golang 死锁 all goroutines are asleep

channel死锁

package main

import "fmt"

func main() {

	ch := make(chan string)

	for i := 0; i < 10; i++ {
		s := <- ch
		fmt.Println(s)
	}

	go func(ch chan string) {
		for i := 0; i < 10; i++ {
			ch <- fmt.Sprintf("%d", i)
		}

	}(ch)


}

报错

all goroutines are asleep - deadlock!

s := <- ch

解决

思路：先开启一个协程让运行接收端/发送端，main主协程继续往下执行。两个协程（接收断/发送端）都准备好后，就开始传输数据。

package main

import "fmt"

func main() {

	ch := make(chan string)

	go func(ch chan string) {
		for i := 0; i < 10; i++ {
			ch <- fmt.Sprintf("%d", i)
		}

	}(ch)

	for i := 0; i < 10; i++ {
		s := <- ch
		fmt.Println(s)
	}


}