The document discusses I/O protection in operating systems. It explains that I/O protection uses privilege levels or rings, with ring 0 being the highest privilege level containing the kernel mode, and ring 3 being the lowest containing user mode. It also discusses how I/O protection controls access to I/O devices through hardware features like memory-mapped I/O and system calls. The primary function of I/O protection is to provide secure access control to I/O devices and prevent unauthorized access.
Protection and Security in Operating Systemsvampugani
The document discusses protection and security in operating systems. It covers two main techniques used by OSes: protection and security. Protection involves guarding against interference from other authorized users, while security guards against external unauthorized entities. The document outlines various security models, policies, threats, and mechanisms used in OSes like access control lists, authentication, and more. It provides an overview of concepts related to information security in operating systems.
Object oriented analysis emphasizes investigating the problem domain to identify relevant objects and their relationships. The key goals are to define relevant classes and their attributes, operations, relationships, and behaviors through iterative refinement. Various analysis methods take different approaches, but generally involve use case modeling, class modeling, and behavior modeling.
The operating system provides several key services to programs and users, including user interface, program execution, input/output operations, file system management, communications, error detection and handling, resource allocation, accounting, protection, command interpretation, and resource management. These services allow for running programs, performing input/output, creating and managing files, connecting between processes, detecting and handling errors, tracking usage for billing, protecting processes from each other, interpreting user commands, and optimizing resource usage.
This document discusses different process state models in operating systems, including two-state, five-state, and seven-state models. The two-state model has running and not running states. The five-state model adds new, ready, running, blocked, and exit states. Processes move between these states during execution. The seven-state model divides the suspended state in the five-state model into blocked/suspend and ready/suspend states to provide more granularity.
Concept of Failure, error, fault and defectchaklee191
1. The document discusses key concepts in software engineering including failure, error, fault, and defect.
2. A failure occurs when software fails to perform its required function, an error is a mistake by a programmer, a fault is a condition that causes software to fail, and a defect is a bug or flaw in software.
3. The differences are that a defect is a programming mistake, an error causes a defect, a fault is a condition from an error that causes failure when the software does not function as required.
The document discusses use case diagrams in object oriented design and analysis. It defines use cases as descriptions of system functionality from a user perspective. Use case diagrams depict system behavior, users, and relationships between actors, use cases, and other use cases. The key components of use case diagrams are described as actors, use cases, the system boundary, and relationships. Common relationships include association, extend, generalization, uses, and include. An example use case diagram for a cellular telephone is provided to illustrate these concepts.
The document discusses context models and their use in system modeling. Context models illustrate the operational context of a system by showing what lies outside its boundaries, including other systems in the environment. They help define a system's boundaries and show how IT applications fit into the context of people and organizations. Two examples are provided: (1) a Mental Health Care Patient Management System (MHC-PMS) and its connections to other clinical systems; (2) an Automated Teller Machine (ATM) and its links to banking systems. Context models on their own do not show relationships between external systems, so additional models are needed.
A brief introduction to Process synchronization in Operating Systems with classical examples and solutions using semaphores. A good starting tutorial for beginners.
Protection and Security in Operating Systemsvampugani
The document discusses protection and security in operating systems. It covers two main techniques used by OSes: protection and security. Protection involves guarding against interference from other authorized users, while security guards against external unauthorized entities. The document outlines various security models, policies, threats, and mechanisms used in OSes like access control lists, authentication, and more. It provides an overview of concepts related to information security in operating systems.
Object oriented analysis emphasizes investigating the problem domain to identify relevant objects and their relationships. The key goals are to define relevant classes and their attributes, operations, relationships, and behaviors through iterative refinement. Various analysis methods take different approaches, but generally involve use case modeling, class modeling, and behavior modeling.
The operating system provides several key services to programs and users, including user interface, program execution, input/output operations, file system management, communications, error detection and handling, resource allocation, accounting, protection, command interpretation, and resource management. These services allow for running programs, performing input/output, creating and managing files, connecting between processes, detecting and handling errors, tracking usage for billing, protecting processes from each other, interpreting user commands, and optimizing resource usage.
This document discusses different process state models in operating systems, including two-state, five-state, and seven-state models. The two-state model has running and not running states. The five-state model adds new, ready, running, blocked, and exit states. Processes move between these states during execution. The seven-state model divides the suspended state in the five-state model into blocked/suspend and ready/suspend states to provide more granularity.
Concept of Failure, error, fault and defectchaklee191
1. The document discusses key concepts in software engineering including failure, error, fault, and defect.
2. A failure occurs when software fails to perform its required function, an error is a mistake by a programmer, a fault is a condition that causes software to fail, and a defect is a bug or flaw in software.
3. The differences are that a defect is a programming mistake, an error causes a defect, a fault is a condition from an error that causes failure when the software does not function as required.
