Add debug features to moq-native

[kixelated]

Summary

• Add tokio-console feature for async task debugging
• Add parking_lot deadlock detector (debug builds only)
• Improve logging configuration with layered tracing subscriber

Details

tokio-console Support

• Opt-in feature flag: --features moq-native/tokio-console
• Spawns console-subscriber layer when enabled
• No impact on default builds

Deadlock Detection

• Automatically enabled in debug builds via cfg(debug_assertions)
• Uses parking_lot's deadlock detector
• Checks for deadlocks every 1 second
• Logs detailed information with thread IDs and backtraces
• Zero overhead in release builds

Logging Improvements

• Migrated to layered tracing subscriber architecture
• Added log directives for tokio and runtime crates
• Maintains backwards compatibility

Test Plan

• Verify compilation without features: cargo check --workspace
• Verify compilation with tokio-console: cargo check --workspace --features moq-native/tokio-console
• Verify deadlock detector compiles in debug mode
• Confirm no impact on release builds

🤖 Generated with Claude Code

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📥 Commits

Reviewing files that changed from the base of the PR and between 576d3f1 and 0b1a38a.

⛔ Files ignored due to path filters (1)

• Cargo.lock is excluded by !**/*.lock

📒 Files selected for processing (2)

• justfile
• rs/moq-native/src/log.rs

Walkthrough

Removed the container property from audio and video codec entries in the TypeScript broadcast config. Refactored Rust logging to use tracing_subscriber layers, added optional tokio-console integration controlled by a feature, and added a debug-only parking_lot deadlock detector thread. Cargo metadata and .cargo/config.toml were updated to enable the tokio-console feature and a tokio-related cfg flag. The justfile was updated to set TOKIO_CONSOLE_BIND for relay and publisher targets, added relay-console and pub-console targets, and the web target now runs from js/hang-demo.

Pre-merge checks and finishing touches

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'Add debug features to moq-native' accurately captures the main objective: introducing debugging features (tokio-console and deadlock detection) to the moq-native crate.
Description check	✅ Passed	The description comprehensively covers all major changes in the PR, including tokio-console support, deadlock detection, and logging improvements, with clear details and test verification.

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Actionable comments posted: 0

🧹 Nitpick comments (1)

rs/moq-native/src/log.rs (1)

60-83: Approve deadlock detection implementation with optional clarity improvement.

The debug-only deadlock detector is well-implemented: properly scoped to debug builds, provides detailed logging, and uses appropriate polling interval.

💡 Optional: Clarify the commented abort suggestion

The commented std::process::abort() could benefit from additional context about when developers should uncomment it:

-						// Optionally: std::process::abort() to get a core dump
+						// Uncomment to abort and generate a core dump for post-mortem analysis:
+						// std::process::abort();

📜 Review details

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 6064eb0 and 77ca6dd.

⛔ Files ignored due to path filters (1)

• Cargo.lock is excluded by !**/*.lock

📒 Files selected for processing (3)

• js/hang/src/publish/element.ts
• rs/moq-native/Cargo.toml
• rs/moq-native/src/log.rs

💤 Files with no reviewable changes (1)

• js/hang/src/publish/element.ts

🧰 Additional context used

📓 Path-based instructions (2)

rs/**/Cargo.toml

📄 CodeRabbit inference engine (CLAUDE.md)

For Rust development, use the workspace configuration in rs/Cargo.toml

Files:

• rs/moq-native/Cargo.toml

**/*.rs

📄 CodeRabbit inference engine (CLAUDE.md)

In Rust crates, tests should be integrated within source files using inline test modules

Files:

• rs/moq-native/src/log.rs

🧠 Learnings (1)

📚 Learning: 2025-12-10T04:00:14.871Z

Learnt from: CR
Repo: moq-dev/moq PR: 0
File: CLAUDE.md:0-0
Timestamp: 2025-12-10T04:00:14.871Z
Learning: Applies to rs/**/Cargo.toml : For Rust development, use the workspace configuration in `rs/Cargo.toml`

Applied to files:

• rs/moq-native/Cargo.toml

🔇 Additional comments (6)

rs/moq-native/Cargo.toml (3)

18-18: LGTM! Feature flag properly configured.

The tokio-console feature correctly uses the dep: prefix to enable the optional console-subscriber dependency.

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23-23: Version 0.5 is already the latest release of console-subscriber (0.5.0, published October 2025) with no known security vulnerabilities. No action required.

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28-28: No action required. Version 0.12 is the current stable release of parking_lot, and there are no known vulnerabilities. The transitive dependency lock_api is at version 0.4.14, which is well above the security fix threshold (0.4.2) for historical CVEs.

Likely an incorrect or invalid review comment.

rs/moq-native/src/log.rs (3)

5-8: LGTM! Imports correctly support layered subscriber architecture.

The new imports enable the composable layer pattern for combining fmt and console subscribers.

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38-40: LGTM! Enhanced log directives improve runtime observability.

The additional directives for tokio and runtime crates provide useful debugging information while maintaining appropriate log levels.

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42-58: LGTM! Layered subscriber architecture properly implemented.

The conditional compilation correctly enables console-subscriber only when the feature is active, while maintaining backwards compatibility with the standard fmt layer.