async await and GCD

Async Await and GCD at WWDC

Sessions Mentioned:

1. A Swift Tour: Explore Swift’s features and design
2. Migrate your app to Swift 6
3. Go further with Swift Testing

Key Points:

1. Async Await in Swift:

   • Suspension and Concurrency: Swift uses the async and await keywords to handle asynchronous operations. When an async function is called, the await keyword indicates that a suspension can occur on that line, allowing the CPU to handle other tasks (A Swift Tour: Explore Swift’s features and design).
   • Actors: Actors in Swift are reference types that encapsulate shared mutable state and automatically protect their state by serializing accesses. Calls to actor methods from outside the actor's context are asynchronous (A Swift Tour: Explore Swift’s features and design).

2. Concurrency in Swift 6:

   • Concurrency Architecture: Swift 6 introduces a more structured concurrency model, moving away from ad hoc concurrency architectures that use multiple dispatch queues. The new model uses actors to handle background operations and the main actor for UI updates (Migrate your app to Swift 6).
   • Data-Race Safety: Swift 6 provides complete data-race protection, ensuring that concurrent code is safe and free from data races (A Swift Tour: Explore Swift’s features and design).

3. Testing Asynchronous Code:

   • Parallel Testing: Swift testing allows tests to run in parallel, and the await keyword works the same way in tests as in production code. This ensures that the CPU remains busy while work is pending (Go further with Swift Testing).
   • Completion Handlers: For older code using completion handlers, Swift provides async overloads. If an async overload is not available, you can use withCheckedContinuation or withCheckedThrowingContinuation to convert it to an awaitable expression (Go further with Swift Testing).

Chapter Markers for Detailed Exploration:

• A Swift Tour: Explore Swift’s features and design
  • Concurrency
• Migrate your app to Swift 6
  • Adopting concurrency features
  • Delegate callbacks and concurrency
• Go further with Swift Testing
  • Asynchronous conditions

These sessions provide a comprehensive overview of how Swift handles asynchronous programming and concurrency, including practical examples and best practices for migrating to Swift 6.