The document discusses use case diagrams in object oriented design and analysis. It defines use cases as descriptions of system functionality from a user perspective. Use case diagrams depict system behavior, users, and relationships between actors, use cases, and other use cases. The key components of use case diagrams are described as actors, use cases, the system boundary, and relationships. Common relationships include association, extend, generalization, uses, and include. An example use case diagram for a cellular telephone is provided to illustrate these concepts.
The document discusses context models and their use in system modeling. Context models illustrate the operational context of a system by showing what lies outside its boundaries, including other systems in the environment. They help define a system's boundaries and show how IT applications fit into the context of people and organizations. Two examples are provided: (1) a Mental Health Care Patient Management System (MHC-PMS) and its connections to other clinical systems; (2) an Automated Teller Machine (ATM) and its links to banking systems. Context models on their own do not show relationships between external systems, so additional models are needed.
A brief introduction to Process synchronization in Operating Systems with classical examples and solutions using semaphores. A good starting tutorial for beginners.
This document discusses file systems and file management. It begins by defining key file concepts like file attributes and operations. It then covers topics like access methods, directory structures, file sharing, protection, and file system implementation details. The objectives are to explain file system functions, describe interfaces, discuss design tradeoffs for components like access methods and directories, and explore file system protection.
Human Computer Interaction Chapter 3 HCI in the Software Process and Design ...VijiPriya Jeyamani
The document discusses various aspects of the software development life cycle and human-computer interaction design rules. It describes the typical phases of software development like requirements specification, architectural design, detailed design, coding, testing, and maintenance. It also discusses design principles, standards, guidelines, heuristics and patterns that can improve usability. Iterative design and prototyping approaches are presented as methods to refine requirements and designs. The importance of documenting design rationale is highlighted.
The document discusses file management concepts including file structures, directories, file allocation methods, and access rights. It describes common file structures like sequential, indexed sequential, and direct files. It also covers directory structures, file sharing concepts like simultaneous access and access rights, and secondary storage management techniques like preallocation and allocation methods.
This chapter discusses file systems and their interfaces. It covers key concepts like files, directories, access methods, mounting file systems, file sharing, and protection. Directories provide structure and organization for files on a file system using tree or graph structures. File systems support operations like creating/deleting files, searching directories, and opening/closing files. They also implement features like file sharing across networks and access control using permissions.
This document discusses different types of mainframe systems, beginning with batch systems where users submit jobs offline and jobs are run sequentially in batches. It then describes multiprogrammed systems which allow multiple jobs to reside in memory simultaneously, improving CPU utilization. Finally, it covers time-sharing systems which enable interactive use by multiple users at once through very fast switching between programs, minimizing response time. The key difference between multiprogrammed and time-sharing systems is the prioritization of maximizing CPU usage versus minimizing response time respectively.
Multithreading and concurrency in androidRakesh Jha
Here you will learn -
What is Multithreading
What is concurrency
Process Vs Thread
Improvements and issues with concurrency
Limits of concurrency gains
Concurrency issues
Threads pools with the Executor Framework
AsyncTask and the UI Thread
Code
Human Computer Interaction Chapter 5 Universal Design and User Support - Dr....VijiPriya Jeyamani
Universal Design:
Introduction
Universal design principles
Multi-modal interaction
Designing for diversity
User Support:
Introduction
Requirements of user support
Approaches to user support
Adaptive help systems
Designing user support systems
The document discusses various concurrency control techniques used in database management systems to ensure transaction isolation. It covers locking techniques like two-phase locking and timestamp ordering. Locking involves associating locks like read/write locks with data items. The two-phase locking protocol defines rules for acquiring and releasing locks in two distinct phases. Timestamp ordering assigns unique timestamps to transactions and ensures conflicting operations are executed based on timestamp order to guarantee serializability.
This document discusses the evolution of the object model in programming. It describes how programming languages have evolved from procedural to object-oriented over several generations, with each generation incorporating new features like data abstraction, modularity, and object-oriented concepts. The core elements of the object model are explained as abstraction, encapsulation, hierarchy, and modularity. Minor elements like typing, concurrency, and persistence are also discussed. Examples are given throughout to illustrate object-oriented concepts.
The document discusses several mobile operating systems including Palm OS, Symbian OS, Pocket PC, Linux OS, Windows Mobile, MXI, and Android. It provides overview information on each OS, such as Palm OS focusing on personal information management, Symbian OS being used in 85% of phones, Pocket PC leveraging Microsoft desktop apps, Linux being used in higher-end phones, and Android being an open source platform used widely in phones and tablets. Key advantages of mobile OSs are noted as portability while disadvantages include limited memory, slow processors, and small screens.
system calls, single user, multiuser os ...myrajendra
The document discusses operating system basics including system calls, operating system structure, and differences between single-user and multi-user operating systems. System calls allow programs to request services from the operating system kernel. A single-user operating system has a monolithic structure with user applications separated from the kernel, while a multi-user operating system uses a layered structure with modules organized in hierarchical layers.
