#!/usr/bin/perl
use threads;

sub something_1 {
  my $thr;
  foreach (1..10){
    my $q = threads->create(\&something_2, $_);
    $thr->{$_} = $q;
  }
  while (1) {
    foreach (keys %$thr) {
      if ($thr->{$_}->is_joinable()){
	$thr->{$_}->join();
	delete $thr->{$_};
      }
    }
    print "trying:". (scalar keys %$thr)."\n";
    last if not scalar keys %$thr;
    sleep 1;
  }
}

sub something_2 {
  my $a = shift;
  my $pid = fork();
  if ($pid==0) {
    print "cocot $a\n";
    exit(0);
  } else {
    waitpid($pid, 0);
    print "done $a\n";
  }
}

# my $q = threads->create(\&something_1);
something_1;