Mastering Swift 5.3 - Sixth Edition

16

Concurrency and Parallelism in Swift

When I first started learning Objective-C, I already had a good understanding of concurrency and multitasking with my background in other languages, such as C and Java. This background made it very easy for me to create multithreaded applications using threads. Then, Apple changed everything when they released Grand Central Dispatch (GCD) with OS X 10.6 and iOS 4. At first, I went into denial; there was no way GCD could manage my application's threads better than I could. Then, I entered the anger phase; GCD was hard to use and understand. Next was the bargaining phase; maybe I could use GCD with my threading code, so I could still control how the threading worked. Then, there was the depression phase; ...