How to get data in TCP client mode

Hi

How are you?

I want to know how to get data in TCP client mode.

In CC3200, TCP Client Mode, First, device connected to server and device sent some packets to server.

After Server get data from client(device), server will send some ack packet to client.

How to get server data in client?    polling? or interrupt ?

When or Where does device run the sl_Recv() ?

code (Send code) is belows

        iStatus = sl_Send(iSockID, &test_req, sizeof(test_req), 0 );     // Send Data

        if( iStatus < 0 )
        {
           sl_Close(iSockID);
           ASSERT_ON_ERROR(SEND_ERROR);
        }
        else Report("Sent packets successfully\n\r");

        iStatus = sl_Recv(iSockID, g_cBsdBuf, sTestBufLen, 0 );

But last time iStatus is always 0. 

How to know whether server sent data ?

and When or Where does device run the sl_Recv() ?

Thank you for reading this article :)