operating system principles by abraham silberschatz ppt

... memory All of the processes in main memory are blocked, and OS brings in Process D 35 Paging • Operating system maintains a page table for each process which contains the frame location for each page ... because the location of a program in main memory is unpredictable • Must be checked at run time by the processor Sharing • Allow several processes to access the same portion of memory – Better ... to the same copy of the program rather than have their own separate copy – Processes that are cooperating on some task may need to share access to the same data structure Logical Organization

Ngày tải lên: 30/01/2020, 00:31

... competing processes • The resource is allocated by means of scheduling - determines which processes will wait and which will progress • The resource provided by a processor is execution time Overall ... The aim of processor scheduling is to assign processes to be executed by the processor over time, – in a way that meets system objectives, such as response time, throughput, and processor efficiency ... and to optimize performance Long-Term Scheduling • Determines which programs are admitted to the system for processing – May be first-come-first-served – According to criteria such as priority,

Ngày tải lên: 30/01/2020, 00:39

... Categories Two general categories of resources: • Reusable – can be safely used by only one process at a time and is not depleted by that use – examples: processors, main and secondary memory, devices, ... free HALT until B is free Two Processes P and Q • Consider two processes P and Q in a uniprocessor system • Each needs exclusive access to a resource A and B for a period of time Joint Progress Diagram ... deadlocked when each process in the set is blocked awaiting an event that can only be triggered by another blocked process in the set – Typically involves processes competing for the same set

Ngày tải lên: 30/01/2020, 01:28

... interleaved with other processes • These two characteristics are treated independently by the operating system Processes and Threads • The unit of dispatching is referred to as a thread or lightweight ... a process share this) One view… • One way to view a thread is as an independent program counter operating within a process Threads vs processes 10 Threads vs processes • The thread control block ... processes • Like processes, thread may synchronize with one another – Any alteration of a resource by one thread affects other threads in the same process • consider two threads each try to add an

Ngày tải lên: 30/01/2020, 02:33

... Evolution of Operating Systems • It may be easier to understand the key requirements of an OS by considering the evolution of Operating Systems • Stages include – Serial Processing – Simple Batch Systems ... Chapter and Computer System and Operating System Overview – The Evolution of Operating Systems – OS Objectives and Functions – Instruction Execution – ... Processing – Simple Batch Systems – Multiprogrammed Batch Systems – Time Sharing Systems Serial Processing (late 1940s to mid-1950s) • No operating system • Machines run from a console with display lights,

Ngày tải lên: 30/01/2020, 02:42

... access rights have been used by various systems – often as a hierarchy, with each right implying those that precede it • None – User may not know the existence of file by not allowing to read the ... users: individual users who are designated by user ID – User groups: a set of users identified as a group – All: all users who have access to this system 32 Simultaneous Access • When access ... performance How to identify and locate a selected file? How to enforce user access control in shared systems? Roadmap • Overview • File organisation and Access • File Directories • File Sharing • Record

Ngày tải lên: 30/01/2020, 05:07

... Support Semaphores Readers/Writers Problem Multiple Processes • Central to the design of modern Operating Systems is managing multiple processes – Multiprogramming – Multiprocessing – Distributed Processing ... keyboard-input character to display chin = getchar(); What would happen if P1 is interrupted here by P2? chout = chin; putchar(chout); } What would happen if only one process is permitted at a time

Ngày tải lên: 30/01/2020, 05:11

... Chapter 11 I/O Management and Disk Scheduling – Operating System Design Issues – I/O Buffering – Disk Scheduling – Disk Cache Goal: Generality • For ... for improving the efficiency of I/O – I/O buffering – Disk scheduling – Disk cache Roadmap – Operating System Design Issues – I/O Buffering – Disk Scheduling – Disk Cache No Buffering • Without ... Reduces the maximum delay experienced by new requests 34 N-step-SCAN • With SSTF, SCAN, C-SCAN, the arm may not move if processes monopolize the device by repeated requests to one track: arm

Ngày tải lên: 30/01/2020, 05:13

... routines called by the user to perform various functions – No need for Process Switch to run OS routine, only Mode Switch 48 Process-based Operating System • Process-based operating system – Implement ... structures to control process execution Requirements of an Operating System • Fundamental Task: Process Management • The Operating System must – Interleave the execution of multiple processes ... the system 51 System access threats • Malicious software (malware) – destroy files and data in main memory – bypass controls to gain privileged access – provide a means for intruders to bypass

Ngày tải lên: 30/01/2020, 05:34

... which secondary memory can be addressed as though it were part of main memory – Size is limited by the amount of secondary memory available • Virtual address is the address assigned to a location ... automatically loads pieces of a process into main memory as required Thrashing • A condition in which the system spends most of its time swapping pieces rather than executing instructions • It happens when ... Least Recently Used (LRU) • Replaces the page that has not been referenced for the longest time • By the principle of locality, this should be the page least likely to be referenced in the near

