sub process {
    my $number = shift;
    # lock %result;
    $result{ threads->tid() } =
      shared_clone( { $number => factorial($number) } );
    $semaphore->up;
}


##</code><code>##

 ./semaphore.pl 
0.0276410579681396
{
  # tied threads::shared::tie
  1 => {
         # tied threads::shared::tie
         10 => 3628800,
       },
  2 => {
         # tied threads::shared::tie
         10 => 3628800,
       },
  3 => {
         # tied threads::shared::tie
         10 => 3628800,
       },
  4 => {
         # tied threads::shared::tie
         11 => 39916800,
       },
}