[英]asyncio - launching infinite loop.create_connection()
I've been trying trying with no luck to create a endless chain of client instances. 我一直在尝试尝试创建无尽的客户端实例链。
I'm developing an asyncio app, this app among many others things, like running a server with loop.create_server(), needs every 10 seconds to connect to a list of servers, send some data and then disconnect. 我正在开发一个异步应用程序,该应用程序还有很多其他事情,例如使用loop.create_server()运行服务器,需要每10秒连接到服务器列表,发送一些数据然后断开连接。
I keep getting 2 errors: "runtimeError: Event loop is running." 我不断收到2个错误:“ runtimeError:事件循环正在运行。” or "asyncio > Task was destroyed but it is pending!"
或“异步>任务已销毁,但仍在等待中!”
The code down below works. 下面的代码有效。
import asyncio
from tcp.client import Client
def send_to_peers(data):
for index in range(1, 3): #this for-loop just for simulating a list of peers
try:
loop = asyncio.get_event_loop()
coro = loop.create_connection(lambda: Client(), '127.0.0.1', 10000 + index)
_, proto = loop.run_until_complete(coro)
msg = data + "-" + str(index) + "\n"
proto.transport.write(str.encode(msg))
proto.transport.close()
except ConnectionRefusedError as exc:
print(exc)
def infinite():
for index in range(5): #again this should be a While True:
#there should be here an asyncio.sleep(10)
send_to_peers(str(index))
infinite()
But when I call it from the main_loop things start to break. 但是当我从main_loop调用它时,事情开始崩溃。
async def infinite_loop():
for index in range(5):
print("loop n " + str(index))
task = asyncio.Task(send_to_peers(str(index)))
await asyncio.sleep(10)
task.cancel()
with suppress(asyncio.CancelledError):
await task
main_loop = asyncio.get_event_loop()
main_loop.run_until_complete(infinite_loop())
main_loop.run_forever()
I've tried to giving the main_loop to send_to_peers , giving it to the Client(loop) class,I tried to stoop & close the loop, delete the task, use weird combination of ensure_future but nothing works. 我试图将main_loop赋予send_to_peers,将其提供给Client(loop)类,我试图弯腰并关闭循环,删除任务,使用sure_future的怪异组合,但没有任何效果。
I googled as much as I could, I read it is not good to nest infinite loops but i didn't find any other way. 我尽可能地用Google搜索,我读到嵌套无限循环不好,但是我没有找到其他方法。
My last hope is to use threading but even if I think it will work, it won't be an elegant solution, nor the right one. 我最后的希望是使用线程,但是即使我认为它可以工作,也不会是一个优雅的解决方案,也不是一个正确的解决方案。
I'm used to work with Node so please excuse me if i made a silly mistake, I thought that after 2 weeks i could make it but here I am. 我曾经和Node一起工作过,所以如果我犯了一个愚蠢的错误,请原谅,我认为两周后我可以做到,但是我来了。
I would really appreciate any help. 我真的很感谢您的帮助。 I'm stuck.
我被卡住了。 Thanks!
谢谢!
PS: The Client() class is very basic: PS:Client()类非常基础:
import asyncio
import logging
import sys
logging.basicConfig(
level=logging.DEBUG,
format='%(name)s > %(message)s',
stream=sys.stderr
)
class Client(asyncio.Protocol):
def __init__(self):
self.log = logging.getLogger('client')
self.address = None
self.transport = None
def connection_made(self, transport):
self.transport = transport
self.address = transport.get_extra_info('peername')
self.log.debug('{}:{} connected'.format(*self.address))
def data_received(self, data):
self.log.debug('{}:{} just sent {!r}'.format(*self.address, data))
def eof_received(self):
self.log.debug('{}:{} sent EOF'.format(*self.address))
def connection_lost(self, error=""):
self.log.debug('{}:{} disconnected'.format(*self.address))
self.transport.close()
I keep getting 2 errors: "runtimeError: Event loop is running."
我不断收到2个错误:“ runtimeError:事件循环正在运行。” or "asyncio > Task was destroyed but it is pending!"
或“异步>任务已销毁,但仍在等待中!”
As you discovered, asyncio event loops do not nest . 如您所见,asyncio事件循环不嵌套 。
To remove the nesting, you should define send_to_peers
as a coroutine using async def
. 要删除嵌套,您应该使用
async def
将send_to_peers
定义为协程。 Inside it loop.run_until_complete(coro)
should be changed to await coro
. 在它里面
loop.run_until_complete(coro)
应该更改为loop.run_until_complete(coro)
await coro
。 Once send_to_peers
is a coroutine, you can call it: 一旦
send_to_peers
是一个协程,就可以调用它:
from blocking code such as infinite
using loop.run_until_complete(send_to_peers(...))
使用
loop.run_until_complete(send_to_peers(...))
阻止代码infinite
from async code such as infinite_loop
using await send_to_peers(...)
. 从异步代码(例如
infinite_loop
使用await send_to_peers(...)
。
In case of infinite_loop
, you can implement the timeout using asyncio.wait_for
: 如果是
infinite_loop
,则可以使用asyncio.wait_for
实现超时:
try:
await asyncio.wait_for(send_to_peers(str(index)), 10)
except asyncio.TimeoutError:
# ... timeout ...
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