Hi Monks,

This one feels like I am abusing Perl's OO concepts in ways they were never meant to be used, but let's see if anybody has any ideas/experience.

I have a module which has some variables that need to be shared amongst threads it spawns.

my $var : shared = 0;

Which works fine for until you declare a second instance of the module. Then it seems like the namespace of the variable is shared with all other instances of this module, and each instance is sharing the variable.

I can see the uses of this, however what I need is a way to narrow the scope of the sharing of the variable to the instance in question.

Here is some simple sample code that replicates this:

package Counter;

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

my $counter : shared = 0;

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

    lock $counter;
    $counter = shift;

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

sub incCounter {
    lock $counter;
    $counter++;
}

sub getCounter {
    return $counter;
}
1;
[download]

and

#!/usr/bin/perl -w
use Counter;
my $x = new Counter( 1 );
my $y = new Counter( 10 );

print $x->getCounter()."\n";
print $y->getCounter()."\n";
print "-------------\n";
$x->incCounter();
print $x->getCounter()."\n";
print $y->getCounter()."\n";
[download]

I've been playing with sharing a hash, and then somehow generating a unique name for each instance, to guarantee independence of these variables, but that seems a bit...nasty.

So can perl do this? Can I have multiple instances of a module with shared variables that are only shared among the child threads of each instance? Again I realize Thread::Pool must be thread safe across multiple instances, so there has to be a way, I think its just a question of how nasty the solution is..

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