Question 1

Which of the following statements is true?

Accepted Answer

A)  A counting semaphore can never be used as a binary semaphore. 
B)  A binary semaphore can never be used as a counting semaphore. 
C)  Spinlocks can be used to prevent busy waiting in the implementation of semaphore. 
D)  Counting semaphores can be used to control access to a resource with a finite number of instances. 
A)  A counting semaphore can never be used as a binary semaphore. 
B)  A binary semaphore can never be used as a counting semaphore. 
C)  Spinlocks can be used to prevent busy waiting in the implementation of semaphore. 
D)  Counting semaphores can be used to control access to a resource with a finite number of instances.

Question 2

Mutex locks and counting semaphores are essentially the same thing.

Accepted Answer

A) True 
 B)False

Question 3

Assume you had a function named update() that updates shared data. Illustrate how a mutex lock named mutex might be used to prevent a race condition in update().

Accepted Answer

void update()
{
mute

Question 4

Which of the following is not true about test_and_set instruction?

Accepted Answer

A)  It is a hardware instruction 
B)  It is executed atomically 
C)  Returns the original value of passed parameter 
D)  Returns the new value of passed parameter 
E)  Set the new value of passed parameter to "TRUE" 
A)  It is a hardware instruction 
B)  It is executed atomically 
C)  Returns the original value of passed parameter 
D)  Returns the new value of passed parameter 
E)  Set the new value of passed parameter to "TRUE"

Question 5

Which of the following is not true about compare_and_swap instruction?

Accepted Answer

A)  It is a hardware instruction 
B)  It is executed atomically 
C)  Returns the original value of passed parameter 
D)  Set the new value of passed parameter to "TRUE" 
E)  Set the variable "value" the value of the passed parameter "new_value" but only if "value" =="expected" 
A)  It is a hardware instruction 
B)  It is executed atomically 
C)  Returns the original value of passed parameter 
D)  Set the new value of passed parameter to "TRUE" 
E)  Set the variable "value" the value of the passed parameter "new_value" but only if "value" =="expected"

Question 6

Explain what race condition is.

Accepted Answer

A situation where several processes acce

Question 7

Semaphores and mutex locks both provide mutual exclusion.

Accepted Answer

A) True 
 B)False

Question 8

Under which of the following contention loads does traditional synchronization become faster than CAS-based synchronization?

Accepted Answer

A)  uncontended 
B)  moderate contention 
C)  high contention 
D)  none of the above 
A)  uncontended 
B)  moderate contention 
C)  high contention 
D)  none of the above

Question 9

Which of the following regarding mutex lock is NOT true?

Accepted Answer

A)  mutex lock is a hardware solution to critical-section problem 
B)  mutex lock is a higher-level software solution to critical-section problem 
C)  mutex lock suffers from busy waiting 
D)  the general rule of thumb is to use a mutex lock if the lock will be held for a duration less than two context switches 
A)  mutex lock is a hardware solution to critical-section problem 
B)  mutex lock is a higher-level software solution to critical-section problem 
C)  mutex lock suffers from busy waiting 
D)  the general rule of thumb is to use a mutex lock if the lock will be held for a duration less than two context switches

Question 10

Which of the following is NOT true for Peterson's solution?

Accepted Answer

A)  Mutual exclusion is preserved 
B)  The progress requirement is satisfied 
C)  The bounded-waiting requirement is met 
D)  Peterson's solution works for synchronization among more than two processes 
A)  Mutual exclusion is preserved 
B)  The progress requirement is satisfied 
C)  The bounded-waiting requirement is met 
D)  Peterson's solution works for synchronization among more than two processes

Question 11

When mutex lock is implemented as a binary semaphore, what should its value be initialized to be?

Accepted Answer

A)  0 
B)  1 
C)  -1 
D)  none of the above 
A)  0 
B)  1 
C)  -1 
D)  none of the above

Question 12

What is the difference between semaphore and mutex lock?

Accepted Answer

Semaphores are similar to mutex lock in

Question 13

Which of the following is true?

Accepted Answer

A)  No deadlock implies no starvation; 
B)  No starvation implies no deadlock; 
C)  Deadlock doesn't imply starvation; 
D)  Starvation implies deadlock. 
A)  No deadlock implies no starvation; 
B)  No starvation implies no deadlock; 
C)  Deadlock doesn't imply starvation; 
D)  Starvation implies deadlock.

