while( 1 ) {
    if (
        my ($readers, $writers, $exceptors) =
            IO::Select::select($selector, $selector, $selector, 0.1)
    ) {
        for( @$readers ) {
            ## See what they have to say
        }
        for( @$writers ) {
            ## Tell'em what they need to know
        }
        for( @$exceptors ) {
            ## Deal with their tantrums
        }
    }
    if( $Qstdin->pending ) {
        my $kbinput = $Qstdin->dequeue;
        ## do whatever
    }
}