use v5.32;
use Parallel::ForkManager;
use Data::Dumper;

my $pm = Parallel::ForkManager->new(8);
$pm->set_waitpid_blocking_sleep(0);

our @results;

$pm->run_on_finish( sub {
    my ($pid, $exit_code, $ident, $exit_signal, $core_dump, $data_ref) = @_;
    push @results, ${$data_ref};
});

our @duplicated = (10..20);
our $ctr = 0;

say "processing duplicates...";
LOOP:
foreach my $pid (@duplicated) {
    unless ($ctr % 1000) {say $ctr;}
    $ctr++;
    $pm->start and next LOOP; # do the fork
    #do stuff
    my $ans = $pid;
    $pm->finish(0, \$ans); # exit the child process
}

$pm->wait_all_children;

say scalar(@results);
# print Dumper(\@results);