# CFSocketCreateWithSocketSignature(_:_:_:_:_:) Creates a CFSocket object using information from a CFSocketSignature structure. ``` func CFSocketCreateWithSocketSignature(_ allocator: CFAllocator!, _ signature: UnsafePointer!, _ callBackTypes: CFOptionFlags, _ callout: CFSocketCallBack!, _ context: UnsafePointer!) -> CFSocket! ``` ## Parameters `allocator` The allocator to use to allocate memory for the new object. Pass `NULL` or [`kCFAllocatorDefault`](/documentation/CoreFoundation/kCFAllocatorDefault) to use the current default allocator. `signature` A [`CFSocketSignature`](/documentation/CoreFoundation/CFSocketSignature) identifying the communication protocol and address with which to create the CFSocket object. `callBackTypes` A bitwise-OR combination of the types of socket activity that should cause `callout` to be called. See [`CFSocketCallBackType`](/documentation/CoreFoundation/CFSocketCallBackType) for the possible activity values. `callout` The function to call when one of the activities indicated by `callBackTypes` occurs. `context` A structure holding contextual information for the CFSocket object. The function copies the information out of the structure, so the memory pointed to by `context` does not need to persist beyond the function call. Can be `NULL`. ## Return Value The new CFSocket object, or `NULL` if an error occurred. 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). ## 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)