circular-references.php

<?php
 
class FOO {
  public $f;
}
 
class BAR {
  public $f;
}
 
while(1) {
  $a = new FOO();
  $b = new BAR();
  $a->f = $b;
  $b->f = $a;
  print "Memory usage: " . number_format(memory_get_usage(true)) . " bytes\n";
  unset($a);
  unset($b);
}