Callback invoked to process and optionally reply to a message received on a version 1 CFRunLoopSource object (Mach port-based sources).
- Core Foundation
The Mach message received on the Mach port. The pointer is to a
machstructure. A version 0 format trailer (
_msg _header _t
mach) is at the end of the Mach message.
_msg _format _0 _trailer _t
Size of the Mach message in
msg, excluding the message trailer.
The allocator object that should be used to allocate a reply message.
infomember of the
CFRunstructure that was used when creating the run loop source.
Loop Source Context1
An optional Mach message to be sent in response to the received message. The message must be allocated using
NULL if you want an empty reply returned to the sender.
You only need to provide this callback if you create your own version 1 run loop source. CFMachPort and CFMessagePort run loop sources already implement this callback to forward the received message to the CFMachPort’s or CFMessagePort’s own callback function, which you do need to implement.
You specify this callback in the
CFRun structure when creating the run loop source.