golang 13. 管道 channel

channel1.go

package main

import "fmt"

func main() {
	//定义一个channel
	c := make(chan int)

	go func() {
		defer fmt.Println("goroutine结束")

		fmt.Println("goroutine 正在运行...")

		c <- 666 //将666 发送给c
	}()

	num := <-c //从c中接受数据，并赋值给num

	fmt.Println("num = ", num)
	fmt.Println("main goroutine 结束...")
}

channel2.go

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))

	go func() {
		defer fmt.Println("子go程结束")

		for i := 0; i < 4; i++ {
			c <- i
			fmt.Println("子go程正在运行, 发送的元素=", i, " len(c)=", len(c), ", cap(c)=", cap(c))
		}
	}()

	time.Sleep(2 * time.Second)

	for i := 0; i < 4; i++ {
		num := <-c //从c中接收数据，并赋值给num
		fmt.Println("num = ", num)
	}

	fmt.Println("main 结束")
}

channel3.go

package main

import "fmt"

func main() {
	c := make(chan int)

	go func() {
		for i := 0; i < 5; i++ {
			c <- i
			//close可以关闭一个channel
			close(c)
		}
	}()

	for {
		//ok如果为true表示channel没有关闭，如果为false表示channel已经关闭
		if data, ok := <-c; ok {
			fmt.Println(data)
		} else {
			break
		}
	}

	fmt.Println("Main Finished..")
}

channel4.go

package main

import "fmt"

func main() {
	c := make(chan int)

	go func() {
		for i := 0; i < 5; i++ {
			c <- i
		}

		//close可以关闭一个channel
		close(c)
	}()

	//可以使用range来迭代不断操作channel
	for data := range c {
		fmt.Println(data)
	}

	fmt.Println("Main Finished..")
}

channel5.go

package main

import "fmt"

func fibonacii(c, quit chan int) {
	x, y := 1, 1

	for {
		select {
		case c <- x:
			//如果c可写，则该case就会进来
			x = y
			y = x + y
		case <-quit:
			fmt.Println("quit")
			return
		}
	}
}

func main() {
	c := make(chan int)
	quit := make(chan int)

	//sub go
	go func() {
		for i := 0; i < 10; i++ {
			fmt.Println(<-c)
		}

		quit <- 0
	}()

	//main go
	fibonacii(c, quit)
}