chapter 13 operating systems an overview n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Chapter 13 Operating Systems: An Overview PowerPoint Presentation
Download Presentation
Chapter 13 Operating Systems: An Overview

Loading in 2 Seconds...

play fullscreen
1 / 34

Chapter 13 Operating Systems: An Overview - PowerPoint PPT Presentation


  • 95 Views
  • Uploaded on

Chapter 13 Operating Systems: An Overview. The Architecture of Computer Hardware and Systems Software: An Information Technology Approach 3rd Edition, Irv Englander John Wiley and Sons  2003. Bare Bones Computer System. Does not load instructions into main memory

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Chapter 13 Operating Systems: An Overview' - zamora


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
chapter 13 operating systems an overview

Chapter 13Operating Systems: An Overview

The Architecture of Computer Hardware and Systems Software: An Information Technology Approach

3rd Edition, Irv Englander

John Wiley and Sons 2003

bare bones computer system
Bare Bones Computer System
  • Does not load instructions into main memory
  • No user interface except for I/O routines provided with executing program
  • Is idle when waiting for user input
  • No facility to store, retrieve, or manipulate files
  • No ability to control peripheral devices
  • Can run only one program at a time

Chapter 13

Operating Systems: An Overview

integrated computer environment
Integrated Computer Environment

Chapter 13

Operating Systems: An Overview

operating system basic services
Operating System – Basic Services
  • Programs that accept commands and requests from a user and a user’s program
  • Manages, loads, and executes programs
  • Manages hardware resources of the computer
  • Act as an interface between the user and the system

Chapter 13

Operating Systems: An Overview

operating system additional services
Operating System – Additional Services
  • Provides interfaces for the user and the user’s programs
  • File support services
  • I/O support services
  • Means of starting the computer
    • Bootstrapping or booting the computer
    • Initial Program Load (IPL)
  • Handles all interrupt processing
  • Network services
  • Provides tools and services for concurrent processing

Chapter 13

Operating Systems: An Overview

additional services required by concurrent processing
Additional Services Required by Concurrent Processing
  • Allocates resources such as memory, CPU time, and I/O devices to programs
  • Protects users and programs from each other and provides for inter-program communication
  • Provides feedback to the system administrators to permit performance optimization of the computer system

Chapter 13

Operating Systems: An Overview

os parts
OS Parts
  • Memory Resident
    • Always loaded in memory
    • Commonly called the kernel
    • Contains essential services required by other parts of the operating system and applications.
    • Typically responsible for managing memory management, processes and tasks, and secondary storage
  • Memory Non-resident
    • Applications
    • Infrequently used programs, software tools, and commands
  • Bootstrap program
  • Diskless workstations or thin clients
    • Programs, including the OS, are located on another computer on the network

Chapter 13

Operating Systems: An Overview

simplified diagram of operating system services
Simplified Diagram of Operating System Services

Chapter 13

Operating Systems: An Overview

os degree of activity
OS Degree of Activity
  • Interactive
    • Also known as conversational systems
  • Batch processing
    • User submits programs or jobs for processing
    • Little to no user interaction
  • Event driven
    • Interrupts or service requests

Chapter 13

Operating Systems: An Overview

hardware and the os
Hardware and the OS
  • A hardware platform may support a variety of operating systems
  • An operating system may work on a variety of platforms
  • A standard operating system that works on different hardware
    • Provides program and file portability
    • Enables user efficiency through recognizable interface
    • Is implemented through a systems programming language like C or C++ as opposed to assembly language

Chapter 13

Operating Systems: An Overview

single job processing
Single Job Processing
  • Only one program is loaded into memory and executed
  • Example: MS-DOS
  • Memory resident components
    • Command interface shell
    • I/O routines, including BIOS
    • File management system
  • User program in control

Chapter 13

Operating Systems: An Overview

os regains control
OS Regains Control
  • When program is finished control is transferred back to the command interpreter
  • If the user’s program requests I/O
  • The user wishes to stop the program execution via a keyboard interrupt
  • System malfunctions

Chapter 13

Operating Systems: An Overview

single job processing1
Single Job Processing

Disadvantages

  • Lack of security
    • Programs can overwrite the resident OS
    • Programs can write directly to I/O devices
  • System provides minimum memory management and no scheduling
  • CPU is often idle awaiting the completion of I/O operations

Chapter 13

Operating Systems: An Overview

slide14
Chapter 13

Operating Systems: An Overview

concurrent operations
Concurrent Operations
  • Multitasking (multiprogramming) vs. multiprocessing which implies multiple CPUs
  • Concurrent processing vs. simultaneous processing

Chapter 13

Operating Systems: An Overview

achieving multitasking
Achieving Multitasking
  • While one program is waiting for I/O to take place, another program is using the CPU to execute instructions.
  • Time-slicing. The CPU may be switched rapidly back and forth between different programs
  • Dispatching is the process of selecting which program to run at any given instant

Chapter 13

Operating Systems: An Overview

sharing the cpu during i o breaks
Sharing the CPU during I/O Breaks
  • I/O represents a large percentage of a typical program’s execution

