Golang utils.PrintPanicStack函数代码示例

// PIPELINE #2: agent
// all the packets from handleClient() will be handled
func agent(sess *Session, in chan []byte, out *Buffer) {
	defer wg.Done() // will decrease waitgroup by one, useful for manual server shutdown
	defer utils.PrintPanicStack()

	// init session
	sess.MQ = make(chan pb.Game_Frame, DEFAULT_MQ_SIZE)
	sess.ConnectTime = time.Now()
	sess.LastPacketTime = time.Now()
	// minute timer
	min_timer := time.After(time.Minute)

	// cleanup work
	defer func() {
		close(sess.Die)
		if sess.Stream != nil {
			sess.Stream.CloseSend()
		}
	}()

	// >> the main message loop <<
	// handles 4 types of message:
	//  1. from client
	//  2. from game service
	//  3. timer
	//  4. server shutdown signal
	for {
		select {
		case msg, ok := <-in: // packet from network
			if !ok {
				return
			}

			sess.PacketCount++
			sess.PacketTime = time.Now()

			if result := proxy_user_request(sess, msg); result != nil {
				out.send(sess, result)
			}
			sess.LastPacketTime = sess.PacketTime
		case frame := <-sess.MQ: // packets from game
			switch frame.Type {
			case pb.Game_Message:
				out.send(sess, frame.Message)
			case pb.Game_Kick:
				sess.Flag |= SESS_KICKED_OUT
			}
		case <-min_timer: // minutes timer
			timer_work(sess, out)
			min_timer = time.After(time.Minute)
		case <-die: // server is shuting down...
			sess.Flag |= SESS_KICKED_OUT
		}

		// see if the player should be kicked out.
		if sess.Flag&SESS_KICKED_OUT != 0 {
			return
		}
	}
}

// agent of user
func agent(sess *Session, in chan []byte, out *Buffer, sess_die chan bool) {
	defer wg.Done()
	defer utils.PrintPanicStack()

	// init session
	sess.MQ = make(chan spp.Game_Frame, DEFAULT_MQ_SIZE)
	sess.ConnectTime = time.Now()
	sess.LastPacketTime = time.Now()
	// minute timer
	min_timer := time.After(time.Minute)

	// cleanup work
	defer func() {
		close(sess_die)
		if sess.Stream != nil {
			sess.Stream.CloseSend()
		}
	}()

	// >> the main message loop <<
	for {
		select {
		case msg, ok := <-in: // packet from network
			if !ok {
				return
			}

			sess.PacketCount++
			sess.PacketTime = time.Now()

			if result := proxy_user_request(sess, msg); result != nil {
				out.send(sess, result)
			}
			sess.LastPacketTime = sess.PacketTime
		case frame := <-sess.MQ:
			switch frame.Type {
			case spp.Game_Message:
				out.send(sess, frame.Message)
			case spp.Game_Kick:
				sess.Flag |= SESS_KICKED_OUT
			}
		case <-min_timer: // minutes timer
			timer_work(sess, out)
			min_timer = time.After(time.Minute)
		case <-die: // server is shuting down...
			sess.Flag |= SESS_KICKED_OUT
		}

		// see if the player should be kicked out.
		if sess.Flag&SESS_KICKED_OUT != 0 {
			return
		}
	}
}

// packet sending goroutine
func (buf *Buffer) start() {
	defer utils.PrintPanicStack()
	for {
		select {
		case data := <-buf.pending:
			buf.raw_send(data)
		case <-buf.ctrl: // receive session end signal
			close(buf.pending)
			// close the connection
			buf.conn.Close()
			return
		}
	}
}

func main() {
	// to catch all uncaught panic
	defer utils.PrintPanicStack()

	// open profiling
	go func() {
		log.Info(http.ListenAndServe("0.0.0.0:6060", nil))
	}()

	// set log prefix
	log.SetPrefix(SERVICE)

