destruct never called

gistfile1.php

<?php

// watch how the destructor is never called

set_time_limit(1);

class Foobar {
    
    public function doIt() {
        while(true) {
        }
    }

    public function __destruct() {
        echo "destruct called?";
    }
}

$foo =new Foobar();
$foo->doIt();