Quiz 3 - Process Synchronization | Attempts: 433 - Trivia , Flashcards & Questions

2.

A counting semaphore ____.

Cannot be used to control access to a thread's critical sections
Is essentially an integer variable
Can be modified simultaneously by multiple threads
Is accessed through only one standard operation

Correct Answer

A. Is essentially an integer variable

Explanation

A counting semaphore is essentially an integer variable because it is used to control access to a shared resource by multiple threads. It maintains a count of the number of available resources and allows or blocks access based on this count. The value of the semaphore is an integer that is incremented or decremented by the threads as they acquire or release the resource.

Rate this question:

1

3.

Mutex locks and counting semaphores are essentially the same thing.

True
False

Correct Answer

A. False

Explanation

Mutex locks and counting semaphores are not essentially the same thing. While both are synchronization mechanisms used in concurrent programming, they have different characteristics and purposes. A mutex lock is used to provide exclusive access to a shared resource, allowing only one thread to access it at a time. On the other hand, a counting semaphore is used to control the number of threads that can access a shared resource simultaneously. It maintains a count and allows a specific number of threads to access the resource concurrently. Therefore, the statement that mutex locks and counting semaphores are essentially the same thing is false.

Rate this question:

4.

A race condition ____.

None of the above
Will result only if the outcome of execution does not depend on the order in which instructions are executed
Results when several threads try to access and modify the same data concurrently
Results when several threads try to access the same data concurrently

Correct Answer

A. Results when several threads try to access and modify the same data concurrently

Explanation

A race condition occurs when several threads try to access and modify the same data concurrently. In this situation, the outcome of the execution may be unpredictable and inconsistent because the threads may interfere with each other's operations. This can lead to errors and bugs in the program.

Rate this question:

5.

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

Signal() followed by wait()
Acquire() followed by release()
Release() followed by acquire()
Wait() followed by signal()

Correct Answer

A. Wait() followed by signal()

Explanation

The correct order of operations for protecting a critical section using a binary semaphore is to first wait for the semaphore (wait()), which blocks the process if the semaphore value is 0, ensuring mutual exclusion. Then, once the critical section is completed, the process signals the semaphore (signal()), allowing other processes to enter the critical section. This order ensures that only one process can enter the critical section at a time, preventing race conditions and ensuring synchronization.

Rate this question:

6.

A mutex lock ______.

Is exactly like a counting semaphore
Is essentially a boolean variable
Can be used to eliminate busy waiting
Is not guaranteed to be atomic

Correct Answer

A. Is essentially a boolean variable

Explanation

A mutex lock is essentially a boolean variable because it can have two states: locked or unlocked. When a thread wants to access a critical section of code, it checks the state of the mutex lock. If it is unlocked, the thread locks it and proceeds with the execution. If it is already locked, the thread waits until it becomes unlocked. This behavior is similar to a boolean variable where true represents locked and false represents unlocked.

Rate this question:

1

7.

The value of a counting semaphore can range only between 0 and 1.

True
False

Correct Answer

A. False

Explanation

A counting semaphore is a synchronization primitive that allows multiple threads to access a shared resource. Unlike a binary semaphore, which can only have two states (0 and 1), a counting semaphore can have any non-negative integer value. Therefore, the given statement that the value of a counting semaphore can range only between 0 and 1 is incorrect.

Rate this question:

1

8.

A solution to the critical section problem does not have to satisfy which of the following requirements?

Atomicity
Bounded waiting
Progress
Mutual exclusion

Correct Answer

A. Atomicity

Explanation

A solution to the critical section problem must satisfy the requirements of mutual exclusion, bounded waiting, and progress. Atomicity, however, is not a requirement for a solution to the critical section problem. Atomicity refers to the property that an operation is indivisible or uninterruptible. While atomicity can be desirable in certain situations, it is not necessary for a solution to the critical section problem.

Rate this question:

1

Quiz 3 - Process Synchronization

Race conditions are prevented by requiring that critical regions be protected by locks.

Quiz Preview

A counting semaphore ____.

Mutex locks and counting semaphores are essentially the same thing.

A race condition ____.

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

A mutex lock ______.

The value of a counting semaphore can range only between 0 and 1.

A solution to the critical section problem does not have to satisfy which of the following requirements?