Servers

• A server's life cycle consists of
  • the creation of a connection-style (tcp) socket,
  • binding an address to its socket,
  • placing a call to listen that enables connections to the socket,
  • placing calls to accept incoming connections,
  • and then closing the socket.
• Data isn't read and written directly via the server socket; instead, each time a program accepts a new connection, Linux creates a separate socket to use in transferring data over that connection.
  • An address must be bound to the server's socket using bind if a client is to find it.
  • When an address is bound to a connection-style socket, it must invoke listen to indicate that it is a server.
  • A server accepts a connection request from a client by invoking accept.
    • The call to accept creates a new socket for communicating with the client and returns the corresponding file descriptor.
    • The original server socket continues to accept new client connections.