Indeed...

use strict;
use warnings;
use Test::More;

use Scalar::Util qw(weaken isweak);
use Devel::Refcount qw(refcount);

my $A = bless {}, 'Monkey';
is(refcount($A), 1, 'an object has a refcount');

my $B = $A;
is(refcount($A), 2, 'additional ref to the object increases the refcou
+nt');

$B = undef;
is(refcount($A), 1, 'removing a ref to the object decreases the refcou
+nt');

do {
    my $C = $A;
    is(refcount($A), 2, 'reference in a scope increases refcount');
};

is(refcount($A), 1, '$C fell out of scope, so decreased ref count');

my $D = $A;
is(refcount($A), 2, 'another ref which will increase ref count');

weaken $D;
is(refcount($A), 1, 'weakening the ref means it is not included in the
+ ref count');
ok($A == $D, 'yet $A and $D are still the same object');

my $destroyed = 0;
sub Monkey::DESTROY { $destroyed++ };

$A = undef;
is($destroyed, 1, 'undefining $A destroyed the object; $D was a weak r
+ef so did not prevent destruction');

ok(!defined $D, '$D is now undefined');

done_testing;

[download]
perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'
/tt); my $B = $A; is(refcount($A), 2,

In reply to Re^2: Timing of garbage collection by tobyink
in thread Timing of garbage collection by dd-b

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