epoll

epoll

func serve()  {
	ep, err := netpoll.EpollCreate(epollConfig())
	if err != nil {
		log.Fatal(err)
	}

	// Create listener on port 4444.
	ln, err := listen(4444)
	if err != nil {
		log.Fatal(err)
	}
	defer unix.Close(ln)
	done := make(chan struct{})

	var received bytes.Buffer
	// Add listener fd to epoll instance to know when there are new incoming
	// connections.
	ep.Add(ln, netpoll.EPOLLIN, func(evt netpoll.EpollEvent) {
		if evt&_EPOLLCLOSED != 0 {
			return
		}

		// Accept new incoming connection.
		nfd, _, err := unix.Accept(ln)
		if err != nil {
			log.Fatalf("could not accept: %s", err)
		}

		// Socket must not block read() from it.
		unix.SetNonblock(nfd, true)

		// Add connection fd to epoll instance to get notifications about
		// available data.
		ep.Add(
			nfd,
			netpoll.EPOLLIN|netpoll.EPOLLET|netpoll.EPOLLHUP|netpoll.EPOLLRDHUP,
			func(evt netpoll.EpollEvent,
			) {
			// If EPOLLRDHUP is supported, it will be triggered after conn
			// close() or shutdown(). In older versions EPOLLHUP is triggered.
			if evt&_EPOLLCLOSED != 0 {
				return
			}

			var buf [128]byte

			for {
				n, err := unix.Read(nfd, buf[:])
				if err != nil {
					break
				}
				if n <= 0 {
					break
				}
				received.Write(buf[:n])
			}
			bIo := bufio.NewReader(bytes.NewReader(received.Bytes()))
			req, err := http.ReadRequest(bIo)
			fmt.Println(req, err, "!!!!!!!!!")
			received.Reset()
		})
	})
	<- done
	if err = ep.Close(); err != nil {
		log.Fatal(err)
	}
}


func listen(port int) (ln int, err error) {
	fmt.Println("start server")
	ln, err = unix.Socket(unix.AF_INET, unix.O_NONBLOCK|unix.SOCK_STREAM, 0)
	if err != nil {
		return
	}

	// Need for avoid receiving EADDRINUSE error.
	// Closed listener could be in TIME_WAIT state some time.
	unix.SetsockoptInt(ln, unix.SOL_SOCKET, unix.SO_REUSEADDR, 1)

	addr := &unix.SockaddrInet4{
		Port: port,
		Addr: [4]byte{0x7f, 0, 0, 1}, // 127.0.0.1
	}

	if err = unix.Bind(ln, addr); err != nil {
		return
	}
	err = unix.Listen(ln, 4)

	return
}

func epollConfig() *netpoll.EpollConfig {
	return &netpoll.EpollConfig{
		OnWaitError: func(err error) {
			log.Fatal(err)
		},
	}
}