Gin为啥需要优雅关闭服务器?

Gin为啥需要优雅关闭服务器?

以前以为关闭服务器没有用，但是当你写个一下子启动多个服务器的端口，多重启几次，就会出现下面报错

[GIN-debug] [ERROR] listen tcp :8081: bind: Only one usage of each socket address (protocol/network address/port) is normally permitted.
[GIN-debug] [ERROR] listen tcp :18083: bind: Only one usage of each socket address (protocol/network address/port) is normally permitted.

报错原因

每个端口就相当于io,底层的socket就是个文件fd,文件的fd一般会有缓存，即使fd.close()也不会刷盘，如果调用关闭服务器接口，就相当于fs.sync()刷盘再去关闭.

关闭服务代码片段

# 片段1
func WaitSignal(srv *Server) {
	c := make(chan os.Signal, 7)
	signal.Notify(c, syscall.SIGINT, syscall.SIGHUP, syscall.SIGTERM, syscall.SIGQUIT, syscall.SIGILL, syscall.SIGTRAP, syscall.SIGABRT)
	var s os.Signal
	for {
		select {
		case s = <-c:
			DEBUG.Println("got os signal ", s.String())
			DEBUG.Println("开始关闭http dashboard服务...")
			srv.HttpServer.Stop()
			time.Sleep(time.Millisecond * 100)

			exec.Command("sync").Run()
			return
		default:
			time.Sleep(time.Second)
		}
	}

}


# 片段2
type HttpServer struct {
	Srv *Server

	Port string

	HttpDashboardServer *HttpDashboardServer
	HttpApiServer *HttpApiServer
}

func NewHttpServer(dashPort string, apiPort string) *HttpServer {
	hs :=  &HttpServer{
		HttpDashboardServer:NewHttpDashboardServer(dashPort),
		HttpApiServer:NewHttpApiServer(apiPort),
	}

	go hs.Start()
	return hs
}


func (hs *HttpServer)Start() {
	// 先让Broker装弹
	time.Sleep(time.Second * 3)

	// 操作api
	go hs.HttpApiServer.Serve()

	// 面板的api
	go hs.HttpDashboardServer.Serve()
}

func (hs *HttpServer) Stop()  {
	hs.HttpApiServer.ShoutDown()
	hs.HttpDashboardServer.ShoutDown()
}