OS.txt

Card Set Information

Author:
fs356
ID:
153785
Filename:
OS.txt
Updated:
2012-05-14 12:20:56
Tags:
OStest
Folders:

Description:
Practiceexam
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user fs356 on FreezingBlue Flashcards. What would you like to do?


  1. What are the 2 main services and function provided by an OS?
    • 1) System Service: Functions that enable the OS to operate properly to perform its duties/Used for the system itself/running on its own
    • 2) Users Services: Allow user to interact with OS/Higher Level/for user
  2. What are the services useful to the user?
    User interface, Program execution , i/o operations, file system manipulations, communications, error detection
  3. What are the services useful to the system?
    • Resource allocation: Many types of resources, cpu cycles, main memory file storage
    • Accounting: Keeps track of which users use how much and what kind of resources
    • Protection and security: One process should not interfere with another. All access to system resources must be controlled.
  4. What is a system call?
    A system call is the main way a user program interacts with the OS. User program make use of system calls to request services provided by the OS
  5. Give an example of system call?
    Example system call sequence/ Acquire input file name/ write prompt to screen/ accept input/ Acquire output file name/ write prompt to screen/ accept input/ Open the input file/ if file does not exist abort Create output file/ If file exist abort/ Loop / read from input file/ write to output file/ Until read fails/ Close output file/ Write completion message to screen/ Terminate normally.
  6. Describe the 6 main types of system calls?
    Process control, File manipulation, Device manipulation, Information maintenance, Communications, Protection
  7. What are the major activities of an OS with regard to file management?
    • � Create & Delete file
    • � Open & Close
    • � Read, Write & Reposition
    • � Get & Set file attributes.
  8. What are the major activities of an OS with regard to device management?
    • � Request & Release device
    • � Read, Write & Reposition
    • � Logically attach & detach devices
    • � Get & Set device attributes
  9. What are the major activities of an OS with regard to process control?
    • � End & Abort
    • � Load & Execute
    • � Create & Terminate process
    • � Wait for time
    • � Allocate & Free memory
    • � Get & Set process attributes
    • Note: Process control is not the same as process managment
  10. What are the major activities of an OS with regard to Information Maintenance?
    • � Get & Set time or date
    • � Get & Set system data
    • � Get & Set process, file or device attributes
  11. What are the major activities of an OS with regard to Communications?
    • � Create & delete communication connection
    • � Send & Receive messages
    • � Transfer status information
    • � Attach or detach remote devices
  12. What are the major activities of an OS with regard to protection?
    • � Mechanism for control of access to system resources
    • � Get & Set Permission
    • � Allow & Deny user

What would you like to do?

Home > Flashcards > Print Preview