Subshells implemented using tornado event loops on 6.x branch

.github/workflows/ci.yml

@@ -49,19 +49,19 @@ jobs:
         timeout-minutes: 15
         if: ${{ !startsWith( matrix.python-version, 'pypy' ) && !startsWith(matrix.os, 'windows') }}
         run: |
-          hatch run cov:test --cov-fail-under 50 || hatch run test:test --lf
+          hatch run cov:test --cov-fail-under 50
 
       - name: Run the tests on pypy
         timeout-minutes: 15
         if: ${{ startsWith( matrix.python-version, 'pypy' ) }}
         run: |
-          hatch run test:nowarn || hatch run test:nowarn --lf
+          hatch run test:nowarn
 
       - name: Run the tests on Windows
         timeout-minutes: 15
         if: ${{  startsWith(matrix.os, 'windows') }}
         run: |
-          hatch run cov:nowarn || hatch run test:nowarn --lf
+          hatch run cov:nowarn
 
       - name: Check Launcher
         run: |
@@ -144,7 +144,7 @@ jobs:
 
       - name: Run the tests
         timeout-minutes: 15
-        run: pytest -W default -vv || pytest --vv -W default --lf
+        run: pytest -W default -vv
 
   test_miniumum_versions:
     name: Test Minimum Versions
@@ -164,7 +164,7 @@ jobs:
 
       - name: Run the unit tests
         run: |
-          hatch -v run test:nowarn || hatch run test:nowarn --lf
+          hatch -v run test:nowarn
 
   test_prereleases:
     name: Test Prereleases
@@ -179,7 +179,7 @@ jobs:
           dependency_type: pre
       - name: Run the tests
         run: |
-          hatch run test:nowarn || hatch run test:nowarn --lf
+          hatch run test:nowarn
 
   make_sdist:
     name: Make SDist

.github/workflows/downstream.yml

@@ -104,7 +104,7 @@ jobs:
         shell: bash -l {0}
         run: |
           cd ${GITHUB_WORKSPACE}/..
-          git clone https://github.com/jupyter/qtconsole.git
+          git clone https://github.com/spyder-ide/qtconsole.git
           cd qtconsole
           ${pythonLocation}/bin/python -m pip install -e ".[test]"
           ${pythonLocation}/bin/python -m pip install pyqt5

.readthedocs.yaml

@@ -3,7 +3,7 @@ version: 2
 build:
   os: ubuntu-22.04
   tools:
-    python: "3.11"
+    python: "3.13"
 
 sphinx:
   configuration: docs/conf.py

docs/api/ipykernel.comm.rst

@@ -7,19 +7,19 @@ Submodules
 
 .. automodule:: ipykernel.comm.comm
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.comm.manager
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 Module contents
 ---------------
 
 .. automodule:: ipykernel.comm
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:

docs/api/ipykernel.inprocess.rst

@@ -7,49 +7,49 @@ Submodules
 
 .. automodule:: ipykernel.inprocess.blocking
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.inprocess.channels
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.inprocess.client
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.inprocess.constants
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.inprocess.ipkernel
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.inprocess.manager
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.inprocess.socket
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 Module contents
 ---------------
 
 .. automodule:: ipykernel.inprocess
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:

docs/api/ipykernel.rst

@@ -16,115 +16,145 @@ Submodules
 
 .. automodule:: ipykernel.compiler
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.connect
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.control
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.debugger
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.displayhook
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.embed
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.eventloops
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.heartbeat
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.iostream
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.ipkernel
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.jsonutil
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.kernelapp
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.kernelbase
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.kernelspec
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.log
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.parentpoller
    :members:
+   :undoc-members:
    :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:
    :show-inheritance:
+
+
+.. automodule:: ipykernel.utils
+   :members:
    :undoc-members:
+   :show-inheritance:
 
 
 .. automodule:: ipykernel.zmqshell
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:
 
 Module contents
 ---------------
 
 .. automodule:: ipykernel
    :members:
-   :show-inheritance:
    :undoc-members:
+   :show-inheritance:

ipykernel/control.py

@@ -1,32 +1,11 @@
 """A thread for a control channel."""
-from threading import Thread
 
-from tornado.ioloop import IOLoop
+from .thread import CONTROL_THREAD_NAME, 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.io_loop = IOLoop(make_current=False)
-        self.pydev_do_not_trace = True
-        self.is_pydev_daemon_thread = True
-
-    def run(self):
-        """Run the thread."""
-        self.name = CONTROL_THREAD_NAME
-        try:
-            self.io_loop.start()
-        finally:
-            self.io_loop.close()
-
-    def stop(self):
-        """Stop the thread.
-
-        This method is threadsafe.
-        """
-        self.io_loop.add_callback(self.io_loop.stop)
+        super().__init__(name=CONTROL_THREAD_NAME, **kwargs)

ipykernel/ipkernel.py

@@ -361,6 +361,11 @@ def set_sigint_result():
             # restore the previous sigint handler
             signal.signal(signal.SIGINT, save_sigint)
 
+    @contextmanager
+    def _dummy_context_manager(self, *args):
+        # Signals only work in main thread, so cannot use _cancel_on_sigint in subshells.
+        yield
+
     async def execute_request(self, stream, ident, parent):
         """Override for cell output - cell reconciliation."""
         parent_header = extract_header(parent)
@@ -439,7 +444,12 @@ async def run_cell(*args, **kwargs):
 
                 coro_future = asyncio.ensure_future(coro)
 
-                with self._cancel_on_sigint(coro_future):
+                cm = (
+                    self._cancel_on_sigint
+                    if threading.current_thread() == threading.main_thread()
+                    else self._dummy_context_manager
+                )
+                with cm(coro_future):  # type:ignore[operator]
                     res = None
                     try:
                         res = await coro_future