Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to report
a bug at http://bugs.php.net/how-to-report.php

B::$instances[spl_object_hash($b)] = &$b;
// ...
$b = false;

In this case, B::$instances[$the_hash] will be false ($b being a referencing variable [it's the variable reference which is assigned, not an object reference]) too, so there's no pointer outside nor inside the object to the object. It'll be destructed.

If you'd have written:
B::$instances[spl_object_hash($b)] = $b; // note: no reference

You'd observe the same behaviour as in A.


In case of A, you assign the reference to $this, but $this won't be changed, whether it's a reference or not makes no difference. So it still will have some pointer inside the object to the object itself - it'll only be destructed when the garbage collector fires.

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Some note about your refcounts... Objects have a separate refcounter, the variable outside the object, holding it, is not the same one than $this!

bwoebi@php.net, thank you for explanation!
But I missed one thing - you tell that $this destructed only when gc fired. But this should mean that all objects should be destroyed only on gc hit, because all objects has cycle references, yes? But, in my example, object of B class destructed right after setting $b to false.
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About refcounter of object. Is there any documentation about it? Because I am trying to found memory leaks in my application and I am really can not understand why my objects are not destroyed even with refcount == 1.