The EmojiArt app runs a lot of tasks in parallel: Concurrent tasks add downloaded images to a collection and update progress values, so there’s a lot of potential for data races. Learn how to use the Actor protocol to protect shared mutable state and convert EmojiArtModel from a class to an actor.
This is a companion discussion topic for the original entry at https://www.raywenderlich.com/32059632-modern-concurrency-beyond-the-basics/lessons/14