What are the Basic Components of computer



Southeastern University

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Final Exam: June 2005

Course: COSC 513 Operating Systems

Instructor: Prof. M. Anvari

1. Concurrency plays a major part in which of the following specific contexts:

a. Multiple applications

b. Structured applications

c. O/S structure

d. All of the above

ANS: D

2. Examples of solutions to the concurrency problem that do not involve busy waiting are the following:

a. Semaphores and monitors

b. Message passing and caching

c. Producers and consumers

d. None of the above

ANS: D (all software solutions involve some form of busy waiting)

3. A basic echo procedure (that echoes a typed character to the screen) running on a multiprocessor system can produce erroneous output if:

a. Two processes deadlock while in the echo code

b. Access to the echo procedure is unsynchronized

c. Access to the echo procedure is synchronized

d. None of the above

ANS: B

4. In order to implement mutual exclusion on a critical resource for competing processes, only one program at a time should be allowed:

a. In the critical section of the program

b. To perform message passing

c. To Exhibit cooperation

d. None of the above

ANS: A

5. The following requirement must be met by any facility or capability that is to provide support for mutual exclusion:

a. Only one process at a time can be allowed into a critical code section

b. A process remains in its critical code section for a finite time only

c. No assumptions can be made about relative process speeds

d. All of the above

ANS: D

6. Processes that are designed to be able to pass execution control back and forth between themselves are referred to as:

a. Threads

b. Coroutines

c. Busy waiting processes

d. None of the above

ANS: B

7. In a uniprocessor system, mutual exclusion can be guaranteed by:

a. Overlapping processes

b. Interleaving processes

c. Disabling interrupts

d. All of the above

ANS: C

8. A semaphore that does not specify the order in which processes are removed from the queue is called a:

a. Weak semaphore

b. Strong semaphore

c. Binary semaphore

d. None of the above

ANS: A

9. The finite circular buffer is used to implement which of the following basic queuing strategies:

a. FILO

b. LIFO

c. FIFO

d. None of the above

ANS: C

10. A chief characteristic of a monitor is:

a. A maximum of two processes may be executing in a monitor at a time

b. Local data variables of the monitor are accessible by any procedure requesting use of the monitor

c. A process enters the monitor by invoking one of its procedures

d. All of the above

ANS: C

11. In synchronization involving message passing, the sender of a message can be:

a. Either blocking or non-blocking

b. Only blocking

c. Only non-blocking

d. All of the above

ANS: A

12. In a system employing message passing, when a message is sent to a shared temporary data structure, this general approach is known as:

a. Direct addressing

b. Indirect addressing

c. Blocking

d. None of the above

ANS: B

13. In a system employing message passing, the typical message is divided into two primary sections:

a. Header and mailbox

b. Body and mailbox

c. Destination ID and Source ID

d. None of the above

ANS: D (header and body)

14. The Reader/Writer problem requires that certain conditions be satisfied, such as:

a. Readers may read from the file while writers are writing to it

b. Multiple writers may write to the file simultaneously

c. Any number of readers may simultaneously read from the file

d. None of the above

ANS: C

15. A reason why the Producer/Consumer problem cannot be considered a special case of the Reader/Writer problem with a single writer (the producer) and a single reader (the consumer) is:

a. The producer and consumer must be both reader and writer

b. The consumer must perform writes while the reader performs reads

c. The Producer/Consumer problem doesn’t deal with concurrency issues

d. None of the above

ANS: A

16. The permanent blocking of a set of processes that either compete for system resources or communicate with each other is called:

