Bug report

Bug description:

When writing an asyncio based service, you basically have this sequence:

1. Create an event loop
2. Register a SIGTERM handler
3. Start your server
4. loop.run_forever()
5. SIGTERM causes aloop.stop()
6. Close the server
7. Close event loop

If there are any connections active at this point, then they don't get discarded until interpreter shutdown, with the result that you get a bunch of ResourceWarnings (and cleanup code might not run).

It would be very useful if there was aServer.close_clients() or something like that. Even aServer.all_transports() would be useful, as then you could do something similar as when doing aTask.cancel() on what you get fromloop.all_tasks().

We could poke atServer._transports, but that is something internal that might change in the future.

There isServer.wait_closed(), but that hangs until all clients have gracefully disconnected. It doesn't help us when we want to shut down the servicenow.

CPython versions tested on:

3.12

Operating systems tested on:

Linux

Linked PRs

• gh-113538: Don't crash in stream reader protocol callback when task is cancelled #113690
• [3.12] gh-113538: Don't error in stream reader protocol callback when task is cancelled (GH-113690) #113713
• [3.11] gh-113538: Don't error in stream reader protocol callback when task is cancelled (GH-113690) #113714
• gh-113538: Allow client connections to be closed #114432
• gh-113538: Revert "gh-113538: Add asycio.Server.{close,abort}_clients (#114432)" #116632
• gh-113538: Allow client connections to be closed #116784