Introduction

Channels are Go’s primary tool for goroutine communication. Most developers know the basics - sending and receiving values - but advanced patterns unlock much more powerful concurrent designs.

Beyond Basic Channels

Basic channel operations are straightforward:

ch := make(chan int)
go func() { ch <- 42 }()
value := <-ch

But real systems need more sophisticated coordination:

• Pipeline Processing: Chain operations together
• Fan-Out/Fan-In: Distribute work and collect results
• Rate Limiting: Control operation flow
• Timeouts: Handle operations that take too long
• Cancellation: Stop work when it’s no longer needed

Common Channel Pitfalls

Before diving into patterns, understand the traps:

• Deadlocks: Goroutines waiting forever for each other
• Goroutine Leaks: Forgetting to close channels or handle cancellation
• Race Conditions: Channels don’t solve all concurrency issues
• Blocking Operations: Not handling channel operations that might block

Channel Patterns You’ll Learn

This guide covers practical channel patterns:

1. Select Patterns: Non-blocking operations and timeouts
2. Pipeline Patterns: Chaining processing stages
3. Fan Patterns: Distributing and collecting work
4. Cancellation Patterns: Stopping work gracefully
5. Rate Limiting: Controlling operation frequency
6. Worker Pools: Managing goroutines efficiently

Each pattern includes examples showing when and how to use it effectively.

When to Use Channels vs Sync Primitives

Channels excel at:

• Passing data between goroutines
• Coordinating goroutine lifecycles
• Implementing timeouts and cancellation
• Building processing pipelines

Use sync primitives (mutexes, etc.) for:

• Protecting shared state
• Simple coordination (WaitGroup)
• Performance-critical sections