swift-concurrency

To fix data races in Swift using actors, you isolate shared mutable state within an actor. This enforces serialized access to the data, preventing multiple tasks from executing concurrent modifications and resolving thread safety issues safely.

In Swift concurrency, async let is used for a fixed, static number of parallel operations, whereas Task Groups allow you to dynamically spawn a variable number of concurrent child tasks. Task Groups provide greater flexibility for dynamic concurrent workloads.

Migrating to Swift 6 concurrency requires adopting Sendable conformance for safe data sharing across threads. You must also address isolation boundaries and update asynchronous patterns to resolve strict concurrency compiler warnings and errors.

You should use Sendable conformance in Swift when a custom type needs to be safely passed across actor isolation boundaries or concurrent tasks. Marking a type as Sendable guarantees compile-time data race safety for concurrent code architecture.

Structured concurrency in Swift works by establishing a strict parent-child relationship between concurrent tasks. This architecture ensures that parent tasks cannot complete until all child tasks finish, enabling automatic cancellation and error propagation.