发送数据完成后是否需要关闭通道？

Question

这是我的程序。

package main

import "fmt"

func init() {
    fmt.Println("init function")
}

func main() {
    // gen number to naturals channel
    naturals := gen(1, 2, 3)
    // write the squars in a channel
    squar := dosquar(naturals)

    for p := range squar {
        fmt.Println("printer shows----- ", p)
    }
}

func gen(nums ...int) chan int {
    naturals := make(chan int)
    go func() {
        for _, n := range nums {
            fmt.Println("generating number ", n)
            naturals <- n
            fmt.Println("generated number ", n)
        }
        //close(naturals)
    }()
    return naturals
}

func dosquar(naturals chan int) chan int {
    // write the squars the values
    squar := make(chan int)
    go func() {
        for number := range naturals {
            fmt.Println("recieved number ", number)
            squar <- number * number
            fmt.Println("sent squar of number ", number*number)
        }
        //close(squar)
    }()
    return squar
}

它给出以下错误。

init function
generating number  1
generated number  1
generating number  2
recieved number  1
sent squar of number  1
recieved number  2
generated number  2
generating number  3
printer shows-----  1
printer shows-----  4
sent squar of number  4
recieved number  3
sent squar of number  9
printer shows-----  9
generated number  3
fatal error: all goroutines are asleep - deadlock!

goroutine 1 [chan receive]:
main.main()
        /Users/siyaram/go/src/github.com/SrmHitter9062/go-pipeline/main.go:15 +0x127

goroutine 19 [chan receive]:

我希望它在频道被划分时运行。这让我想到一个问题，我们是否需要每次都关闭频道，当我们完成它们时？

请有人帮助澄清为什么程序没有按预期运行。

Answer 1

你可以做任何你想做的事，但是在频道关闭之前，range 循环不会退出频道。