Curio does not correctly handle the windows OSError that is raised when select is called with empty lists since python 3.10.5

Steps to reproduce:

On windows, install python 3.10.5
Run the following:

In [1]: import curio

In [2]: async def f():
   ...:     print("a")
   ...:     await curio.sleep(1)
   ...:     print("b")
   ...:

In [3]: curio.run(f)

This results in the following traceback:

---------------------------------------------------------------------------
OSError                                   Traceback (most recent call last)
File C:\path\to\some\venv\lib\site-packages\curio\kernel.py:822, in run(corofunc, with_monitor, selector, debug, activations, *args, **kernel_extra)
    821 with kernel:
--> 822     return kernel.run(corofunc, *args)

File C:\path\to\some\venv\lib\site-packages\curio\kernel.py:146, in Kernel.run(self, corofunc, shutdown, *args)
    145 if coro or not shutdown:
--> 146     task = self._runner(coro)
    147     if task:

File C:\path\to\some\venv\lib\site-packages\curio\kernel.py:641, in Kernel._make_kernel_runtime.<locals>.kernel_run(***failed resolving arguments***)
    640 try:
--> 641     events = selector_select(timeout)
    642 except OSError as e:
    643     # If there is nothing to select, windows throws an
    644     # OSError, so just set events to an empty list.

File ~\AppData\Local\Programs\Python\Python310\lib\selectors.py:325, in SelectSelector.select(self, timeout)
    324 try:
--> 325     r, w, _ = self._select(self._readers, self._writers, [], timeout)
    326 except InterruptedError:

File ~\AppData\Local\Programs\Python\Python310\lib\selectors.py:315, in SelectSelector._select(self, r, w, _, timeout)
    314 print(r, w, _, timeout)
--> 315 r, w, x = select.select(r, w, w, timeout)
    316 return r, w + x, []

OSError: [WinError 10022] An invalid argument was supplied

During handling of the above exception, another exception occurred:

OSError                                   Traceback (most recent call last)

The reason for this is the handling of OSError in kernel.py:645

The problem is that in 3.10.5, the error codes that get set changed. From the changelog:

bpo-46775: Some Windows system error codes(>= 10000) are now mapped into the correct errno and may now raise a subclass of OSError. Patch by Dong-hee Na.

This is the linked issue in cpython: https://github.com/python/cpython/issues/90931

In this case, checking e.errno against errno.WSAEINVAL is no longer sufficent.

I propose changing this:

            try:
                events = selector_select(timeout)
            except OSError as e:
                # If there is nothing to select, windows throws an
                # OSError, so just set events to an empty list.
                if e.errno != getattr(errno, 'WSAEINVAL', None):
                    raise
                events = []

to:

            try:
                events = selector_select(timeout)
            except OSError as e:
                # If there is nothing to select, windows throws an
                # OSError, so just set events to an empty list.
                wsaeinval = getattr(errno, 'WSAEINVAL', None)
                einval = getattr(errno, 'EINVAL', None)
                if e.errno not in (wsaeinval, einval):
                    raise
                events = []

I've made this in my fork and it corrected the issue. I am happy to to submit a PR with this change.

Cheers

dabeaz / curio

Curio does not correctly handle the windows OSError that is raised when select is called with empty lists since python 3.10.5 #353