---
title: Go Concurrency Patterns
category: product
entity_type: skill
price: $15
canonical: https://forgehouse.ai/skills/go-concurrency-patterns/
lang: en
hreflang_alt: https://forgehouse.ai/tr/skiller/go-concurrency-patterns/
last_updated: 2026-06-20
---

# Go Concurrency Patterns

> Master Go concurrency with goroutines, channels, sync primitives, and context.

Production-grade Go concurrency built on the CSP philosophy, share memory by communicating, not the other way around. It delivers worker pools, fan-out/fan-in pipelines, bounded concurrency, error groups and graceful shutdown as ready patterns, each wired with context cancellation so goroutines never leak and races get caught.

## Use cases
- Build a worker pool over a job channel
- Run a fan-out/fan-in processing pipeline
- Bound concurrency with a semaphore or errgroup limit
- Fetch multiple URLs concurrently with first-error cancellation
- Implement graceful shutdown on SIGINT/SIGTERM
- Debug and prevent race conditions with the -race detector

## Benefits
- Stop goroutine leaks by making every channel listen on ctx.Done()
- Cut API latency with parallel fan-out instead of sequential calls
- Use far less memory per goroutine than per-thread models, with bounded worker counts
- Shut down cleanly without losing in-flight work or leaking resources

## What’s included
- Worker pool, fan-out/fan-in and bounded-concurrency semaphore patterns
- errgroup with cancellation and a SetLimit concurrency cap
- Graceful shutdown with signal handling and a shutdown timeout
- Concurrent map patterns: sync.Map for read-heavy, sharded map for write-heavy
- Select patterns for timeout, non-blocking send and priority handling
- Race-detector commands for test, build and run

## Who it’s for
For Go engineers building concurrent services, pipelines and worker systems who need leak-free, race-safe patterns with proper context and shutdown handling.

## How it runs
Concurrency bugs in Go are mostly missing discipline. This skill chooses channels over mutexes by CSP default, puts ctx.Done() in every select, bounds goroutines before load arrives, and makes the race detector a CI gate.
1. Picks the communication primitive first: channel over mutex by CSP default ('share memory by communicating'). Mutex is only allowed for simple counters or read-heavy caches, and the choice gets documented.
2. Builds the worker pool or fan-out/fan-in pipeline with the canonical signature func(ctx, <-chan T) <-chan U, so closing the input channel propagates shutdown through every stage. Fan-in waits on a sync.WaitGroup before closing the output, never earlier.
3. Puts a ctx.Done() case into every single channel select. A select without it is a goroutine leak, so the skill treats it as a hard rule, with time.After for timeouts and default for non-blocking tries.
4. Bounds concurrency before load hits: semaphore.NewWeighted or a buffered struct{} channel for raw limits, errgroup.SetLimit(N) for I/O-bound batches because it bundles limit, error propagation and cancel in one API.
5. Wires graceful shutdown: signal.Notify catches SIGINT/SIGTERM, context cancel propagates to all workers, each worker cleans up in its ctx.Done() branch, and a shutdown timeout forces exit if cleanup hangs.
6. Runs go test -race and go build -race as a mandatory CI gate, then reviews mutex usage: defer Unlock everywhere, RWMutex for read-heavy paths, sharded map for write-heavy ones.

## FAQ
### I'm writing a small CLI tool, not a big service, is this overkill?
The patterns scale down. A worker pool, an errgroup limit, or graceful shutdown works the same in a three-file tool as in a service running hundreds of goroutines, and context cancellation prevents leaks at any size.

### How does it concretely stop goroutine leaks?
Every channel pattern is wired to listen on ctx.Done(), errgroup cancels the whole group on first error, and SetLimit caps concurrency. For races, the package includes the -race detector commands for test, build, and run.

### Will it speed up single-threaded, CPU-bound code?
No. These patterns parallelize work that waits on I/O: network calls, channels, pipelines. Single-core algorithm optimization and GC tuning are different problems this package doesn't address.

## Price
$15, one-time, no subscription. VAT included.

Related guide: [AI code review and developer workflow](https://forgehouse.ai/guides/ai-code-review/)