A semaphore is an abstract data type managed by the OS to synchronize access by multiple threads to shared resources and data. It consists of an internal variable that identifies the amount of concurrent access to a resource with which it is associated.
Thread synchronization with semaphores
Getting ready
The operation of a semaphore is based on two functions: acquire() and release(), as explained here:
- Whenever a thread wants to access a given or a resource that is associated with a semaphore, it must invoke the acquire() operation, which decreases the internal variable of the semaphore and allows access to the resource if the value of this variable appears to be non-negative. If the value is negative, then the thread will be suspended...