Computer Science - Operating Systems Concepts - Discussion

Semaphores are of two types:

Binary Semaphore".

This is also known as mutex lock. It can have only two values " 0 and 1. "Its value is initialized to 1". It is used to implement the solution of critical section problems with multiple processes.

Counting Semaphore".

Its value can range over an unrestricted domain. It is used to control access to a resource that has multiple instances.

Thanks for the explanation.

Thank you all.

A semaphore is a variable. There are 2 types of semaphores:

Binary semaphores
Counting semaphores

Binary semaphores have 2 methods associated with it. (up, down / lock, unlock)
Binary semaphores can take only 2 values (0/1). They are used to acquire locks. When a resource is available, the process in charge set the semaphore to 1 else 0.

Counting Semaphore may have value to be greater than one, typically used to allocate resources from a pool of identical resources.