a. Starvation

b. Deadlock

c. Prioritization

d. All of the above

ANS: B

17. All deadlocks involve conflicting needs for resources by:

a. One or more processes

b. Two or more processes

c. Three or more processes

d. None of the above

ANS: B

18. A resource that can be created and destroyed is called a:

a. Reusable resource

b. Producible resource

c. Consumable resource

d. All of the above

ANS: C

19. An example of a consumable resource is the following:

a. Messages

b. Printers

c. Main Memory

d. All of the above

ANS: A

20. A condition of policy that must be present for a deadlock to be possible is:

a. Mutual exclusion

b. Hold and wait

c. No preemption

d. All of the above

ANS: D

21. A direct method of deadlock prevention is to prevent the occurrence of:

a. Mutual exclusion

b. Hold and wait

c. Circular wait

d. All of the above

ANS: C

22. One approach to deadlock avoidance is called:

a. Process Termination Denial

b. Resource Allocation Denial

c. Hold and wait

d. None of the above

ANS: B

23. In the Resource Allocation Denial approach to Deadlock Avoidance, a safe state is defined as one in which:

a. At least one potential process sequence does not result in a deadlock

b. All potential process sequences do not result in a deadlock:

c. Several potential process sequences do not result in a deadlock:

d. None of the above

ANS: A

24. A conservative strategy for dealing with deadlocks that involves limiting access to resources and imposing restrictions on processes is called:

a. Deadlock Prevention

b. Deadlock Avoidance

c. Deadlock Detection

d. None of the above

ANS: A

25. In deadlocked process recovery, selection criteria for choosing a particular process to abort or rollback includes designating the process with the:

a. Most estimated time remaining

b. Lowest priority

c. Least total resources allocated so far

d. All of the above

ANS: D

26. One approach to an integrated strategy for dealing with deadlocks involves the implementation of:

a. Resource classes

b. Process rollbacks

c. Virtual memory

d. None of the above

ANS: A

27. The Dining Philosopher’s Problem is a standard test case for evaluating approaches to implementing:

a. Deadlock

b. Starvation

c. Synchronization

d. All of the above

ANS: C

28. A software mechanism that informs a process of the occurrences of asynchronous events in UNIX are called:

a. Pipes

b. Messages

c. Signals

d. All of the above

ANS: C

29. Thread synchronization primitives supported by Solaris include:

a. Mutual exclusion (mutex) locks

b. Semaphores

c. Condition variables

d. All of the above

ANS: D

30. The family of synchronization objects implemented by W2K include:

a. Mutex objects

b. Semaphore objects

c. Event objects

d. All of the above

ANS: D

31. The task of subdividing memory between the O/S and processes is performed automatically by the O/S and is called:

a. Protection

b. Relocation

c. Memory Management

d. All of the above

ANS: C

32. The concept of Memory Management satisfies certain system requirements, including:

a. Protection

b. Relocation

c. Physical organization

d. All of the above

ANS: D

33. The practice in which a program and data are organized in such a way that various modules can be assigned the same region of memory is called:

a. Overlaying

b. Sharing

c. Relocation

d. None of the above

ANS: A

34. The concept of virtual memory is based on one or both of two basic techniques:

a. Overlaying and relocation

b. Segmentation and paging

c. Segmentation and partitioning

d. None of the above

ANS: B

35. A problem with the largely obsolete Fixed Partitioning memory management technique is that of:

a. Allowing only a fixed number of Processes

b. Inefficient use of memory

c. Internal fragmentation

d. All of the above

ANS: D

36. The problem of internal fragmentation can be lessened in systems employing a fixed-partition memory management scheme by using:

a. Random size partitions

b. Equal size partitions

c. Unequal size partitions

d. None of the above

ANS: C

37. In the Dynamic Partitioning technique of memory management, the phenomenon that results in unused blocks of memory outside of existing partitions is called:

a. Internal fragmentation

b. External fragmentation

c. Compaction

d. None of the above

ANS: B

38. In the Dynamic Partitioning technique of memory management, the placement algorithm that chooses the block that is closest in size to the request is called:

a. Best-fit

b. First-fit

c. Next-fit

d. All of the above

ANS: A

39. In the Dynamic Partitioning technique of memory management, the placement algorithm that scans memory from the location of the last placement and chooses the next available block that large enough to satisfy the request is called:

