package Counter;

use strict;
use threads;
use threads::shared;

sub new {
    my $proto = shift;
    my $class = ref($proto) || $proto;
    my $self = {};

    my $counter :shared = shift; ## Local shared variable

    $self->{ counter } = \$counter; ## Store a reference to it in the object

    bless($self,$class);
    return $self;
}

sub incCounter {
    my $self = shift;
    lock ${ $self->{ counter } };
    ++${ $self->{ counter } };
}

sub getCounter {
    my $self = shift;
    lock ${ $self->{ counter } };
    ${ $self->{ counter } };
}
1


##</code><code>##

#! perl -slw
use strict;
use threads;
use Counter;

my $t1 = async{
    my $c1 = Counter->new( 100 );
   $c1->incCounter while $c1->getCounter < 10000;
   return $c1->getCounter;
};

my $t2 = async{
    my $c2 = Counter->new( 100 );
   $c2->incCounter while $c2->getCounter < 30000;
   return $c2->getCounter;
};

print $t1->join;
print $t2->join;

__END__
C:\test>junk54
10000
30000