#!/usr/bin/perl

use strict;
use warnings;

use Config;
use threads;

use Time::HiRes qw( usleep );

$Config{useithreads} or die('Recompile Perl with threads to run this program.');

foreach my $i (1 .. 100000) {
        while ((my $nthreads = scalar  threads->list()) >= 10) {
                print $nthreads . " running. waiting 1 second.\n";
                sleep(1);

                foreach my $thread (threads->list(threads::joinable)) {
                        $thread->join();
                }
        }

        threads->create(\&sub1);

        usleep(333333);

        foreach my $thread (threads->list(threads::joinable)) {
                $thread->join();
        }
}

foreach my $thread (threads->list()) {
        $thread->join();
}

sub sub1 {
        my $sleep_value = int(rand(2) * 100) / 100;
        print "thread id " . threads->tid() . ": Start sleeping " . $sleep_value . " seconds\n";
        usleep($sleep_value * 1000000);
        print "thread id " . threads->tid() . ": Done  sleeping " . $sleep_value . " seconds\n";
}