使用channel實現goroutine

使用channel實現goroutine

1.無緩衝channel

---

    package main

    import (
        "fmt"
        "time"
    )

    var message = make(chan string)

    //往channel中輸入信息
    func sample1()  {
        message <- "hello gorotine."
    }

    //消費channel中的信息
    func sample2()  {
        str := <- message
        str = str + " run fast,run the world."
        message <- str

    }

    func main()  {
        go sample1()
        go sample2()
        time.Sleep(time.Second)
        fmt.Println(<-message)
        fmt.Println("message")

    }

2.buffer channel（緩衝channel）

---

    package main

    import (
        "fmt"
        "time"
    )

    /*
        1.buffer channel
        2.在函數中傳遞channel，而不是申明一個全局變量channel
        3.FIFO：first input first output
     */

    //往channel中輸入信息
    func sample1(message chan string)  {
        message <- "hello gorotine.1"
        message <- "hello gorotine.2"
        message <- "hello gorotine.3"
        message <- "hello gorotine.4"
    }

    //消費channel中的信息
    func sample2(message chan  string)  {
        str := <- message
        str = str + " run fast,run the world."
        message <- str

    }

    func main()  {
        var message = make(chan string, 4)
        go sample1(message)
        go sample2(message)
        time.Sleep(time.Second)
        fmt.Println(<-message)
        fmt.Println(<-message)
        fmt.Println(<-message)
        //fmt.Println(<-message)

        fmt.Println("message")

    }

   // 2.1 output1
    hello gorotine.2
    hello gorotine.3
    hello gorotine.4
    message

---

取消這行代碼的註釋//fmt.Println(<-message)，將會得到如下的輸出，這正好說明了先進先出的概念

  //2.2 output2
    hello gorotine.2
    hello gorotine.3
    hello gorotine.4
    hello gorotine.1 run fast,run the world.
    message

3.遍歷channel及關閉遍歷channel

package main

import (
    "fmt"
    "time"
)

/*
    1.buffer channel
    2.在函數中傳遞channel，而不是申明一個全局變量channel
    3.FIFO：first input first output
 */

//往channel中輸入信息
func sample1(message chan string)  {
    message <- "hello gorotine.1"
    message <- "hello gorotine.2"
    message <- "hello gorotine.3"
    message <- "hello gorotine.4"
}

//消費channel中的信息
func sample2(message chan  string)  {
    str := <- message
    str = str + " run fast,run the world."
    message <- str

}

func main()  {
    var message = make(chan string, 4)
    go sample1(message)
    go sample2(message)
    time.Sleep(time.Second)
    //使用range遍歷channel
    for str := range message {
        fmt.Println(str)
    }

    fmt.Println("message")

}

不關閉channel，那麼channel默認爲空；那此時如果遍歷，則會拋出異常

//3.1output1
hello gorotine.2
hello gorotine.3
hello gorotine.4
hello gorotine.1 run fast,run the world.
fatal error: all goroutines are asleep - deadlock!

goroutine 1 [chan receive]:
main.main()
    D:/run/pms/src/test.go:37 +0x126

下面演示關閉channel的遍歷

package main

import (
    "fmt"
    "time"
)

/*
    1.buffer channel
    2.在函數中傳遞channel，而不是申明一個全局變量channel
    3.FIFO：first input first output
 */

//往channel中輸入信息
func sample1(message chan string)  {
    message <- "hello gorotine.1"
    message <- "hello gorotine.2"
    message <- "hello gorotine.3"
    message <- "hello gorotine.4"
}

//消費channel中的信息
func sample2(message chan  string)  {
    str := <- message
    str = str + " run fast,run the world."
    message <- str
    close(message)

}

func main()  {
    var message = make(chan string, 4)
    go sample1(message)
    go sample2(message)
    time.Sleep(time.Second)
    //使用range遍歷channel
    for str := range message {
        fmt.Println(str)
    }

    fmt.Println("message")

}

//3.2output2
hello gorotine.2
hello gorotine.3
hello gorotine.4
hello gorotine.1 run fast,run the world.
message