Question

此aiohttp服务器在线程中的示例失败，并显示RuntimeError: There is no current event loop in thread 'Thread-1'.错误：

import threading
from aiohttp import web


def aiohttp_server():
    def say_hello(request):
        return web.Response(text='Hello, world')

    app = web.Application(debug=True)
    app.add_routes([web.get('/', say_hello)])
    web.run_app(app)


t = threading.Thread(target=aiohttp_server)
t.start()

如何在线程中运行aiohttp服务器？

Answer 1

我们必须在主线程中使用app.make_handler处理程序，例如：

import asyncio
import threading
from aiohttp import web

loop = asyncio.get_event_loop()


def say_hello(request):
    return web.Response(text='Hello, world')


app = web.Application(debug=True)
app.add_routes([web.get('/', say_hello)])

handler = app.make_handler()
server = loop.create_server(handler, host='127.0.0.1', port=8080)


def aiohttp_server():
    loop.run_until_complete(server)
    loop.run_forever()


t = threading.Thread(target=aiohttp_server)
t.start()

Answer 2

在主线程中创建handler，然后在子线程中手动创建事件循环。

import asyncio
import threading
from aiohttp import web


def aiohttp_server():
    def say_hello(request):
        return web.Response(text='Hello, world')

    app = web.Application(debug=True)
    app.add_routes([web.get('/', say_hello)])
    handler = app.make_handler()
    return handler


def run_server(handler):
    loop = asyncio.new_event_loop()
    asyncio.set_event_loop(loop)
    server = loop.create_server(handler, host='127.0.0.1', port=8089)
    loop.run_until_complete(server)
    loop.run_forever()


t = threading.Thread(target=run_server, args=(aiohttp_server(),))
t.start()

Answer 3

针对此用例有一个新的API：

https://docs.aiohttp.org/en/stable/web_advanced.html#application-runners

from aiohttp import web
import asyncio


async def healthz(request):
    return web.Response(text="OK")

app = web.Application()
app.add_routes([web.get("/", healthz)])


async def runner():
    runner = web.AppRunner(app)
    await runner.setup()
    site = web.TCPSite(runner, "localhost", 8080)
    await site.start()


loop = asyncio.get_event_loop()
loop.run_until_complete(runner())

Answer 4

可以使用web.run_app，只需创建一个新的事件循环（并设置handle_signals=False来避免RuntimeError: set_wakeup_fd only works in main thread）：

import threading
import asyncio
from aiohttp import web

def aiohttp_server():
    def say_hello(request):
        return web.Response(text='Hello, world')

    asyncio.set_event_loop(asyncio.new_event_loop())  # create a new event loop here
    app = web.Application(debug=True)
    app.add_routes([web.get('/', say_hello)])
    web.run_app(app, handle_signals=False)

如何在线程中运行aiohttp服务器？

4 个答案: