upg.Exit() do not effective in go routine ? about tableflip

[ljluestc]

package main

import (
	"fmt"
	"log"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/cloudflare/tableflip"
)

const version = "v0.0.1"

func main() {
	upg, err := tableflip.New(tableflip.Options{})
	if err != nil {
		panic(err)
	}
	defer upg.Stop()

	time.Sleep(time.Second)
	log.SetPrefix(fmt.Sprintf("[PID: %d] ", os.Getpid()))

	go func() {
		sig := make(chan os.Signal, 1)
		signal.Notify(sig, syscall.SIGHUP)
		for range sig {
			err := upg.Upgrade()
			if err != nil {
				log.Println("Upgrade failed:", err)
			}
		}
	}()

	ln, err := upg.Listen("tcp", ":8080")
	if err != nil {
		log.Fatalln("Can't listen:", err)
	}

	mux := http.NewServeMux()
	mux.HandleFunc("/version", func(rw http.ResponseWriter, r *http.Request) {
		log.Println(version)
		rw.Write([]byte(version + "\n"))
	})
	server := http.Server{
		Handler: mux,
	}

	go func() {
		err := server.Serve(ln)
		if err != http.ErrServerClosed {
			log.Println("HTTP server:", err)
		}
	}()

	if err := upg.Ready(); err != nil {
		panic(err)
	}

	go func() {
		<-upg.Exit() // Wait for the exit signal
		fmt.Println("Exit111111111111111111111111111")
	}()

	select {
	case <-upg.Exit():
		// Handle any cleanup or additional exit logic here
	}

	time.Sleep(10 * time.Hour)
}