Kernel Stop Fix

[rakhmaevao]

Hello. I found this floating problem. If you start sessions and stop them, then the 500th error occurs (see the tracing and video below).

Screencast.from.2025-03-08.14-37-26.mp4

  File "/home/rakhmaevao/Projects/jupyverse/plugins/kernels/fps_kernels/kernel_server/server.py", line 137, in start
    await self._wait_for_ready()
  File "/home/rakhmaevao/Projects/jupyverse/plugins/kernels/fps_kernels/kernel_server/server.py", line 233, in _wait_for_ready
    msg = await receive_message(self.iopub_channel, timeout=0.2)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/rakhmaevao/Projects/jupyverse/plugins/kernels/fps_kernels/kernel_driver/message.py", line 136, in receive_message
    ready = await sock.apoll(timeout).wait()
                  ^^^^^^^^^^^^^^^^^^^
  File "/home/rakhmaevao/.local/share/hatch/env/virtual/jupyverse/u_XNhuOG/dev.jupyterlab-auth/lib/python3.12/site-packages/zmq_anyio/_socket.py", line 503, in apoll
    self._check_started()
  File "/home/rakhmaevao/.local/share/hatch/env/virtual/jupyverse/u_XNhuOG/dev.jupyterlab-auth/lib/python3.12/site-packages/zmq_anyio/_socket.py", line 939, in _check_started
    self._task_group.start_soon(self._start)
  File "/home/rakhmaevao/.local/share/hatch/env/virtual/jupyverse/u_XNhuOG/dev.jupyterlab-auth/lib/python3.12/site-packages/anyio/_backends/_asyncio.py", line 880, in start_soon
    self._spawn(func, args, name)
  File "/home/rakhmaevao/.local/share/hatch/env/virtual/jupyverse/u_XNhuOG/dev.jupyterlab-auth/lib/python3.12/site-packages/anyio/_backends/_asyncio.py", line 832, in _spawn
    raise RuntimeError(
RuntimeError: This task group is not active; no new tasks can be started

I fixed this error (see plugins/kernels/fps_kernels/kernel_server/server.py). I guarantee that sockets will close. Now the problem is gone.

To eliminate this problem in the future, I wrote a test. This test is e2e. That's why I put it in a separate package. I want to expand the tests in the future. I have a few more cases that I found. But first I want to make sure that you like this way of fixing bugs. The method is to write tests.

I also added the CONTRIBUTING.md file. I think this will help the community.

I also deleted the .fileid.db file and moved it to .gitignore. It may have ended up in the index by accident.