Kernel subshells (JEP91) implementation

docs/api/ipykernel.rst

@@ -110,6 +110,30 @@ Submodules
    :show-inheritance:
 
 
+.. automodule:: ipykernel.shellchannel
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+
+.. automodule:: ipykernel.subshell
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+
+.. automodule:: ipykernel.subshell_manager
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+
+.. automodule:: ipykernel.thread
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
+
 .. automodule:: ipykernel.trio_runner
    :members:
    :undoc-members:

ipykernel/control.py

@@ -1,40 +1,18 @@
 """A thread for a control channel."""
-from threading import Event, Thread
 
-from anyio import create_task_group, run, to_thread
+from .thread import BaseThread
 
 CONTROL_THREAD_NAME = "Control"
 
 
-class ControlThread(Thread):
+class ControlThread(BaseThread):
     """A thread for a control channel."""
 
     def __init__(self, **kwargs):
         """Initialize the thread."""
-        Thread.__init__(self, name=CONTROL_THREAD_NAME, **kwargs)
-        self.pydev_do_not_trace = True
-        self.is_pydev_daemon_thread = True
-        self.__stop = Event()
-        self._task = None
-
-    def set_task(self, task):
-        self._task = task
+        super().__init__(name=CONTROL_THREAD_NAME, **kwargs)
 
     def run(self):
         """Run the thread."""
         self.name = CONTROL_THREAD_NAME
-        run(self._main)
-
-    async def _main(self):
-        async with create_task_group() as tg:
-            if self._task is not None:
-                tg.start_soon(self._task)
-            await to_thread.run_sync(self.__stop.wait)
-            tg.cancel_scope.cancel()
-
-    def stop(self):
-        """Stop the thread.
-
-        This method is threadsafe.
-        """
-        self.__stop.set()
+        super().run()

ipykernel/kernelapp.py

@@ -53,6 +53,7 @@
 from .iostream import IOPubThread
 from .ipkernel import IPythonKernel
 from .parentpoller import ParentPollerUnix, ParentPollerWindows
+from .shellchannel import ShellChannelThread
 from .zmqshell import ZMQInteractiveShell
 
 # -----------------------------------------------------------------------------
@@ -143,6 +144,7 @@ class IPKernelApp(BaseIPythonApplication, InteractiveShellApp, ConnectionFileMix
     iopub_socket = Any()
     iopub_thread = Any()
     control_thread = Any()
+    shell_channel_thread = Any()
 
     _ports = Dict()
 
@@ -367,6 +369,7 @@ def init_control(self, context):
             self.control_socket.router_handover = 1
 
         self.control_thread = ControlThread(daemon=True)
+        self.shell_channel_thread = ShellChannelThread(context, self.shell_socket, daemon=True)
 
     def init_iopub(self, context):
         """Initialize the iopub channel."""
@@ -406,6 +409,10 @@ def close(self):
             self.log.debug("Closing control thread")
             self.control_thread.stop()
             self.control_thread.join()
+        if self.shell_channel_thread and self.shell_channel_thread.is_alive():
+            self.log.debug("Closing shell channel thread")
+            self.shell_channel_thread.stop()
+            self.shell_channel_thread.join()
 
         if self.debugpy_socket and not self.debugpy_socket.closed:
             self.debugpy_socket.close()
@@ -562,6 +569,7 @@ def init_kernel(self):
             debug_shell_socket=self.debug_shell_socket,
             shell_socket=self.shell_socket,
             control_thread=self.control_thread,
+            shell_channel_thread=self.shell_channel_thread,
             iopub_thread=self.iopub_thread,
             iopub_socket=self.iopub_socket,
             stdin_socket=self.stdin_socket,