Operating System Course
1
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
2
Operating System Syllabus
•
•
•
•
•
•
•
•
•
•
Chapter 1: Introducing Operating Systems.
Chapter 2: Memory Management: Early Systems.
Chapter 3: Memory Management: Virtual Memory.
Chapter 4: Processor Management
Chapter 5: Process Management
Chapter 6: Concurrent Processes
Chapter 7: Device Management
Chapter 8: File Management
Chapter 9: Network Organization Concepts
Chapter 10: Management of Network Functions
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
3
Operating System Syllabus cont.
•
•
•
•
•
•
Chapter 11: Security and Ethics
Chapter 12: System Management
Chapter 13: UNIX Operating System
Chapter 14: MS-DOS Operating System
Chapter 15: Windows Operating System
Chapter 16: Linux Operating System
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
4
Chapter 1
Introducing Operating Systems
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
5
Learning Objectives
After completing this chapter, you should be able to describe:
• How operating systems have evolved through the decades
• The basic role of an operating system
• How operating system software manages its subsystems
• The role of computer system hardware on the development of its operating
system
• How operations systems are adapted to serve batch, interactive, real-time,
hybrid, and embedded systems
• How operating systems designers envision their role and plan their work
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
6
Introduction
• Operating systems
o Manage computer system hardware and software
• This text explores:
o What they are
o How they work
o What they do
o Why they do it
• This chapter briefly describes:
o The workings of operating systems
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
7
What is an Operating System?
• Computer system
o Software (programs)
o Hardware (tangible machine/electronic components)
• Operating system
o Chief software component
o Manages all hardware and all software and controls:
• Every file, device, section of main memory, and moment of processing time
• Who can use the system and how system is used
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
8
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
9
Operating System Software (1 of 5)
• Includes four essential subsystem managers
o Memory Manager
o Processor Manager
o Device Manager
o File Manager
• Each manager:
o Works closely with other managers
o Performs a unique role
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
10
Operating System Software (2 of 5)
(figure 1.1)
This pyramid represents an operating
system on a stand-alone computer
unconnected to a network. It shows the
four subsystem managers and the User
Interface.
© Cengage Learning 2018
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
11
Operating System Software (3 of 5)
• User Interface
o Allows the user to issue commands to the operating system
• Manager tasks
o Monitor the system’s resources continuously
o Enforce policies determining:
• Who gets what, when, and how much
o Allocate a resource (when appropriate)
o Deallocate a resource (when appropriate)
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
12
Operating System Software (4 of 5)
(figure 1.2)
Each manager at the base of the pyramid takes
responsibility for its own tasks while working
harmoniously with every other manager.
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
13
Operating System Software (5 of 5)
• Network Manager
o Coordinates the services required for multiple systems to work cohesively
together
• Shared network resources: memory space, processors, printers, databases,
applications, etc.
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
14
Main Memory Management (1 of 2)
• In charge of main memory
o Random access memory (RAM)
• Requires constant flow of electricity to hold data
• Responsibilities include:
o Checking validity and legality of memory space request
o Reallocating memory to make more useable space available
o Deallocating memory to reclaim it
o Protecting space in main memory occupied by operating system
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
15
Main Memory Management (2 of 2)
• Read-only memory (ROM)
o Another type of memory
o Critical when computer is powered on
o Holds firmware: programming code
• When and how to load each piece of the operating system after the power is turned
on
o Non-volatile
• Contents retained when the power is turned off
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
16
Processor Management
• Allocation of Central Processing Unit (CPU)
• Tracks process status
o Program’s “instance of execution”
• Comparable to a traffic controller
o When a process is finished or maximum computation time expired
• Processor Manager reclaims the CPU and allocates to next waiting process
o Computer with multiple CPUs
• More complex management
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
17
Device Management
• In charge of connecting with every available device
o Printers, ports, disk drives, etc.
• Responsibilities include:
o Choosing most efficient resource allocation method
• Based on scheduling policy
o Identifying each device uniquely
o Starting device operation (when appropriate)
o Monitoring device progress
o Deallocating the device
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
18
File Management
• In charge of tracking every file in the system
o Data files, program files, compilers, application programs, etc.
