Fix event loop handling

[blink1073]

Fixes jupyter/jupyter_client#959

Fixes spyder-ide/spyder#21338

[blink1073]

cc @maartenbreddels this was a nice typing cleanup. :)

[blink1073]

I'll make the release tomorrow.

[maartenbreddels]

Nice indeed :)

[samuelan]

I have some codes that use run_sync(coroutine_a), and with jupyter_core==5.3.2, it stops working. The code complains
File "/opt/conda/lib/python3.9/site-packages/jupyter_core/utils/init.py", line 168, in wrapped
return loop.run_until_complete(inner)
File "/opt/conda/lib/python3.9/asyncio/base_events.py", line 623, in run_until_complete
self._check_running()
File "/opt/conda/lib/python3.9/asyncio/base_events.py", line 583, in _check_running
raise RuntimeError('This event loop is already running')
RuntimeError: This event loop is already running

once I revert to 5.3.1 version. It started to work. Do codes that depend on jupyter_core need to change after this change, any documentation?

[blink1073]

Hi @samuelan, can you please open a new issue with some code that reproduces the error?

[samuelan]

Hi @samuelan, can you please open a new issue with some code that reproduces the error?

Sure. It's a bit involved. I will try a repro with simplified codes, and circle back when I get it.

[tornaria]

Do you actually want loop = asyncio.get_running_loop() here?

According to https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.get_event_loop this is deprecated in python 3.12 and will emit https://docs.python.org/3/library/asyncio-eventloop.html#asyncio.get_event_loop. This causes some test failures (e.g. in jupyter_client).

[tornaria]

What I suggested above does fix the test failures in jupyter_client I was getting, at the expense of causing other test failures in jupyter_client.

The only thing that makes the jupyter_client testsuite pass (on python 3.12) is reverting the current PR. I'll downgrade to jupyter_core 5.3.1 for the time being.

[blink1073]

Thanks for the heads up @tornaria, I opened #367