[Go]多通道監聽器

package main

import (
	"fmt"
)

func foo(i int) chan int {
	ch := make(chan int)
	go func() { ch <- i }()
	return ch
}

func main() {
	ch1, ch2, ch3 := foo(3), foo(6), foo(9)

	ch := make(chan int)

	//開一個goroutine監視各個通道資料輸出並收集資料到通道ch
	go func() {
		for {
			//timeout是一個計時通道, 如果達到時間了，就會發出一個訊號出來
			timeout := time.After(1 * time.Second)
				for isTimeout := false; !isTimeout; {
					//監視通道ch1, ch2, ch3, timeout通道的資料流出
					select { //監視通道ch1, ch2, ch3, timeout通道的資料流出
						case v1 := <-ch1:
							fmt.Printf("received %d from ch1", v1)
						case v2 := <-ch2:
							fmt.Printf("received %d from ch2", v2)
						case v3 := <-ch3:
							fmt.Printf("received %d from ch3", v3)
						case <-timeout:
							isTimeout = true //超時
					}
				}
		}
	}()

	//阻塞主線，取出通道ch的數據
	for i := 0; i < 3; i++ {
		fmt.Println(<-ch)
	}
}​