data race without race condition swift

In Swift, a data race occurs when two or more threads access the same memory location concurrently, and at least one of the accesses is a write. This can lead to unpredictable behavior and crashes. Swift 6 introduces compile-time data race safety, which helps prevent data races by diagnosing concurrent access to memory across your project. This is achieved through mechanisms like actors and the Sendable protocol, which ensure safe data sharing and isolation between concurrency domains.

Even if your code does not currently exhibit race conditions, adopting Swift 6's data race safety features can protect against future bugs when adding new features or refactoring. The Swift 6 language mode turns potential data race issues into compile-time errors, allowing you to address them before they become runtime problems.

For more details on Swift 6's data race safety, you can refer to the session Migrate your app to Swift 6 (03:20) and What’s new in Swift (26:07).