CFMessagePortCallBack
Callback invoked to process a message received on a CFMessagePort object.
Declaration
typealias CFMessagePortCallBack = (CFMessagePort?, Int32, CFData?, UnsafeMutableRawPointer?) -> Unmanaged<CFData>?Parameters
- local:
The local message port that received the message.
- msgid:
An arbitrary integer value assigned to the message by the sender.
- data:
The message data.
- info:
The
infomember of the Cfmessageportcontext structure that was used when creatinglocal.
Return Value
Data to send back to the sender of the message. The system releases the returned CFData object. Return NULL if you want an empty reply returned to the sender.
Discussion
If you want the message data to persist beyond this callback, you must explicitly create a copy of data rather than merely retain it; the contents of data will be deallocated after the callback exits.