# Core Library

from typing import TypeVar, Callable

from typing_extensions import ParamSpec

# Third party

from anyio import Semaphore

from starlette.concurrency import run_in_threadpool

​

# To not have too many threads running (which could happen on too many concurrent

# requests, we limit it with a semaphore.

MAX_CONCURRENT_THREADS = 10

MAX_THREADS_GUARD = Semaphore(MAX_CONCURRENT_THREADS)

T = TypeVar("T")

P = ParamSpec("P")

​

​

async def run_async(func: Callable[P, T], *args: P.args, **kwargs: P.kwargs) -> T:

    async with MAX_THREADS_GUARD:

        return await run_in_threadpool(func, args, kwargs)