Description:
------------
If objects' classes extends ArrayIterator/ArrayObject, and recursively refer to 
each other, they will not be garbage collected.

I tried reproduction code in https://bugs.php.net/bug.php?id=33595, modified A to 
extend ArrayIterator, B to extend ArrayObject.

And is there a way to work around it currently?

Test script:
---------------
<?php
class A extends ArrayIterator {
    function __construct () {
        $this->b = new B($this);
    }
}

class B extends ArrayObject {
    function __construct ($parent = NULL) {
        $this->parent = $parent;
    }
}

for ($i = 0 ; $i < 1000000 ; $i++) {
    $a = new A();
    printf("gc: %d, %f\n", gc_collect_cycles(), memory_get_usage()/1024/1024);
}