Well, the question in the title of the article you quoted was based on a misunderstanding: Objects are references (this has been pointed out by dseroh in the other thread as well). There is no performance penalty if you store an object as an attribute of another object.

In your example, you are creating a closure over $self and store this sub in a Helper object which you keep as an attribute: This results in a cyclic reference. But the cycle is not on the subroutine reference, it is on $self. So by weakening the sub reference, which only has this one reference in the helper object, you kill it and the second call fails.

Your alternate solution does not create a circular reference because you are using $_[0] instead of $self: $_[0] is the class name 'A', and not an object.

So if you don't actually need the object in the closure, as the alternate solution suggests, then just don't pass it into the closure.