Re^4: refering to 1 shared hash from another

[Random_Walk]

use strict ;
use warnings;
use threads;
use threads::shared;
use Data::Dumper;
my %HoH           :shared;
my %hash          :shared;     

$hash{pre_key} = "Before";
$HoH{hash}=\%hash;
$hash{post_key} = "After";

if (\%hash eq $HoH{hash}) {
   print "OK\n";
} else {
   print "Copied, I suspect\n";
}

print Data::Dumper->Dump ([\%hash], ["hash"]);
print Data::Dumper->Dump ([$HoH{hash}], ["HoH"]);

print "But looks like they still stay in sych\n

Output

Copied, I suspect
$hash = {
          'pre_key' => 'Before',
          'post_key' => 'After'
        };
$HoH = {
         'pre_key' => 'Before',
         'post_key' => 'After'
       };
But looks like they still stay in sych

Update

I just read the docco for threads::shared and found this gem, which explains your issue:

Using refaddr()) is unreliable for testing whether or not two shared references are equivalent (e.g., when testing for circular references). Use is_shared(), instead:

There is more detail, and an example of the correct way to test in said docco

Cheers,
R.