This document summarizes Chapter 7 from the textbook "Operating System Concepts - 9th Edition" which covers deadlocks in computer systems. It defines the four conditions required for deadlock, characterizes deadlocks, and presents various methods for handling deadlocks including prevention, avoidance, detection, and recovery. Prevention methods restrain how processes request resources to ensure deadlock cannot occur, while avoidance methods dynamically determine safe resource allocations to guarantee no deadlocks. Detection finds and recovers from existing deadlocks.
This document summarizes key concepts about virtual memory from the textbook chapter:
- Virtual memory allows processes to have a logical address space larger than physical memory by paging portions of processes into and out of frames in physical memory on demand.
- Demand paging brings pages into memory only when they are needed, reducing I/O compared to loading the whole process at once. It can cause page faults when accessing pages not yet loaded.
- Page replacement algorithms select pages to swap out to disk when free frames are needed, aiming to minimize future page faults. The choice of replacement algorithm impacts memory performance.
This document provides an overview of memory management techniques in operating systems, including paging and segmentation. It describes how programs are loaded into memory to be executed, and the need for logical and physical address spaces. Paging is explained as a method of dividing memory into fixed-sized frames and logical addresses into pages, with a page table mapping pages to frames. Segmentation uses base and limit registers to define memory segments. The Intel Pentium supports both segmentation and paging.
The document discusses operating system services and how they are accessed. It describes how operating systems provide services like user interfaces, program execution, I/O operations, and more. These services are accessed through system calls via an application programming interface. System calls allow programs to request lower-level services from the operating system kernel. Common system calls involve process management, file operations, communications, and more.
The document discusses process synchronization and solving the critical section problem in operating systems. It covers topics like mutual exclusion, semaphores, monitors, and solutions to classical synchronization problems like the producer-consumer problem. Various hardware and software techniques for implementing critical sections and managing access to shared resources by concurrent processes are presented, including locks, mutexes, and Peterson's algorithm.
This document provides an overview of CPU scheduling algorithms in operating systems. It begins with basic concepts like CPU utilization and I/O burst cycles. It then discusses various scheduling criteria like throughput and turnaround time. Common scheduling algorithms covered include first-come first-served, shortest job first, round robin, priority scheduling, and multilevel queue scheduling. It also addresses thread scheduling, multiprocessor scheduling, and real-time scheduling. The objectives are to describe and evaluate various CPU scheduling algorithms based on scheduling criteria.
This document discusses synchronization tools used to solve the critical section problem in operating systems. It begins with an overview and objectives, then describes the critical section problem and race conditions that can occur. It presents Peterson's solution and discusses how hardware support like mutex locks, semaphores, and monitors can provide synchronization. Memory barriers are introduced to address instruction reordering issues on modern architectures. The document evaluates different synchronization tools for low, moderate, and high contention scenarios.
The document provides an overview of operating system concepts, including:
- The role of an operating system is to act as an intermediary between the user and computer hardware to execute programs and allocate resources efficiently.
- A computer system consists of hardware, operating system, application programs, and users. The operating system controls and manages the hardware resources.
- Operating systems perform functions like process management, memory management, storage management, I/O management, and security.
This document discusses processes and interprocess communication. It begins by defining a process as a program in execution. Processes have multiple parts including code, activity, stack, data, and heap. Processes exist in various states like running, ready, waiting, and terminate. The operating system uses a process control block to manage information about each process. Processes can communicate through either shared memory or message passing. Shared memory allows processes to access the same memory regions, while message passing involves processes explicitly sending and receiving messages.
This document summarizes key concepts about virtual memory from the textbook chapter:
- Virtual memory allows processes to have a logical address space larger than physical memory by paging portions of processes into and out of frames in physical memory on demand.
- Demand paging brings pages into memory only when they are needed, reducing I/O compared to loading the whole process at once. It can cause page faults when accessing pages not yet loaded.
- Page replacement algorithms select pages to swap out to disk when free frames are needed, aiming to minimize future page faults. The choice of replacement algorithm impacts memory performance.
This document provides an overview of memory management techniques in operating systems, including paging and segmentation. It describes how programs are loaded into memory to be executed, and the need for logical and physical address spaces. Paging is explained as a method of dividing memory into fixed-sized frames and logical addresses into pages, with a page table mapping pages to frames. Segmentation uses base and limit registers to define memory segments. The Intel Pentium supports both segmentation and paging.
