From 66a72ad24c6695546fd78cb17d7c90088a8e3604 Mon Sep 17 00:00:00 2001
From: Nathaniel Nicandro <nathanielnicandro@gmail.com>
Date: Wed, 9 Sep 2020 14:21:49 -0500
Subject: [PATCH] Resurrect `jupyter-finalized-object`

---
 jupyter-base.el   | 20 +++++++++++++-------
 jupyter-client.el |  6 +++---
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/jupyter-base.el b/jupyter-base.el
index 59090f3..32abb39 100644
--- a/jupyter-base.el
+++ b/jupyter-base.el
@@ -371,14 +371,20 @@ class corresponding to the symbol `jupyter-instance-tracker'."
       (cl-assert (get sym 'jupyter-instance-tracker) t)
       (hash-table-keys table))))
 
-(defvar jupyter-finalizers (make-hash-table :weakness 'key :test #'eq))
+(defclass jupyter-finalized-object ()
+  ((finalizers :type list :initform nil))
+  :documentation "A list of finalizers."
+  :documentation "A base class for cleaning up resources.
+Adds the method `jupyter-add-finalizer' which maintains a list of
+finalizer functions to be called when the object is garbage
+collected.")
 
-(defun jupyter-add-finalizer (obj fn)
-  "Add FN to the finalizers of OBJ."
-  (declare (indent 1))
-  (cl-check-type fn function)
-  (cl-callf append (gethash obj jupyter-finalizers)
-    (list (make-finalizer fn))))
+(cl-defgeneric jupyter-add-finalizer ((obj jupyter-finalized-object) finalizer)
+  "Cleanup resources automatically.
+FINALIZER if a function to be added to a list of finalizers that
+will be called when OBJ is garbage collected."
+  (cl-check-type finalizer function)
+  (push (make-finalizer finalizer) (oref obj finalizers)))
 
 ;;; Session object definition
 
diff --git a/jupyter-client.el b/jupyter-client.el
index fc12f3d..b2338fd 100644
--- a/jupyter-client.el
+++ b/jupyter-client.el
@@ -176,7 +176,8 @@ requests like the above example.")
 
 ;; Define channel classes for method dispatching based on the channel type
 
-(defclass jupyter-kernel-client (jupyter-instance-tracker)
+(defclass jupyter-kernel-client (jupyter-instance-tracker
+                                 jupyter-finalized-object)
   ((tracking-symbol :initform 'jupyter--clients)
    (execution-state
     :type string
@@ -295,8 +296,7 @@ method is called."
     (jupyter-add-finalizer client
       (lambda ()
         (when (buffer-live-p buffer)
-          (kill-buffer buffer))
-        (jupyter-stop-channels client)))))
+          (kill-buffer buffer))))))
 
 (cl-defmethod jupyter-kernel-alive-p ((client jupyter-kernel-client))
   "Return non-nil if the kernel CLIENT is connected to is alive."