Asyncio Queue maxsize parameter is not being used

[V-H-R-Oliveira]

Bug report

Bug description:

Hello, in the Asyncio Queue class the maxsize argument is not being used, so it seems to always create an unbounded queue.

If it is a bug, the solution is very simple: self._queue = collections.deque(maxsize)

Current implementation:
https://github.com/python/cpython/blob/e68d4b08ff13a06a2c2877f63bf856e6bf3c2e77/Lib/asyncio/queues.py#L33C1-L61C42

CPython versions tested on:

3.12

Operating systems tested on:

Windows

[zware]

Thanks for the report!

However, I don't believe we want to make any change here. When a deque reaches maxlen, adding anything else to it discards items from the other end, which we never want from a Queue. The queue manages its own size separately, and there's no significant advantage to limiting the size of a deque.

Please correct me if I've misunderstood the suggestion, but I'm going to go ahead and close the issue.