golang sync.WaitGroup

//阻塞，直到WaitGroup中的所以过程完成。

import (

    "fmt"

    "sync"

)



func wgProcess(wg *sync.WaitGroup, id int) {

    fmt.Printf("process:%d is going!\n", id)

    //if id == 2 {

    //    return

    //}

    wg.Done()

}



func main() {

    //var wg sync.WaitGroup

    wg := new(sync.WaitGroup)

    for i := 0; i < 3; i++ {

        wg.Add(1)

        go wgProcess(wg, i)

    }

    wg.Wait()

    fmt.Println("after wait group")

}