go errgroup 用法示例

一、demo

package main

import (
    "fmt"
    "time"

    xContext "golang.org/x/net/context"
    "golang.org/x/sync/errgroup"
)

func main() {
    ctx, cancel := xContext.WithCancel(xContext.Background())
    group, errCtx := errgroup.WithContext(ctx)

    for index := 0; index