Seems datachannel.send() blocked by reading channel

while True in rtcsctptransport.py blocks event loop if queue full on receive here

My suggestion is to rewrite it using asyncio.Queue but it is not trivial

[lgrahl]

^ FYI: I might actually pick this up at some point and implement it myself. Don’t rely on it though. 😺

[lgrahl]

Something like this:

class DataChannel:
    def __init__():
        self._send_queue = asyncio.Queue(maxsize=1)
        self._receive_queue = asyncio.Queue(maxsize=1)

    async def send(message: bytes = None) -> Union[None, asyncio.StreamWriter]:
        result = None
        if message is None:
            result = message = asyncio.StreamWriter(...)
        else:
            # This would need to create a task
            message = bytes_to_stream(message)
        await self._send_queue.put(message)
        return result

    async def receive(as_bytes: bool = False) -> Union[bytes, asyncio.StreamReader]:
        message = await self._receive_queue.get()
        if as_bytes:
            message = await stream_to_bytes(message)
        return message

If the user is interested in controlling the flow in its fullest form, it needs to use streams for messages. Otherwise, if it expects message size to not be an issue, it can also utilise bytes.

send could also be split up into send(message: Union[bytes, asyncio.StreamWriter]) and create_message() -> asyncio.StreamWriter.