	// resolve address & start listening
	tcpAddr, err := net.ResolveTCPAddr("tcp4", _port)
	checkError(err)

	listener, err := net.ListenTCP("tcp", tcpAddr)
	checkError(err)

	log.Info("listening on:", listener.Addr())

	// startup
	startup()

LOOP:
	// loop accepting
	for {
		conn, err := listener.AcceptTCP()
		if err != nil {
			log.Warning("accept failed:", err)
			continue
		}
		go handleClient(conn) // start a goroutine for every incoming connection for reading

		// check server close signal
		select {
		case <-die:
			listener.Close()
			break LOOP
		default:
		}
	}

	// server closed, wait forever
	// other options:
	// select{} 	-- may cause deadlock detected error, not tested yet
	for {
		<-time.After(time.Second)
	}
}

func main() {
	defer utils.PrintPanicStack()
	go func() {
		log.Info(http.ListenAndServe("0.0.0.0:6060", nil))
	}()

	log.SetPrefix(SERVICE)

	// resolve
	tcpAddr, err := net.ResolveTCPAddr("tcp4", _port)
	checkError(err)

	listener, err := net.ListenTCP("tcp", tcpAddr)
	checkError(err)

	log.Info("listening on:", listener.Addr())

	// init services
	sp.Init()

	// startup
	startup()

	// loop accepting
LOOP:
	for {
		conn, err := listener.AcceptTCP()
		if err != nil {
			log.Warning("accept failed:", err)
			continue
		}
		go handleClient(conn)

		// check server close signal
		select {
		case <-die:
			listener.Close()
			break LOOP
		default:
		}
	}

	// server closed, wait forever
	for {
		<-time.After(time.Second)
	}
}

// handle unix signals
func sig_handler() {
	defer utils.PrintPanicStack()
	ch := make(chan os.Signal, 1)
	signal.Notify(ch, syscall.SIGTERM)

	for {
		msg := <-ch
		switch msg {
		case syscall.SIGTERM: // 关闭agent
			close(die)
			log.Info("sigterm received")
			log.Info("waiting for agents close, please wait...")
			wg.Wait()
			log.Info("agent shutdown.")
			os.Exit(0)
		}
	}
}

// packet sending goroutine
// 数据包发送协程
func (buf *Buffer) start() {
	defer utils.PrintPanicStack()
	for {
		select {
		//监听数据包管道
		case data := <-buf.pending:
			buf.raw_send(data)
		//监听关闭管道
		//?Important
		//ctrl 指向的是 sess_die, 在main.go里面,已经有select监听了? 此处会不会造成问题
		case <-buf.ctrl: //receive session end signal
			//关闭接收管道
			close(buf.pending)
			//关闭conn连接
			buf.conn.Close()
			return
		}
	}
}

//游戏入口
func main() {
	defer utils.PrintPanicStack()
	go func() {
		log.Info(http.ListenAndServe("0.0.0.0:6060", nil))
	}()

	log.SetPrefix(SERVICE)

	tcpAddr, err := net.ResolveTCPAddr("tcp4", _port)
	checkError(err)

	listener, err := net.ListenTCP("tcp", tcpAddr)
	checkError(err)

	log.Info("listening on:", listener.Addr())

	// loop accepting
	for {
		conn, err := listener.AcceptTCP()
		if err != nil {
			log.Warning("accept failed:", err)
			continue
		}
		go handleClient(conn)

		// check server close signal
		select {
		case <-die:
			listener.Close()
			goto FINAL
		default:
		}
	}
FINAL:
	// server closed, wait forever
	// 此处为什么要等1秒
	// 此处等待1秒钟，只是为了wg.Wait() 可以执行到，从而阻塞主线程
	for {
		<-time.After(time.Second)
	}
}

// client protocol handle proxy
func proxy_user_request(sess *Session, p []byte) []byte {
	start := time.Now()
	defer utils.PrintPanicStack()
	//解密
	if sess.Flag&SESS_ENCRYPT != 0 {
		//使用2组密钥匙, 增加破解难度
		sess.Decoder.XORKeyStream(p, p)
	}

	//封装成reader
	reader := packet.Reader(p)

	// 读客户端数据包序列号(1,2,3...)
	// 可避免重放攻击-REPLAY-ATTACK
	//数据包的前4个字节存放的是客户端的发包数量
	//客户端每次发包要包含第几次发包信息
	seq_id, err := reader.ReadU32()
	if err != nil {
		log.Error("read client timestamp failed:", err)
		sess.Flag |= SESS_KICKED_OUT
		return nil
	}

	// 数据包个数验证
	if seq_id != sess.PacketCount {
		//数据包真实长度是，总长度-4个字节的包个数长度-2个字节的协议号长度
		log.Errorf("illegal packet sequeue id:%v should be:%v size:%v", seq_id, sess.PacketCount, len(p)-6)
		sess.Flag |= SESS_KICKED_OUT
		return nil
	}

	// 读协议号
	b, err := reader.ReadS16()
	if err != nil {
		log.Error("read protocol number failed.")
		sess.Flag |= SESS_KICKED_OUT
		return nil
	}

	//根据协议号段 做服务划分
	var ret []byte
	if b > MAX_PROTO_NUM {
		//去除4字节发包个数,将其余的向前传递
		if err := forward(sess, p[4:]); err != nil {
			log.Errorf("service id:%v execute failed, error:%v", b, err)
			sess.Flag |= SESS_KICKED_OUT
			return nil
		}
	} else {
		if h := client_handler.Handlers[b]; h != nil {
			ret = h(sess, reader)
		} else {
			log.Errorf("service id:%v not bind", b)
			sess.Flag |= SESS_KICKED_OUT
			return nil
		}
	}

	// 统计处理时间
	elasped := time.Now().Sub(start)
	if b != 0 { //排除心跳包日志
		log.Trace("[REQ]", client_handler.RCode[b])
		_statter.Timing(1.0, fmt.Sprintf("%v%v", STATSD_PREFIX, client_handler.RCode[b]), elasped)
	}
	return ret
}

// start a goroutine when a new connection is accepted
func handleClient(conn *net.TCPConn) {
	defer utils.PrintPanicStack()
	// set per-connection socket buffer
	conn.SetReadBuffer(SO_RCVBUF)

	// set initial socket buffer
	conn.SetWriteBuffer(SO_SNDBUF)

	// initial network control struct
	header := make([]byte, 2)
	in := make(chan []byte)
	defer func() {
		close(in) // session will close
	}()

	// create a new session object for the connection
	var sess Session
	host, port, err := net.SplitHostPort(conn.RemoteAddr().String())
	if err != nil {
		log.Error("cannot get remote address:", err)
		return
	}
	sess.IP = net.ParseIP(host)
	log.Infof("new connection from:%v port:%v", host, port)

	// session die signal
	sess.Die = make(chan struct{})

	// create a write buffer
	out := new_buffer(conn, sess.Die)
	go out.start()

	// start one agent for handling packet
	wg.Add(1)
	go agent(&sess, in, out)

	// network loop
	for {
		// solve dead link problem
		conn.SetReadDeadline(time.Now().Add(TCP_READ_DEADLINE * time.Second))
		n, err := io.ReadFull(conn, header)
		if err != nil {
			log.Warningf("read header failed, ip:%v reason:%v size:%v", sess.IP, err, n)
			return
		}
		size := binary.BigEndian.Uint16(header)

		// alloc a byte slice for reading
		payload := make([]byte, size)
		// read msg
		n, err = io.ReadFull(conn, payload)
		if err != nil {
			log.Warningf("read payload failed, ip:%v reason:%v size:%v", sess.IP, err, n)
			return
		}

		select {
		case in <- payload: // payload queued
		case <-sess.Die:
			log.Warningf("connection closed by logic, flag:%v ip:%v", sess.Flag, sess.IP)
			return
		}
	}
}

