use strict;
use warnings;
use threads;
use threads::shared;
$|++;

my $DONE :shared = 0;
my $lock :shared;

my $execMethod = $ARGV[0] || 0;
if($execMethod !~ /[12345]/){
	print "Must pass an exec method:\n";
	print "1 = backticks\n";
	print "2 = backticks synchronized\n";
	print "3 = open\n";
	print "4 = open synchronized\n";
	print "5 = system\n";
	exit 1;
}
sub execute{
	my $cmd = shift;
	if($execMethod == 1){
		`$cmd`
	}elsif($execMethod == 2){
		lock $lock;
		`$cmd`
	}elsif($execMethod == 3){
		open(my $fs, "-|", $cmd);
		foreach(<$fs>){};
		close $fs;
	}elsif($execMethod == 4){
		lock $lock;
		open(my $fs, "-|", $cmd);
		foreach(<$fs>){};
		close $fs;
	}elsif($execMethod == 5){
		system($cmd . ">nul");
	}
}

sub worker{
	while(!$DONE){
		execute('echo hello world');
	}
}
my @workers = map threads->create( \&worker), (1..30);
print "Press <enter> to terminate\n";
<STDIN>;
$DONE = 1;

$_->join() for @workers;


##</code><code>##

This is perl 5, version 18, subversion 1 (v5.18.1) built for MSWin32-x64-multi-thread
(with 1 registered patch, see perl -V for more detail)

Copyright 1987-2013, Larry Wall

Binary build 1800 [297570] provided by ActiveState http://www.ActiveState.com
Built Sep 20 2013 15:07:17

Perl may be copied only under the terms of either the Artistic License or the
GNU General Public License, which may be found in the Perl 5 source kit.

Complete documentation for Perl, including FAQ lists, should be found on
this system using "man perl" or "perldoc perl".  If you have access to the
Internet, point your browser at http://www.perl.org/, the Perl Home Page.


##</code><code>##

Host Name:                 VCLOUD291
OS Name:                   Microsoft Windows Server 2008 R2 Enterprise
OS Version:                6.1.7601 Service Pack 1 Build 7601
OS Manufacturer:           Microsoft Corporation
OS Configuration:          Standalone Server
OS Build Type:             Multiprocessor Free
Registered Owner:          Windows User
Registered Organization:
Product ID:                55041-507-5915375-84291
Original Install Date:     4/23/2014, 12:10:03 PM
System Boot Time:          7/31/2015, 1:49:06 PM
System Manufacturer:       Microsoft Corporation
System Model:              Virtual Machine
System Type:               x64-based PC
Processor(s):              1 Processor(s) Installed.
                           [01]: Intel64 Family 6 Model 46 Stepping 6 GenuineIntel ~1862 M
hz
BIOS Version:              American Megatrends Inc. 090004 , 3/19/2009
Windows Directory:         C:\Windows
System Directory:          C:\Windows\system32
Boot Device:               \Device\HarddiskVolume1
System Locale:             en-us;English (United States)
Input Locale:              en-us;English (United States)
Time Zone:                 (UTC-07:00) Arizona
Total Physical Memory:     4,096 MB
Available Physical Memory: 1,635 MB
Virtual Memory: Max Size:  6,143 MB
Virtual Memory: Available: 3,364 MB
Virtual Memory: In Use:    2,779 MB
Page File Location(s):     C:\pagefile.sys
Domain:                    WORKGROUP
Logon Server:              \\VCLOUD291
Hotfix(s):                 46 Hotfix(s) Installed.