while( $again ) {
        #--
        # Initial loop to spawn children
        #--
        if ( $ref < $max ) {
            if ( $cpid = fork ) {
                $kids{ $cpid } = 1;
            }
            else {
                #do interesting process here
                exit;
            }
            $ref++;
        }
        else {
            do {
                select undef, undef, undef, 0.5;
                $dpid = waitpid( -1, 1 );
            } until $dpid;
            last if ( $dpid == -1 );  # No children left
            delete $kids{$dpid};
            if ( $cpid = fork ) {
                $kids{ $cpid } = 1;
            }
            else {
                # Same interesting process
                exit;
            }

        }
        $total++;
    }