how is async & await better over traditional blocking methods ?

Async and await provide several advantages over traditional blocking methods, particularly in the context of Swift's concurrency model:

1. Efficient CPU Utilization: When a task is waiting for an asynchronous operation to complete, such as reading from a disk or messaging another service, it suspends and yields the CPU to other tasks that have work to do. This efficient use of CPU resources is a significant improvement over traditional blocking methods, which would hold onto the CPU even while waiting, thus wasting valuable processing time. A Swift Tour: Explore Swift’s features and design

2. Memory Management: Async functions in Swift are designed to manage memory more efficiently. They keep their local state on a separate stack from the C stack and are split into multiple functions at runtime. This allows for more efficient memory allocation and deallocation, as the memory is managed in slabs that are faster than traditional malloc operations. Explore Swift performance

3. Concurrency and Safety: Swift's concurrency model, which includes async and await, provides guarantees about task execution and data access. This helps prevent data races and makes it easier to reason about code execution, especially when dealing with shared mutable state. Actors in Swift further enhance this by serializing access to their state, ensuring that only one task can execute at a time. A Swift Tour: Explore Swift’s features and design

4. Parallel Testing: In the context of testing, async and await allow tests to run in parallel, improving test performance. This is particularly useful when writing concurrent test code, as it allows other test code to keep the CPU busy while work is pending. Go further with Swift Testing

Overall, async and await in Swift provide a more efficient, safe, and manageable approach to handling asynchronous operations compared to traditional blocking methods.