Uvicorn在接受连接之前直接关闭连接时不关闭连接答案

【问题标题】：Uvicorn not closing connection when directly closing connection before accepting connectionUvicorn在接受连接之前直接关闭连接时不关闭连接
【发布时间】：2019-05-21 15:47:37
【问题描述】：

我正在使用带有 uvicorn 的 Django 频道，并且我有以下类型的代码：

async def connect(self): 
    """Accept connect if user has been provided by middleware"""  
    self.user = self.scope.get('user') 
    if self.user: 
        await self.accept() 
    else: 
        await self.close()

基本上，如果在通过中间件之后如果没有使用，我将关闭连接。当我用 Daphne 运行它时，它工作得非常好。否则，当我通过 uvicorn 服务器运行它时，它会抛出以下错误：

ERROR: Exception in ASGI application
Traceback (most recent call last):
  File "/home/coldbrewtech/frnd/backend/env/lib/python3.6/site-packages/uvicorn/protocols/websockets/websockets_impl.py", line 146, in run_asgi
    result = await self.app(self.scope, self.asgi_receive, self.asgi_send)
  File "/home/coldbrewtech/frnd/backend/env/lib/python3.6/site-packages/uvicorn/middleware/asgi2.py", line 7, in __call__
    await instance(receive, send)
  File "/home/coldbrewtech/frnd/backend/env/lib/python3.6/site-packages/channels/consumer.py", line 59, in __call__
    [receive, self.channel_receive], self.dispatch
  File "/home/coldbrewtech/frnd/backend/env/lib/python3.6/site-packages/channels/utils.py", line 59, in await_many_dispatch
    await task
  File "/home/coldbrewtech/frnd/backend/env/lib/python3.6/site-packages/channels/utils.py", line 51, in await_many_dispatch
    result = task.result()
  File "/home/coldbrewtech/frnd/backend/env/lib/python3.6/site-packages/uvicorn/protocols/websockets/websockets_impl.py", line 226, in asgi_receive
    data = await self.recv()
  File "/home/coldbrewtech/frnd/backend/env/lib/python3.6/site-packages/websockets/protocol.py", line 419, in recv
    return_when=asyncio.FIRST_COMPLETED,
  File "/usr/lib/python3.6/asyncio/tasks.py", line 311, in wait
    fs = {ensure_future(f, loop=loop) for f in set(fs)}
  File "/usr/lib/python3.6/asyncio/tasks.py", line 311, in <setcomp>
    fs = {ensure_future(f, loop=loop) for f in set(fs)}
  File "/usr/lib/python3.6/asyncio/tasks.py", line 526, in ensure_future
    raise TypeError('An asyncio.Future, a coroutine or an awaitable is '
TypeError: An asyncio.Future, a coroutine or an awaitable is required

但是当我在await self.close() 之前添加await self.accept() 时，它不会抛出任何错误。谁能帮我解决这个问题。

提前致谢！！！

【问题讨论】：

Uvicorn 问题同样的错误：github.com/encode/uvicorn/issues/415

标签： django django-channels daphne uvicorn

【解决方案1】：

这显然是一个issue in channels，其中close() 方法尚未准备好在套接字设置期间被调用。

从我在问题中看到的内容来看，解决方案正是您正在做的，即先接受连接然后关闭它。

【讨论】：