import asyncio
from typing import Awaitable, Callable


_queue: asyncio.Queue = asyncio.Queue()


async def enqueue(job: Callable[[], Awaitable[None]]) -> int:
    await _queue.put(job)
    return _queue.qsize()


async def worker():
    while True:
        job = await _queue.get()
        try:
            await job()
        finally:
            _queue.task_done()