Clifford sugerman
Upcoming SlideShare
Loading in...5
×
 

Clifford sugerman

on

  • 433 views

He was a very compassionate and was very courageous. He always remained ready to work for the cause of humanity. His family was spiritually inclined and he had inherited this inclination .This ...

He was a very compassionate and was very courageous. He always remained ready to work for the cause of humanity. His family was spiritually inclined and he had inherited this inclination .This spiritual environment throw a deep impact on his upbringing. From the very beginning he was a man of ethics and values.

Statistics

Views

Total Views
433
Views on SlideShare
432
Embed Views
1

Actions

Likes
0
Downloads
3
Comments
0

1 Embed 1

https://twitter.com 1

Accessibility

Categories

Upload Details

Uploaded via as Adobe PDF

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

Clifford sugerman Clifford sugerman Document Transcript

  • 1 1.1 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Chapter 1: IntroductionChapter 1: Introduction n What is an Operating System? n Mainframe Systems n Desktop Systems n Multiprocessor Systems n Distributed Systems n Clustered System n Real -Time Systems n Handheld Systems n Feature Migration n Computing Environments 1.2 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java What is an Operating System?What is an Operating System? n A program that acts as an intermediary between a user of a computer and the computer hardware n Operating system goals: l Execute user programs and make solving user problems easier. l Make the computer system convenient to use n Use the computer hardware in an efficient manner
  • 2 1.3 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java What is an OS?What is an OS? n Think about some of the things you do with a computer and think about how the OS supports them. © 2004 D.A. Menascé 1.4 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java OS FunctionsOS Functions Action OS Functions Login process creation, authentication, resource allocation Create a text document application launching, file management. Running applications Scheduling, resource (e.g., memory, disk) allocation. © 2004 D.A. Menascé
  • 3 1.5 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Some OS FunctionsSome OS Functions • User authentication • Processor allocation (process scheduling) • File Management • Memory Management • Device Management • Network Management • Providing a user interface (graphical or not) to system functions and resources • Process synchronization • Interprocess communication. © 2004 D.A. Menascé 1.6 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java What is an Operating SystemWhat is an Operating System n Resource Manager n Extended Machine: provides higher level abstractions of lower level and complex objects (e.g., files, processes, devices) l complexity hidden from user l homogeneous treatment of different low level objects (e.g., one single read function can be used to read a block from any disk) © 2004 D.A. Menascé
  • 4 1.7 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java OS OperationOS Operation Bare Machine user processes waiting to run user processes waiting to run OS is sleeping Bare Machine user process is running OS is running © 2004 D.A. Menascé 1.8 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Computer System ComponentsComputer System Components 1. Hardware – provides basic computing resources (CPU, memory, I/O devices) 2. Operating system – controls and coordinates the use of the hardware among the various application programs for the various users 3. Applications programs – define the ways in which the system resources are used to solve the computing problems of the users (compilers, database systems, video games, business programs) 4. Users (people, machines, other computers)
  • 5 1.9 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Abstract View of System ComponentsAbstract View of System Components 1.10 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Operating System DefinitionsOperating System Definitions n Resource allocator – manages and allocates resources n Control program – controls the execution of user programs and operations of I/O devices n Kernel – the one program running at all times (all else being application programs)
  • 6 1.11 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Mainframe SystemsMainframe Systems n Reduce setup time by batching similar jobs n Automatic job sequencing – automatically transfers control from one job to another. First rudimentary operating system n Resident monitor l initial control in monitor l control transfers to job l when job completes control transfers back to monitor 1.12 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java IBM 7094 MainframeIBM 7094 Mainframe –– Columbia UniversityColumbia University 19651965 © 2004 D.A. Menascé
  • 7 1.13 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Memory Layout for a Simple Batch SystemMemory Layout for a Simple Batch System 1.14 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java MultiprogrammedMultiprogrammed Batch SystemsBatch Systems Several jobs are kept in main memory at the same time, and the CPU is multiplexed among them
  • 8 1.15 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Utilization inUtilization in MultiprogrammedMultiprogrammed SystemsSystems 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0 1 2 3 4 5 6 7 8 9 10 Degree of Multiprogramming Utilization CPU Utilization Disk Utilization © 2004 D.A. Menascé 1.16 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Throughput inThroughput in MultiprogrammedMultiprogrammed SystemsSystems 0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0 1 2 3 4 5 6 7 8 9 10 Degree of multiprogramming Throughput(jobs/msec) © 2004 D.A. Menascé
  • 9 1.17 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java OS Features Needed for MultiprogrammingOS Features Needed for Multiprogramming n I/O routine supplied by the system n Memory management – the system must allocate the memory to several jobs n CPU scheduling – the system must choose among several jobs ready to run n Allocation of devices 1.18 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java MultiprogrammingMultiprogramming P1 P2 P3 P4 process using the CPU © 2004 D.A. Menascé