• Responsibilities include:
o Enforcing user/program resource access restrictions
• Uses predetermined access policies
o Controlling user/program modification restrictions
• Read-only, read-write, create, delete
o Allocating space for a file on secondary storage
• One large storage area or smaller linked pieces
o Retrieving files efficiently
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
19
Network Management
• Included in operating systems with networking capability
• Authorizes users to share resources
o Overall responsibility for every aspect of network connectivity
• Devices, files, memory space, CPU capacity, etc.
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
20
User Interface
• Portion of the operating system
o Direct interaction with users
• Two primary types
o Graphical user interface (GUI)
• Input from pointing device
• Menu options, desktops, and formats vary
o Command line interface
• Keyboard-typed commands that display on a monitor
• Strict requirements for every command: typed accurately; correct syntax;
combinations of commands assembled correctly
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
21
Cooperation Issues
• No single manager performs tasks in isolation
• Each element of an operating system
o Performs individual tasks and
o Harmoniously interacts with other managers
• Incredible precision required for operating system to work smoothly
• More complicated when networking is involved
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
22
Cloud Computing
• Practice of using Internet-connected resources
o Performing processing, storage, or other operations
• Operating system maintains responsibility
o Managing all local resources and coordinating data transfer to and from the cloud
• Role of the operating system
o Accessing resources
o Managing the system efficiently
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
23
An Evolution of Computing Hardware (1 of 4)
• Hardware: physical machine and electronic components
Essential Aspects of computer system hardware:
o Main memory (RAM)
• Data/Instruction storage and execution
o Central processing unit (CPU)
• Controls interpretation and execution of instructions
• Initiates or performs these operations: storage, data manipulation and input/output
o Input/output devices (I/O devices)
• All peripheral devices in the system: printers, disk drives, CD/DVD drives, keyboards,
etc.
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
24
An Evolution of Computing Hardware (2 of 4)
• Computer classification
o At one time: based on memory capacity
• Current platforms
Platform
Operating System
(table 1.1)
Laptops, desktops
Linux, Mac OS X, Unix, Windows
Mainframe computers
Linux, UNIX, Windows, IBM z/OS
Supercomputers
Linux, UNIX
A brief list of platforms and a
few of the operating systems
designed to run on them, listed
in alphabetical order.
Telephones, tablets
Android, iOS, Windows
© Cengage Learning 2018
Workstations, servers
Linux, Mac OS X Server, UNIX,
Windows
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
25
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
26
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
27
An Evolution of Computing Hardware (3 of 4)
• Moore’s Law: Gordon Moore, 1965
o Each new processor chip compared to its predecessor
• Twice as much capacity
• Released within 18 to 24 months
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
28
An Evolution of Computing Hardware (4 of 4)
(figure 1.9)
Gordon Moore’s 1965 paper
included the prediction that the
number of transistors incorporated
in a chip will approximately double
every 24 months (Moore, 19 65).
Courtesy of Intel Corporation.
Number of components per integrated function for
minimum cost per component extrapolated versus time.
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
29
Types of Operating Systems (1 of 6)
• Five categories
o Batch
o Interactive
o Real-time
o Hybrid
o Embedded
• Two distinguishing features
o Response time
o Method of data entry into the system
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
30
Types of Operating Systems (2 of 6)
• Batch systems: jobs entered as a whole and in sequence
o Input relied on punched cards or tape
o Efficiency measured in throughput
• Interactive systems: allow multiple jobs
o Faster turnaround than batch systems
o Slower than real-time systems
o Introduced to provide fast turnaround when debugging
programs
o Complex algorithms: share processing power
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
31
Types of Operating Systems (3 of 6)
• Hybrid systems
o Combination of batch and interactive
o Light interactive load
• Accepts and runs batch programs in the background
• Real-time systems
o Reliability is critical
o Used in time-critical environments
• Spacecraft, airport traffic control, fly-by-wire aircraft, critical industrial processes, medical
systems, etc.
o Two types of real-time systems
• Hard real-time systems: risk total system failure if the predicted time deadline is missed
• Soft real-time systems: suffer performance degradation as a consequence of a missed
deadline
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
32
Types of Operating Systems (4 of 6)
• Network operating systems
o Special class software
o Network Operating System runs on a server and gives the server the capability to
manage data, users, groups, security, applications, and other networking
functions
o Microsoft Windows Server 2003, Microsoft Windows Server 2008, UNIX, Linux,
Mac OS X, Novell NetWare, and BSD
o Wireless networking capability
• Standard feature in many computing devices: cell phones, tablets, and other
handheld Web browsers
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
33
Types of Operating Systems (5 of 6)
(figure 1.10)
Example of a simple network. The
server is connected by cable to the
router and other devices connect
wirelessly.
