两个包之间的通道通信死锁 - Golang

Question

两个包之间的通道通信死锁 - Golang。

我有两个包通过两个渠道进行通信。一个是主要的，另一个是功能。当我运行它时，我会遇到死锁。

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

}

这就是僵局。

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>

你能给我解释一下问题出在哪里吗？

Answer 1

通道functionspackage.ChannelOutFunct未初始化，因此它是一个零通道。写入零通道或从零通道读取将始终阻塞。https://dave.cheney.net/2014/03/19/channel-axioms

Answer 2

我让它工作。这是代码package mainimport (&nbsp; &nbsp; packagefunctions "GoEjemplos/subFolder"&nbsp; &nbsp; "fmt"&nbsp; &nbsp; "sync")func main() {&nbsp; &nbsp; var wg sync.WaitGroup&nbsp; &nbsp; var ChannelSendData = make(chan packagefunctions.FunctionStruct, 0)&nbsp; &nbsp; defer close(ChannelSendData)&nbsp; &nbsp; var ChanReturn = make(chan float64)&nbsp; &nbsp; defer close(ChanReturn)&nbsp; &nbsp; data := packagefunctions.FunctionStruct{&nbsp; &nbsp; &nbsp; &nbsp; FieldOne: 3.56,&nbsp; &nbsp; &nbsp; &nbsp; FieldTwo: 2,&nbsp; &nbsp; }&nbsp; &nbsp; wg.Add(1)&nbsp; &nbsp; go func() { ChannelSendData <- data }()&nbsp; &nbsp; wg.Add(1)&nbsp; &nbsp; go func() {&nbsp; &nbsp; &nbsp; &nbsp; ChanReturn = packagefunctions.FunctionExt(ChannelSendData, &wg)&nbsp; &nbsp; &nbsp; &nbsp; recibeChanReturn := <-ChanReturn&nbsp; &nbsp; &nbsp; &nbsp; fmt.Println("channelOut: ", recibeChanReturn)&nbsp; &nbsp; &nbsp; &nbsp; wg.Done()&nbsp; &nbsp; }()&nbsp; &nbsp; wg.Wait()}另一个包是package packagefunctionsimport (&nbsp; &nbsp; "fmt"&nbsp; &nbsp; "sync")type FunctionStruct struct {&nbsp; &nbsp; FieldOne float64&nbsp; &nbsp; FieldTwo int}func FunctionExt(ChanIn chan FunctionStruct, wg *sync.WaitGroup) chan float64 {&nbsp; &nbsp; reciveData, ok := <-ChanIn&nbsp; &nbsp; if ok == false {&nbsp; &nbsp; &nbsp; &nbsp; fmt.Println("channel closed")&nbsp; &nbsp; }&nbsp; &nbsp; var result float64&nbsp; &nbsp; result = reciveData.FieldOne * float64(reciveData.FieldTwo)&nbsp; &nbsp; var ChannelReturn = make(chan float64, 1)&nbsp; &nbsp; defer close(ChannelReturn)&nbsp; &nbsp; ChannelReturn <- result&nbsp; &nbsp; wg.Done()&nbsp; &nbsp; return ChannelReturn}