Question 1

Which of the following is true regarding the requirements for the solutions to critical-section problem?

Accepted Answer

A)   mutual exclusion implies progress
B)   progress implies bounded waiting
C)   bounded waiting implies progress
D)   none of the above C

Question 2

What is the difference between counting semaphore and binary semaphore.

Accepted Answer

The value of a counting semaphore can range over an unrestricted domain. The value of a binary semaphore can range only between 0 and 1.

Question 3

Which of the following critical-section problem's requirements ensures programs will cooperatively determine what process will next enter its critical section?

Accepted Answer

A)   mutual exclusion
B)   progress
C)   bounded waiting
D)   none of the above B

Question 4

Which of the following indicates that Pi can enter the critical section in Peterson's solution?

Accepted Answer

A)   flag[j] == false or turn == i
B)   flag[j] == true or turn == i
C)   flag[j] == false or turn == j
D)   flag[j] == true and turn == j

Question 5

Spinlocks are not appropriate for single-processor systems.

Accepted Answer

A) True 
 B)False

Question 6

Which of the following variables are shared between the processes in Peterson's solution?

Accepted Answer

A)   int turn
B)   boolean flag[2]
C)   both of the above
D)   none of the above

Question 7

Which of the following is a software-based solution to the critical-section problem?

Accepted Answer

A)   Peterson's solution
B)   test_and_set
C)   compare_and_swap
D)   all of the above

Question 8

A semaphore has an integer value.

Accepted Answer

A) True 
 B)False

Question 9

Which of the following critical-section problem's requirements ensures only one process is active in its critical section at a time?

Accepted Answer

A)   mutual exclusion
B)   progress
C)   bounded waiting
D)   none of the above

Question 10

Which of the following is NOT true regarding semaphore implementation?

Accepted Answer

A)   It suffers from the busy waiting problem
B)   Semaphore has a waiting queue associated with the semaphore
C)   When a process executes the wait()  operation and finds that the semaphore value is not positive, it will suspend itself
D)   A process that is suspended, waiting on the semaphore, should be restarted when some other process executes a signal()  operation.

Question 11

Which of the following critical-section problem's requirements limits the amount of time a program will wait before it can enter its critical section?

Accepted Answer

A)   mutual exclusion
B)   progress
C)   bounded waiting
D)   none of the above

Question 12

Which of the following is true for the solutions to critical-section problems?

Accepted Answer

A)   No deadlock implies progress, and progress implies bounded waiting
B)   Bounded waiting implies progress, and progress implies no deadlock
C)   Progress implies no deadlock, and no deadlock implies bounded waiting
D)   Bounded waiting implies no deadlock, and no deadlock implies progress

Question 13

Assume count is a variable name, which of the following operations is atomic?

Accepted Answer

A)   count++
B)   count--
C)   both of the above
D)   none of the above

Question 14

Which of the following is NOT true regarding conditional variable, e.g. x?

Accepted Answer

A)   The only operations that can be invoked on a condition variable are wait()  and signal() 
B)   x.wait()  means that the process invoking this operation is suspended until another process invokes x.signal() 
C)   The x.signal()  operation resumes exactly one suspended process
D)   If no process is suspended, then the signal()  operation still affects the state of the semaphore

Question 15

Solutions to the critical section problem may suffer from liveness failures.

Accepted Answer

A) True 
 B)False

Question 16

Explain what a deadlock is.

Accepted Answer

The answer of Explain what a deadlock is....

Question 17

Mutex lock variable is binary.

Accepted Answer

A) True 
 B)False

Question 18

Bounded waiting implies progress, and progress implies mutual exclusion.

Accepted Answer

A) True 
 B)False

Question 19

Write two short methods that implement the simple semaphore wait() and signal() operations on global variable S.

Accepted Answer

The answer of Write two short methods that implement the...

Question 20

Explain what critical section problem is.

Accepted Answer

The answer of Explain what critical section problem is....

Exam 6: Synchronization Tools

Which of the following is true regarding the requirements for the solutions to critical-section problem?

What is the difference between counting semaphore and binary semaphore.

Which of the following critical-section problem's requirements ensures programs will cooperatively determine what process will next enter its critical section?

Which of the following indicates that P_i can enter the critical section in Peterson's solution?

Spinlocks are not appropriate for single-processor systems.

Which of the following variables are shared between the processes in Peterson's solution?

Which of the following is a software-based solution to the critical-section problem?

A semaphore has an integer value.

Which of the following critical-section problem's requirements ensures only one process is active in its critical section at a time?

Which of the following is NOT true regarding semaphore implementation?

Which of the following critical-section problem's requirements limits the amount of time a program will wait before it can enter its critical section?

Which of the following is true for the solutions to critical-section problems?

Assume count is a variable name, which of the following operations is atomic?

Which of the following is NOT true regarding conditional variable, e.g. x?

Solutions to the critical section problem may suffer from liveness failures.

Explain what a deadlock is.

Mutex lock variable is binary.

Bounded waiting implies progress, and progress implies mutual exclusion.

Write two short methods that implement the simple semaphore wait() and signal() operations on global variable S.

Explain what critical section problem is.