Mojo IOLoop synchronization example

ioloop.pl

use strict;
use warnings;
use v5.10;  

use Mojo::UserAgent;
use Mojo::IOLoop;

use Data::Dumper;

my $delay = Mojo::IOLoop->delay(sub { shift; say Dumper([@_]); });

for my $i (1 .. 3) {
  my $end = $delay->begin;
  Mojo::IOLoop->timer($i => sub {
    $delay->pass( "step $i" );
    $end->();
 });
}
$delay->wait;