Concurrency Patterns in Go: Goroutines, Worker Pools, and Context

Goroutines are Lightweight, Not Free

While a goroutine begins with only 2 to 4 KB of stack space compared to 1 to 2 MB for an operating system thread, unbounded spawning under high-throughput conditions will rapidly exhaust memory or file descriptors. Production services demand bounded concurrency.

Implementing a Clean Worker Pool

A worker pool decouples job producers from consumers using buffered channels and a synchronizing wait group:

package main

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

type Job struct {
	ID   int
	Data string
}

func Worker(ctx context.Context, id int, jobs <-chan Job, results chan<- string, wg *sync.WaitGroup) {
	defer wg.Done()
	for {
		select {
		case <-ctx.Done():
			return
		case job, ok := <-jobs:
			if !ok {
				return
			}
			// Simulate work
			time.Sleep(50 * time.Millisecond)
			results <- fmt.Sprintf("worker %d processed job %d", id, job.ID)
		}
	}
}

Graceful Shutdown with Context Propagation

Always tie background processing to a top-level context.WithTimeout or signal.NotifyContext so in-flight requests finish cleanly without dropping connections during container redeployments.