Unlocking the Power of Concurrency in Swift
When Apple introduced Swift in 2014, it revolutionized the world of modern programming languages. Chris Lattner, the mastermind behind Swift, aimed to create a language that could be used for both teaching programming and building software for operating systems. Since then, Apple has open-sourced Swift, allowing it to continuously evolve and improve.
The Missing Piece: Concurrency and Parallelism
Despite significant advancements, Swift still lacks a crucial feature: primitives for concurrency and parallelism. However, with the introduction of the async and await keywords, we can now enforce concurrency in our code.
Why Concurrency Matters
In recent years, processor design has undergone a significant shift. While clock speed improvements have stagnated, the number of CPU cores on each chip has increased dramatically. Apple’s A14 processor, found in the iPhone 12, boasts six CPU cores, while the M1 processor, used in Macs and iPads, has eight CPU cores. To fully utilize these modern processors, we need to master concurrent programming.
The Problem of Long-Running Tasks
In most modern computer systems, the main thread is responsible for rendering and handling user interactions. However, long-running tasks like network requests, file system interactions, or database queries can block the main thread, causing the UI to freeze. To prevent this, Apple provides various tools to offload tasks to background threads or queues.
Concurrency Options in Swift
Frameworks like Grand Central Dispatch (GCD) and libdispatch have made concurrent programming more accessible. The current best practice is to offload tasks to background threads or queues, using blocks or trailing closures to handle the results. However, this approach can lead to complex, hard-to-read code.
A New Era of Concurrency: Async/Await
In 2017, Chris Lattner proposed the Swift Concurrency Manifesto, outlining his vision for adding concurrency to Swift using async/await. With the release of iOS 15 and macOS 12, developers can now use this syntax to write concurrent code.
Using Async/Await in Your Code
By adding the async keyword to a function, we can return a value without using a completion handler. Inside the function, we use the await keyword to suspend execution until the task is complete. This approach leads to cleaner, more readable code.
The Future of Concurrency in Swift
With async/await, Swift has taken a significant step forward in managing concurrency and parallelism. By leveraging these new keywords, we can write more efficient, easier-to-read code that takes full advantage of modern processors. As Swift continues to evolve, we can expect even more exciting features, such as actor objects, which allow developers to create shared mutable state without race conditions.
Get Started with Async/Await Today
Download Xcode 13 and start exploring the new concurrency features in iOS 15 and macOS 12. Watch Apple’s WWDC21 presentation to learn more about async/await in Swift. The future of concurrency is here – are you ready to unlock its power?