PHP5 - self referencing classes

Hi all,

I have a class which creates a new object and caches this object (see source
at the bottom). The new object holds a link on the creator class.
The __descructor function of both classes are never called - because the
classes are destroyed (killed), when the script terminates.

Is there a way to "destruct" a class on another way manually?

Does anyone know about any deeper documentation about objects in PHP5?

Thanks!

Bye,
Thomas.

-

<?php

class a {

private $p_b;

function __construct() {
echo __CLASS__ . '::' . __FUNCTION__ . '<br>';
}

function __destruct() {
echo __CLASS__ . '::' . __FUNCTION__ . '<br>';
}

function get_b() {
if (!isset($this->b)) {
$this->b=new b($this);
}
return $this->b;
}
}

class b {
private $p_caller;

function __construct($caller) {
echo __CLASS__ . '::' . __FUNCTION__ . '<br>';
$this->p_caller=$caller;
}

function __destruct() {
echo __CLASS__ . '::' . __FUNCTION__ . '<br>';
}
}

$a=new a;
$b=$a->get_b();
unset($a);
unset($b);

?>

Just prints:

a::__construct
b::__construct