Merge pull request #3759 from minrk/flush-iopub

flush iopub before sending restarting/dead status messages
jupyter · Aug 13, 2018 · 34baae5 · 34baae5
2 parents eed1caf + a53d2c8
commit 34baae5
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/notebook/services/kernels/handlers.py b/notebook/services/kernels/handlers.py
@@ -456,6 +456,12 @@ def on_close(self):
         self._close_future.set_result(None)
 
     def _send_status_message(self, status):
+        iopub = self.channels.get('iopub', None)
+        if iopub and not iopub.closed():
+            # flush IOPub before sending a restarting/dead status message
+            # ensures proper ordering on the IOPub channel
+            # that all messages from the stopped kernel have been delivered
+            iopub.flush()
         msg = self.session.msg("status",
             {'execution_state': status}
         )