example of errgroup

errgroup.go

package main

import "golang.org/x/sync/errgroup"

func doData1() (string, error)
func doData2() (string, error)
func doData3() (string, error)

func main() {
	var data1, data2, data3 string

	g := new(errgroup.Group)
	g.Go(func() error {
		var err error
		data1, err = doData1()
		return err
	})

	g.Go(func() error {
		var err error
		data2, err = doData2()
		return err
	})
	g.Go(func() error {
		var err error
		data3, err = doData3()
		return err
	})

	err := g.Wait()
	if err != nil {
		panic(err)
	}

	// do something with data1 data2 data3
}