CIS343|510           Chapter Two Review    w/ Answers

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

1-3.

          convenience, efficiency, ability to evolve

4. As a user/computer interface, in which of these areas are services not typically provided by the operating system:

a. Mail merge                                      d. User fingerprinting

b. Program creation                             e. Error detection and response

c. Controlled access to files                  f. Design and analysis of algorithms

                             a, d, f

Identify these services provided by the operating system:

5. Collect usage statistics; monitor performance parameters.

          accounting

6. Takes care of the details of corresponding with "the outside world".

          access to i/o devices

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

          program creation

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

          system access

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

          error detection and response

10. Perform the tasks, such as loading a program into memory, needed in order to run user programs.

          program execution

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

          controlled access to files

 

 

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

          set of resources

13. And the chief task of an operating system can defined as _____.

          managing these resources

14-15. The above describes the operating system 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

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

                   nucleus or kernel

17. Which of these are not reasons why major OSs evolve over time?

a. New software purchased by user                d. Hardware upgrades

b. New services desired by user            e. Fixes of bugs in the OS

c. Non-von-Neumann architectures                f. New types of hardware

                   a, c

Identify the stage in the evolution of OSs described below:

18. Jobs are run in batches, but memory holds several jobs at a time.

                   Multiprogramming Batch systems

19. A piece of software called the monitor handles the running of jobs submitted by users.

                   Simple batch systems

20. Programmer interacts directly with the computer hardware. Basically, there is no OS.

                   Serial Processing

21. Many users interact with running programs.

                   Time-Sharing Systems

22. Match the type of OS on the left with typical problems / advantages / hardware-software requirements on the right.

          Time-Sharing System                          memory protection

                                                                   setup time

          Serial Processing                                 memory management

                                                                   contention for resources

          Multiprogrammed Batch Systems         job control language

                                                                   privileged instructions

          Simple Batch Systems                         sign-up sheets to reserve

                                                                             machine time

          TSS - contention

          SP - sign-up, setup time

          MBS - mem mgmt

          SBS - mem protect, priv. instr., JCL

Identify these hardware features which are desireable for modern operating systems.

23. Facilitates the OS relinquishing and regaining control of the processor.

                   interrupts

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

                   timer

25. Detect attemps by user program to write to OS area of memory.

                   memory protection

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

                   privileged instructions

What are the 5 major intellectual achievements in the development of OSs?

27-31.

                   Information protection and security

                   Memory management

                   processes

                   Scheduling and resource management

                   System structure

32. Give a definition of process.

                   A program in execution

Identify the three major lines of computer system development which gave rise to problems in timing and synchronization, which, in turn, gave rise to the concept of a process.

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

                   multiprogramming

34. Support many users simultaneously.

                   general-purpose time sharing

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

                   real-time transaction processing

Identify these errors in system software which occurred in early attempts to coordinate the various activities mentioned above.

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

                   improper synchronization

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

                   failed mutual exclusion

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

                   nondeterminate program operation

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

                   deadlock

40. Name the three components that comprise a process

                   executable program; associated data; execution context

With respect to Figure 2.9:

41. Which process is currently executing? Give two ways this answer can be determined.

          Process i :: (a) it is found in the Process Index; (b) PC points into its program area

42. What is the value "b" that is found in the base register?

                   It is the address of the beginning of Process i’s memory area

43. What is the value "h" that is found in the limit register?

                   It is the amount of memory allocated to Process i

44. In what way did a change in hardware provide the solution for a system software problem? What was the software problem? How was the problem solved by hardware?

                   Problem:: how to keep one process from writing into (or reading from)

                   the memory area of another process

                   Solution:: Check memory address requests against base & limit registers

Identify these principal storage management responsibilities:

45. Programmers should be able to create & destroy modules and alter their size dynamically.

                   support of modular programming

46. Prevent independent processes from interfering with each other.

                   process isolation

47. Store information for extended periods of time.

                   long-term storage

48. Allocate memory across the hierarchy without burden to the programmer.

                   automatic allocation and management

49. Allow sharing of memory while preventing inappropriate access.

                   protection and access controls

Identify these goals of a resource allocation and scheduling policy

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

                   efficiency

51. Give all processes approximately equal access to resources.

                   fairness

52. Discriminate among different classes of jobs with different service requirements.

                   differential responsiveness