use constant NEW_SOCK_EVERY => 1000;
...
    my $server_sock = new IO::Socket::INET(
        Listen => 1,LocalPort => 19,Reuse=> 1
    );
    my $sel = new IO::Select( $server_sock  );
	my $i = NEW_SOCK_EVERY;
    while($server_sock) {
		if (++$i>=NEW_SOCK_EVERY) {
			$i=0;
			foreach my $socket ($sel->can_read(0.0001)) {
				if($socket == $server_sock ) {
					new_socket($socket);
				}else{
					if(defined ($socket)) {
						close_socket($socket);
					}
				}
			}
		}
        foreach my $wsocket ($sel->can_write(0.0001)) {
            gen_chars($wsocket);
        }
    }
...