Is this too complicated for you?

#! perl -slw
use strict;
use threads;
use threads::shared::Scalar;

my $shared = threads::shared::Scalar->new;

for ( 1.. 10 ) {
    async {
        sleep 1 + rand 3;
        $shared->value .= ":$_";
    };
}
$_->join for threads->list;
print $shared->value;

__END__
C:\test>579015
:1:2:3:5:6:9:4:7:8:10

C:\test>579015
:1:2:6:9:3:5:7:10:4:8

C:\test>579015
:4:5:6:7:8:9:3:1:2:10
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Update: A slightly simpler version:

#! perl -slw
use strict;
use threads::shared::Scalar;

our $T ||= 10;
our $N ||= 1000;

my $shared = threads::shared::Scalar->new;

for( 1 .. $T ) {
    async{
        for( 1 .. $N ) {
            $shared->value++;
        }
    };
}
waitall;
print $shared->value;
__END__
C:\test>sharedScalar.plt -T=1000 -N=1000
1000000
C:\test>sharedScalar.plt -T=500 -N=1000
500000
C:\test>sharedScalar.plt -T=500 -N=12345
6172500
C:\test>sharedScalar.plt -T=123 -N=10
1230
[download]