Instance Property Set Callback
Set the completion handler to be called once the command completes asynchronous execution .
macOS 10.0+ Mac Catalyst 13.0+ Parameters
The command object interface of interest
A callback handler. Passing nil forces the command object to execute synchronously.
Availability: (for interfaces obtained with ID)
k IOFire Wire Async Stream Command Interface ID YES
k IOFire Wire Compare Swap Command Interface ID YES
k IOFire Wire Write Quadlet Command Interface ID YES
k IOFire Wire Read Quadlet Command Interface ID YES
k IOFire Wire Write Command Interface ID _v2 YES
k IOFire Wire Write Command Interface ID YES
k IOFire Wire Read Command Interface ID _v2 YES
k IOFire Wire Read Command Interface ID YES
See Also Miscellaneous Get Transferred Bytes
Return number of bytes transferred by this command object when it last completed execution.
Set FireWire bus generation for which the command object shall be valid. If the failOnReset attribute has been set, the command will only be considered for execution during the bus generation specified by this function.
Set Ref Con
Set the user refCon value. This is the user defined value that will be passed in the refCon argument to the completion function.