package main

import (
    "fmt"
    "math/rand"
    "time"
)

func task(name string, delay time.Duration, ch chan<- string) {
    time.Sleep(delay)
    ch <- fmt.Sprintf("任務(wù) %s 完成（耗時 %v）", name, delay)
}

func main() {
    rand.Seed(time.Now().UnixNano())

    task1Ch := make(chan string)
    task2Ch := make(chan string)

    // 啟動兩個任務(wù)
    go task("A", time.Duration(rand.Intn(2000))*time.Millisecond, task1Ch)
    go task("B", time.Duration(rand.Intn(2000))*time.Millisecond, task2Ch)

    // 使用 select 監(jiān)聽兩個任務(wù)完成情況
    timeout := time.After(2 * time.Second) // 超時設(shè)置

    for i := 0; i < 2; i++ {
        select {
        case res := <-task1Ch:
            fmt.Println("[監(jiān)聽] 收到任務(wù)1結(jié)果：", res)
        case res := <-task2Ch:
            fmt.Println("[監(jiān)聽] 收到任務(wù)2結(jié)果：", res)
        case <-timeout:
            fmt.Println("[監(jiān)聽] 等待超時！")
            return
        }
    }

    fmt.Println("主程序退出。")
}

timeout := time.After(2 * time.Second)

select {
case msg := <-ch:
    fmt.Println("收到消息：", msg)
default:
    fmt.Println("沒有消息，非阻塞處理")
}

func main() {
    dataCh := make(chan string)
    quitCh := make(chan bool)

    // 模擬異步數(shù)據(jù)流
    go func() {
        for i := 0; i < 5; i++ {
            dataCh <- fmt.Sprintf("數(shù)據(jù)包 #%d", i)
            time.Sleep(time.Millisecond * 500)
        }
        quitCh <- true
    }()

    for {
        select {
        case msg := <-dataCh:
            fmt.Println("接收數(shù)據(jù)：", msg)
        case <-quitCh:
            fmt.Println("任務(wù)結(jié)束，退出監(jiān)聽循環(huán)")
            return
        case <-time.After(1 * time.Second):
            fmt.Println("1秒無數(shù)據(jù)，超時處理...")
        }
    }
}