c++ winsock strange error

Question

I am making a C++ network application and I am creating the server,but I have a strange problem.When I call listen,it should wait for a connection,but the application continues like if the listen call doesn't exist.This is my code:

#include "includes.hpp"
using namespace std;
SOCKET sv;
WSADATA w;

int serverStart(int port)
{
    int error = WSAStartup(0x0202,&w);
    if(error)
    {
        fprintf(stderr,"Error de startup:%i",error);
        return false;
    }
    if(w.wVersion != 0x0202)
    {
        fprintf(stderr,"Error versión incorrecta de wsadata: Esperada 202.Obtenida %X",w.wVersion);
        WSACleanup();
        return false;
    }
    SOCKADDR_IN addr;
    addr.sin_family = AF_INET;
    addr.sin_port = htons(port);
    addr.sin_addr.s_addr = htonl(INADDR_ANY);
    sv = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
    if(sv == INVALID_SOCKET)
    {
        fprintf(stderr,"Error de socket");
        return false;
    }
    if(bind(sv,(LPSOCKADDR)&addr,sizeof(addr)) == SOCKET_ERROR){
        fprintf(stderr,"Error de bind");
        return false;
    }
    fprintf(stdout,"Listen..");
    listen(sv,SOMAXCONN);
    fprintf(stdout,"Fin");
}

I am calling serverStart from main.I also have the firewall deactivated to see if it was the problem,but it didn't worked.

Thanks

Answer 1

The call to listen only places the socket in a state that accepts incomming connections. In order to actually accept a connection, you need to call the accept function. The call to accept blocks the program until you get a connection.

SOCKET ClientSocket = INVALID_SOCKET;
// Accept a client socket
ClientSocket = accept(sv, NULL, NULL);
if (ClientSocket == INVALID_SOCKET) {
    printf("accept failed: %d\n", WSAGetLastError());
    closesocket(sv);
    WSACleanup();
    return 1;
}

Answer 2

listen() is not a blocking function. It just puts the socket into listening state. It is accept() that is the blocking function, and recv(), and send().