Goroute, single running, cancellable, running on an interval

understanding-goroutines.go

func main() {
	manager := make(chan struct{})
	_ = publisher(manager)

	time.Sleep(10 * time.Second)
	close(manager)
}

func publisher(manager chan struct{}) chan<- struct{} {
	pubch := make(chan struct{})
	printerCh := printer(manager)

	go func() {
		ticker := time.NewTicker(2 * time.Second).C

		defer fmt.Println("Stopping Publisher.")
		defer close(printerCh)

		for {
			select {
			case <- manager:
				return
			case <- pubch:
				return
			case <- ticker:
				printerCh <- struct{}{}
			}
		}
	}()

	return pubch
}

// <- means externally it's write only
func printer(manager chan struct{}) chan<- struct{} {
	ch := make(chan struct{})

	go func() {
		for {
			select {
			case <-manager:
				return
			case <-ch:
				fmt.Println("Sleeping for 5 seconds")
				time.Sleep(time.Duration(5 * time.Second))
			}
		}
	}()

	return ch
}