package main

import (

	"fmt"

	"time"

)

/*

·循环从一写两读三条管道中随机选择一条能走的路

·等所有路都走不通了就退出循环

*/

func main041() {

	chA := make(chan int, 5)

	chB := make(chan int, 4)

	chB <- 123

	chB <- 123

	chB <- 123

	chB <- 123

	chC := make(chan int, 3)

	chC <- 123

	chC <- 123

	chC <- 123

	go TaskA(chA)

	go TaskB(chB)

	go TaskC(chC)

	time.Sleep(10 * time.Second)

	fmt.Println("main over")

}

func main() {

	chA := make(chan int, 5)

	chB := make(chan int, 4)

	chB <- 123

	chB <- 123

	chB <- 123

	chB <- 123

	chC := make(chan int, 3)

	chC <- 123

	chC <- 123

	chC <- 123

OUTER:

	for true {

		/*随机选择一条能走通的case

		所有case都走不通时，走default

		可以通过break跳出select，break XXX跳出指定标签*/

		select {

		case chA <- 123:

			fmt.Println("执行任务A")

			time.Sleep(time.Second)

		case x := <-chB:

			fmt.Println("执行任务B", x)

			time.Sleep(time.Second)

		case <-chC:

			fmt.Println("执行任务C")

			time.Sleep(time.Second)

		default:

			fmt.Println("全部任务已结束")

			//break//跳出select

			break OUTER

		}

	}

	fmt.Println("main over")

}

func TaskA(ch chan int) {

	for true {

		fmt.Println("TaskA")

		ch <- 123

		time.Sleep(time.Second)

	}

}

func TaskB(ch chan int) {

	for true {

		fmt.Println("TaskB")

		<-ch

		time.Sleep(time.Second)

	}

}

func TaskC(ch chan int) {

	for true {

		fmt.Println("TaskC")

		<-ch

		time.Sleep(time.Second)

	}

}