Independent processes operate concurrently without affecting each other, while cooperating processes can impact one another. Inter-process communication (IPC) allows processes to share information, improve computation speed, and share resources. The two main types of IPC are shared memory and message passing. Shared memory uses a common memory region for fast communication, while message passing involves establishing communication links and exchanging messages without shared variables. Key considerations for message passing include direct vs indirect communication and synchronous vs asynchronous messaging.
A class diagram shows the structure of a system through classes, attributes, operations, and relationships between classes. It includes classes and their properties like attributes and methods. It also shows relationships between classes like associations, aggregations, generalizations, and dependencies. The class diagram is a key tool in object-oriented analysis and design.
The document discusses different aspects of file systems and file structures. It describes files as collections of data that have long-term existence, can be shared between processes, and organized hierarchically. File systems provide storage for files and functions to manipulate them, maintaining attributes. Common file structures include sequential, indexed sequential, and direct/hashed files. The document also outlines the components of a file system software architecture and operations performed on directories.
Operating System Process SynchronizationHaziq Naeem
This document discusses synchronization between processes. It defines synchronization as the mutual understanding between two or more processes when sharing system resources. It describes critical section problems, solutions like locks, Peterson's solution, and semaphores. It also covers major synchronization problems like bounded buffer, reader-writer, and dining philosophers. Windows uses interrupts to protect shared resources while Linux uses semaphores. Synchronization is important for preventing deadlocks and data inconsistencies to improve efficiency.
This document provides an introduction to basic operating system concepts. It defines what an operating system is and discusses its main goals of executing user programs, making the computer convenient to use, and efficiently utilizing computer hardware. It then describes different types of systems that operating systems support, including mainframe, desktop, multiprocessor, distributed, clustered, and real-time systems. The key aspects and features required of operating systems to support these different system types are also outlined.
The document discusses input/output (I/O) and file management in operating systems. It covers several key topics:
1) I/O devices are controlled by the OS and include input devices like keyboards and output devices like monitors. Files are managed through a logical, uniform view abstracted from physical storage properties.
2) A file is a collection of related information defined by its creator, such as programs, data, text, or formatted records. File management involves creation, deletion, mapping to storage, and backup.
3) The OS implements I/O buffering and caching to improve performance and address speed mismatches between devices. It also performs disk scheduling and structures file storage through directories, indexing,
CSI-503 - 10. Security & Protection (Operating System) ghayour abbas
The document discusses security and protection in operating systems. It defines security as a mechanism that analyzes users and permits authorized access to system resources through authentication and encryption. Protection deals with controlling access to system resources and determining which files a user can access. The document provides examples of how organizations implement security and protection measures to restrict access to information.
chapter 3 opreating system lecture note and its is impaortamt concept for mndejenehundaol91
This document provides an overview of operating system concepts including:
- An operating system acts as an intermediary between the user and computer hardware. It manages resources and controls program execution.
- Operating systems provide functions like program loading and execution, I/O operations, file manipulation, communications, error detection, and resource allocation and security.
- The user interface to an operating system can be via a command line interface (CLI) which allows direct command entry, or a graphical user interface (GUI) with a desktop metaphor.
This document discusses file systems and file management. It begins by defining key file concepts like file attributes and operations. It then covers topics like access methods, directory structures, file sharing, protection, and file system implementation details. The objectives are to explain file system functions, describe interfaces, discuss design tradeoffs for components like access methods and directories, and explore file system protection.
Human Computer Interaction Chapter 3 HCI in the Software Process and Design ...VijiPriya Jeyamani
The document discusses various aspects of the software development life cycle and human-computer interaction design rules. It describes the typical phases of software development like requirements specification, architectural design, detailed design, coding, testing, and maintenance. It also discusses design principles, standards, guidelines, heuristics and patterns that can improve usability. Iterative design and prototyping approaches are presented as methods to refine requirements and designs. The importance of documenting design rationale is highlighted.
The document discusses file management concepts including file structures, directories, file allocation methods, and access rights. It describes common file structures like sequential, indexed sequential, and direct files. It also covers directory structures, file sharing concepts like simultaneous access and access rights, and secondary storage management techniques like preallocation and allocation methods.
This chapter discusses file systems and their interfaces. It covers key concepts like files, directories, access methods, mounting file systems, file sharing, and protection. Directories provide structure and organization for files on a file system using tree or graph structures. File systems support operations like creating/deleting files, searching directories, and opening/closing files. They also implement features like file sharing across networks and access control using permissions.
This document discusses different types of mainframe systems, beginning with batch systems where users submit jobs offline and jobs are run sequentially in batches. It then describes multiprogrammed systems which allow multiple jobs to reside in memory simultaneously, improving CPU utilization. Finally, it covers time-sharing systems which enable interactive use by multiple users at once through very fast switching between programs, minimizing response time. The key difference between multiprogrammed and time-sharing systems is the prioritization of maximizing CPU usage versus minimizing response time respectively.