The document discusses operating system services and how they are accessed. It describes how operating systems provide services like user interfaces, program execution, I/O operations, and more. These services are accessed through system calls via an application programming interface. System calls allow programs to request lower-level services from the operating system kernel. Common system calls involve process management, file operations, communications, and more.
The document discusses process synchronization and solving the critical section problem in operating systems. It covers topics like mutual exclusion, semaphores, monitors, and solutions to classical synchronization problems like the producer-consumer problem. Various hardware and software techniques for implementing critical sections and managing access to shared resources by concurrent processes are presented, including locks, mutexes, and Peterson's algorithm.
This document provides an overview of CPU scheduling algorithms in operating systems. It begins with basic concepts like CPU utilization and I/O burst cycles. It then discusses various scheduling criteria like throughput and turnaround time. Common scheduling algorithms covered include first-come first-served, shortest job first, round robin, priority scheduling, and multilevel queue scheduling. It also addresses thread scheduling, multiprocessor scheduling, and real-time scheduling. The objectives are to describe and evaluate various CPU scheduling algorithms based on scheduling criteria.
This document discusses synchronization tools used to solve the critical section problem in operating systems. It begins with an overview and objectives, then describes the critical section problem and race conditions that can occur. It presents Peterson's solution and discusses how hardware support like mutex locks, semaphores, and monitors can provide synchronization. Memory barriers are introduced to address instruction reordering issues on modern architectures. The document evaluates different synchronization tools for low, moderate, and high contention scenarios.
The document provides an overview of operating system concepts, including:
- The role of an operating system is to act as an intermediary between the user and computer hardware to execute programs and allocate resources efficiently.
- A computer system consists of hardware, operating system, application programs, and users. The operating system controls and manages the hardware resources.
- Operating systems perform functions like process management, memory management, storage management, I/O management, and security.
This document discusses processes and interprocess communication. It begins by defining a process as a program in execution. Processes have multiple parts including code, activity, stack, data, and heap. Processes exist in various states like running, ready, waiting, and terminate. The operating system uses a process control block to manage information about each process. Processes can communicate through either shared memory or message passing. Shared memory allows processes to access the same memory regions, while message passing involves processes explicitly sending and receiving messages.
This document provides an overview of memory management techniques in operating systems. It discusses contiguous memory allocation, paging, segmentation, and virtual memory. Paging divides memory into fixed-size blocks called frames and logical memory into pages of the same size. A page table maps logical to physical addresses through a page number and page offset. Hardware support for paging includes a translation lookaside buffer (TLB) to speed up address translation by caching recent translations. The document also covers memory protection, shared pages, and internal and external fragmentation in memory allocation schemes.
This document provides an overview of operating system concepts from the textbook "Operating System Concepts - 9th Edition" by Silberschatz, Galvin and Gagne. It describes the basic organization of computer systems including hardware components, operating system structure, and operating system operations. It also discusses key operating system concepts such as process management, memory management, storage management, and protection/security.
This chapter discusses process synchronization and solving the critical section problem. It introduces Peterson's solution to the critical section problem and other synchronization methods like mutex locks, semaphores, and monitors. Classical synchronization problems covered include the bounded buffer problem, dining philosophers problem, and readers-writers problem. The chapter aims to present concepts of process synchronization and tools to solve synchronization issues.
The document discusses threads and threading models in operating systems. It defines a thread as the basic unit of CPU utilization comprising a thread ID, program counter, and register set. It describes single-threaded and multithreaded processes, benefits of multithreading, and concurrent/parallel execution. It also covers user threads, kernel threads, threading libraries like Pthreads and Java threads, and threading issues around fork(), exec(), signals, thread pools and more. It provides examples of threading in Windows XP and Linux.
Process synchonization : operating system ( Btech cse )HimanshuSharma1389
This chapter discusses process synchronization and solving the critical section problem. It covers Peterson's algorithm, mutex locks, semaphores, and classical synchronization problems like the bounded buffer, readers-writers, and dining philosophers problems. Monitors are also introduced as a higher-level abstraction for process synchronization using condition variables.
The document provides an overview of operating system concepts, including:
- The four main components of a computer system: hardware, operating system, applications, and users.
- What operating systems do, such as managing resources and controlling programs.
- Computer system organization involving CPUs, memory, I/O devices, and interrupts.
