Golang sync.WaitGroup基础用法

package main

import (
    "fmt"
    "sync"
    "time"
)

func main() {
    var wg sync.WaitGroup
    wg.Add(1)
    go func() {
        defer wg.Done()
        fmt.Println("First goroutine sleep")
        time.Sleep(1 * time.Second)
    }()

    wg.Add(1)
    go func() {
        defer wg.Done()
        fmt.Println("Second goroutine sleep")
        time.Sleep(2 * time.Second)
    }()
    wg.Wait()
    fmt.Println("All goroutines complete")
}

程序输出如下，