Answers to

Quiz - Chapter Two

CIS343                         

 

(1-3) List 3 areas of service typically provided by an operating system.

1-3.

  Program creation

  Controlled access to files

  Error detection and response

 

As an interface between the user and the computer hardware, the operating system can be thought of as having three objectives:

4-6.

            convenience, efficiency, ability to evolve

 

(5 - 9) Identify these services provided by the operating system:

5. Respond to error conditions by clearing the condition with the least amount of impact on running applications.

          error detection and response

6. Collect usage statistics; monitor performance parameters.

          accounting

7. Control access to all the resources of the system; provide protection; resolve conflicts for resource contention.

            system access

8. Give user access to programs for editing and debugging programs.

          program creation

9. Handle the details of reading from & writing to files; provide protection mechanisms for these files.

          controlled access to files

 

(10-13) Describe these hardware features of modern operating systems.

10. Interrupt

Facilitates the OS relinquishing and regaining control of the processor.

11. Timer

Can be used to prevent a single job from monopolizing the system.

12. Memory protection

Detect attempts by user program to write to OS area of memory.

13. Privileged instructions

Does not allow user program to execute the full set of machine instructions.

 

14. Give a definition of process.

                        A program in execution

 

15-17. Name the three components that comprise a process

                        executable program; associated data; execution context

 

(18-20) Identify the three major lines of computer system development which gave rise to problems in timing and synchronization.

18. Processor is switched among various programs residing in memory.

            Multiprogramming

19. Support many users simultaneously.

            General-purpose time sharing

20. Online entry of queries and updates against a database.

            Real-time transaction processing

 

21. The problems in timing and synchronization eventually gave rise to the concept of . . .

process

 

(22-25) Identify these errors in system software which occurred in early attempts to coordinate the various activities of a complex computer system.

22. Two or more programs cannot proceed until the other does.

            Deadlock

23. Two or more programs make use of a resource which can only be used sequentially (not simultaneously).

            Failed mutual exclusion

24. Signals needed to coordinate events and routines are lost or duplicate signals are received.

            Improper synchronization

25. Unexpected interaction between programs in a shared system, interfering with the operation of one or the other or both.

            Nondeterminate program operation

 

(26 - 28) Describe these goals of a resource allocation and scheduling policy

26. Efficiency

Maximize throughput, minimize response time, accommodate as many users as possible.

27. Fairness

Give all processes approximately equal access to resources.

28. Differential responsiveness

Discriminate among different classes of jobs with different service requirements.

 

29-30. The operating system can be thought of as a control mechanism.  In what two ways does the OS differ from most other control mechanisms?

            ++ it is a program executed by the processor, just as user programs are

            ++ it frequently relinquishes control and depends on the processor to allow it to

                        regain control

 

31. A computer system can be thought of as a _____ for movement, storage and processing of data and for the control of these functions.

   a. monolithic bracket              c. neolithic brain          e. all of the above

   b. set of resources                 d. set of megaliths        f. none of the above

            b

32. The chief task of an operating system can defined as _____.

   a. manipulating user intentions          d. managing user funds

   b. managing system resources                   e. all of the above

   c. communicating with devices         f. none of the above

            b

33. The portion of the OS which contains the most frequently-used functions and which resides in main memory is known as the...

   a. kernel                                 c. all of the above

   b. nucleus                              d. none of the above

            c