race.pl

#!/usr/bin/env perl
use strict;
use Mojo::Promise;
use Mojo::IOLoop::Subprocess;
use Mojo::UserAgent;

my $subprocess = Mojo::IOLoop::Subprocess->new;
$subprocess->run(
    sub {
        my $subprocess = shift;

        my $ua = Mojo::UserAgent->new;


        my @titles;
        my %promises;
        my $id = 0;
        for (1 .. 10) {
            $id++;

            my $request_p = $ua->get_p(('https://perlcon.eu/'));

            my $mine_id = $id;
            $promises{$mine_id} = $request_p;

            $request_p->then(
                sub {
                    my ($tx) = @_;
                    push @titles, $tx->res->dom->at('title')->text;
                }
              )->catch(
                sub {
                    print STDERR @_;
                }
              )->finally(
                sub {
                    print gmtime . ": finished job $mine_id\n";
                    delete $promises{$mine_id};
                }
              );


            Mojo::Promise->race(values %promises)->wait() if scalar keys %promises > 2;
        }

        print gmtime . ": waiting for all jobs to end.\n";

        Mojo::Promise->all(values %promises)->wait() if scalar keys %promises;

        print gmtime . ": all done!\n";

        return @titles;

    },
    sub {
        my ($self, @titles) = @_;

        print join "\n", @titles, '';
    }
);


$subprocess->ioloop->start unless $subprocess->ioloop->is_running;