I'm writing a small proxy. Basically I spawn a thread for each client that connects, and use blocking sockets (with timeouts) to service the client.
However, with that approach I've run into a snag. Basically my pseudo code is:
However, the server doesn't want to send me any data yet. Since it's waiting for the full client request. So the call basically blocks forever.
while(client or server connection open)
buffer = read_from_client()
buffer = read_from_server() /* blocks here */
I've thought of peeking at the server socket to see if there's any data to read, and skipping it if not. However, MSG_PEEK has bad performance. Even though I'm only targeting around 64 client threads at a given time.
So what would be the suggested route here? I could peek, or multiplex between the client and server socket (i.e. with select())? But I'm sure that would hurt performance (each thread would then need to multiplex.
MSG_PEEK isn't an option. It's recommended against using it in Winsock (I'm targeting Windows and Linux).
select() or poll() aren't really options.
Could I just use non-blocking sockets in a loop? Although that may mean I'm using a lot of CPU just to see if data arrived.