## main
for my $y ( 0 .. $Y ) {
    my @colors;
    for my $x ( 0 .. $X ) {
        push @colors, Mandelbrot( $x, $y );
    }
    $Q->enqueue( [ $Y, @colors ] );
}

### thread

while( my( $y, @colors ) = @{ $Q->dequeue } ) {
    $image->setpixel( $_, $y, $colors[ $_ ] ) for 0 .. $#colors;
}