go实现服务优雅关闭的示例

c := make(chan os.Signal, 1)
signals := []os.Signal{
   syscall.SIGINT,
   syscall.SIGTERM,
   syscall.SIGQUIT,
}

signal.Notify(c, signals...)
<-c

srv.inShutdown.setTrue()
lnerr := srv.closeListenersLocked()
srv.closeDoneChanLocked()

for {
   rw, err := l.Accept()
   if err != nil {
      select {
      case <-srv.getDoneChan():
         return ErrServerClosed
   // ...       
}

for _, f := range srv.onShutdown {
   go f()
}

timer := time.NewTimer(nextPollInterval())
defer timer.Stop()
for {
   if srv.closeIdleConns() && srv.numListeners() == 0 {
      return lnerr
   }
   select {
   case <-ctx.Done():
      return ctx.Err()
   case <-timer.C:
      timer.Reset(nextPollInterval())
   }
}

func main() {
   // 注册路由
   http.Handle("/aaa", http.HandlerFunc(func(writer http.ResponseWriter, req *http.Request) {
      time.Sleep(time.Second * 10)
      fmt.Println(111)
   }))
   server := http.Server{
      Addr:    "localhost:8080",
      Handler: http.DefaultServeMux,
   }

   close := make(chan int)
   go func() {
      quit := make(chan os.Signal)
      signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT)
      <-quit

      ctx, cancel := context.WithTimeout(context.Background(), time.Second*30)
      defer cancel()
      err := server.Shutdown(ctx)
      log.Print(err)
      
      // 控制外层退出
      close <- 1
   }()

   err := server.ListenAndServe()
   fmt.Println(err)

   <-close
}

close := make(chan int, 2)
go func() {
   quit := make(chan os.Signal)
   signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT)
   <-quit
   go func() {
      <-quit
      os.Exit(1)
   }()

   // ...
}()