What is Sendable?
Asked on 07/31/2024
2 searches
Sendable is a concept in Swift that ensures a type can be safely transferred across concurrency domains without causing data races. A type is considered sendable if it protects its state from concurrent accesses. This is particularly important when dealing with actors and other concurrency features in Swift.
For example, in the session Migrate your app to Swift 6, it is explained that Swift does not infer sendability for public types automatically because marking a type as sendable is a guarantee to your clients that the type contains no mutable state. Therefore, you need to explicitly add sendable conformances on public types.
Additionally, in the session A Swift Tour: Explore Swift’s features and design, it is mentioned that data race safety in Swift 6 is achieved by requiring that values shared between concurrency domains are sendable. This ensures that the values protect their state from concurrent accesses, which is crucial for avoiding crashes or unpredictable behavior in concurrent programming.
Relevant Sessions
Consume noncopyable types in Swift
Get started with noncopyable types in Swift. Discover what copying means in Swift, when you might want to use a noncopyable type, and how value ownership lets you state your intentions clearly.
Migrate your app to Swift 6
Experience Swift 6 migration in action as we update an existing sample app. Learn how to migrate incrementally, module by module, and how the compiler helps you identify code that’s at risk of data races. Discover different techniques for ensuring clear isolation boundaries and eliminating concurrent access to shared mutable state.
What’s new in App Intents
Learn about improvements and all-new features with App Intents, and discover how this framework can help you expose your app’s functionality to Siri, Spotlight, Shortcuts, and more. We’ll show you how to make your entities more meaningful to the platform with the Transferable API, File Representations, new IntentFile APIs, and Spotlight Indexing, opening up powerful functionality in Siri and the Shortcuts app. Empower your intents to take people deep into your app with URL Representable Entities. Explore new techniques to model your entities and intents with new APIs for error handling and union values.