server-session-connected avoids assert-lock of server-connected

syndicate/distributed/client.rkt

@@ -23,6 +23,7 @@
   (on-start (log-syndicate/distributed-info "Connected to ~v" address))
   (on-stop (log-syndicate/distributed-info "Disconnected from ~v" address))
   (assert (server-connected address))
+  (assert (server-session-connected address))
 
   (when (log-level? syndicate/distributed-logger 'debug)
     (set! w (let ((w* w))

syndicate/distributed/client/tcp.rkt

@@ -17,7 +17,7 @@
                       (retracted (tcp-accepted id))
                       (asserted (tcp-rejected id _))
                       (retracted (server-transport-connected address))
-                      (retracted (server-connected address)))
+                      (retracted (server-session-connected address)))
 
          (during (tcp-accepted id)
            (on-start (issue-unbounded-credit! tcp-in id))

syndicate/distributed/internal-protocol.rkt

@@ -11,6 +11,11 @@
 ;; `server-packet` messages. Implementation-facing, where
 ;; `server-connected` is part of the API.
 (assertion-struct server-transport-connected (address))
+;; Like `server-connected`, but for reflecting the state of the
+;; session to the transport driver. Observation of
+;; `server-session-connected` is not creative (of `server-connected`),
+;; unlike observation of `server-connected`.
+(assertion-struct server-session-connected (address))
 
 ;; Internal connection protocol
 (assertion-struct server-poa (connection-id)) ;; "Point of Attachment"