for $i (0..$number) {
  $thr_{$i} = new Thread \&sub_routine, arg1, @array_of args;
}

sub sub_routine {
  do something;
  return "Thread completed successfully";
}

##</code><code>##

my @threads_return_data
for $i (0 .. $number) {
		push @threads_return_data, $thr_{$i}->join;
	}
post_processing_subroutine();