Go Concurrency Patterns

When to use this skill

Use Go Concurrency Patterns when an AI agent needs a reusable SKILL.md workflow for this job: Master Go concurrency with goroutines, channels, sync primitives, and context. Use when building concurrent Go applications, implementing worker pools, or debugging race conditions.

When not to use it

Skip Go Concurrency Patterns when the task is outside the coding category, or when a more specific skill in this directory already covers the same workflow with clearer triggers.

How to install

1. Personal install: create ~/.claude/skills/go-concurrency-patterns/SKILL.md (and any bundled scripts) so Claude Code, Claude Desktop, and compatible agents can load it in every project.
2. Project install: commit the same folder at .claude/skills/go-concurrency-patterns/ so teammates get the skill with the repo.
3. Restart the agent session after copying files so it re-scans the skills directory, then ask for the task in words that match the skill description.

Full install guide for Claude, Cursor, and Codex

What this skill does

# Go Concurrency Patterns

Production patterns for Go concurrency including goroutines, channels, synchronization primitives, and context management.

## When to Use This Skill

- Building concurrent Go applications - Implementing worker pools and pipelines - Managing goroutine lifecycles - Using channels for communication - Debugging race conditions - Implementing graceful shutdown

## Core Concepts

### 1. Go Concurrency Primitives

| Primitive | Purpose | | ----------------- | -------------------------------- | | `goroutine` | Lightweight concurrent execution | | `channel` | Communication between goroutines | | `select` | Multiplex channel operations | | `sync.Mutex` | Mutual exclusion | | `sync.WaitGroup` | Wait for goroutines to complete | | `context.Context` | Cancellation and deadlines |

### 2. Go Concurrency Mantra

``` Don't communicate by sharing memory; share memory by communicating. ```

## Quick Start

```go package main

import ( "context" "fmt" "sync" "time" )

func main() { ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second) defer cancel()

results := make(chan string, 10) var wg sync.WaitGroup

// Spawn workers for i := 0; i < 3; i++ { wg.Add(1) go worker(ctx, i, results, &wg) }

// Close results when done go func() { wg.Wait() close(results) }()

// Collect results for result := range results { fmt.Println(result) } }

func worker(ctx context.Context, id int, results chan<- string, wg *sync.WaitGroup) { defer wg.Done()

select { case <-ctx.Done(): return case results <- fmt.Sprintf("Worker %d done", id): } } ```

## Detailed patterns and worked examples

Detailed pattern documentation lives in `references/details.md`. Read that file when the navigation tier above is insufficient.

## Best Practices

### Do's

- **Use context** - For cancellation and deadlines - **Close channels** - From sender side only - **Use errgroup** - For concurrent operations with errors - **Buffer channels** - When you know the count - **Prefer channels** - Over mutexes when possible

### Don'ts

- **Don't leak goroutines** - Always have exit path - **Don't close from receiver** - Causes panic - **Don't use shared memory** - Unless necessary - **Don't ignore context cancellation** - Check ctx.Done() - **Don't use time.Sleep for sync** - Use proper primitives

Intended uses

• Building concurrent Go applications
• Implementing worker pools and pipelines
• Managing goroutine lifecycles
• Using channels for communication
• Debugging race conditions
• Implementing graceful shutdown