sub DESTROY { print "Destroying $_[0][0]\n"; }

{
    my $x = bless [ '$x' ];
    my $y = bless [ '$y' ];
    $x->[1] = $y;
}

print("\n");

{
    my $x = bless [ '$x' ];
    my $y = bless [ '$y' ];
    $y->[1] = $x;
}

##</code><code>##

Destroying $x
Destroying $y

Destroying $y
Destroying $x

##</code><code>##

sub DESTROY { print "Destroying $_[0][0]\n"; }

{
    my $l3 = bless [ 'l3' ];
    my $l2 = bless [ 'l2', $l3 ];
    my $l1 = bless [ 'l1', $l2 ];
}

print("\n");

{
               my $l1 = bless [ 'l1' ];
    $l1->[1] = my $l2 = bless [ 'l2' ];
    $l2->[1] = my $l3 = bless [ 'l3' ];
}

##</code><code>##

Destroying l1
Destroying l2
Destroying l3

Destroying l1
Destroying l2
Destroying l3

##</code><code>##

sub DESTROY { print "Destroying $_[0][0]\n"; }

my $x = bless [ '$x' ];

my $y = bless [ '$y' ];
$y->[1] = $y;             # cycle

our $z = bless [ '$z' ];  # pkg var

END { print "Entering global destruction\n" }

##</code><code>##

$ perl a.pl
Destroying $x
Entering global destruction
Destroying $z    # Can occur in any order
Destroying $y    #