Backend specific options don't appear to be used

[DaGenix]

Things to check first

• I have searched the existing issues and didn't find my bug already reported there

• I have checked that my bug is still present in the latest release

AnyIO version

4.1.0

Python version

3.11

What happened?

As best as I can tell, the backend specific options for both the asyncio and trio options aren't being used

anyio/src/anyio/_backends/_asyncio.py

Lines 1939 to 1960 in cc18942

	def run(
	cls,
	func: Callable[..., Awaitable[T_Retval]],
	args: tuple,
	kwargs: dict[str, Any],
	options: dict[str, Any],
	) -> T_Retval:
	@wraps(func)
	async def wrapper() -> T_Retval:
	task = cast(asyncio.Task, current_task())
	task.set_name(get_callable_name(func))
	_task_states[task] = TaskState(None, None)
	try:
	return await func(*args)
	finally:
	del _task_states[task]
	debug = options.get("debug", False)
	options.get("loop_factory", None)
	options.get("use_uvloop", False)
	return native_run(wrapper(), debug=debug)

anyio/src/anyio/_backends/_trio.py

Lines 807 to 814 in cc18942

	def run(
	cls,
	func: Callable[..., Awaitable[T_Retval]],
	args: tuple,
	kwargs: dict[str, Any],
	options: dict[str, Any],
	) -> T_Retval:
	return trio.run(func, *args)

How can we reproduce the bug?

I'm sorry if I'm missing something, but the backend options don't appear to be used, except for debug for asyncio. I don't have a test case, however, so, I apologize again if I'm not seeing how the options are getting applied.

[agronholm]

What backend options are you trying to pass?

[DaGenix]

I was looking into enabling the uvloop option and was overall interested in which options where available. But, looking at the code, it appeared that the options weren't being used.

[agronholm]

On the asyncio backend, the debug, loop_factory and use_uvloop options are used, as indicated in the code you pasted. What other options are you looking to pass?

[DaGenix]

@agronholm In the code I posted, the only mention of use_uvloop is:

     options.get("use_uvloop", False) 

Which fetches it from the options dictionary, but then does nothing with the value.

I'm not super familiar with the anyio code, however, so, I apologize if its being used somewhere else.

However, I tried the following test program:

import anyio
import asyncio


async def inside_asyncio() -> None:
    print(asyncio.get_running_loop())


anyio.run(inside_asyncio, backend_options={"use_uvloop": True})

When I run the above with anyio 3.7.1, it prints out:

<uvloop.Loop running=True closed=False debug=False>

However, when I run it with 4.1.0, it prints out:

<_UnixSelectorEventLoop running=True closed=False debug=False>

[agronholm]

Oh wow, I didn't see that. So apparently while they are used for the test runner, they're ignored for anyio.run(). This is a big oversight. I'll get this sorted out for the next release.

[agronholm]

@DaGenix I trust that the linked PR fixes the issue? Would you mind taking a peek?

[DaGenix]

@agronholm cool. that looks good to me!