use warnings;
use strict;

use Data::Dumper;
use Parallel::ForkManager;

my @files = qw(one.txt two.txt);
my %info;

my $pm = Parallel::ForkManager->new;

FILE:
for my $file (@files){
    $pm->start and next FILE;
    $info{$file}{size} = -s $file;
    $pm->finish;
}
$pm->wait_all_children;

print Dumper \%info;

__END__
$VAR1 = {
          'two.txt' => {
                         'size' => 21
                       },
          'one.txt' => {
                         'size' => 30
                       }
        };