1、有缓冲channel

示例：  有缓存会阻塞，当读取完其中数值时，又可以写入。

package mainimport (	"fmt"	"time")func main() {	//创建一个有缓存的channel	ch := make(chan int, 3)	//len(ch)缓冲区剩余数据个数， cap(ch)缓冲区大小	fmt.Printf("len(ch) = %d, cap(ch)= %d\n", len(ch), cap(ch))	//新建协程	go func() {		for i := 0; i < 10; i++ {			ch <- i //往chan写内容			fmt.Printf("子协程[%d]: len(ch) = %d, cap(ch)= %d\n", i, len(ch), cap(ch))		}	}()	//延时	time.Sleep(2 * time.Second)	for i := 0; i < 10; i++ {		num := <-ch //读管道中内容，没有内容前，阻塞		fmt.Println("num = ", num)	}}

执行结果：

len(ch) = 0, cap(ch)= 3子协程[0]: len(ch) = 1, cap(ch)= 3子协程[1]: len(ch) = 2, cap(ch)= 3子协程[2]: len(ch) = 3, cap(ch)= 3num =  0num =  1num =  2num =  3子协程[3]: len(ch) = 3, cap(ch)= 3子协程[4]: len(ch) = 0, cap(ch)= 3num =  4num =  5子协程[5]: len(ch) = 1, cap(ch)= 3子协程[6]: len(ch) = 0, cap(ch)= 3子协程[7]: len(ch) = 1, cap(ch)= 3子协程[8]: len(ch) = 2, cap(ch)= 3子协程[9]: len(ch) = 3, cap(ch)= 3num =  6num =  7num =  8num =  9