Swift Programming Tutorial: Retain Cycle
Understand Retain Cycle in Just a Few Minutes
Welcome to the thrilling tale of retain cycles, where memory hangs onto things like a clingy ex, and your app starts hoarding unused objects like it’s on an episode of Swift Coders: Extreme Memory Leaks. Don’t worry, though! By the end of this article, you’ll know how to tame these pesky cycles and keep your app running smooth and squeaky-clean.
This article is part of my Swift Programming Tutorial series.
Act 1: Meet the Villain — The Retain Cycle
Imagine this: you’ve got two objects, Object A and Object B. They’re besties — so close that Object A says, “I’ll hold onto you forever!” and Object B replies, “No way, I’m holding onto you forever!” Cute? Sure. Healthy? Not so much.
In Swift, this “clinginess” is known as a retain cycle. It happens when two (or more) objects hold strong references to each other. Since neither object will let go, ARC (Automatic Reference Counting, aka Swift’s memory cleanup crew) can’t swoop in and free up that memory. The result? These objects linger in memory forever, even though you don’t need them anymore. That’s a memory leak, and it’s basically the software equivalent of leaving the lights on in an empty house.
