channel详解

无缓冲通道

只有当读写都准备好时才不会被阻塞

func main() {
    ch := make(chan struct{})

    go func() {
        <-ch
    }()

    ch <- struct{}{}

    fmt.Println("done")
}

输出：

done

Process finished with exit code 0

有缓冲通道

• 当有缓冲通道长度未满时，写入是无阻塞的

func main() {
    ch := make(chan struct{}, 2)
    ch <- struct{}{}
    fmt.Println("done")
}

输出：

done

Process finished with exit code 0

• 当有缓冲通道长度已满时，写入是阻塞的

func main() {
    ch := make(chan struct{}, 2)

    go func() {
        ch <- struct{}{}
        fmt.Println("append ch")
    }()

    for i := 0; i < 2; i++ {
        ch <- struct{}{}
    }

    time.Sleep(time.Second)
    fmt.Println("done")
}

输出：

done

Process finished with exit code 0