Go Chan有缓冲无缓冲区别

go chan有缓冲无缓冲区别

同步非同步区别

  • 有缓冲与无缓冲
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    c1:=make(chan int)        //无缓冲
    c2:=make(chan int,1)      //有缓冲
    c1 <- 1
  • 无缓冲c1 通道放入1后需要有携程一直处理，不然一直会阻塞下去
  • 方向论证代码(错误示例)
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    package main

    func main()  {
    	c1 := make(chan int)
    	c1 <- 1 //没有处理接收就堵塞这里了  //fatal error: all goroutines are asleep - deadlock!
    	<-c1
    }
  • 正确示例
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    package main

    import (
    	"fmt"
    	"time"
    )

    func read(out chan int) {
    	for {
    		fmt.Println("waiting => ", time.Now())
    		fmt.Println("read => ", <-out)
    	}
    }

    func main() {
    	out := make(chan int)
    	go read(out)

    	for i := 1; i <= 5; i++ {
    		time.Sleep(time.Second)
    		fmt.Println("set => ", i, time.Now())
    		out <- i
    	}

    }
  • 有缓冲示例
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       c2 := make(chan int,2)
    c2 <- 1 //这里不会阻塞 因为缓冲大小是2  只有当满了2个值后还无取出 则会阻塞
    fmt.Println(<-c2) // 1