在使用通道的循环内触发通道

Question

如何在消耗相同通道的循环内装配通道。下面是一个不起作用的示例代码。这是如何实现的？

https://go.dev/play/p/o5ZhNfw4IFu

package main

import (

    "context"

    "fmt"

    "time"

)

func main() {

    ch1 := make(chan struct{})

    ch2 := make(chan struct{})

    defer close(ch1)

    defer close(ch2)

    ctx, cancel := context.WithTimeout(context.Background(), time.Second*3)

    defer cancel()

    go func() {

        time.Sleep(time.Second * 1)

        ch1 <- struct{}{}

    }()

loop:

    for {

        select {

        case <-ctx.Done():

            fmt.Println("timeout")

            break loop

        case <-ch1:

            fmt.Println("ch1")

            ch2 <- struct{}{} // This here does not work!

        case <-ch2:

            fmt.Println("ch2")

        }

    }

}

去

Answer 1

1.发送数据到goroutine里面的ch2package mainimport (&nbsp; &nbsp; "context"&nbsp; &nbsp; "fmt"&nbsp; &nbsp; "time")func main() {&nbsp; &nbsp; ch1 := make(chan struct{})&nbsp; &nbsp; ch2 := make(chan struct{})&nbsp; &nbsp; defer close(ch1)&nbsp; &nbsp; defer close(ch2)&nbsp; &nbsp; ctx, cancel := context.WithTimeout(context.Background(), time.Second*3)&nbsp; &nbsp; defer cancel()&nbsp; &nbsp; go func() {&nbsp; &nbsp; &nbsp; &nbsp; time.Sleep(time.Second * 1)&nbsp; &nbsp; &nbsp; &nbsp; ch1 <- struct{}{}&nbsp; &nbsp; }()loop:&nbsp; &nbsp; for {&nbsp; &nbsp; &nbsp; &nbsp; select {&nbsp; &nbsp; &nbsp; &nbsp; case <-ctx.Done():&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; fmt.Println("timeout")&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; break loop&nbsp; &nbsp; &nbsp; &nbsp; case <-ch1:&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; fmt.Println("ch1")&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; go func() {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ch2 <- struct{}{}&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }()&nbsp; &nbsp; &nbsp; &nbsp; case <-ch2:&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; fmt.Println("ch2")&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }}或者2. 使 ch2 缓冲package mainimport (&nbsp; &nbsp; "context"&nbsp; &nbsp; "fmt"&nbsp; &nbsp; "time")func main() {&nbsp; &nbsp; ch1 := make(chan struct{})&nbsp; &nbsp; ch2 := make(chan struct{}, 1)&nbsp; &nbsp; defer close(ch1)&nbsp; &nbsp; defer close(ch2)&nbsp; &nbsp; ctx, cancel := context.WithTimeout(context.Background(), time.Second*3)&nbsp; &nbsp; defer cancel()&nbsp; &nbsp; go func() {&nbsp; &nbsp; &nbsp; &nbsp; time.Sleep(time.Second * 1)&nbsp; &nbsp; &nbsp; &nbsp; ch1 <- struct{}{}&nbsp; &nbsp; }()loop:&nbsp; &nbsp; for {&nbsp; &nbsp; &nbsp; &nbsp; select {&nbsp; &nbsp; &nbsp; &nbsp; case <-ctx.Done():&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; fmt.Println("timeout")&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; break loop&nbsp; &nbsp; &nbsp; &nbsp; case <-ch1:&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; fmt.Println("ch1")&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ch2 <- struct{}{}&nbsp; &nbsp; &nbsp; &nbsp; case <-ch2:&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; fmt.Println("ch2")&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }}