# CFMachPortCreate(_:_:_:_:) Creates a CFMachPort object with a new Mach port. ``` func CFMachPortCreate(_ allocator: CFAllocator!, _ callout: CFMachPortCallBack!, _ context: UnsafeMutablePointer!, _ shouldFreeInfo: UnsafeMutablePointer!) -> CFMachPort! ``` ## 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. `callout` The callback function invoked when a message is received on the new Mach port. `context` A structure holding contextual information for the new Mach port. 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. `shouldFreeInfo` A flag set by the function to indicate whether the `info` member of `context` should be freed. The flag is set to `true` on failure, `false` otherwise. `shouldFreeInfo` can be `NULL`. ## Return Value The new CFMachPort object or `NULL` on failure. The CFMachPort object has both send and receive rights. 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)