Ch2 - Chapter 2 Operating-System Structures Chapter Adapted to COP4610 by Robert van Engelen Operating System Services s One set of

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 2: Operating-System Structures Chapter 2: Operating-System Structures Adapted to COP4610 by Robert van Engelen
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2.2 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts – 7 th Edition, Jan 14, 2005 Operating System Services Operating System Services One set of operating-system services provides functions that are helpful to the user: User interface - Almost all operating systems have a user interface (UI) Varies between Command-Line Interface (CLI), Graphics User Interface (GUI) , and Batch CLI (shell) GUI (Mac OS X)
Background image of page 2
2.3 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts – 7 th Edition, Jan 14, 2005 Operating System Services (Cont.) Operating System Services (Cont.) Functions that are helpful to the user and to processes: Program execution - Load a program into memory and run it File-system manipulation - Move, copy, and delete files, create directories, change permissions, etc. Communications – Processes may exchange information, on the same computer or between computers over a network Communications may be via shared memory or through message passing (packets moved by the OS) Error detection – OS needs to be constantly aware of possible errors May occur in the CPU and memory hardware, in I/O devices, etc. For each type of error, OS should take the appropriate action to ensure correct and consistent computing Debugging facilities can greatly enhance the user’s and programmer’s abilities to efficiently use the system
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2.4 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts – 7 th Edition, Jan 14, 2005 Operating System Services (Cont.) Operating System Services (Cont.) Another set of OS functions exists for ensuring the efficient operation of the system itself via resource sharing Resource allocation - When multiple users or multiple jobs running concurrently, resources must be allocated to each of them Many types of resources - Some (such as CPU cycles, main memory, and file storage) may have special allocation code, others (such as I/O devices) may have general request and release code. Accounting - To keep track of which users use how much and what kinds of computer resources Protection and security - The owners of information stored in a multiuser or networked computer system may want to control use of that information, concurrent processes should not interfere with each other Protection involves ensuring that all access to system resources is controlled Security of the system from outsiders requires user authentication, extends to defending external I/O devices from invalid access attempts If a system is to be protected and secure, precautions must be instituted throughout it (a chain is only as strong as its weakest link)
Background image of page 4
2.5 Silberschatz, Galvin and Gagne ©2005 Operating System Concepts – 7 th Edition, Jan 14, 2005 User Operating System Interface - CLI User Operating System Interface - CLI CLI allows direct command
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/11/2011 for the course COP 4610 taught by Professor Robertengelen during the Spring '11 term at FSU.

Page1 / 35

Ch2 - Chapter 2 Operating-System Structures Chapter Adapted to COP4610 by Robert van Engelen Operating System Services s One set of

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online