Long SSL handshake on a connection freezes whole server

[bmourgues]

❓ I'm submitting a ...

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

🐞 Describe the bug. What is the current behavior?
When a SSL handshake takes some time, cheroot stop responding to new requests

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

💡 To Reproduce
Configure cheroot using its ssl builtin adapter

Steps to reproduce the behavior:

1. Start cheroot SSL, increasing its timeout to 300s for example
2. Launch a simple telnet on host and port of cheroot server from a terminal
3. cheroot does not respond anymore to other requests

💡 Expected behavior
cheroot should be able to take new connections while ssl handshake negociation on other connections

📋 Details

📋 Environment

• Cheroot version: 10.0.1
• Python version: 3.11.11
• OS: Linux (any)

📋 Additional context

[bmourgues]

As a workaround, we have built a monkey patch which delegates ssl_handshake job to worker threads. Here is the code, in case it may help someone :
cheroot_monkey_patch.txt

[webknjaz]

Could you send that as a pull request?

[bmourgues]

I have built a pull request (all feedback is welcome), I hope this may help

[webknjaz]

I just realized that another pre-existing issue probably reports the same thing. So I'm closing this as a duplicate of #709. Feel free to post any extra context over there so we could track this bug in one place.