docs: def select(sockets, remain=conf.recv_poll_rate):
          """This function is called during sendrecv() routine to select
          the available sockets.
  
          params:
           - sockets: an array of sockets that need to be selected
          returns:
           - an array of sockets that were selected
           - the function to be called next to get the packets (i.g. recv)
          """
          try:
              inp, _, _ = select(sockets, [], [], remain)
          except (IOError, select_error) as exc:
              # select.error has no .errno attribute
              if exc.args[0] != errno.EINTR:
                  raise
          return inp, None