foreach (@go_do_something){
  my $thr = threads->new(\&some_sub,$_);
  $thr -> detach();
}

##</code><code>##

foreach (@go_do_something){
  $used_threads++;
  @thr_ll[$used_threads] = threads -> new(\&some_sub,$_);
  @thr_ll[$used_threads] -> detach();
}