package waitgroups

import (
	"fmt"
	"math/rand"
	"sync"
	"time"
)

func worker(id int, wg *sync.WaitGroup) {
	defer wg.Done()
	fmt.Printf("worker #%d starting\n", id)
	time.Sleep(time.Duration((1 + rand.Intn(2))) * time.Second)
	fmt.Printf("worker #%d exiting\n", id)
}

func WaitGroups() {
	numJobs := 3
	wg := sync.WaitGroup{}

	for i := range numJobs {
		wg.Add(1)
		go worker(i, &wg)
	}

	wg.Wait()

	fmt.Println("Program exiting")
}