Is safe to remove value from list in asyncio

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Example Code

class ConnectionManager:
    def __init__(self):
        self.active_connections: List[WebSocket] = []

    async def connect(self, websocket: WebSocket):
        await websocket.accept()
        self.active_connections.append(websocket)

    def disconnect(self, websocket: WebSocket):
        self.active_connections.remove(websocket)

    async def send_personal_message(self, message: str, websocket: WebSocket):
        await websocket.send_text(message)

    async def broadcast(self, message: str):
        for connection in self.active_connections:
            await connection.send_text(message)

Description

I find the example from doc.

I am wondering that it is safe to remove value from list.In this example, when websocketA broadcast message, await websocketB.send_text(message), websocketB is disconnect, what would happen?

Operating System

Linux

Operating System Details

No response

FastAPI Version

0.78.0

Python Version

python3.8.13

Additional Context

No response

[JarroVGIT]

I would disagree with that statement. The purpose of the code block is to give an example on how to handle multiple connections and disconnects. It’s purpose is not to demonstrate how that should work in a threadsafe manner.

The code as-is, is perfectly safe to use. If you need multithreading or multiprocessing, then it is up to the developer to think about the ramifications and thing like race conditions. I don’t feel that should be very explicit in the examples though, as it just might confuse people more rather than helping the point of explaining how websockets work in FastAPI

[xiazhibin]

Yes， as a example it’s pretty good! Thanks