- Operating system structures like processes, memory management, and storage management.
The document summarizes key concepts from Chapter 6 of Operating System Concepts - 9th Edition about CPU scheduling. It discusses the goals of CPU scheduling, including maximizing CPU utilization and throughput. It describes common scheduling algorithms like first-come first-served (FCFS), shortest job first (SJF), priority scheduling, and round robin. It also covers more advanced techniques such as multilevel queue scheduling and multilevel feedback queue scheduling. Evaluation methods like deterministic modeling are presented to analyze and compare the performance of different scheduling algorithms.
This document summarizes chapters 9 of the textbook "Operating System Concepts – 9th Edition" by Silberschatz, Galvin and Gagne. It discusses memory management techniques including contiguous memory allocation, segmentation, paging and page tables. Segmentation divides a program into segments that can reside in different parts of memory. Paging divides memory into fixed-size pages that can also reside in non-contiguous locations. Address translation uses a page table to map logical addresses to physical frames. Hardware support in the form of base/limit registers and TLB caches is required for these memory management schemes.
This document summarizes key concepts from Chapter 4 of the textbook "Operating System Concepts - 9th Edition" about threads. It discusses how threads allow applications to take advantage of multicore systems through parallelism and concurrency. Different threading models like many-to-one, one-to-one, and many-to-many are described based on how user threads map to kernel threads. Popular thread libraries like POSIX pthreads and how they provide APIs for thread creation and synchronization are also covered. The document concludes with sections on implicit threading, threading issues, and thread cancellation approaches.
This document discusses CPU scheduling in operating systems. It introduces CPU scheduling as the basis for multiprogrammed operating systems. Various scheduling algorithms are described such as first-come first-served (FCFS), shortest job first (SJF), priority scheduling, and round robin (RR). Evaluation criteria for scheduling algorithms like CPU utilization, throughput, turnaround time, and waiting time are also presented. Multilevel queue and multilevel feedback queue scheduling are discussed as ways to improve performance.
The document summarizes key concepts about virtual memory from the 10th edition of the textbook "Operating System Concepts". It discusses how virtual memory allows processes to have a logical address space larger than physical memory by swapping pages between main memory and secondary storage as needed. When a process attempts to access a memory page not currently in RAM, a page fault occurs which is handled by the operating system by finding a free frame, loading the requested page, and resuming execution. Page replacement algorithms like FIFO are used when free frames are unavailable. Demand paging loads pages lazily on first access rather than up front.
The document summarizes key concepts about deadlocks from the 9th edition of Operating System Concepts by Silberschatz, Galvin and Gagne. It defines the four conditions for deadlock, describes different methods for handling deadlocks including prevention, avoidance, detection and recovery, and provides examples of algorithms for deadlock avoidance using resource allocation graphs and the banker's algorithm.
This document provides an overview of file system implementation and concepts. It describes the layered structure of a typical file system, with different layers managing devices, basic file system functions, logical file system metadata, and the user interface. Common file system data structures are discussed, including file control blocks, directories implemented as lists or hash tables, and allocation methods like contiguous, linked, indexed, and extent-based allocation. The document also covers in-memory file system structures, free space management using bitmaps or linked lists, techniques for improving efficiency and performance, and recovery through logging file system updates.
This document summarizes key concepts about deadlocks from Chapter 7 of the textbook "Operating System Concepts – 9th Edition" by Silberschatz, Galvin and Gagne. It defines the four conditions required for deadlock, describes methods for handling deadlocks including prevention, avoidance, detection and recovery, and provides examples to illustrate resource allocation graphs and the banker's algorithm for deadlock avoidance.
This document provides an overview of an operating systems concepts textbook. It introduces key topics covered in the book like computer system organization, operating system structure and functions, process management, memory management, storage management, and security. The objectives are to provide a tour of major OS components and coverage of basic computer system organization. It describes the four main components of a computer system and how the operating system acts as an intermediary between the user, hardware, and application programs.
The document discusses various aspects of operating system structures including:
- Operating system services like user interfaces, program execution, I/O operations, and more.
- The user-OS interface including command-line and graphical user interfaces.
- System calls which are the programming interface to OS services.
- Common approaches to structuring operating systems like layered designs, microkernel architectures, and virtual machines.
