# withLock(flags:_:) ``` func withLock(flags: OSAllocatedUnfairLockFlags, _ body: @Sendable (inout State) throws -> R) rethrows -> R where R : Sendable ``` --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)