What is async await?

Async/await is a concurrency model used in Swift to handle asynchronous operations more efficiently. It allows functions to be marked as async, indicating that they may suspend execution to wait for an asynchronous operation to complete. When calling an async function, the await keyword is used to indicate that the function may suspend at that point.

Here are some key points about async/await in Swift:

1. Task Suspension: When a task is waiting for an asynchronous operation to complete, it suspends to yield the CPU to other tasks that have work to do. This is modeled in code using the async and await keywords. (A Swift Tour: Explore Swift’s features and design)

2. Memory Management: Async functions keep their local state on a separate stack from the C stack and are split into multiple functions at runtime. This allows them to manage memory more efficiently and avoid blocking precious C threads. (Explore Swift performance)

3. Partial Functions: Async functions are split into partial functions that span the gaps between potential suspension points. This means that each partial function runs like an ordinary C function until the next suspension point. (Explore Swift performance)

4. Concurrency Safety: Swift's concurrency model, including async/await, ensures data-race protection, making it safer to write concurrent code. (A Swift Tour: Explore Swift’s features and design)

For more detailed information, you can refer to the sessions:

• A Swift Tour: Explore Swift’s features and design
• Explore Swift performance

Relevant Sessions

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