#!/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;