The chapter discusses the Linux operating system. It provides an overview of Linux's history and development. Key topics covered include the Linux kernel, process and memory management, scheduling, file systems, and interprocess communication. The chapter describes how Linux implements these operating system concepts and compares Linux's approach to traditional UNIX implementations.
The document describes the key concepts in operating system structures from the 9th edition of the textbook "Operating System Concepts" by Silberschatz, Galvin and Gagne. It discusses the services provided by operating systems, including user interfaces, program execution, file manipulation and security. It also explains how operating systems are implemented through system calls and system programs, and the importance of separating policy from mechanism in operating system design.
This document discusses CPU scheduling in operating systems. It covers basic scheduling concepts like processes alternating between CPU and I/O bursts. It then discusses scheduling criteria like response time and algorithms like first-come first-served (FCFS), shortest job first (SJF), priority scheduling, and round robin. It also covers more advanced topics like multilevel queue scheduling, multiple processor scheduling, and real-time scheduling. Evaluation methods for scheduling algorithms like simulation and queueing models are also mentioned.
The document summarizes key concepts about processes from an operating systems textbook. It discusses process concepts like process state, process control blocks (PCB), and process scheduling queues. It also covers process creation, termination, and cooperation between processes. Interprocess communication methods like message passing and synchronization are presented. The document concludes with an overview of client-server communication techniques using sockets, remote procedure calls, and remote method invocation.
This document summarizes key concepts from Chapter 7 of the textbook "Operating System Concepts - 9th Edition" regarding deadlocks. It describes the four conditions required for deadlock, characterizes deadlocks using a resource-allocation graph, and presents various methods for handling deadlocks including prevention, avoidance, detection, and recovery. Specifically, it covers deadlock prevention techniques like mutual exclusion and no preemption. It also details the banker's algorithm for deadlock avoidance using multiple resource instances and a safety algorithm.
This document summarizes key concepts from Chapter 7 of the textbook Operating System Concepts by Silberschatz, Galvin and Gagne. It discusses deadlocks in computer systems, including their characterization and conditions for their occurrence. It also describes several approaches for handling deadlocks, such as prevention, avoidance, detection and recovery methods. The resource allocation graph and banker's algorithm are presented as techniques for deadlock avoidance when multiple instances of resources are present.
This document provides an overview of memory management techniques in operating systems. It discusses contiguous memory allocation, paging, segmentation, and virtual memory. Paging divides memory into fixed-size blocks called frames and logical memory into pages of the same size. A page table maps logical to physical addresses through a page number and page offset. Hardware support for paging includes a translation lookaside buffer (TLB) to speed up address translation by caching recent translations. The document also covers memory protection, shared pages, and internal and external fragmentation in memory allocation schemes.
This document provides an overview of operating system concepts from the textbook "Operating System Concepts - 9th Edition" by Silberschatz, Galvin and Gagne. It describes the basic organization of computer systems including hardware components, operating system structure, and operating system operations. It also discusses key operating system concepts such as process management, memory management, storage management, and protection/security.
This chapter discusses process synchronization and solving the critical section problem. It introduces Peterson's solution to the critical section problem and other synchronization methods like mutex locks, semaphores, and monitors. Classical synchronization problems covered include the bounded buffer problem, dining philosophers problem, and readers-writers problem. The chapter aims to present concepts of process synchronization and tools to solve synchronization issues.
The document discusses threads and threading models in operating systems. It defines a thread as the basic unit of CPU utilization comprising a thread ID, program counter, and register set. It describes single-threaded and multithreaded processes, benefits of multithreading, and concurrent/parallel execution. It also covers user threads, kernel threads, threading libraries like Pthreads and Java threads, and threading issues around fork(), exec(), signals, thread pools and more. It provides examples of threading in Windows XP and Linux.
Process synchonization : operating system ( Btech cse )HimanshuSharma1389
This chapter discusses process synchronization and solving the critical section problem. It covers Peterson's algorithm, mutex locks, semaphores, and classical synchronization problems like the bounded buffer, readers-writers, and dining philosophers problems. Monitors are also introduced as a higher-level abstraction for process synchronization using condition variables.
The document provides an overview of operating system concepts, including:
- The four main components of a computer system: hardware, operating system, applications, and users.
- What operating systems do, such as managing resources and controlling programs.
- Computer system organization involving CPUs, memory, I/O devices, and interrupts.
- Operating system structures like processes, memory management, and storage management.
