Question

I am trying to implement a socket server that listens to a particular port number. When I write the code without any class, it works fine. But fails to work when I implement the class as below:

import socket;
from ServerConfig import ServerConfig;

class SyncServerRK:
    def __init__(self):
        self.config = ServerConfig()         #Call Initialize config class        
        #Send my IP address to managing_agent
        self.Listener()         #Call listener method

    def Listener(self):
        s = socket.socket()          # Create a socket object
        host = socket.gethostname()                     # Get local machine name
        port = self.config.Connect_Port()               # Reserve a port for your service.
        s.bind((host, port))         # Bind to the port
        while True:
            c, addr = s.accept()     # Establish connection with client.
            print ('Got connection from', addr)
            c.send('Thank you for connecting'.encode())
            print ('Message received:',c.recv(1024).decode())
            c.close()                # Close the connection            
        print(self.config.Managing_Agent())

if __name__ == "__main__":
    SyncServerRK()

The error I received is:

Traceback (most recent call last):
  File "C:/Share/SyncServerRK.py", line 24, in <module>
    SyncServerRK()
  File "C:/Share/SyncServerRK.py", line 8, in __init__
    self.Listener()         #Call listener method
  File "C:/Share/SyncServerRK.py", line 16, in Listener
    c, addr = s.accept()     # Establish connection with client.
  File "C:\Python33\lib\socket.py", line 135, in accept
    fd, addr = self._accept()
OSError: [WinError 10022] An invalid argument was supplied

Can someone please advise how to implement a server socket with threads using object-oriented philosophy.

The Non class version that worked well:

import socket               # Import socket module

s = socket.socket()         # Create a socket object
host = socket.gethostname() # Get local machine name
port = 12345                # Reserve a port for your service.
s.bind((host, port))        # Bind to the port

s.listen(5)                 # Now wait for client connection.
while True:
   c, addr = s.accept()     # Establish connection with client.
   print ('Got connection from', addr)
   c.send('Thank you for connecting'.encode())
   print ('Message received:',c.recv(1024).decode())
   c.close()                # Close the connection      

Answer 1

You are missing the s.listen(5) in your class based version.
The socket must be bound to an address and listening for connections before accepting connections.