When using a semaphore, a value of ____ indicates that a critical region is in use.
A) -100
B) 0
C) 100
D) 9999

Question

Quizplus · Accepted Answer

In semaphore, a value of 0 indicates that a critical region is in use. This means that the resource is currently being accessed by a process, and other processes must wait until the resource is released. A value of greater than 0 indicates the number of available resources, and a value of less than 0 indicates that there are processes waiting for the resource. A value of -1, in particular, is commonly used to indicate that the semaphore is binary (i.e. it can only take on values of 0 or 1). A value of 100 or 9999 would be arbitrary and have no specific meaning in the context of a semaphore. Similarly, a value of -100 would be used to indicate something specific (e.g. a particular error or condition), but would not be a standard way of representing the status of a critical region.

When Using a Semaphore, a Value of ____ Indicates That