The document summarizes key concepts from Chapter 6 of Operating System Concepts - 9th Edition about CPU scheduling. It discusses the goals of CPU scheduling, including maximizing CPU utilization and throughput. It describes common scheduling algorithms like first-come first-served (FCFS), shortest job first (SJF), priority scheduling, and round robin. It also covers more advanced techniques such as multilevel queue scheduling and multilevel feedback queue scheduling. Evaluation methods like deterministic modeling are presented to analyze and compare the performance of different scheduling algorithms.
This document summarizes chapters 9 of the textbook "Operating System Concepts – 9th Edition" by Silberschatz, Galvin and Gagne. It discusses memory management techniques including contiguous memory allocation, segmentation, paging and page tables. Segmentation divides a program into segments that can reside in different parts of memory. Paging divides memory into fixed-size pages that can also reside in non-contiguous locations. Address translation uses a page table to map logical addresses to physical frames. Hardware support in the form of base/limit registers and TLB caches is required for these memory management schemes.
This document summarizes key concepts from Chapter 4 of the textbook "Operating System Concepts - 9th Edition" about threads. It discusses how threads allow applications to take advantage of multicore systems through parallelism and concurrency. Different threading models like many-to-one, one-to-one, and many-to-many are described based on how user threads map to kernel threads. Popular thread libraries like POSIX pthreads and how they provide APIs for thread creation and synchronization are also covered. The document concludes with sections on implicit threading, threading issues, and thread cancellation approaches.
This document discusses CPU scheduling in operating systems. It introduces CPU scheduling as the basis for multiprogrammed operating systems. Various scheduling algorithms are described such as first-come first-served (FCFS), shortest job first (SJF), priority scheduling, and round robin (RR). Evaluation criteria for scheduling algorithms like CPU utilization, throughput, turnaround time, and waiting time are also presented. Multilevel queue and multilevel feedback queue scheduling are discussed as ways to improve performance.
The document summarizes key concepts about virtual memory from the 10th edition of the textbook "Operating System Concepts". It discusses how virtual memory allows processes to have a logical address space larger than physical memory by swapping pages between main memory and secondary storage as needed. When a process attempts to access a memory page not currently in RAM, a page fault occurs which is handled by the operating system by finding a free frame, loading the requested page, and resuming execution. Page replacement algorithms like FIFO are used when free frames are unavailable. Demand paging loads pages lazily on first access rather than up front.
The document summarizes key concepts about deadlocks from the 9th edition of Operating System Concepts by Silberschatz, Galvin and Gagne. It defines the four conditions for deadlock, describes different methods for handling deadlocks including prevention, avoidance, detection and recovery, and provides examples of algorithms for deadlock avoidance using resource allocation graphs and the banker's algorithm.
This document provides an overview of file system implementation and concepts. It describes the layered structure of a typical file system, with different layers managing devices, basic file system functions, logical file system metadata, and the user interface. Common file system data structures are discussed, including file control blocks, directories implemented as lists or hash tables, and allocation methods like contiguous, linked, indexed, and extent-based allocation. The document also covers in-memory file system structures, free space management using bitmaps or linked lists, techniques for improving efficiency and performance, and recovery through logging file system updates.
This document summarizes key concepts about deadlocks from Chapter 7 of the textbook "Operating System Concepts – 9th Edition" by Silberschatz, Galvin and Gagne. It defines the four conditions required for deadlock, describes methods for handling deadlocks including prevention, avoidance, detection and recovery, and provides examples to illustrate resource allocation graphs and the banker's algorithm for deadlock avoidance.
This document provides an overview of an operating systems concepts textbook. It introduces key topics covered in the book like computer system organization, operating system structure and functions, process management, memory management, storage management, and security. The objectives are to provide a tour of major OS components and coverage of basic computer system organization. It describes the four main components of a computer system and how the operating system acts as an intermediary between the user, hardware, and application programs.
The document discusses various aspects of operating system structures including:
- Operating system services like user interfaces, program execution, I/O operations, and more.
- The user-OS interface including command-line and graphical user interfaces.
- System calls which are the programming interface to OS services.
- Common approaches to structuring operating systems like layered designs, microkernel architectures, and virtual machines.
The chapter discusses the Linux operating system. It provides an overview of Linux's history and development. Key topics covered include the Linux kernel, process and memory management, scheduling, file systems, and interprocess communication. The chapter describes how Linux implements these operating system concepts and compares Linux's approach to traditional UNIX implementations.
