max 4 parallell jobs while testing syntax

gistfile1.txt

#!/usr/bin/perl

use strict;
use warnings;

use Test::More;
use Test::Strict;
use Test2::AsyncSubtest;

use POSIX ":sys_wait_h";
use Time::HiRes qw/sleep/;

my $dir = 'bin';

my @files = Test::Strict::_all_perl_files($dir);

run_parallel_tests(4, [ map { my $file = $_; sub { all_perl_files_ok($file); }; } @files ], 'Syntax and strict checks for '. $dir);

sub run_parallel_tests {
  my ($MAX_JOBS, $tests, $name) = @_;

  my $ast = Test2::AsyncSubtest->new(name => $name);

  my @tests = @{ $tests || [] };

  my %children;

  while (@tests) {
    if (keys %children < $MAX_JOBS) {
      my $pid = $ast->run_fork(shift @tests);
      $children{$pid}++;
    }
    waitpid($_, WNOHANG) && delete $children{$_} for keys %children;

    last if ! @tests;
    sleep 0.01;
  }
  $ast->finish;
}