仅需任意任务完成

func runTask(id int) string {
    time.Sleep(10 * time.Millisecond)
    return fmt.Sprintf("The result is from %d", id)
}

func FirstResponse() string {
    numOfRunner := 10
    ch := make(chan string, numOfRunner)
    for i := 0; i < numOfRunner; i++ {
        go func(i int) {
            ret := runTask(i)
            ch <- ret
        }(i)
    }
    return <-ch
}

func TestFirstResponse(t *testing.T) {
    t.Log("Before:", runtime.NumGoroutine())
    t.Log(FirstResponse())
    time.Sleep(time.Second * 1)
    t.Log("After:", runtime.NumGoroutine())
}

必需所有任务完成

func runTask(id int) string {
    time.Sleep(10 * time.Millisecond)
    return fmt.Sprintf("The result is from %d", id)
}

func AllResponse() string {
    numOfRunner := 10
    ch := make(chan string, numOfRunner)
    for i := 0; i < numOfRunner; i++ {
        go func(i int) {
            ret := runTask(i)
            ch <- ret
        }(i)
    }
    finalRet := ""
    for j := 0; j < numOfRunner; j++ {
        finalRet += <-ch + "\n"
    }
    return finalRet
}

func TestFirstResponse(t *testing.T) {
    t.Log("Before:", runtime.NumGoroutine())
    t.Log(AllResponse())
    time.Sleep(time.Second * 1)
    t.Log("After:", runtime.NumGoroutine())

}

也可以用waitgroup等待所有任务的完成