The document describes the key concepts in operating system structures from the 9th edition of the textbook "Operating System Concepts" by Silberschatz, Galvin and Gagne. It discusses the services provided by operating systems, including user interfaces, program execution, file manipulation and security. It also explains how operating systems are implemented through system calls and system programs, and the importance of separating policy from mechanism in operating system design.
This document discusses CPU scheduling in operating systems. It covers basic scheduling concepts like processes alternating between CPU and I/O bursts. It then discusses scheduling criteria like response time and algorithms like first-come first-served (FCFS), shortest job first (SJF), priority scheduling, and round robin. It also covers more advanced topics like multilevel queue scheduling, multiple processor scheduling, and real-time scheduling. Evaluation methods for scheduling algorithms like simulation and queueing models are also mentioned.
The document summarizes key concepts about processes from an operating systems textbook. It discusses process concepts like process state, process control blocks (PCB), and process scheduling queues. It also covers process creation, termination, and cooperation between processes. Interprocess communication methods like message passing and synchronization are presented. The document concludes with an overview of client-server communication techniques using sockets, remote procedure calls, and remote method invocation.
This document summarizes key concepts from Chapter 7 of the textbook "Operating System Concepts - 9th Edition" regarding deadlocks. It describes the four conditions required for deadlock, characterizes deadlocks using a resource-allocation graph, and presents various methods for handling deadlocks including prevention, avoidance, detection, and recovery. Specifically, it covers deadlock prevention techniques like mutual exclusion and no preemption. It also details the banker's algorithm for deadlock avoidance using multiple resource instances and a safety algorithm.
This document summarizes key concepts from Chapter 7 of the textbook Operating System Concepts by Silberschatz, Galvin and Gagne. It discusses deadlocks in computer systems, including their characterization and conditions for their occurrence. It also describes several approaches for handling deadlocks, such as prevention, avoidance, detection and recovery methods. The resource allocation graph and banker's algorithm are presented as techniques for deadlock avoidance when multiple instances of resources are present.
The document summarizes Chapter 7 on deadlocks from the textbook "Operating System Concepts". It describes the deadlock problem, different methods for handling deadlocks including prevention, avoidance and detection. Key aspects covered include the four conditions for deadlock, resource allocation graphs, characterization of safe and unsafe states, and algorithms like the banker's algorithm for deadlock avoidance in systems with multiple instances of resources.
The document discusses deadlocks in operating systems. It defines four conditions for deadlock to occur: mutual exclusion, hold and wait, no preemption, and circular wait. It presents the resource-allocation graph model and shows examples of graphs with and without deadlocks. It also describes three main methods for handling deadlocks: prevention, avoidance, and recovery. Deadlock prevention methods restrain the system to ensure a deadlock cannot occur, while avoidance allows requests as long as the system is kept in a safe state to prevent deadlocks.
This document summarizes a chapter from an operating systems textbook that discusses deadlocks. It describes the deadlock problem, different methods for handling deadlocks including prevention, avoidance, and detection. Prevention methods aim to ensure a system will never enter a deadlock state, while avoidance allows the system to enter unsafe states but prevents deadlocks, and detection allows deadlocks to occur but includes an algorithm to detect them for recovery. The chapter covers characterization of deadlocks, resource allocation graphs to model deadlock states, and algorithms like the banker's algorithm for deadlock avoidance in systems with multiple resource instances.
deadlocks operation systems explaining concepts in deadlocks which occur when a process or thread enters a waiting state because a requested system resource is held by another waiting process, which in turn is waiting for another resource held by another waiting process.
Chapter 8 Operating Systems silberschatz : deadlocksGiulianoRanauro
The document discusses deadlocks in operating systems. It defines deadlock and outlines the four necessary conditions for deadlock to occur. Methods for handling deadlocks include prevention, avoidance, detection, and recovery. Prevention ensures deadlocks never occur by invalidating one of the four conditions. Avoidance uses algorithms like the banker's algorithm to ensure the system remains in a safe state where deadlocks cannot form. Detection allows deadlocks to occur but uses algorithms to detect cycles in wait-for graphs. Recovery schemes aim to recover from detected deadlocks.
