Is calling aio_return necessary after aio_cancel?

Question

As I understand it calling aio_return is necessary to finalize aio_read and aio_write calls. So the normal flow is something like

1. Call aio_read
2. Determine that the read has completed (with aio_error, aio_suspend or receiving a signal via aio_sigevent
3. Call aio_return to finalize the read.

(steps 2 and 3 can be done with the aio_waitcomplete extension)

Is it necessary to call aio_return if the io is cancelled with aio_cancel, or does the cancel also finalise the io?

Also, does this depend on the implementation?