Multithreading and concurrency in androidRakesh Jha
Here you will learn -
What is Multithreading
What is concurrency
Process Vs Thread
Improvements and issues with concurrency
Limits of concurrency gains
Concurrency issues
Threads pools with the Executor Framework
AsyncTask and the UI Thread
Code
Human Computer Interaction Chapter 5 Universal Design and User Support - Dr....VijiPriya Jeyamani
Universal Design:
Introduction
Universal design principles
Multi-modal interaction
Designing for diversity
User Support:
Introduction
Requirements of user support
Approaches to user support
Adaptive help systems
Designing user support systems
The document discusses various concurrency control techniques used in database management systems to ensure transaction isolation. It covers locking techniques like two-phase locking and timestamp ordering. Locking involves associating locks like read/write locks with data items. The two-phase locking protocol defines rules for acquiring and releasing locks in two distinct phases. Timestamp ordering assigns unique timestamps to transactions and ensures conflicting operations are executed based on timestamp order to guarantee serializability.
This document discusses the evolution of the object model in programming. It describes how programming languages have evolved from procedural to object-oriented over several generations, with each generation incorporating new features like data abstraction, modularity, and object-oriented concepts. The core elements of the object model are explained as abstraction, encapsulation, hierarchy, and modularity. Minor elements like typing, concurrency, and persistence are also discussed. Examples are given throughout to illustrate object-oriented concepts.
The document discusses several mobile operating systems including Palm OS, Symbian OS, Pocket PC, Linux OS, Windows Mobile, MXI, and Android. It provides overview information on each OS, such as Palm OS focusing on personal information management, Symbian OS being used in 85% of phones, Pocket PC leveraging Microsoft desktop apps, Linux being used in higher-end phones, and Android being an open source platform used widely in phones and tablets. Key advantages of mobile OSs are noted as portability while disadvantages include limited memory, slow processors, and small screens.
system calls, single user, multiuser os ...myrajendra
The document discusses operating system basics including system calls, operating system structure, and differences between single-user and multi-user operating systems. System calls allow programs to request services from the operating system kernel. A single-user operating system has a monolithic structure with user applications separated from the kernel, while a multi-user operating system uses a layered structure with modules organized in hierarchical layers.
Independent processes operate concurrently without affecting each other, while cooperating processes can impact one another. Inter-process communication (IPC) allows processes to share information, improve computation speed, and share resources. The two main types of IPC are shared memory and message passing. Shared memory uses a common memory region for fast communication, while message passing involves establishing communication links and exchanging messages without shared variables. Key considerations for message passing include direct vs indirect communication and synchronous vs asynchronous messaging.
A class diagram shows the structure of a system through classes, attributes, operations, and relationships between classes. It includes classes and their properties like attributes and methods. It also shows relationships between classes like associations, aggregations, generalizations, and dependencies. The class diagram is a key tool in object-oriented analysis and design.
The document discusses different aspects of file systems and file structures. It describes files as collections of data that have long-term existence, can be shared between processes, and organized hierarchically. File systems provide storage for files and functions to manipulate them, maintaining attributes. Common file structures include sequential, indexed sequential, and direct/hashed files. The document also outlines the components of a file system software architecture and operations performed on directories.
Operating System Process SynchronizationHaziq Naeem
This document discusses synchronization between processes. It defines synchronization as the mutual understanding between two or more processes when sharing system resources. It describes critical section problems, solutions like locks, Peterson's solution, and semaphores. It also covers major synchronization problems like bounded buffer, reader-writer, and dining philosophers. Windows uses interrupts to protect shared resources while Linux uses semaphores. Synchronization is important for preventing deadlocks and data inconsistencies to improve efficiency.
This document provides an introduction to basic operating system concepts. It defines what an operating system is and discusses its main goals of executing user programs, making the computer convenient to use, and efficiently utilizing computer hardware. It then describes different types of systems that operating systems support, including mainframe, desktop, multiprocessor, distributed, clustered, and real-time systems. The key aspects and features required of operating systems to support these different system types are also outlined.
The document discusses input/output (I/O) and file management in operating systems. It covers several key topics:
1) I/O devices are controlled by the OS and include input devices like keyboards and output devices like monitors. Files are managed through a logical, uniform view abstracted from physical storage properties.
2) A file is a collection of related information defined by its creator, such as programs, data, text, or formatted records. File management involves creation, deletion, mapping to storage, and backup.
3) The OS implements I/O buffering and caching to improve performance and address speed mismatches between devices. It also performs disk scheduling and structures file storage through directories, indexing,
CSI-503 - 10. Security & Protection (Operating System) ghayour abbas
The document discusses security and protection in operating systems. It defines security as a mechanism that analyzes users and permits authorized access to system resources through authentication and encryption. Protection deals with controlling access to system resources and determining which files a user can access. The document provides examples of how organizations implement security and protection measures to restrict access to information.
chapter 3 opreating system lecture note and its is impaortamt concept for mndejenehundaol91
This document provides an overview of operating system concepts including:
- An operating system acts as an intermediary between the user and computer hardware. It manages resources and controls program execution.
