Operating System » Semaphores 1
An un-interruptible unit is known as ____________

A. Single
B. Atomic
C. Static
D. None of the mentioned

TestAndSet instruction is executed ____________

A. After a particular process
B. Periodically
C. Atomically
D. None of the mentioned

Semaphore is a/an _______ to solve the critical section problem.

A. Hardware for a system
B. Special program for a system
C. Integer variable
D. None of the mentioned

What are the two atomic operations permissible on semaphores?

A. Wait and signal
B. Stop and wait
C. Hold and signal
D. None of the mentioned

What are Spinlocks?

A. Cpu cycles wasting locks over critical sections of programs
B. Locks that avoid time wastage in context switches
C. Locks that work better on multiprocessor systems
D. All of the mentioned

What is the main disadvantage of spinlocks?

A. They are not sufficient for many process
B. They require busy waiting
C. They are unreliable sometimes
D. They are too complex for programmers

If the semaphore value is negative ____________

A. Its magnitude is the number of processes waiting on that semaphore
B. It is invalid
C. No operation can be further performed on it until the signal operation is performed on it
D. None of the mentioned

The code that changes the value of the semaphore is ____________

A. Remainder section code
B. Non €? critical section code
C. Critical section code
D. None of the mentioned