CSCI 373 Computer Networking — Chapter 9 comments

The API’s

• socket — low-level networking interface
  • socket.socket
  • s.bind — for servers
  • s.listen — for servers
  • s.accept — for servers
  • s.connect — for clients
  • s.recv
  • s.sendall
  • s.close
• Unix-style process management
  • os.fork — for servers
  • os.execve — sometimes for handlers
  • os._exit — for handlers or they can just return
  • os.wait — for servers
  • signal.signal — for servers to avoid need for os.wait
• threading
  • threading.Thread — for servers to create handlers
  • t.start — for servers to start handlers
  • normal return — for handlers
  • t.join — for servers
  • t.daemon — for servers
• SocketServer — use complex OOP for simplification
  • SocketServer.BaseRequestHandler — extend (or subclass) by overriding handle
  • SocketServer.TCPServer — creates TCPServer object using host and port tuple and a BaseRequestHandler object
  • SocketServer.ThreadingMixInM — “overrides” some methods of SocketServer.TCPServer to support threading using multiple inheritance to define an extension of SocketServer.TCPServer
• poll — for single-process non-threading servers

Types of servers

• handle Only one connection and exit
• handle multiple connections but one at a time
• handle multiple concurrent connections but don”t let them share — using Unix fork
• handle multiple concurrent connections and let them share — using threading
• handle multiple concurrent connections with poll