- Operating systems provide functions like program loading and execution, I/O operations, file manipulation, communications, error detection, and resource allocation and security.
- The user interface to an operating system can be via a command line interface (CLI) which allows direct command entry, or a graphical user interface (GUI) with a desktop metaphor.
1. Protection and security are mechanisms used in operating systems to control access to resources and safeguard them from threats. Protection focuses on internal threats while security addresses external threats.
2. Protection involves setting and changing access permissions for resources and checking access for users. Security involves authenticating users, adding/removing them, and using anti-malware software to protect from external threats.
3. A security model like the access matrix model defines the set of subjects, objects, and access rules to represent an organization's security policy for controlling access between users and resources.
The document discusses the key components and functions of an operating system:
1. It manages computer hardware resources and allows for the execution of user programs and applications.
2. It provides services like process management, memory management, file management, I/O management, and protection to programs and users.
3. Operating systems provide an interface between the user and computer system through functions like command interpretation.
Chapter 1 Introduction to Operating System ConceptsMeenalJabde
The document provides an overview of operating systems including:
- The definition of an operating system as a program that controls hardware and acts as an interface between users and computers.
- The key functions of operating systems including providing convenience, efficiency, and ability to evolve.
- Concepts such as processes, process states, process control blocks, and system calls. It describes what they are and their purpose.
- A brief history of operating systems from first to fourth generation systems.
- The main types of operating systems including batch, time-sharing, distributed, network, and real-time operating systems.
- Common services offered by most operating systems such as user interface, program execution, file
The document discusses the structure of operating systems and the services they provide. It describes how operating systems provide 1) a user interface, 2) program execution, 3) I/O operations, 4) file system manipulation, 5) communications, 6) error detection, and 7) resource allocation. It also discusses how operating systems provide accounting, protection, and security services. The document uses an example of copying a file to illustrate how programs use system calls to request services from the operating system.
An operating system manages computer hardware and software resources and acts as an interface between users and applications. It performs basic tasks like memory management, process scheduling, input/output control, and file management. There are different types of operating systems including batch, time-sharing, distributed, network, and real-time operating systems. An operating system allocates resources, schedules processes, manages memory and devices, handles security and errors, and provides file management functionality.
1. Operating systems are an essential part of any computer system that act as an interface between the user and hardware. They manage computer resources like the CPU, memory, disk space, and I/O devices.
2. The course covers fundamental operating system concepts like processes, process scheduling, memory management, security and protection, virtualization, distributed systems, and kernel data structures.
3. Key topics include operating system operations, resource management, security methods like authentication and protection from threats, virtual machine architecture, features of distributed systems, and important kernel data structures for process and file management.
This document discusses computer system protection. It outlines goals of protection like preventing unauthorized access. Principles like least privilege aim to minimize damage from compromised access. Protection domains define which objects and operations processes can access. Access matrices represent these access rights. Examples of early capability-based and language-based protection systems are described.
An operating system manages computer hardware and provides an environment for application programs to run. It acts as an interface between the computer and user, providing graphical or command line interfaces. There are different types of operating systems like real-time, distributed, and embedded operating systems. Key components of an operating system include the kernel, which manages system resources, and processes, which the operating system schedules. Memory, storage, security, and input/output management are also important operating system functions. Popular operating systems include Linux, a free and open-source UNIX-like system, and Windows XP, designed by Microsoft.
The document discusses operating systems and their core functions. It covers:
1) Operating systems control computers by managing processes, memory, networking, protection, and scheduling.
2) Operating systems aim to allocate resources to processes, manage main memory, and protect systems from unauthorized access.
3) Key components of operating systems include processes, threads, scheduling algorithms, system calls, interprocess communication using semaphores, and memory management.
The document summarizes security vulnerabilities in dial back systems used for computer login authentication. It explains that dial back systems are not foolproof because a hacker could intercept the callback phone call by not hanging up after initial login, taking advantage of caller control phone switches. It also describes other techniques a hacker could use to fool modems and bypass dial back security, such as recording dial tones, ringing, or waiting for the modem to pickup before supplying an answer.
The document discusses several key services provided by operating systems, including program execution, I/O operations, file manipulation, communications, and error detection. It notes that operating systems provide functions helpful to users like user interfaces, as well as ensuring efficient system operation through resource allocation, accounting, protection, and security.
The document discusses several key concepts in distributed systems:
1. Code migration in distributed systems involves transferring software code between machines to achieve goals like load balancing and fault tolerance. It requires identifying code to migrate, creating a migration plan, and testing migrated code.
