# CTFontManagerCreateFontRequestRunLoopSource(_:_:) Creates a reference to a run loop source used to convey font requests from the Font Manager. ``` func CTFontManagerCreateFontRequestRunLoopSource(_ sourceOrder: CFIndex, _ createMatchesCallback: @escaping (CFDictionary, pid_t) -> Unmanaged) -> CFRunLoopSource? ``` ## Parameters `sourceOrder` The order of the created run loop source. `createMatchesCallback` A block to handle the font request. ## Return Value A reference to a CFRunLoopSource object that should be added to the run loop. To stop receiving requests, invalidate this run loop source. Returns `NULL` on error, in the case of a duplicate `requestPortName`, or invalid context structure. ## Discussion --- 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)