feat(serve): Add graceful Ctrl+C handling with exit message

[revidious]

Graceful Ctrl+C Handling

Implements reliable Ctrl+C handling for BAML's Python interface with a clean shutdown message. This fixes issues with signal handling across the Python/Rust boundary and improves user experience when stopping BAML processes.

Changes

• Added custom signal handling using the ctrlc crate
• Implemented clean "Shutting Down BAML..." message on interrupt
• Bypassed Python's signal handling to ensure reliable behavior
• Added proper exit code (130) following Unix conventions
• Added detailed documentation explaining the implementation

Testing

• Tested Python CLI server start/stop
• Manual Ctrl+C testing in various scenarios
• Verified clean shutdown message display
• Tested cross-platform signal handling behavior

Technical Details

• Uses ctrlc crate for reliable cross-platform signal handling
• Implements channel-based communication between signal handler and main thread
• Follows Unix conventions for interrupt handling (exit code 130)
• Properly documented implementation rationale and technical decisions

Notes

• While this is a workaround, it provides reliable interrupt handling without requiring major architectural changes
• The implementation bypasses Python's signal handling entirely to avoid conflicts
• Future improvements could involve deeper integration with BAML's architecture

---

Important

Enhances BAML's Python interface with reliable Ctrl+C handling and clean shutdown message using the ctrlc crate.

• Behavior:
  • Implements custom signal handling to bypass Python's signal handlers
  • Displays "Shutting Down BAML..." message on interrupt
  • Ensures proper process termination with standard exit codes
• Implementation:
  • Uses ctrlc crate for cross-platform signal handling
  • Implements channel-based communication for safe signal handling
  • Follows Unix conventions with exit code 130 for SIGINT

^{This description was created by for the latest commit. It will automatically update as commits are pushed.}

[vercel]

@revidious is attempting to deploy a commit to the Gloo Team on Vercel.

A member of the Team first needs to authorize it.

[sxlijin]

Started a discussion thread in https://discord.com/channels/1119368998161752075/1316923453814734959 - I have some questions about how this plays with pyo3 and different architectures (it sounds like we handle this fine in N-API world?)

Thanks for digging into this!

[sxlijin]

This is clever! Nice work with this

We could use a oneshot channel for the signal but I really like this - on the one hand spawning an additional thread feels overkill, but it's also a neat way to avoid wiring in Python::check_signals everywhere

[vercel]

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Name	Status	Preview	Comments	Updated (UTC)
baml	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Dec 18, 2024 6:06pm

[sxlijin]

Sorry for the delay! I was in a GitHub beta for a new UI and couldn't figure out how to trigger workflows on your PR (maintainers need to explicitly approve PRs from new contributors)

[sxlijin]

Hmm - looks like I can't push to your branch to update Cargo.lock. Can you commit that change?