more docs on |message-pump
:: The following equation is always true:
:: .next - .current == number of messages in flight
::
+:: At the end of a task, |message-pump sends a %flush task to
+:: |packet-pump, which can trigger a timer to be set or cleared based
+:: on congestion control calculations. When it fires, the timer will
+:: generally cause one or more packets to be resent.
+::
:: current: sequence number of message being sent
:: next: sequence number of next message to send
:: unsent-messages: messages to be sent after current message
:: $packet-pump-state: persistent state for |packet-pump
::
:: next-wake: last timer we've set, or null
-:: live: packets in flight
-:: lost: packets to retry
+:: live: packets in flight; sent but not yet acked
+:: lost: packets to retry, since they timed out with no ack
:: pump-metrics: congestion control information
::
+$ packet-pump-state
