// 有缓冲的channel
package main

import (
	"fmt"
	"time"
)

func main() {
	c := make(chan int, 3) // 带有缓冲的channel

	fmt.Println("len(c) = ", len(c), ", cap(c) = ", cap(c))

	// 做一个go程
	go func() {
		defer fmt.Println("子go程结束")
		// 如果循环3将不会阻塞，大于3就会阻塞
		for i := 0; i < 4; i++ {
			// 把i传递给channel
			c <- i
			fmt.Println("子go程正在运行, 发送元素: ", i, ", len(c) = ", len(c), ", cap(c) = ", cap(c))
		}
	}()

	time.Sleep(2 * time.Second)

	for i := 0; i < 4; i++ {
		num := <-c
		fmt.Println("num = ", num)
		// 如果这里不阻塞的话，那么子go程在第2轮之后有可能不会打印
		time.Sleep(1 * time.Second)
	}

	fmt.Println("主进程main结束")
}