  • 10 1.19 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java MultiprogrammingMultiprogramming • The OS gives each process a certain timeslice (quantum) to run. • Control is passed to another process if: • running process ends before timeslice expires running process leaves the system. • running process needs and I/O operation running process joins the I/O device queue, • timeslice expires running process goes back to the CPU queue. © 2004 D.A. Menascé 1.20 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Process States in aProcess States in a MultiprogrammedMultiprogrammed OSOS Running Blocked Ready IO request end of timeslice scheduling IO operation completion © 2004 D.A. Menascé
  • 11 1.21 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java TimeTime--Sharing SystemsSharing Systems––Interactive ComputingInteractive Computing n The CPU is multiplexed among several jobs that are kept in memory and on disk (the CPU is allocated to a job only if the job is in memory) n A job is swapped in and out of memory to the disk n On-line communication between the user and the system is provided l When the operating system finishes the execution of one command, it seeks the next “control statement” from the user’s keyboard n On-line system must be available for users to access data and code 1.22 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java TimeTime--sharing Queuessharing Queues Swapping disk CPU disk Jobs in memory Arriving job Completing job a b c Ready queue © 2004 D.A. Menascé
  • 12 1.23 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Desktop SystemsDesktop Systems n Personal computers – computer system dedicated to a single user n I/O devices – keyboards, mice, display screens, small printers n User convenience and responsiveness n Can adopt technology developed for larger operating system l Often individuals have sole use of computer and do not need advanced CPU utilization of protection features n May run several different types of operating systems (Windows, MacOS, UNIX, Linux) 1.24 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Parallel SystemsParallel Systems n Systems with more than one CPU in close communication l Also known as multiprocessor systems n Tightly coupled system – processors share memory and a clock; communication usually takes place through the shared memory n Advantages of parallel system: l Increased throughput l Economical l Increased reliability (in some cases) 4graceful degradation 4fail-soft systems
  • 13 1.25 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Parallel SystemsParallel Systems P1 P2 Pn . . .Job queue Prob. System is Up = Prob. at least one processor is up = 1 – Prob (all processors are down) = 1 - pn n 1- p^n 1 0.200 2 0.360 3 0.488 4 0.590 5 0.672 6 0.738 7 0.790 8 0.832 9 0.866 10 0.893 © 2004 D.A. Menascé 1.26 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Parallel Systems (Cont.)Parallel Systems (Cont.) n Asymmetric multiprocessing l Each processor is assigned a specific task; master processor schedules and allocated work to slave processors l More common in extremely large systems n Symmetric multiprocessing (SMP) l Each processor runs and identical copy of the operating system l Many processes can run at once without performance deterioration l Most modern operating systems support SMP
  • 14 1.27 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Symmetric Multiprocessing ArchitectureSymmetric Multiprocessing Architecture 1.28 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Distributed SystemsDistributed Systems n Distribute the computation among several physical processors n Loosely coupled system – each processor has its own local memory; processors communicate with one another through various communications lines, such as high- speed buses or telephone lines n Advantages of distributed systems l Resources Sharing l Computation speed up – load sharing l Reliability l Communications
  • 15 1.29 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Distributed Systems (cont)Distributed Systems (cont) n Requires networking infrastructure n Local area networks (LAN) or Wide area networks (WAN) n May be either client-server or peer-to-peer systems 1.30 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java General Structure of ClientGeneral Structure of Client--ServerServer
  • 16 1.31 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Clustered SystemsClustered Systems n Clustering allows two or more systems to share storage n Provides high reliability n Asymmetric clustering: one server runs the application or applications while other servers standby n Symmetric clustering: all N hosts are running the application or applications 1.32 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java RealReal--Time SystemsTime Systems n Often used as a control device in a dedicated application such as controlling scientific experiments, medical imaging systems, industrial control systems, and some display systems n Well-defined fixed-time constraints n Real-Time systems may be either hard or soft real-time
  • 17 1.33 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java RealReal--Time Systems (Cont.)Time Systems (Cont.) n Hard real-time: l Secondary storage limited or absent, data stored in short term memory, or read-only memory (ROM) l Conflicts with time-sharing systems, not supported by general-purpose operating systems n Soft real-time l Limited utility in industrial control of robotics l Integrate-able with time-share systems l Useful in applications (multimedia, virtual reality) requiring tight response times 1.34 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Handheld SystemsHandheld Systems n Personal Digital Assistants (PDAs) n Cellular telephones n Issues: l Limited memory l Slow processors l Small display screens
  • 18 1.35 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Migration of OperatingMigration of Operating--System Concepts and FeaturesSystem Concepts and Features 1.36 Silberschatz, Galvin and Gagne ©2003Operating System Concepts with Java Computing EnvironmentsComputing Environments n Traditional computing l PCs, Servers, limited remote access n Web-Based Computing l Client-server and web services, convenient remote access, location- less servers n Embedded Computing l Most computers (auto engine controllers, microwaves) l Very limited operating system features l Little or no user interface, remote access