Synchronization between pieces and results in golang

pieces_results_sync.go

type Piece struct {
	index  int
	length int
}

type Result struct {
	index  int
}

func main() {
	results := make(chan Result)
	var wg sync.WaitGroup

	peers := []int{1,2,3,4,5,6,7,8,9,10,11,12}
	for idx, p := range peers {
	  piece := Piece{
		  index:  idx,
		  length: p,
	  }
	  wg.Add(1)
	  go startWorker(&wg, piece, results)
	}

	go func(){
		wg.Wait()
		close(results)
	}()

	for r := range results {
		fmt.Printf("Result with index %d has arrived\n", r.index)
	}
}

func startWorker(wg *sync.WaitGroup, p Piece, res chan<- Result){
	defer wg.Done()

	time.Sleep(5 * time.Second)
	res <- Result{index:p.index}
}