2. Logical clocks order events in distributed systems based on their relative occurrence, while physical clocks measure absolute time. Logical clocks are needed because physical clocks cannot be synchronized across all machines.
3. A distributed deadlock system model describes a situation where multiple processes across different machines are deadlocked waiting for resources held by other processes, requiring specialized algorithms to detect and resolve deadlocks.
This document provides definitions and terminology related to computer security architecture and models. It defines key terms like access control, authentication, authorization, confidentiality, integrity, and availability. It also summarizes several influential security models like Bell-LaPadula, Biba, Clark-Wilson, and discusses certification and accreditation procedures. The document also briefly outlines the IPSEC standard and some general network and host security concepts.
The document discusses operating system interview questions and answers. It covers topics such as the definition of an operating system, basic functions of an OS, types of operating systems, kernel functions, process states, virtual memory, deadlocks, threads, synchronization, scheduling algorithms, and memory management. Some key points covered are that an OS acts as an intermediary between the user and hardware, the kernel provides basic services, processes can be in states like running, waiting, or ready, and virtual memory uses timesharing to simulate more memory than physically available.
This document provides an introduction to computer operating systems. It discusses key topics like the functions of an operating system, examples of common operating systems like Linux and Windows, and the basic tasks of an operating system like memory management, file management, and process management. The document also covers different types of operating systems like batch, time-sharing, single-user and multi-user systems, and components of an operating system like the kernel, microkernel, and user interface.
This document provides an introduction to computer operating systems. It discusses key topics like the functions of an operating system, examples of common operating systems like Linux and Windows, and the basic tasks of an operating system like memory management, file management, and process management. The document also covers different types of operating systems like batch, time-sharing, single-user and multi-user systems, and components of an operating system like the kernel, microkernel, and user interface.
1Discuss the major components of an OS including file system, proc.pdffeelingcomputors
1
Discuss the major components of an OS including file system, processes, and the kernel.
Describe what an operating system does for users and software by providing access to a
computer’s physical components.
Describe the concept of threads, and multithreaded applications that are designed to be run on
multiprocessing systems. You should discuss the prevalence of multicore processors and
distinguish these from multiprocessor systems.
Describe the components of virtualization and virtualization products. Describe a real world
situation when you would set up a network using these.
2
Discuss how to create and manage permissions on storage volumes.
Describe a real world scenario where you would implement this.
Solution
Major components of Operating system include memory management, process management,
networking, security, and disk and file systems.
Memory management : Operating system manages memory by coordinating different
memories(registers, CPU cache, random access memory , disk storage) as per their availability
and which one of them needs to be allocated and how to move data across them. And this
process is called virtual memory management and by practicing this we get increased amount of
memory for all processes. And second part handled by memory management is managing virtual
addresses, in case there are multiple processes then they should not be interfering with each other
and to achieve this we need to maintain separate address space.
Process Management: Process is a part which tells system that it got a job to perform. And
operating system manages these processes by concurrent execution at one go by performing
multitasking at CPU level. As the number of process increases either the time slice becomes
smaller or else there will be delay in time given to a process to run. Process management
includes computing time and then distributing it to resources.
Networking: Operating system includes TCP/IP network protocols which enable one system to
be available on another system and share the resources.
Security: Security which is based on two facts ,one is operating system gives access to resources
which includes privileged system calls , information about users. And other is operating system
is capable of distinguishing the authorized users to access the resources and those which are not.
How to Add Chatter in the odoo 17 ERP ModuleCeline George
In Odoo, the chatter is like a chat tool that helps you work together on records. You can leave notes and track things, making it easier to talk with your team and partners. Inside chatter, all communication history, activity, and changes will be displayed.
Physiology and chemistry of skin and pigmentation, hairs, scalp, lips and nail, Cleansing cream, Lotions, Face powders, Face packs, Lipsticks, Bath products, soaps and baby product,
Preparation and standardization of the following : Tonic, Bleaches, Dentifrices and Mouth washes & Tooth Pastes, Cosmetics for Nails.
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
A review of the growth of the Israel Genealogy Research Association Database Collection for the last 12 months. Our collection is now passed the 3 million mark and still growing. See which archives have contributed the most. See the different types of records we have, and which years have had records added. You can also see what we have for the future.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
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Assessment and Planning in Educational technology.pptxKavitha Krishnan
In an education system, it is understood that assessment is only for the students, but on the other hand, the Assessment of teachers is also an important aspect of the education system that ensures teachers are providing high-quality instruction to students. The assessment process can be used to provide feedback and support for professional development, to inform decisions about teacher retention or promotion, or to evaluate teacher effectiveness for accountability purposes.