Question 14

Explain what busy waiting is.

Accepted Answer

While a process is in its critical secti

Question 15

What is the correct order of operations for protecting a critical section using a binary semaphore?

Accepted Answer

A)  release() followed by acquire() 
B)  acquire() followed by release() 
C)  wait() followed by signal() 
D)  signal() followed by wait() 
A)  release() followed by acquire() 
B)  acquire() followed by release() 
C)  wait() followed by signal() 
D)  signal() followed by wait()

Question 16

In _________, the process may be changing common variables, updating a table, writing a file, and so on.

Accepted Answer

A)  entry section 
B)  critical section 
C)  exit section 
D)  remainder section 
A)  entry section 
B)  critical section 
C)  exit section 
D)  remainder section

Question 17

The preemptive kernel may be more responsive than non-preemptive kernel.

Accepted Answer

A) True 
 B)False

Question 18

Semaphore implementation overcomes the busy waiting problem.

Accepted Answer

A) True 
 B)False

Question 19

In _________, the process requests permission to access and modify variables shared with others.

Accepted Answer

A)  entry section 
B)  critical section 
C)  exit section 
D)  remainder section 
A)  entry section 
B)  critical section 
C)  exit section 
D)  remainder section

Question 20

Explain two general approaches to handle critical sections in operating systems.

Accepted Answer

Critical sections may use preemptive or

Which of the following statements is true?

Mutex locks and counting semaphores are essentially the same thing.

Assume you had a function named update() that updates shared data. Illustrate how a mutex lock named mutex might be used to prevent a race condition in update().

Which of the following is not true about test_and_set instruction?

Which of the following is not true about compare_and_swap instruction?

Explain what race condition is.

Semaphores and mutex locks both provide mutual exclusion.

Under which of the following contention loads does traditional synchronization become faster than CAS-based synchronization?

Which of the following regarding mutex lock is NOT true?

Which of the following is NOT true for Peterson's solution?

When mutex lock is implemented as a binary semaphore, what should its value be initialized to be?

What is the difference between semaphore and mutex lock?

Which of the following is true?

Explain what busy waiting is.

What is the correct order of operations for protecting a critical section using a binary semaphore?

In _________, the process may be changing common variables, updating a table, writing a file, and so on.

The preemptive kernel may be more responsive than non-preemptive kernel.

Semaphore implementation overcomes the busy waiting problem.

In _________, the process requests permission to access and modify variables shared with others.

Explain two general approaches to handle critical sections in operating systems.

Introduction

Operating-System Structures

Processes

Threads Concurrency

Cpu Scheduling

Synchronization Examples

Deadlocks

Main Memory

Virtual Memory

Mass-Storage Structure

Io Systems

File-System Interface

File-System Implementation

File-System Internals

Security

Protection

Filters

Exam 6: Synchronization Tools

Which of the following statements is true?

Mutex locks and counting semaphores are essentially the same thing.

Assume you had a function named update() that updates shared data. Illustrate how a mutex lock named mutex might be used to prevent a race condition in update().

Which of the following is not true about test_and_set instruction?

Which of the following is not true about compare_and_swap instruction?

Explain what race condition is.

Semaphores and mutex locks both provide mutual exclusion.

Under which of the following contention loads does traditional synchronization become faster than CAS-based synchronization?

Which of the following regarding mutex lock is NOT true?

Which of the following is NOT true for Peterson's solution?

When mutex lock is implemented as a binary semaphore, what should its value be initialized to be?

What is the difference between semaphore and mutex lock?

Which of the following is true?

Explain what busy waiting is.

What is the correct order of operations for protecting a critical section using a binary semaphore?

In _________, the process may be changing common variables, updating a table, writing a file, and so on.

The preemptive kernel may be more responsive than non-preemptive kernel.

Semaphore implementation overcomes the busy waiting problem.

In _________, the process requests permission to access and modify variables shared with others.

Explain two general approaches to handle critical sections in operating systems.

Introduction

Operating-System Structures

Processes

Threads Concurrency

Cpu Scheduling

Synchronization Examples

Deadlocks

Main Memory

Virtual Memory

Mass-Storage Structure

Io Systems

File-System Interface

File-System Implementation

File-System Internals

Security

Protection

Filters