Fix shutdown

Author: davidbrochart

ipykernel/kernelbase.py

@@ -275,7 +275,7 @@ def __init__(self, **kwargs):
             self.control_handlers[msg_type] = getattr(self, msg_type)
 
         self.control_queue: Queue[t.Any] = Queue()
-        self.subshell_threads: dict[str, SubshellThread] = dict()
+        self.subshell_threads: dict[str, SubshellThread] = {}
 
     async def handle_main_shell(self):
         self.msg_queue: janus.Queue[t.Any] = janus.Queue()
@@ -890,9 +890,8 @@ async def shutdown_request(self, stream, ident, parent):
         control_io_loop = self.control_stream.io_loop
         control_io_loop.add_callback(control_io_loop.stop)
 
-        self.log.debug("Stopping shell ioloop")
-        shell_io_loop = self.shell_stream.io_loop
-        shell_io_loop.add_callback(shell_io_loop.stop)
+        self.log.debug("Stopping main ioloop")
+        self.io_loop.add_callback(self.io_loop.stop)
 
     async def subshell_request(self, stream, ident, parent):
         shell_id = parent.get("content", {}).get("shell_id")

ipykernel/shell.py

@@ -32,7 +32,7 @@ async def handle_messages(msg_queue, kernel, is_main):
             # flush to ensure reply is sent before
             # handling the next request
             kernel.shell_stream.flush(zmq.POLLOUT)
-            return
+            continue
 
         # Print some info about this message and leave a '--->' marker, so it's
         # easier to trace visually the message chain when debugging.  Each
@@ -41,7 +41,7 @@ async def handle_messages(msg_queue, kernel, is_main):
         kernel.log.debug("   Content: %s\n   --->\n   ", msg["content"])
 
         if not kernel.should_handle(kernel.shell_stream, msg, idents):
-            return
+            continue
 
         handler = kernel.shell_handlers.get(msg_type, None)
         if handler is None: