#!/usr/bin/env perl

use strict;
use warnings;
use threads;
use MCE::Loop;
use MCE::Shared;
use LWP::Simple;
use feature qw(say);
use constant AMOUNT => 0;

my $result = MCE::Shared->hash;
my @urls   = qw(http://perlmonks.org http://www.whitehouse.org );

MCE::Loop::init {
    max_workers => 'auto',
    chunk_size  => 1
};

my $fetch = sub { head(shift) };

mce_loop {
    my @data = $fetch->($_);
    sleep AMOUNT;
    $result->set( $_ => \@data );
}
@urls;

{
    no warnings qw(uninitialized);
    my $iter = $result->iterator();
    while ( my ( $url, $data ) = $iter->() ) {
        say $url;
        say for @$data;
        say q(---);
    }
}
__END__