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By Dr. Vinod Kumar Kanvaria
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Odoo 17 CRM allows us to track why we lose sales opportunities with "Lost Reasons." This helps analyze our sales process and identify areas for improvement. Here's how to configure lost reasons in Odoo 17 CRM
2. Introduction:
I/O protection in operating systems is an essential mechanism to provide
secure access to I/O devices from user and kernel modes
In most operating systems, I/O protection is implemented using the concept
of I/O privilege levels or rings. The processor and the operating system define
four different privilege levels, also called rings, where ring 0 is the highest
and contains the kernel mode, while ring 3 is the lowest and contains the user
mode.
3. I/O Protection Issued:
An I/O instruction issued by a process in user mode has to be executed with a
privileged instruction in the kernel mode. The kernel mode is the only ring
that can directly access the hardware. The operating system sets up I/O
privilege levels to control access to I/O devices by processes running at
different privilege levels.
4. Importance:
The protection is provided through hardware-based features like device
controllers, memory-mapped I/O, and system calls, used in the operating
system to provide access to I/O devices.
In I/O protection, every I/O device is allocated a unique I/O space or I/O
ports that are accessible only by the kernels to avoid unauthorized access.
The operating system maintains a mapping between the device drivers and
memory buffers, and the device controllers are programmed to treat all I/O
addresses generated by user processes as invalid.
The operating system also provides mechanisms such as input and output
permission bits that restrict the access to I/O devices for all the user
processes. The permission bits help ensure that no unauthorized process can
gain access to the device.
The I/O protection in modern operating systems also incorporates Virtual
Memory Management (VMM) technology with page-level protection. With this
technology, the kernel provides a different map of the physical memory in
each process's virtual address space, and every process can access a unique
copy of the data.
5. Function:
The primary function of I/O protection in operating systems is to provide a
secure layer of access control to Input/output (I/O) devices, ensuring that
only authorized processes and users can access I/O devices. Here are some of
the main functions of I/O protection:
6. 1. Prevent unauthorized access:
I/O protection mechanisms ensure that only authenticated and authorized
processes can interact with I/O devices. Unauthorized access can lead to data
theft, data loss, or other security breaches
7. 2. Maintain data integrity:
I/O protection ensures that data being read from or written to I/O devices is
protected from unauthorized access, unauthorized modification or deletion,
and corruption.
8. 3. Provide isolation:
By implementing I/O protection, processes are prevented from accessing
other processes' I/O data, enhancing security and preventing critical data
breaches.
9. 4. Prevent system crashes:
The proper protection of I/O devices prevents device drivers from accessing
memory outside their allocated memory space, thereby preventing system
crashes.
10. 5. Support multi-user environment:
I/O protection plays a crucial role in supporting a multi-user operating
system environment by ensuring that each user can only access and
communicate with the devices authorized for their account
11. 6. Support virtual machines:
In virtual machine environments, I/O protection mechanisms ensure that
virtual machine guests cannot access I/O devices other than those allowed by
their virtual machine host.
12. Summary:
In summary, I/O protection mechanisms are essential in operating systems to
control access to I/O devices and to prevent unauthorized access, thereby
ensuring the security of the system.
14. Introduction
Synchronization refers to the coordination of activities or processes to ensure
that they happen in the correct order and at the right time. In computing,
synchronization is particularly important when multiple processes or threads
are accessing shared resources, as it ensures that all processes have access to
the resource at the correct time and in the correct order.
In an operating system, process synchronization refers to the techniques and
mechanisms used to ensure that multiple processes or threads do not
interfere with each other and that they access shared resources in a
coordinated and controlled manner. Some common examples of shared
resources include memory, files, and hardware devices.
15. Example:
Where two processes try to update the same variable in memory. If both
processes attempt to update the variable at the same time, its values can
become inconsistent or corrupt. To avoid this, synchronization mechanisms
can be used to enforce mutual exclusion and ensure that only one process can
update the variable at a time. One way to achieve this is using a mutex. In
this case, the variable and a corresponding mutex are shared between the
two processes. Before accessing the variable, each process checks if the
mutex is locked by another process, and if it is, it waits until the mutex is
released. Once the mutex is released, the process can acquire it, update the
variable, and release the mutex to allow other processes to access it.
16. Example:
Here's an example in pseudocode:
Process 1:
acquire(mutex)
variable = variable + 1
release(mutex)
Process 2:
acquire(mutex)
variable = variable – 1
release(mutex)
In this example, each process acquires the mutex and updates the variable inside a critical
section. The mutex ensures that only one process can update the variable at a time,
preventing any race conditions or inconsistencies. This is just one example of how
synchronization can be used to ensure correct and efficient execution of processes in an
operating system. Other synchronization mechanisms like semaphores, monitors, and
barriers can also be used to manage access to shared resources and prevent conflicts
between processes
17. There are several common techniques for
achieving synchronization in computer
systems. These include
18. 1. locking:
A lock is a synchronization mechanism that ensures that only one process or
thread can access a shared resource at a time. Locking is typically
implemented using mutexes or semaphores to ensure that the resource is
properly protected
2. Atomic operations:
An atomic operation is an operation that is indivisible and uninterruptible.
