golang-concurrency-safety

Golang Concurrency Safety

Expert-level concurrency safety review for Go applications. Detects common concurrency bugs that cause production failures, race conditions, deadlocks, and resource leaks.

When to Apply

Use this skill when:

• Reviewing code with goroutines or channels
• Debugging race conditions or deadlocks
• Auditing concurrent data access
• Investigating goroutine leaks or memory issues
• Writing new concurrent code
• Preparing concurrent code for production

Rule Categories by Priority

Priority	Count	Focus
Critical	5	Prevents crashes, leaks, deadlocks
High	4	Correctness and reliability
Medium	3	Code quality and idioms

Rules Covered (12 total)

Critical Issues (5)

• critical-goroutine-leak - Goroutines must have exit conditions
• critical-race-condition - Protect shared state with mutex/channels
• critical-channel-deadlock - Ensure paired send/receive operations
• critical-close-panic - Sender closes channel, not receiver
• critical-defer-in-loop - Avoid defer in loops (resource leaks)

High-Impact Patterns (4)

• high-goroutine-unbounded - Limit concurrent goroutines (worker pool)
• high-channel-not-closed - Always close channels when done
• high-loop-variable-capture - Avoid closure over loop variables
• high-waitgroup-mismatch - Match Add() and Done() calls

Medium Improvements (3)

• medium-directional-channels - Use send/receive-only channels
• medium-buffered-channel-size - Choose appropriate buffer size
• medium-select-default - Avoid busy-wait with select

How to Use

For Code Review

1. Scan code for goroutine launches and channel operations
2. Check against rules in priority order (Critical first)
3. For each violation found, reference the specific rule file
4. Provide exact line numbers and explanation
5. Show corrected code example

Accessing Detailed Rules

Each rule file in rules/ contains:

• Brief explanation of why it matters
• Detection criteria (how to spot the issue)
• Incorrect code example (❌ BAD)
• Correct code example (✅ GOOD)
• Impact assessment
• References