How to Use Context with Goroutines

Pass a context.Context to your goroutines to signal cancellation or timeouts, and check ctx.Done() inside the goroutine to stop work immediately. This prevents goroutines from running indefinitely after the parent operation is done.

package main

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

func worker(ctx context.Context, id int) {
	for {
		select {
		case <-ctx.Done():
			fmt.Printf("Worker %d stopped\n", id)
			return
		default:
			// Do work
			time.Sleep(100 * time.Millisecond)
		}
	}
}

func main() {
	ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond)
	defer cancel()

	go worker(ctx, 1)
	go worker(ctx, 2)

	<-ctx.Done()
	fmt.Println("All workers stopped")
}

Context is like a remote control for your background tasks. You pass it to your goroutines so they know when to stop if the main program is done or a timeout hits. Without it, your program might keep running tasks in the background even after it should have finished.