Question

Servers can be designed to limit the number of open connections. For example, a server may wish to have only N socket connections at any point in time. As soon as N connections are made, the server will not accept another incoming connection until an existing connection is released. Explain how semaphores can be used by a server to limit the number of concurrect connections.

Answer 1

Semaphores are designed to protect one or more shared resources, usually using a counter for the remaining resources available in the server. The semaphore coordinates all the clients and the server simultaneously. The client acquires the semaphore, writes its command and then releases the semaphore. Then, the server acquires the semaphore, reads the command and does whatever processing it needs, and finally releases the semaphore again, for the next client to use it.

Step-by-step explanation: