go - 两个软件包之间的 channel 通信陷入僵局-Golang

Question

两个软件包之间的 channel 通信陷入僵局-Golang。
我有两个通过两个 channel 沟通的包裹。一个是主要功能，另一个具有功能。运行它时，会出现死锁。

package main

import (
    functionspackage "GoEjemplos/subFolder"
    "fmt"
    "sync"
)

func main() {
    var wg sync.WaitGroup

    ChannelSendData := make(chan functionspackage.FunctionStruct, 1)
    defer close(ChannelSendData)

    data := functionspackage.FunctionStruct{
        FieldOne: 3.56,
        FieldTwo: 23,
    }

    ChannelSendData <- data

    wg.Add(1)
    go functionspackage.FunctionExt(ChannelSendData, &wg)

    recibe := <-functionspackage.ChannelOutFunct

    fmt.Println("channelOut: ", recibe)

    close(functionspackage.ChannelOutFunct)

    wg.Wait()
}

另一个包是

package functionspackage

import "sync"

type FunctionStruct struct {
    FieldOne float64
    FieldTwo int
}

var ChannelOutFunct chan float64

func FunctionExt(RecibeChan chan FunctionStruct, wg *sync.WaitGroup) (ChannelOutFunct chan float64) {

    reciveData := <-RecibeChan

    result := reciveData.FieldOne * float64(reciveData.FieldTwo)

    ChannelOutFunct <- result

    wg.Done()

    return ChannelOutFunct
}

这是僵局。

PS C:\Go-Project\src\GoEjemplos> go run main.go
fatal error: all goroutines are asleep - deadlock!

goroutine 1 [chan receive (nil chan)]:
main.main()
        C:/Go-Project/src/GoEjemplos/main.go:32 +0x13d

goroutine 19 [chan send (nil chan)]:
GoEjemplos/subFolder.FunctionExt(0xc0000d4000, 0xc0000a2070, 0xc0000c9f18)
        C:/Go-Project/src/GoEjemplos/subFolder/functionsPackage.go:19 +0x85
created by main.main
        C:/Go-Project/src/GoEjemplos/main.go:30 +0x11a
exit status 2
PS C:\Go-Project\src\GoEjemplos>

您能告诉我问题出在哪里吗？
谢谢!

Answer 1

channel functionspackage.ChannelOutFunct尚未初始化，因此为nil channel 。写入零 channel 或从零 channel 读取将始终阻塞。
https://dave.cheney.net/2014/03/19/channel-axioms