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
34
Types of Operating Systems (6 of 6)
• Embedded systems
o Computers placed inside other products
• Automobiles, digital music players, elevators, pacemakers, etc.
o Adds features and capabilities
o Operating system requirements
• Perform specific set of programs
• Non-interchangeable among systems
• Small kernel and flexible function capabilities
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
35
Timeline of Operating Systems Development (1 of 9)
• Evolution of operating systems: parallels evolution of computer hardware
• 1940s
o Computers operated by programmers presiding from the main console
o Fixing a program error
• 1) stop the processor
• 2) read register contents
• 3) make corrections in memory
• 4) resume operations
o Poor machine utilization
• CPU processed data and performed calculations for fraction of available time
o “Bug”: system not working correctly
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
36
Timeline of Operating Systems Development (2 of 9)
(figure 1.11)
Dr. Grace Hopper’s research journal
included the first computer bug.
Taped to the page are the remains of
a moth that became trapped in the
computer’s relays, causing the
system to crash.
[Photo © 2002 IEEE]
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
37
Timeline of Operating Systems Development (3 of 9)
• 1950s
o Two widely adopted improvements
• Computer operators: humans hired to facilitate machine operation
• Job scheduling: programs with similar requirements grouped together (batch)
o Expensive time lags between CPU and I/O devices
o Improvements to the CPU and the system
• I/O devices (tape drives and disks): gradually became faster
• Records blocked before retrieval or storage
• Control unit placed between I/O and CPU as a buffer: reduced speed discrepancy
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
38
Timeline of Operating Systems Development (4 of 9)
• 1960s
o Faster CPUs
o Speed caused problems with slower I/O devices
o Multiprogramming: many programs loaded and sharing the CPU
• Passive multiprogramming: interrupts
• Active multiprogramming: time slicing
• 1970s
o Faster CPUs: caused problems with slower I/O devices
o Main memory physical capacity limitations
• Multiprogramming schemes: increase CPU use
• Virtual memory system: solves physical limitation
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
39
Timeline of Operating Systems Development (5 of 9)
• 1980s
o More flexible hardware
• Logical functions built on replaceable circuit boards
o Operating system functions
• Made part of the hardware (firmware)
o Multiprocessing: more than one processor
• Allowed parallel program execution
o Evolution of personal computers and high-speed communications
• Led to distributed processing/networked systems
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
40
Timeline of Operating Systems Development (6 of 9)
• 1990s
o Demand for Internet capability
o Increased networking
o Increased tighter security demands
• Protect system assets from Internet threats
o Multimedia applications
• Demanded additional power, flexibility, device compatibility for most operating
systems, etc.
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
41
Timeline of Operating Systems Development (8 of 9)
• 2000s
o Need for improved flexibility, reliability, and speed
o Virtual machines
• Accommodated multiple operating systems that run at the same time and share
resources
• Required OS to have an intermediate manager
• Oversee the access of each operating system to the server’s physical resources
o Multicore processors: two to many cores
• What capabilities does the operating system need for these processors?
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
42
Timeline of Operating Systems Development (9 of 9)
• 2010s
o Increased mobility and wireless connectivity
• Proliferation of dual-core, quad-core, and other multicore CPUs
o Multicore technology
• Single chip equipped with two or more processor cores
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
43
Role of the Software Designer/Developer
• Most common overall goal
o Maximize use of the system’s resources (memory, processing, devices, and files)
and minimize downtime
• Factors included in developmental efforts
o RAM resources
o CPUs: number and type available
o Peripheral devices: variety likely to be connected
o Networking capability
o Security requirements, etc.
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
44
Conclusion
• Overall function of operating systems
• Evolution of operating systems
o Capable of running complex computers and computer systems
• Operating system designer/developer
o Chooses the policies that best match the system’s environment
Mchoes/Flynn, Understanding Operating Systems, 8th Edition. © 2018 Cengage. All Rights Reserved.
May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
45