use MCE::Simple -strict, -signatures;
use MCE::Barrier;

sub task ($barrier, $number) {

    for (1 .. 400) {
        say "$_: $number";
        $barrier->wait;
    }
}

sub main () {

    STDOUT->autoflush(1);
    my $num_workers = 500;

    # create a barrier
    my $barrier = MCE::Barrier->new($num_workers);

    # create the worker processes
    spawn task($barrier, $_) for 1 .. $num_workers;

    # wait for all processes to finish
    $_->join for MCE::Simple->list; # same as sync;
}

main();