Task AsyncStream await

The concept of async and await in Swift is a key feature for handling asynchronous operations. When a task is waiting for an asynchronous operation to complete, it suspends to yield the CPU to other tasks. This is modeled in Swift using the async and await syntax. A function that may suspend is marked with the async keyword, and the await keyword is used to indicate that a suspension can occur on that line.

In the session titled "Explore Swift performance," it is explained that async functions are implemented in a way that they keep their local state on a separate stack from the C stack and are split into multiple functions at runtime. This allows for efficient memory allocation and deallocation, which is crucial for performance.

For more detailed information on how async functions work, you can refer to the session Explore Swift performance (24:33).

Additionally, in the session "Go further with Swift Testing," it is mentioned that when writing concurrent test code, you can use the same concurrency features in Swift as in production code. The await keyword will suspend a test, allowing other test code to keep the CPU busy while work is pending.

For more on testing asynchronous conditions, you can check the session Go further with Swift Testing (24:26).