while(1) {
  for my $socket ($ioset->can_read) {
   if ($socket == $server) {
     new_connection($server, $remote_host, $remote_port);
   }else {
     next unless exists $socket_map{$socket};
     my $remote = $socket_map{$socket};
     my $buffer;
     my $read = $socket->sysread($buffer, 512);
     if ($read) {
      $remote->syswrite($buffer);
     } else {
      close_connection($socket);
     }
    }
  }
}