# CFMessagePortSendRequest(_:_:_:_:_:_:_:) Sends a message to a remote CFMessagePort object. ``` func CFMessagePortSendRequest(_ remote: CFMessagePort!, _ msgid: Int32, _ data: CFData!, _ sendTimeout: CFTimeInterval, _ rcvTimeout: CFTimeInterval, _ replyMode: CFString!, _ returnData: UnsafeMutablePointer?>!) -> Int32 ``` ## Parameters `remote` The message port to which `data` should be sent. `msgid` An arbitrary integer value that you can send with the message. `data` The data to send to `remote`. `sendTimeout` The time to wait for `data` to be sent. `rcvTimeout` The time to wait for a reply to be returned. `replyMode` The run loop mode in which the function should wait for a reply. If the message is a `oneway` (so no response is expected), then `replyMode` should be `NULL`. If `replyMode` is non-`NULL`, the function runs the run loop waiting for a reply, in that mode. `replyMode` can be any string name of a run loop mode, but it should be one with input sources installed. You should use the `kCFRunLoopDefaultMode` constant unless you have a specific reason to use a different mode. `returnData` Upon return, contains a CFData object containing the reply data. Ownership follows the [The Create Rule](https://developer.apple.com/library/archive/documentation/CoreFoundation/Conceptual/CFMemoryMgmt/Concepts/Ownership.html#//apple_ref/doc/uid/20001148-103029). ## Return Value Error code indicating success or failure. See [CFMessagePortSendRequest Error Codes](/documentation/CoreFoundation/1561514-cfmessageportsendrequest-error-c) for the possible return values. ## 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)