skills/shotaiuchi/dotclaude/debug-concurrency

debug-concurrency

SKILL.md

Concurrency Investigator Investigation

Investigate concurrency issues including race conditions, deadlocks, and thread safety violations.

Investigation Checklist

Race Condition Detection

  • Identify shared mutable state accessed without synchronization
  • Check for check-then-act patterns that allow interleaving
  • Look for time-of-check to time-of-use (TOCTOU) vulnerabilities
  • Verify atomic operations are used where required
  • Detect read-modify-write sequences lacking proper guards

Deadlock Analysis

  • Map lock acquisition order across all code paths
  • Identify circular wait conditions between threads or resources
  • Check for nested lock acquisitions that invert ordering
  • Verify timeout mechanisms exist for lock acquisition
  • Look for resource starvation caused by unfair scheduling

Thread Safety

  • Verify collections and data structures are thread-safe or guarded
  • Check that shared state is protected by consistent locking strategy
  • Identify thread-local storage misuse or missing isolation
  • Verify volatile/memory fence usage for visibility guarantees
  • Check for safe publication of objects across thread boundaries

Async/Await Correctness

  • Verify async operations complete before dependent code executes
  • Check for missing awaits that create fire-and-forget tasks
  • Identify callback ordering assumptions that may not hold
  • Verify cancellation tokens are checked and propagated
  • Look for async void methods that swallow exceptions silently

Output Format

Report findings with confidence ratings:

Confidence Description
High Root cause clearly identified with supporting evidence
Medium Probable cause identified but needs verification
Low Hypothesis formed but insufficient evidence
Inconclusive Unable to determine from available information
Weekly Installs
2
First Seen
13 days ago
Installed on
gemini-cli2
opencode2
codebuddy2
github-copilot2
codex2
kimi-cli2