无法在 go 例程中获取多个通道值

Question

I have written 2 goroutines for web socket read and write the message. For Example,

ch := make(chan bool)
folderName := make(chan string)

go func(co *websocket.Conn) {
    m, d, err := co.ReadMessage()
    fmt.Println(m, string(d), err)

    folderName <- string(d)
    ch <- true

    if string(d) == "closed" {
        ch <- true
        co.Close()
    }
}(conn)

This goroutine is used to read the message from the socket and update the channels.

go func(co *websocket.Conn) {
    value := <-ch
    fldr := <-folderName

    fmt.Println(fldr, value)
}(conn)

This goroutine is for writing the message. But I couldn't get folderName and ch channel values. I don't know how to find the issues.

If I pass the single channel, I can get a message from the channel. But I need to get 2 values in that goroutine.

Could anyone help to resolve the issues? Thanks in advance.

Answer 1

In your case since your reading a single message from the websocket.Connection you need to change the sequence in which you read from the channels since your channels are unbuffered your writes will be blocked as longs as there are no consumers and vice versa. In your case, you write to the folderName channel in the first goroutine and then read from the other channel ch so both of your goroutines will be blocked.

package main

import (
    "fmt"
    "time"
)

func main() {
    ch := make(chan bool)
    folderName := make(chan string)

    go func() {
        ch <- true
        folderName <- "Some text"

        .
                .
                .
    }()

    go func() {
        value := <-ch
        fldr := <-folderName

        fmt.Println(fldr, value)
    }()

    time.Sleep(time.Second)
}

Playground example