Interrupt handler : It handles all requests from the various hardware
devices which compete for kernel services.
4. Memory manager : allocates space in memory for all users of kernel
service.
kernel provides services for process management, file management,
I/O management, memory management.
System calls are used to provide these type of services.
15. System Call
System call is the programmatic way in which a computer program/user
application requests a service from the kernel of the operating system on
which it is executed.
Application program is just a user-process. Due to security reasons , user
applications are not given access to privileged resources(the ones controlled
by OS).
When they need to do any I/O or have some more memory or
spawn a process or wait for signal/interrupt, it requests operating
system to facilitate all these. This request is made through System
Call.
System calls are also called software-interrupts.
17. How System Call Works?
Step 1) The processes executed in the user mode till the time a system call interrupts it.
Step 2) After that, the system call is executed in the kernel-mode on a priority basis.
Step 3) Once system call execution is over, control returns to the user mode.,
Step 4) The execution of user processes resumed in Kernel mode.
18. Why do you need System Calls in OS?
Following are situations which need system calls in OS:
Reading and writing from files demand system calls.
If a file system wants to create or delete files, system calls are required.
System calls are used for the creation and management of new processes.
Network connections need system calls for sending and receiving packets.
Access to hardware devices like scanner, printer, need a system call.
27. Important System Calls Used in OS
for process control
wait()
In some systems, a process needs to wait for another process to complete its
execution. This type of situation occurs when a parent process creates a child
process, and the execution of the parent process remains suspended until its child
process executes.
The suspension of the parent process automatically occurs with a wait() system call.
When the child process ends execution, the control moves back to the parent process.
fork()
Processes use this system call to create processes that are a copy of themselves.
With the help of this system Call parent process creates a child process, and the
execution of the parent process will be suspended till the child process executes.
exec()
This system call runs when an executable file in the context of an already running
process that replaces the older executable file. However, the original process identifier
remains as a new process is not built, but stack, data, head, data, etc. are replaced by
the new process.
28. Important System Calls Used in OS
for process control
kill():
The kill() system call is used by OS to send a termination signal to a process that
urges the process to exit. However, a kill system call does not necessarily mean killing
the process and can have various meanings.
exit():
The exit() system call is used to terminate program execution. Specially in the multi-
threaded environment, this call defines that the thread execution is complete. The OS
reclaims resources that were used by the process after the use of exit() system call.
29. Summary system calls:
Categories Windows Unix
Process control
CreateProcess()
ExitProcess()
WaitForSingleObject()
fork()
exit()
wait()
Device manipulation
SetConsoleMode()
ReadConsole()
WriteConsole()
loctl()
read()
write()
File manipulation
CreateFile()
ReadFile()
WriteFile()
CloseHandle()
Open()
Read()
write()
close()
30. Summary system calls:
Categories Windows Unix
Communication
CreatePipe()
CreateFileMapping()
MapViewOfFile()
Pipe()
shm_open()
mmap()
Protection
SetFileSecurity()
InitlializeSecurityDescriptor()
SetSecurityDescriptorGroup ()
Chmod()
Umask()
Chown()
32. 1. Process Management
A process is a program in execution.
A process needs certain resources, including CPU time,
memory, files, and I/O devices to accomplish its task.
Simultaneous execution leads to multiple processes. Hence
creation, execution and termination of a process are the
most basic functionality of an OS
If processes are dependent, than they may try to share
same resources. thus task of process synchronization
comes to the picture.
If processes are independent, than a due care needs to be
taken to avoid their overlapping in memory area.
Based on priority, it is important to allow more important
processes to execute first than others.
37. 2. 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. When the computer made turn
off everything stored in RAM will be erased automatically.
In addition to the physical RAM installed in your computer, most modern
operating systems allow your computer to use a virtual memory system.
Virtual memory allows your computer to use part of a permanent storage
device (such as a hard disk) as extra memory.
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 de-allocate memory space as needed.
40. 2. Memory management: Paging
In Operating Systems, Paging is a storage mechanism used to
retrieve processes from the secondary storage into the main
memory in the form of pages.
The main idea behind the paging is to divide each process in the
form of pages. The main memory will also be divided in the form
of frames.
One page of the process is to be stored in one of the frames of the
memory. The pages can be stored at the different locations of the
memory but the priority is always to find the contiguous frames
or holes.
Pages of the process are brought into the main memory only
when they are required otherwise they reside in the secondary
storage.
43. 2. Memory management: Paging
Let us consider that, P2 and P4 are moved to waiting state after some time.
44. 2. Memory management: Segmentation
It is better to have segmentation which divides the process into the segments. Each
segment contains the same type of functions such as the main function can be
included in one segment and the library functions can be included in the other
segment.
49. 2. Memory management: Fragmentation
User processes are loaded and unloaded from the main memory, and processes are
kept in memory blocks in the main memory. Many spaces remain after process
loading and swapping that another process cannot load due to their size. Main
memory is available, but its space is insufficient to load another process because
of the dynamical allocation of main memory processes.
51. 2. Memory management: Swapping
Swapping is a memory management scheme in which any process
can be temporarily swapped from main memory to secondary
memory so that the main memory can be made available for other
processes. It is used to improve main memory utilization. In
secondary memory, the place where the swapped-out process is
stored is called swap space.
52. 3. File Management
A file is a collection of related information defined by its
creator.
File systems provide the conventions for the
encoding, storage and management of data on a
storage device such as a hard disk.
FAT12 (floppy disks)
FAT16 (DOS and older versions of Windows)
FAT32 (older versions of Windows)
NTFS (newer versions of Windows)
EXT3 (Unix/Linux)
HFS+ (Max OS X)
The operating system is responsible for the following activities
in connections with file management:
✦ File creation and deletion.
✦ Directory creation and deletion.
✦ Support of primitives for manipulating files and directories.
✦ Mapping files onto secondary storage.
✦ File backup on stable (nonvolatile) storage media.
60. 4. Device Management or I/O Management
Device controllers are components on the motherboard (or on expansion
cards) that act as an interface between the CPU and the actual
device.
Device drivers, which are the operating system software components that
interact with the devices controllers.
A special device (inside CPU) called the Interrupt Controller handles the
task of receiving interrupt requests and prioritizes them to be forwarded
to the processor.
Deadlocks can occur when two (or more) processes have control of
different I/O resources that are needed by the other processes, and they
are unwilling to give up control of the device.
It performs the following activities for device management.
Keeps tracks of all devices connected to system.
Designates a program responsible for every device known as Input/output
controller.
Decides which process gets access to a certain device and for how long.
Allocates devices in an effective and efficient way.
Deallocates devices when they are no longer required.
61. 5. Security & Protection
The operating system uses password protection to protect user data and
similar other techniques.
It also prevents unauthorized access to programs and user data by assigning
access right permission to files and directories.
The owners of information stored in a multiuser or networked computer
system may want to control use of that information, concurrent processes
should not interfere with each other.
62. 6. User
Interfac
e
Mechani
sm
A user interface (UI) controls how you enter data and
instructions and how information is displayed on the
screen
There are two types of user interfaces
1. Command Line Interface
2. Graphical user Interface
63. 1.
Comma
nd-line
interfac
e
In a command-line interface, a user types commands represented by short
keywords or abbreviations or presses special keys on the keyboard to enter
data and instructions