Assignment: Implementing a Multi-Client Server Using poll()

Objective:

Implement a basic multi-client server that listens for incoming client connections and handles multiple clients using the poll() system call. This task requires building a server from scratch that can manage multiple client connections, read data from clients, and broadcast messages to all connected clients.

Requirements:

1. Server Setup:

   • The server should listen on a specified port and accept incoming client connections.

   • It should handle multiple clients simultaneously without blocking by using the poll() system call.

2. Using poll() for I/O Multiplexing:

   • The server should maintain an array of pollfd structures to track multiple client connections and the server socket.

   • Use the poll() system call to wait for events on the server socket (new connections) and on each client socket (data to read).

   • When a new connection is made, the server should accept the connection and add it to the pollfd array.

3. Broadcasting Messages:

   • When a client sends data, the server should read the data and broadcast it to all connected clients.

   • Handle client disconnects by closing their sockets and updating the pollfd array.

4. Error Handling:

   • The server should handle errors such as failed socket creation, connection issues, and disconnections.

Code Outline:

1. make an array of poll structs

2. socket = MakeServerSocket

3. stick socket into the array of poll structs[0]

4. loop

   1. poll

   2. if [0] is triggered

      1. this_client = accept(…)

      2. stick this_client into the poll struct array

   3. else

      1. for every other element in the array

         1. if triggered

         2. read

         3. if error remove

         4. else broadcast