Should the new _serve_unservicable thread be daemon?

[manthey]

❓ I'm submitting a ...

• 🐞 bug report
• 🐣 feature request
• ❓ question about the decisions made in the repository

🐞 Describe the bug. What is the current behavior?
The most recent change in 11.0.0 that added a non-daemon thread makes the library harder to use through pytest. Specifically, I have an existing project that uses pytest to create a server in a fixture, and this thread is not closing at the end of pytest. I can hack around it by disabling the new feature (cheroot.server.HTTPServer._serve_unservicable = lambda: None), but this definitely feels wrong.

❓ What is the motivation / use case for changing the behavior?

I think that if the _serve_unservicable thread was daemon it would make using this in tests easier. The side effect is that when shutting down a server it wouldn't drain the 503 responses; but prior to 11.x those didn't exist.

💡 To Reproduce
Steps to reproduce the behavior:

I assume in my tests where I start and stop a server, some request is getting queued after I ask the server to stop and this test, rather than that being ignored is stopping the process from stopping.

💡 Expected behavior
I'd like to be able to start and stop servers in pytest fixtures without worrying about exact timing from client tests.

📋 Environment

• Cheroot version: 11.0
• CherryPy version: 18.10.0
• Python version: 3.9 through 3.13
• OS: Ubuntu

[manthey]

If in a pytest fixture using cherrypy, I've unsubscribed to cherrypy.engine events and called cherrypy.engine.stop() and cherrypy.engine.exit(), is there something more I need to do to ensure stopping with the current code? If not, either the unservicable thread should be daemonized or there should be some other mechanism to stop things.

[nijel]

Hitting issue with this thread as well translate/translate#5709 as well. The _serve_unservicable thread keeps running even after calling Server.stop().

[webknjaz]

@itamarst mentioned that it'd be useful @ #745 (comment).

Does anybody want to put a pull request up for discussion?