Atomic operations are typically used to ensure that multiple processes do not
interfere with each other when accessing the same memory location.
19. 3. Barrier synchronization:
A barrier is a synchronization mechanism that ensures that all processes or
threads have reached a certain point in their execution before continuing.
Barriers are commonly used in parallel processing to ensure that all processes
have completed their work before continuing to the next phase of processing
4. Message passing:
Message passing is a communication mechanism where processes or threads
send messages to each other to coordinate their activities. This mechanism is
commonly used in distributed systems to ensure that all processes are aware
of each other's activities and progress.
20. 5. Semaphores:
A semaphore is a data structure that is used to control access to shared
resources. It can be used to ensure that only one process or thread can access
a shared resource at any given time. Semaphores can be either binary or
counting, and they can be used to enforce mutual exclusion, synchronization,
and resource allocation.
6. Mutexes:
A mutex is a programming object used to protect shared resources by creating
a critical section. Only one thread can access the shared resource when the
mutex is locked. If another thread tries to access the same resource while it
is locked, it will wait until the mutex is released
21. 7. Monitors:
A monitor is a higher-level abstraction of a mutex. A monitor provides a
mechanism for multiple threads to access shared resources in a synchronized
way. Programmers use monitors to specify which code is a critical section or a
region that requires exclusive access to shared resources
22. Function of Synchronization
Here are some specific functions of synchronization in an operating system:
1. Mutual Exclusion: With mutual exclusion, only one process or thread can access a
shared resource at any given time, ensuring data consistency and preventing conflicts
that may arise when multiple processes are trying to access the same resource
simultaneously.
2. 2. Coordination: Coordination mechanisms are used to ensure the correct order of
execution of operations involving shared resources among concurrent processes. For
example, a synchronization mechanism can be used to ensure that a dependent process
waits until a required resource is available and can access it.
3. : Deadlocks can occur when multiple processes are waiting to acquire resources that
are locked by other processes. Using synchronization mechanisms such as timeouts or
prioritization can help prevent deadlocks by ensuring that resources are released or
given higher priority to certain processes
23. Summary
Overall, synchronization is a vital aspect of computer systems, particularly in
multi-process or multi-threaded environments where shared resources are
common. By using synchronization mechanisms like locking and barrier
synchronization, systems can ensure that all processes and threads operate
correctly and in the appropriate order
24. MCQS
1. Which of the following is a technique used for thread communication?
A. Pipes
B. Signals
C. Shared memory
D. All of the above.
2. What is the difference between synchronization and concurrency?
A. Synchronization refers to the process of coordinating access to shared resources,
while concurrency refers to the ability of multiple tasks to execute at the same
time.
B. Synchronization refers to the ability of multiple tasks to execute at the same
time, while concurrency refers to the process of coordinating access to shared
resources.
C. Synchronization and concurrency are the same thing.
D. None of the above.
3. Which of the following is a technique used to prevent deadlocks?
A. Resource allocation graphs
B. Banker's algorithm
C. Timeouts
D. All of the above
25. MCQS
4. What is a deadlock?
A. A situation where two or more threads are waiting indefinitely for a resource to
become available.
B. A situation where two or more threads access a shared resource and try to
change its value at the same time.
C. A situation where two or more threads are competing for the same resource.
D. A situation where two or more threads are executing in parallel
5. Which of the following is true about monitors?
A. Monitors are a synchronization mechanism used for thread communication and
synchronization.
B. Monitors use signals and wait queues to coordinate access to shared resources.
C. Monitors are implemented as a class with methods that are synchronized.
D. All of the above.
6. What is a mutex?
A. A type of lock that allows multiple threads to access a shared resource
simultaneously.
B. A synchronization mechanism that prevents deadlocks.
C. A data structure used for parallel processing.
D. A variable used for inter-process communication
26. MCQS
7. What is a semaphore?
A. A type of lock that allows multiple threads to access a shared resource
simultaneously.
B. A variable used for inter-process communication.
C. A synchronization mechanism that prevents deadlocks.
D. A data structure used for parallel processing.
8. What is a race condition?
A. A situation where two or more threads access a shared resource and try to
change its value at the same time.
B. A situation where two or more threads are waiting indefinitely for a resource to
become available.
C. A situation where two or more threads are competing for the same resource.
D. A situation where two or more threads are executing in parallel
9. Which of the following is NOT an example of synchronization in computer
science?
A. Locks
B. Semaphores
C. Interrupts
D. Monitors
27. What is synchronization in computer science?
A. The process of maintaining consistency and order between two or more
processes.
B. The process of managing multiple tasks on a single processor.
C. The process of preventing deadlocks in a system.
D. The process of parallel processing.
Short question
1. What is synchronization?
2. Write the function of synchronization?
3. What is mutexes?
4. What is semaphores?
5. How synchronization work ?
Long question
Write the technique to achieve the synchronization?