Lecture # 10-11 for deadlock operating system.pptRiaanSadiq
A deadlock is a state in a computer system where two or more processes are unable to proceed because each is waiting for the other to release a resource. This impasse leads to a standstill in the execution of programs, resulting in a halt of system operations. Deadlocks typically occur in multitasking or multi-process environments, where processes compete for shared resources such as memory, files, or hardware devices.
The deadlock scenario involves a cyclic waiting condition, where each process holds a resource and waits for another resource held by a different process. This circular dependency prevents any of the involved processes from making progress, causing the entire system to become unresponsive.
Key conditions for a deadlock to occur include mutual exclusion, where resources cannot be simultaneously shared; hold and wait, where a process holds resources while waiting for additional ones; no preemption, where resources cannot be forcibly taken away from a process; and circular wait, where a cycle of processes forms, each waiting for the next to release a resource.
Deadlock prevention and resolution strategies are crucial in system design to ensure efficient resource utilization and prevent the potential negative impacts of deadlocks on overall system performance.A deadlock is a state in a computer system where two or more processes are unable to proceed because each is waiting for the other to release a resource. This impasse leads to a standstill in the execution of programs, resulting in a halt of system operations. Deadlocks typically occur in multitasking or multi-process environments, where processes compete for shared resources such as memory, files, or hardware devices.
The deadlock scenario involves a cyclic waiting condition, where each process holds a resource and waits for another resource held by a different process. This circular dependency prevents any of the involved processes from making progress, causing the entire system to become unresponsive.
Key conditions for a deadlock to occur include mutual exclusion, where resources cannot be simultaneously shared; hold and wait, where a process holds resources while waiting for additional ones; no preemption, where resources cannot be forcibly taken away from a process; and circular wait, where a cycle of processes forms, each waiting for the next to release a resource.
Deadlock prevention and resolution strategies are crucial in system design to ensure efficient resource utilization and prevent the potential negative impacts of deadlocks on overall system performance.A deadlock is a state in a computer system where two or more processes are unable to proceed because each is waiting for the other to release a resource. This impasse leads to a standstill in the execution of programs, resulting in a halt of system operations.
Senthilkanth,MCA..
The following ppt's full topic covers Operating System for BSc CS, BCA, MSc CS, MCA students..
1.Introduction
2.OS Structures
3.Process
4.Threads
5.CPU Scheduling
6.Process Synchronization
7.Dead Locks
8.Memory Management
9.Virtual Memory
10.File system Interface
11.File system implementation
12.Mass Storage System
13.IO Systems
14.Protection
15.Security
16.Distributed System Structure
17.Distributed File System
18.Distributed Co Ordination
19.Real Time System
20.Multimedia Systems
21.Linux
22.Windows
The document summarizes deadlock concepts including:
1) Deadlock occurs when a set of processes are blocked waiting for resources held by each other in a cyclic manner, preventing any progress.
2) Four conditions must hold simultaneously for deadlock: mutual exclusion, hold and wait, no preemption, and circular wait.
3) Methods to handle deadlocks include prevention, avoidance, detection, and recovery. Prevention ensures deadlocks cannot occur by violating one of the four conditions. Avoidance dynamically ensures the system is always in a safe state where deadlocks cannot occur.
This document discusses different approaches to handling deadlocks in operating systems, including prevention, avoidance, detection, and recovery. Deadlock prevention methods restrain how processes request resources to ensure deadlocks cannot occur. Deadlock avoidance uses information about maximum resource needs to dynamically monitor the system's allocation state and ensure it never enters an unsafe state where deadlock is possible. The Banker's Algorithm is presented as a deadlock avoidance technique that models the system and checks if allocating resources leaves the system in a safe state.
System Model
Deadlock Characterization
Methods for Handling Deadlocks
Deadlock Prevention
Deadlock Avoidance
Deadlock Detection
Recovery from Deadlock
Combined Approach to Deadlock Handling
This document summarizes key points about deadlocks from Chapter 7 of the textbook "Operating System Concepts". It discusses the deadlock problem, system model, characterization of deadlocks, and various methods for handling deadlocks including prevention, avoidance, detection and recovery. Specific techniques are explained like the resource allocation graph, banker's algorithm and safety algorithm. The document contains diagrams and examples to illustrate deadlock situations and different states like safe, unsafe and deadlocked states.