Ngày tải lên: 30/01/2020, 05:38

... topic of operating systems and a handful of important concepts (multiprogramming, time sharing, distributed system, and so on) The purpose is to show why operating systems are what they are by showing ... by the operating system for the following two settings: (a) handheld devices and (b) real-time systems a Batch programming b Virtual memory c Time sharing Answer: For real-time systems, the operating ... www.elsolucionario.net Preface This volume is an instructor’s manual for the Seventh Edition of OperatingSystem Concepts, by Abraham Silberschatz, Peter Baer Galvin, and Greg Gagne It consists of answers to the

Ngày tải lên: 16/10/2021, 15:40

... section 3.4 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts - 7 th Edition, Feb 7, 2006 Process in Memory Process in Memory 3.5 Silberschatz, Galvin and Gagne ©2005 Operating System ... Operations on Processes  Cooperating Processes  Interprocess Communication  Communication in Client-Server Systems 3.3 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts - 7 th Edition, ... 3.6 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts - 7 th Edition, Feb 7, 2006 Diagram of Process State Diagram of Process State 3.7 Silberschatz, Galvin and Gagne ©2005 Operating

Ngày tải lên: 28/06/2014, 02:20

... topic of operating systems and a handful of important concepts (multiprogramming, time sharing, distributed system, and so on) The purpose is to show why operating systems are what they are by showing ... by the operating system for the following two settings: (a) handheld devices and (b) real-time systems a Batch programming b Virtual memory c Time sharing Answer: For real-time systems, the operating ... College Preface This volume is an instructor’s manual for the Seventh Edition of OperatingSystem Concepts, by Abraham Silberschatz, Peter Baer Galvin, and Greg Gagne It consists of answers to the

Ngày tải lên: 17/10/2017, 23:16

... mainmemory references by optimizing register use • Control and status registers – Used by processor to control operating of the processor – Used by privileged operating-system routines to control ... Computer System Overview Chapter 1 Operating System • Exploits the hardware resources of one or more processors • Provides a set of services to system users • Manages secondary ... execution of programs User-Visible Registers • May be referenced by machine language • Available to all programs - application programs and system programs • Types of registers – Data – Address • Index

Ngày tải lên: 09/01/2018, 12:01

... Operating System Overview Chapter Operating System • A program that controls the execution of application programs • An interface between applications and hardware Operating System Objectives ... the Executive • Polymorphism 62 UNIX • Hardware is surrounded by the operating system software • Operating system is called the system kernel • Comes with a number of user services and interfaces ... Arithmetic overflow • Access forbidden memory locations – Operating system cannot grant request of application Services Provided by the Operating System • Accounting – Collect usage statistics – Monitor

Ngày tải lên: 09/01/2018, 12:01

... Processes – Operating system software within context of a user process – Process executes in privileged mode when executing operating system code 52 53 54 Execution of the Operating System • Process-Based ... Process-Based Operating System – Implement operating system as a collection of system processes – Useful in multi-processor or multicomputer environment 55 UNIX SVR4 Process Management • Most of the operating ... context of the selected process 51 Execution of the Operating System • Non-process Kernel – Execute kernel outside of any process – Operating system code is executed as a separate entity that operates

Ngày tải lên: 09/01/2018, 12:01

... independently by the operating system Process • Dispatching is referred to as a thread or lightweight process • Resource of ownership is referred to as a process or task Multithreading • Operating system ... communicate with each other without invoking the kernel Uses of Threads in a SingleUser Multiprocessing System • • • • Foreground to background work Asynchronous processing Speed of execution Modular ... Windows Process Object 41 Windows Thread Object 42 Windows 2000 Thread States • • • • • • Ready Standby Running Waiting Transition Terminated 43 44 Solaris • Process includes the user’s address space,

Ngày tải lên: 09/01/2018, 12:01

... applications • Structured applications • Operating system structure Concurrency Difficulties of Concurrency • Sharing of global resources • Operating system managing the allocation of resources ... Structured application – Application can be a set of concurrent processes • Operating-system structure – Operating system is a set of processes or threads A Simple Example void echo() { chin ... chout = chin; putchar(chout); Process P2 chin = getchar(); chout = chin; putchar(chout); Operating System Concerns • Keep track of various processes • Allocate and deallocate resources – – –

Ngày tải lên: 09/01/2018, 12:01

... available for allocation of 200Kbytes, and the following sequence of events occur P1 Request 80 Kbytes; P2 Request 70 Kbytes; Request 60 Kbytes; Request 80 Kbytes; • Deadlock occurs if both ... either compete for system resources or communicate with each other • No efficient solution • Involve conflicting needs for resources by two or more processes Reusable Resources • Used by only one process ... Resources • Used by only one process at a time and not depleted by that use • Processes obtain resources that they later release for reuse by other processes • Processors, I/O channels, main and secondary

Ngày tải lên: 09/01/2018, 12:01

... time – Memory protection requirement must be satisfied by the processor (hardware) rather than the operating system (software) • Operating system cannot anticipate all of the memory references ... partition size can be loaded into an available partition – If all partitions are full, the operating system can swap a process out of a partition – A program may not fit in a partition The programmer ... the bounds register • If the address is not within bounds, an interrupt is generated to the operating system 27 Paging • Partition memory into small equal fixed-size chunks and divide each process

Ngày tải lên: 09/01/2018, 12:01