Use <kernel> records to represent proxies.

* guix-jupyter-kernel.scm (<proxy>): Remove.
(register-proxy): Add docstring.
(new-container-connect): Return a <kernel> object.
(reply-execute-request, kill-containers): Adjust accordingly.

guix-jupyter-kernel.scm

@@ -19,7 +19,6 @@
 (use-modules (json)
              (simple-zmq)
 	     (srfi srfi-1)
-	     (srfi srfi-9)
              (srfi srfi-11)
              (srfi srfi-13)
              (srfi srfi-19)
@@ -43,14 +42,6 @@
                            (seed->random-state
                             (time-second (current-time time-utc)))))
 
-;; Kernel proxy running in a container.
-(define-record-type <proxy>
-  (proxy pid socket start)
-  proxy?
-  (pid     proxy-pid)                             ;integer
-  (socket  proxy-socket)                          ;zmq socket
-  (start   proxy-start-time))                     ;integer
-
 ;;
 ;; Container tools.
 ;;
@@ -62,6 +53,8 @@
                   (+ (string-rindex (car (command-line)) #\/) 1)))
 
 (define (register-proxy vhash name proxy)
+  "Register PROXY, a kernel object for a process running in a container that
+acts as a proxy to an actual kernel."
   (vhash-cons name proxy vhash))
 
 (define (proxy-by-name vhash name)
@@ -135,12 +128,12 @@
                       (container (new-container-connect env-name id))
                       (new       (register-proxy containers env-name
                                                  container)))
-                 (relay-message (proxy-socket container) kernel
+                 (relay-message (kernel-shell container) kernel
                                 (string->utf8 env-name)
                                 message)
                  (values new (+ count 1))))
-              ((? proxy? proxy)
-               (relay-message (proxy-socket proxy) kernel
+              ((? kernel? proxy)
+               (relay-message (kernel-shell proxy) kernel
                               (string->utf8 env-name)
                               message)
                (values containers (+ count 1))))))
@@ -149,7 +142,7 @@
           (let* ((list     (string-split magic #\ ))
                  (env-name (list-ref list 2))
                  (proxy    (proxy-by-name containers env-name)))
-            (relay-message (proxy-socket proxy) kernel
+            (relay-message (kernel-shell proxy) kernel
                            (string->utf8 env-name)
                            message)
             (values containers (+ count 1))))
@@ -159,7 +152,7 @@
                               (delete-magic code)
                               count)))
          (else
-          (relay-message (proxy-socket
+          (relay-message (kernel-shell
                           (proxy-by-name containers "default"))
                          kernel (string->utf8 "default")
                          message)
@@ -202,11 +195,11 @@ MESSAGE."
                     ((name . proxy)
                      (format (current-error-port)
                              "terminating proxy ~s (PID ~s)...~%"
-                             name (proxy-pid proxy))
-                     (relay-message (proxy-socket proxy) kernel
+                             name (kernel-pid proxy))
+                     (relay-message (kernel-shell proxy) kernel
                                     (string->utf8 name) message)
-                     (zmq-close-socket (proxy-socket proxy))
-                     (false-if-exception (kill (proxy-pid proxy) SIGTERM))))
+                     (zmq-close-socket (kernel-shell proxy))
+                     (false-if-exception (kill (kernel-pid proxy) SIGTERM))))
                   containers))
 
 ;;
@@ -214,7 +207,7 @@ MESSAGE."
 ;;
 
 (define (new-container-connect name pid)
-  "Return a proxy object for process PID."
+  "Return a kernel object for process PID."
   (let* ((ipc-dir  (string-append "/tmp/guix-kernel/ipc/" name "-"
                                   (number->string session-id) "/"))
          (container-addr (string-append "ipc://" ipc-dir))
@@ -228,7 +221,9 @@ MESSAGE."
       (zmq-bind-socket container-socket container-addr-sock)
       (display "+")
 
-      (proxy pid container-socket (current-time time-utc)))))
+      (kernel name pid
+              #:shell container-socket
+              #:iosub container-socket))))
 
 (define %network-file-systems
   ;; The list of <file-system> objects corresponding to bind-mounts required