# withExclusiveControl(_:) Attempts to acquire immediate, exclusive control over the download manager. ``` @backDeployed(before: iOS 27, macOS 27, tvOS 27, visionOS 27) final func withExclusiveControl(_ body: @escaping () throws -> sending ReturnType) async throws -> sending ReturnType ``` ## Parameters `body` A closure to execute with exclusive control over the download manager. Once the closure returns or throws, you lose exclusive control. ## Return Value `body`’s return value. ## Discussion To avoid races between your main app and your downloader extension, perform operations on the download manager—*e.g.*, fetching current downloads, scheduling new downloads, *etc.*—while maintaining exclusive control over it. Unlike [`withExclusiveControl(_:)`](/documentation/BackgroundAssets/BADownloadManager/withExclusiveControl(_:)-2ang9), this method waits for exclusive control to be acquired and then relinquished before it returns. > Throws: When `body` throws or when exclusive control over the download manager can’t be acquired. --- 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)