#!/usr/bin/env perl
use Mojo::Base -strict;
use Mojo::IOLoop::ForkCall 'fork_call';

for my $id (1..2) {
  fork_call(
    sub { 
      sleep 1;
      return "my id is $_[0]";
    },
    $id,
    sub {
      die $@ if $@; # error
      say $_[0]; # "my id is ..."
    },
  );
};

Mojo::IOLoop->start;