This document summarizes key concepts around deadlocks from the 10th edition of the textbook "Operating System Concepts" by Silberschatz, Galvin and Gagne. It discusses deadlock characterization, methods for handling deadlocks including prevention, avoidance, detection and recovery. Specifically, it covers the four conditions for deadlock, resource allocation graphs, avoidance techniques like the banker's algorithm, and detection using wait-for graphs.
This document discusses process synchronization techniques in operating systems. It begins by describing the critical section problem that arises from concurrent access to shared data. It then presents Peterson's solution and semaphores as approaches to solving the critical section problem without busy waiting. Classical synchronization problems like the bounded buffer, readers-writers, and dining philosophers problems are covered. Monitors are introduced as a higher-level abstraction for synchronization. Condition variables are described as a mechanism for processes to wait on specific conditions within a monitor.
For Complete Learning- http://www.thelearnet.com/
System Model
Deadlock Characterization
Methods for Handling Deadlocks
Deadlock Prevention
Deadlock Avoidance
Deadlock Detection
Recovery from Deadlock
Combined Approach to Deadlock Handling
This document summarizes key concepts from Chapter 4 of the textbook "Operating System Concepts - 10th Edition" by Silberschatz, Galvin and Gagne:
1) It introduces the critical section problem which occurs when multiple processes need exclusive access to shared resources, and describes three requirements (mutual exclusion, progress, and bounded waiting) for solving this problem.
2) It discusses different synchronization techniques for solving the critical section problem including mutex locks, semaphores, and monitors. Semaphores provide a more sophisticated way than mutex locks for processes to synchronize activities.
3) It presents three classical problems used to test synchronization schemes - the bounded buffer problem, readers-writers problem, and
This document summarizes chapter 5 from the textbook "Operating System Concepts - 9th Edition" which covers process synchronization. It introduces the critical section problem where multiple processes need orderly access to shared resources. Peterson's algorithm and solutions using locks, mutexes, and semaphores are presented. These synchronization methods use atomic instructions to safely coordinate access to critical sections and ensure processes follow rules of mutual exclusion, progress, and bounded waiting.
This document summarizes key concepts around process synchronization from the 8th edition of the textbook "Operating System Concepts" by Silberschatz, Galvin and Gagne. It introduces the critical section problem, describes Peterson's solution using shared variables, discusses synchronization hardware like test-and-set instructions, and covers semaphores, classic synchronization problems like the bounded buffer problem, and monitors.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
Remote Sensing and Computational, Evolutionary, Supercomputing, and Intellige...University of Maribor
Slides from talk:
Aleš Zamuda: Remote Sensing and Computational, Evolutionary, Supercomputing, and Intelligent Systems.
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Inter-Society Networking Panel GRSS/MTT-S/CIS Panel Session: Promoting Connection and Cooperation
https://www.etran.rs/2024/en/home-english/
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
Unlocking the mysteries of reproduction: Exploring fecundity and gonadosomati...AbdullaAlAsif1
The pygmy halfbeak Dermogenys colletei, is known for its viviparous nature, this presents an intriguing case of relatively low fecundity, raising questions about potential compensatory reproductive strategies employed by this species. Our study delves into the examination of fecundity and the Gonadosomatic Index (GSI) in the Pygmy Halfbeak, D. colletei (Meisner, 2001), an intriguing viviparous fish indigenous to Sarawak, Borneo. We hypothesize that the Pygmy halfbeak, D. colletei, may exhibit unique reproductive adaptations to offset its low fecundity, thus enhancing its survival and fitness. To address this, we conducted a comprehensive study utilizing 28 mature female specimens of D. colletei, carefully measuring fecundity and GSI to shed light on the reproductive adaptations of this species. Our findings reveal that D. colletei indeed exhibits low fecundity, with a mean of 16.76 ± 2.01, and a mean GSI of 12.83 ± 1.27, providing crucial insights into the reproductive mechanisms at play in this species. These results underscore the existence of unique reproductive strategies in D. colletei, enabling its adaptation and persistence in Borneo's diverse aquatic ecosystems, and call for further ecological research to elucidate these mechanisms. This study lends to a better understanding of viviparous fish in Borneo and contributes to the broader field of aquatic ecology, enhancing our knowledge of species adaptations to unique ecological challenges.
ESPP presentation to EU Waste Water Network, 4th June 2024 “EU policies driving nutrient removal and recycling
and the revised UWWTD (Urban Waste Water Treatment Directive)”
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.