# CFHostStartInfoResolution(_:_:_:) Starts resolution for a host object. ``` func CFHostStartInfoResolution(_ theHost: CFHost, _ info: CFHostInfoType, _ error: UnsafeMutablePointer?) -> Bool ``` ## Parameters `theHost` The host, obtained by previously calling [`CFHostCreateCopy(_:_:)`](/documentation/CFNetwork/CFHostCreateCopy(_:_:)), [`CFHostCreateWithAddress(_:_:)`](/documentation/CFNetwork/CFHostCreateWithAddress(_:_:)), or [`CFHostCreateWithName(_:_:)`](/documentation/CFNetwork/CFHostCreateWithName(_:_:)), that is to be resolved. This value must not be `NULL`. `info` A value of type `CFHostInfoType` specifying the type of information that is to be retrieved. See [`CFHostInfoType`](/documentation/CFNetwork/CFHostInfoType) for possible values. `error` A pointer to a structure, that, if an error occurs, is set to the error and the error’s domain. In synchronous mode, the error indicates why resolution failed, and in asynchronous mode, the error indicates why resolution failed to start. ## Return Value `TRUE` if the resolution was started (asynchronous mode); `FALSE` if another resolution is already in progress for `theHost` or if an error occurred. ## Discussion This function retrieves the information specified by `info` and stores it in the host. In synchronous mode, this function blocks until the resolution has completed, in which case this function returns `TRUE`, until the resolution is stopped by calling [`CFHostCancelInfoResolution(_:_:)`](/documentation/CFNetwork/CFHostCancelInfoResolution(_:_:)) from another thread, in which case this function returns `FALSE`, or until an error occurs. ### Special Considerations This function is thread safe. --- 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)