send-off is the other function that we can use to update agents:
(send-off play-time - 1)
In the preceding example, we have subtracted 1 using Clojure's function - . The - function uses current value of play-time to subtract 1 that we passed as an argument to send-off.
We can check the current value of play-time:
@play-time
Dereferencing agent gives us an updated state, as follows:
=> 1
We used the send-off function in the same manner that we used send. The difference between them is that send-off uses a different thread pool than the one used by send. The send-off thread pool can also grow in size.