Two-way communication in socket programming using C

Question

I have a small doubt in socket programming. i am able to send my data from client to server and my server processes the data. The o/p of the data processed, I want to send b

Answer 1

Technically it is right, the socket is duplex and you can send the data to the same socket you read from:

   SOCKET s = socket()
   ... //Connect
   int size = receive(s,...);
   //make response 
   send(s, ...);

But in practice it depends on what are you going to do. It is possible to hang out socket if you have the following situation:

1. Process 1 sends very big data (<100K) over the socket by one send operation

2. Process 2 receives data from 1 by portions and sends small packets to 1 (~20b). It is not a

   confirmations, but some external events. The situation goes into hangout, where the sending buffer of the 2 is full and it stops sending confirmations to 1. 2 and 1 are hanging in their send operations making a deadlock. In this case I'd recommend using two sockets. One for read, one for write.