uvicorn 是如何监听 HTTP 请求的？

Question

uvicorn/server.py

https://github.com/encode/uvicorn/blob/master/uvicorn/server.py

else:
    # Standard case. Create a socket from a host/port pair.
    try:
        server = await loop.create_server(
            create_protocol,
            host=config.host,
            port=config.port,
            ssl=config.ssl,
            backlog=config.backlog,
        )
    except OSError as exc:
        logger.error(exc)
        await self.lifespan.shutdown()
        sys.exit(1)

    assert server.sockets is not None
    listeners = server.sockets
    self.servers = [server]

if sockets is None:
    self._log_started_message(listeners)
else:
    # We're most likely running multiple workers, so a message has already been
    # logged by `config.bind_socket()`.
    pass

调用 server = await loop.create_server 创建了一个 server 时候，需要调用 server.serve_forever() 才能一直监听吧？

但是没有从 uvicorn 代码中看到有调用 serve_forever 的地方。那么 uvicorn 死循环监听 HTTP 的代码在哪里呢？

---

我为什么有这个疑问，是因为下面的 demo 代码，运行就退出了，不会一直死循环监听

import asyncio
from asyncio.base_events import Server


async def handle_client(reader, writer):
    while True:
        data = await reader.read(100)
        if not data:
            break
        writer.write(data)
    writer.close()


async def main():
    loop = asyncio.get_running_loop()
    server: Server = await loop.create_server(
        handle_client, '127.0.0.1', 8888)


asyncio.run(main())

如果要一直监听，需要加 server.serve_forever()

import asyncio
from asyncio.base_events import Server


async def handle_client(reader, writer):
    while True:
        data = await reader.read(100)
        if not data:
            break
        writer.write(data)
    writer.close()


async def main():
    loop = asyncio.get_running_loop()
    server: Server = await loop.create_server(
        handle_client, '127.0.0.1', 8888)

    async with server:
        await server.serve_forever()

asyncio.run(main())

Answer 1

它的代码中不就有loop = asyncio.get_running_loop()调用么？等于是用了asyncio的event loop事件，在event loop中监听端口的，而asyncio就提供了创建tcp server的方法: https://docs.python.org/3/library/asyncio-eventloop.html#asyn...

它那个create_server不就调用了这个方法？