erlang who close the tcp socket

Question

http://erlangcentral.org/wiki/index.php/Building_a_Non-blocking_TCP_server_using_OTP_principles describe how to build a non-blocking tcp server, and one question about inet_async message.

handle_info({inet_async, ListSock, Ref, Error}, #state{listener=ListSock, acceptor=Ref} = State) ->
    error_logger:error_msg("Error in socket acceptor: ~p.\n", [Error]),
    {stop, Error, State};

If Error = {error, close}, who close the socket, client or server?

Answer 1

It depends, if you get that error, the socket may not have been opened in the first place. So if you try gen_tcp:send(Socket, "Message") you will get that the connection is closed.

Other reasons that the connection closed could be that the listening socket timed out waiting on a connection, or that gen_tcp:close(Socket) was called before the attempt to send a message.

Also you need to make sure you are connecting to the same port that the server initially opened the listening socket. So to answer your question, it could be either closed the connection.