Chapter 13

Operating Systems: An Overview

time sharing the cpu
Time-sharing the CPU

Time slicing

Chapter 13

Operating Systems: An Overview

services and facilities
Services and Facilities
  • Command processor
  • File management system
  • I/O control system
  • Process control management and interprocess communication
  • Memory management
  • Scheduling system
  • Secondary storage management
  • System protection management
  • Network management, communication support, and communication interfaces
  • System Administration

Chapter 13

Operating Systems: An Overview

user interface and command execution services
User Interface and Command Execution Services
  • Types of user interfaces
    • CLI - Command Line Interface
    • GUI - Graphical User Interface
    • Menu environment
  • Shell
    • User interface and command processor that interacts with the kernel
    • UNIX: C, Bourne and Korn shells
  • Command Languages
    • IBM Mainframes – JCL
    • MS Windows – BAT files, Windows Scripting Host
    • UNIX – shell scripts

Chapter 13

Operating Systems: An Overview

file management
File Management
  • File - logical unit of storage
  • Basic file management system provides
    • Directory structures for each I/O device
    • Tools to copy and move files
    • Information about each file in the system and the tools to access that information
    • Security mechanisms to protects files and control access
  • Additional file management features
    • Backup, emergency retrieval and recovery
    • File compression
    • Transparent network file access
    • auditing

Chapter 13

Operating Systems: An Overview

i o services and process control management
I/O Services andProcess Control Management
  • I/O services
    • Startup configuration
    • Device drives that implement interrupts and provide other techniques for handling I/O
    • Plug and play: hot swapping, hot plugging
  • Process control management
    • A process is an executing program
    • A thread is an individually executable part of a process
    • Interprocess messaging services
      • Example: a pipe in UNIX or DOS that is a temporary software connection between two programs or commands

Chapter 13

Operating Systems: An Overview

memory management
Memory Management
  • Keeps track of memory
    • Identifies programs loaded into memory
    • Amount of space each program uses
    • Available remaining space
    • Prevents programs from reading and writing memory outside of their allocated space
  • Maintains queues of waiting programs
  • Allocates memory to programs that are next to be loaded
  • Deallocates a program’s memory space upon program completion

Chapter 13

Operating Systems: An Overview

scheduling
Scheduling
  • High-level scheduling
    • Placed in queue based on level of priority and eventually executed
  • Dispatching
    • Actual selection of processes that will be executed at any given time
    • Preemptive – uses clock interrupts
    • Non-preemptive – program voluntarily gives up control
  • Context switching
    • Transfer control to the process that is being dispatched
    • Nonpreemptive: program voluntarily gives up control
    • Preemptive: uses clock interrupt for multitasking
  • Processing requirements
    • CPU vs. I/O bound

Chapter 13

Operating Systems: An Overview

secondary storage and security
Secondary Storage and Security
  • Secondary storage management
    • Optimizes completion of I/O tasks for efficient disk usage
    • Combination of hardware and software
  • Security and protection services
    • Protect OS from users
    • Protect users from other users
    • Prevent unauthorized entry to system
    • Prevent unauthorized system use by authorized users

Chapter 13

Operating Systems: An Overview

network and communication services
Network and Communication Services
  • TCP-IP protocol suite
    • Locate and connect to other computers
    • Access files, I/O devices, and programs from remote systems
    • Support distributed processing
  • Network Applications
    • Email, remote login, Web services, streaming multimedia, voice over IP telephony, VPN
  • Interface between communication software and OS I/O control system that provides network access

Chapter 13

Operating Systems: An Overview

system administration support
System configuration and setting group configuration policies

Adding and deleting users

Modifying user privileges

System security

Files systems management

Network administration

Backups

Software installations and upgrades

OS installations (system generation), patches, and upgrades

System tuning and optimization

System Administration Support

Chapter 13

Operating Systems: An Overview

monolithic kernel
Monolithic Kernel
  • Drawback: stability and integrity
  • Examples:
    • UNIX
    • Windows NT

Chapter 13

Operating Systems: An Overview

hierarchical
Hierarchical
  • Requests passthrough intermediatelayers
  • Examples
    • Multics
    • Data General

Chapter 13

Operating Systems: An Overview

microkernel
Microkernel
  • Minimum essential functionality
  • Client-server system on same system
    • Clients request services from microkernel which passes message onto appropriate server

Chapter 13

Operating Systems: An Overview

mach os kernel
Mach OS Kernel
  • Microkernel implementation
  • Includes
    • Message passing
    • Interrupt processing
    • Virtual memory management
    • Scheduling
    • Basic set of I/O drivers
  • Macintosh OS X, IBM AIX on RS/6000

Chapter 13

Operating Systems: An Overview

types of operating systems
Types of Operating Systems
  • Single user, single tasking
  • Single user, multitasking
  • Multi-user, multitasking
  • Distributed systems
    • Processing power distributed among computers in a cluster or network
  • Network servers
  • Real-time systems
  • Embedded systems

Chapter 13

Operating Systems: An Overview

bootstrapping
Bootstrapping
  • Execution begins with bootstrap loader (mini-loader, IPL) stored in ROM
  • Looks for OS program in a fixed location
  • Loads OS into RAM
  • Transfers control to starting location of OS
  • Loader program in OS used to load and execute user programs

Chapter 13

Operating Systems: An Overview

bootstrapping1
Bootstrapping
  • Cold vs.warm boot(does not retest the system)

Chapter 13

Operating Systems: An Overview