func main() {
    intChan := make(chan int, 5)
    waitCount := 5
    for i := 0; i < waitCount; i++ {
       go func() {
          intChan <- 1
       }()
    }

    for i := 0; i < waitCount; i++ {
       <-intChan

    }
    fmt.Println("主進(jìn)程結(jié)束")
}

func main() {
    wg := sync.WaitGroup{}
    wg.Add(2)
    go func() {
       time.Sleep(3 * time.Second)
       fmt.Println("等待三分鐘的協(xié)程結(jié)束了")
       wg.Done()
    }()

    go func() {
       time.Sleep(3 * time.Second)
       fmt.Println("等待三分鐘的協(xié)程結(jié)束了")
       wg.Done()
    }()

    wg.Wait()
}

func main() {
	ctx, cancelFunc := context.WithCancel(context.Background())
	deadline, ok := ctx.Deadline()
	fmt.Println(deadline, ok)
	done := ctx.Done()
	fmt.Println(reflect.TypeOf(done))
	fmt.Println(done)

	go HandelRequest(ctx)
	//<-done 阻塞當(dāng)前一層的goroutine
	time.Sleep(5 * time.Second)
	fmt.Println("all goroutines is stopping!")
	cancelFunc()
	err := ctx.Err()
	fmt.Println(err) //context canceled
	time.Sleep(5 * time.Second)
}

func HandelRequest(ctx context.Context) {
	go WriteMysql(ctx)
	go WriteRedis(ctx)
	for {
		select {
		case <-ctx.Done():
			fmt.Println("HandelRequest Done")
			return
		default:
			fmt.Println("等一等,Handler正在執(zhí)行中")
			time.Sleep(2 * time.Second)
		}
	}
}

func WriteRedis(ctx context.Context) {
	for {
		select {
		case <-ctx.Done():
			fmt.Println("WriteRedis Done.")
			return
		default:
			fmt.Println("等一等,Redis正在執(zhí)行中")
			time.Sleep(2 * time.Second)
		}
	}
}

func WriteMysql(ctx context.Context) {
	for {
		select {
		case <-ctx.Done():
			fmt.Println("WriteMysql Done.")
			return
		default:
			fmt.Println("等一等,Mysql正在執(zhí)行中")
			time.Sleep(2 * time.Second)
		}
	}
}

func main() {
	deadline, _ := context.WithTimeout(context.Background(), 5*time.Second)
	go HandelRequest(deadline)

	time.Sleep(10 * time.Second)

}

func HandelRequest(ctx context.Context) {
	go WriteMysql(ctx)
	go WriteRedis(ctx)
	for {
		select {
		case <-ctx.Done():
			fmt.Println("HandelRequest Done")
			return
		default:
			fmt.Println("等一等,Handler正在執(zhí)行中")
			time.Sleep(2 * time.Second)
		}
	}
}

func WriteRedis(ctx context.Context) {
	for {
		select {
		case <-ctx.Done():
			fmt.Println("WriteRedis Done.")
			return
		default:
			fmt.Println("等一等,Redis正在執(zhí)行中")
			time.Sleep(2 * time.Second)
		}
	}
}

func WriteMysql(ctx context.Context) {
	for {
		select {
		case <-ctx.Done():
			fmt.Println("WriteMysql Done.")
			return
		default:
			fmt.Println("等一等,Mysql正在執(zhí)行中")
			time.Sleep(2 * time.Second)
		}
	}
}

func main() {
	ctx, cancelFunc := context.WithCancel(context.Background())
	value1 := context.WithValue(ctx, "param1", 1)
	value2 := context.WithValue(value1, "param2", 2)
	go ReadContextValue(value2)

	time.Sleep(10 * time.Second)
	cancelFunc()
	time.Sleep(5 * time.Second)
}

func ReadContextValue(ctx context.Context) {
	fmt.Println(ctx.Value("param1"))
	fmt.Println(ctx.Value("param2"))
}