Swift Concurrency—Part 1: Tasks, Executors, and Priority Escalation

Swift 6 introduces a new concurrency model built on async/await, actors, and cooperative multitasking to replace error-prone thread-based patterns. This article contrasts preemptive and cooperative multitasking, explains tasks and Task.detached, unpacks the cooperative thread pool and task priorities, and shows how suspension points and continuations make concurrent Swift code safer, more predictable, and easier to reason about.