goroutine的变量没有时间注册

Question

This piece of code gets an array with strings and should mix it and make a response (both multithreaded). The problem is that the text of the answer is randomly cutted. This is probably due to the fact that the variable "dump" does not have time to sign up completely. If it is wrapped in mutexes, the text is returned full, but threads are blocked and the program is executed for a long time. Please help!

const url = "https://yandex.ru/referats/write/?t=astronomy+mathematics"
const parseThreadsNum = 10
const generateThreadsNum = 1000

func startServer(wg *sync.WaitGroup) {
fmt.Println("Server started")
ch := make(chan []byte, generateThreadsNum)

http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
    wg.Add(generateThreadsNum)
    rawText := multiparseText() // text parsing
    prettyText := prettifyText(rawText) // truncates commas, dots etc. Return []string
    for i := 0; i < generateThreadsNum; i++ {
        go func() {
            dump, _ := json.Marshal(shuffle(&prettyText)) //shuffle mixes array randomly
            ch <- dump
        }()
        go func() {
            w.Write(<-ch)
            defer wg.Done()
        }()
    }
    fmt.Println("Text generated")
    wg.Wait()
})
log.Fatal(http.ListenAndServe(":8081", nil))
}

func main() {
var wg sync.WaitGroup
runtime.GOMAXPROCS(runtime.NumCPU())
startServer(&wg)

}