a. Best-fit

b. First-fit

c. Next-fit

d. All of the above

ANS: C

40. A reference to a memory location independent of the current assignment of data to memory is called a(n):

a. Relative address

b. Logical address

c. Absolute address

d. None of the above

ANS: B

41. An actual location in main memory is called a(n):

a. Relative address

b. Logical address

c. Absolute address

d. None of the above

ANS: C

42. The page table for each process maintains:

a. The frame location for each page of the process

b. The page location for each frame of the process

c. The physical memory location of the process

d. None of the above

ANS: A

43. In a system employing a paging scheme for memory management, wasted space is due to:

a. External fragmentation

b. Internal fragmentation

c. Pages and frames of different specified sizes

d. None of the above

ANS: B

44. In a system employing a segmentation scheme for memory management, wasted space is due to:

a. External fragmentation

b. Internal fragmentation

c. Segments of different sizes

d. None of the above

ANS: A

45. In a system employing a segmentation scheme for memory management, a process is divided into:

a. One segment per thread

b. A number of segments which must be of equal size

c. A number of segments which need not be of equal size

d. None of the above

ANS: C

46. A file is generally defined to be:

a. A basic element of data

b. A collection of related fields

c. A collection of similar records

d. All of the above

ANS: C

47. The level of the file system architecture that enables users and applications to access file records is called the:

a. Basic file system level

b. Basic I/O supervisor level

c. Logical I/O level

d. All of the above

ANS: C

48. Record access in a pile file can be conducted by:

a. Exhaustive search

b. Key field

c. Partial index

d. All of the above

ANS: A

49. Sequential files are optimal in scenarios involving:

a. Applications that require frequent queries

b. Applications that require the processing of all records in the file

c. Applications that require infrequent updates

d. All of the above

ANS: B

50. Indexed sequential files similar to sequential files, but contain two added features:

a. Hash function and an overflow file

b. Hash function and file index

c. File index and overflow file

d. All of the above

ANS: C

51. Direct or hashed files are often used where:

a. Very rapid access is required

b. Fixed length records are used

c. Records are always accessed one at a time

d. All of the above

ANS: D

52. The file directory information element that holds information such as the identity of the creator of the file is the:

a. Address information element

b. Access control information element

c. Usage information element

d. All of the above

ANS: C

53. In a tree-structured directory, the series of directory names that culminates in a file name is referred to as the:

a. Pathname

b. Working directory

c. Symbolic name

d. None of the above

ANS: A

54. Access rights on a file typically are considered to constitute a hierarchy, with each right implying those that:

a. Supercede it

b. Precede it

c. Succeed it

d. None of the above

ANS: B

55. Fixed file blocking experiences the following potential problem:

a. Gaps due to hardware design

b. External fragmentation

c. Internal fragmentation

d. None of the above

ANS: C

56. In which of the following file allocation methods is preallocation required:

a. Contiguous

b. Chained

c. Indexed

d. None of the above

ANS: A

57. The technique of free disk space management that employs a pointer and length value of each free portion is the:

a. Free block list

b. Bit tables

c. Indexing

d. None of the above

ANS: D (chained free portions method)

58. The data structure that maintains information on available disk space is called the:

a. File Allocation Table (FAT)

b. Disk Allocation Table

c. Bit Table

d. None of the above

ANS: B

59. File allocation in a UNIX system has the following characteristics:

a. Dynamic allocation using non-contiguous blocks with indexing

b. Dynamic allocation using contiguous blocks without indexing

c. Preallocation using non-contiguous blocks without indexing

d. None of the above

ANS: A

60. In a W2K NTFS file system, the smallest physical storage unit on the disk (almost always 512 bytes) is called a:

a. Cluster

b. Sector

c. Volume

d. None of the above

ANS: B

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