#!/usr/bin/perl -w

use strict;
use threads;

my $maxThreads = 5;

open(LOGGER,'>>logfile') or die();

for my $num (1..50) {

  print "Starting thread # $num\n";
  my $thread = async { &doStuff($num); };

  while (threads->list(threads::running) > $maxThreads) {
    for my $thread (threads->list(threads::all)) {
      if ($thread->is_joinable()) {
        print $thread->join();
      }
    }
  }
}

print "Waiting for the last ". threads->list(threads::running) ." threads to finish\n";
while (threads->list(threads::all)) {
  for my $thread (threads->list(threads::joinable)) {
    print $thread->join();
  }
}

close LOGGER;
sleep(1);



sub doStuff {
  
  my $num = shift;
  my $secs = int(rand(3));
  
  print LOGGER "Thread # $num is napping for $secs seconds.\n";
  sleep $secs;
  print LOGGER "Thread # $num is awake.\n";

  return "This returned from thread # $num\n";

}