Cancels an asynchronous subscription.
void unsubscribe_a (subscriber_t *subscriber, subscription_t *subscription, subscriber_cb_t cbdone, void *cbarg);
subscriber
The disappearing subscriber.
subscription
The subscription to cancel.
cbdone
Called when an unsubscribe completes. It has three parameters:
cbarg (see below).
Status code.
A pointer to an opaque subscription object.
cbarg
The first argument of cbdone.
Nothing.