Shutdown multiple goroutines over channel

goroutine-shutdown-channel.go

package main

import (
	"log"
	"sync"
	"time"
)

func main() {
	var wgDone sync.WaitGroup
	shutdownChan := make(chan bool, 1)

	for i := 1; i <= 2; i++ {
		wgDone.Add(1)
		go worker(i, shutdownChan, &wgDone)
	}

	time.Sleep(time.Second * 5)
	shutdownChan <- false
	time.Sleep(time.Second * 5)

	log.Println("Sending shutdown signal . . .")
	close(shutdownChan)

	wgDone.Wait()
	log.Println("Closing.")
}

func worker(id int, sc chan bool, wg *sync.WaitGroup) {
	defer wg.Done()

	var cnt int

	for {
		cnt++
		log.Printf("Worker #%02d, loop no %d.\n", id, cnt)

		select {
		case _, more := <-sc:
			if !more {
				log.Printf("Worker #%02d got shutdown signal.\n", id)
				return
			}
			log.Printf("Worker #%02d received crap on shutdown channel!\n", id)

		default:
		}

		time.Sleep(time.Second * time.Duration(id+1))
	}
}