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Start your free trialGene Bogdanovich
14,618 PointsWhy we opted out of making fibonacci property weak?
I donβt fully understand why we opted out of making fibonacci property weak to avoid a reference cycle. Can somebody explain in detail please?
1 Answer
Michael Hulet
47,913 PointsThe core issue here is that self
retains the fibonacci
closure, but by default, the fibonacci
closure also retains self
since self
is referenced within the closure. You're right that one way to break the cycle would've been to make the property itself weak
, but that isn't really what we want to do. We want that closure to stay around as long as our object stays around, but that won't happen if we mark it as weak
because nothing else references it, so the closure would get deallocated immediately. The best option here (and what Pasan ended up doing) was to make the closure weakly reference self
instead. This way, self
retains the closure and guarantees it will stay around as long as we want it to, but the closure doesn't also retain self
and cause a reference cycle