# Perl replica of using a Barrier with an Action
# https://superfastpython.com/multiprocessing-barrier-in-python/

use MCE::Simple -strict, -signatures;
use MCE::Barrier;
use Time::HiRes 'sleep';

STDOUT->autoflush(1);

sub report () {
    # report once all processes are done
    say "All processes have their result";
}

sub task ($barrier, $number) {
    # generate a unique value and block for a moment
    my $value = rand() * 10; sleep($value);

    # report result
    say "Process ${number} done, got: ${value}";

    # wait on all other processes to complete
    my ($remaining, $error) = $barrier->wait;

    # an alternative to using the "action" argument
    if ($remaining == 0) {
        say "I, process ${number}, was last...";
    }
}

sub main () {
    # create a barrier, not including the main process
    my $barrier = MCE::Barrier->new(5, before_release => \&report);

    # create the worker processes
    spawn task($barrier, $_) for 1..5;

    # reap the worker processes
    sync;
}

main();

__END__
Process 1 done, got: 1.25912054515542
Process 5 done, got: 2.02445819116296
Process 4 done, got: 4.33312377966107
Process 3 done, got: 6.64178936815919
Process 2 done, got: 8.9504549566573
All processes have their result
I, process 2, was last...