// client protocol handle proxy
func proxy_user_request(sess *Session, p []byte) []byte {
	start := time.Now()
	defer utils.PrintPanicStack(sess, p)
	// 解密
	if sess.Flag&SESS_ENCRYPT != 0 {
		sess.Decoder.Codec(p)
	}

	// 封装为reader
	reader := packet.Reader(p)

	// 读客户端数据包序列号(1,2,3...)
	// 可避免重放攻击-REPLAY-ATTACK
	seq_id, err := reader.ReadU32()
	if err != nil {
		log.Error("read client timestamp failed:", err)
		sess.Flag |= SESS_KICKED_OUT
		return nil
	}

	// 读协议号
	b, err := reader.ReadS16()
	if err != nil {
		log.Error("read protocol number failed.")
		sess.Flag |= SESS_KICKED_OUT
		return nil
	}

	// 数据包序列号验证
	if seq_id != sess.PacketCount {
		log.Errorf("illegal packet sequence id:%v should be:%v proto:%v size:%v", seq_id, sess.PacketCount, b, len(p)-6)
		sess.Flag |= SESS_KICKED_OUT
		return nil
	}

	var ret []byte
	if b > MAX_PROTO_NUM { // game协议
		// 透传
		ret, err = forward(sess, p)
		if err != nil {
			log.Errorf("service id:%v execute failed", b)
			sess.Flag |= SESS_KICKED_OUT
			return nil
		}
	} else { // agent保留协议段 [0, MAX_PROTO_NUM]
		// handle有效性检查
		h := client_handler.Handlers[b]
		if h == nil {
			log.Errorf("service id:%v not bind", b)
			sess.Flag |= SESS_KICKED_OUT
			return nil
		}
		// 执行
		ret = h(sess, reader)
	}

	// 统计处理时间
	elasped := time.Now().Sub(start)
	if b != 0 { // 排除心跳包日志
		log.Trace("[REQ]", b)
		_statter.Timing(1.0, fmt.Sprintf("%v%v", STATSD_PREFIX, b), elasped)
	}
	return ret
}

// start a goroutine when a new connection is accepted
func handleClient(conn *net.TCPConn) {
	defer utils.PrintPanicStack()
	// set per-connection socket buffer
	//设置conn连接接受缓存的大小, 当超过缓存时, 会进入阻塞状态,等待被读取
	conn.SetReadBuffer(SO_RCVBUF)

	// set initial socket buffer
	//设置conn连接发送缓存的大小, 当超过缓存时, 会进入阻塞状态,等待被发送成功
	conn.SetWriteBuffer(SO_SNDBUF)

	// initial network control struct
	// 初始化2个字节数组, 用于存储header长度, 既后面要读取的文件长度
	header := make([]byte, 2)
	// 输入流通道, 解析后的数据将放入，等待被处理
	in := make(chan []byte)

	//设置延迟函数，当玩家断开连接时, 函数退出之前，关闭输入流
	defer func() {
		close(in) // session will close
	}()

	// create a new session object for the connection
	//创建session对象, 用于封装客户端和服务器的信息交换
	var sess Session
	host, port, err := net.SplitHostPort(conn.RemoteAddr().String())
	if err != nil {
		log.Error("cannot get remote address:", err)
		return
	}
	//存储用户ip
	sess.IP = net.ParseIP(host)
	//打印用户的ip和端口, 用户可能会双开？
	log.Infof("new connection from:%v port:%v", host, port)

	// session die signal
	sess_die := make(chan bool)

	//SESSION_DIE 监控有问题.................

	// create a write buffer
	// 创建写入buffer对象
	out := new_buffer(conn, sess_die)
	go out.start()

	// start one agent for handling packet
	//记录goroutine个数，让系统接收到关闭命令后，会阻塞主线程，至少所有agent线程退出，已保证数据落地
	wg.Add(1)
	go agent(&sess, in, out, sess_die)

	//network loop
	for {
		// solve dead line problem
		// 设置读超时时间, 如果在任意一次执行Read syscall 返回的时候，超过这个时间点， 则算超时
		conn.SetReadDeadline(time.Now().Add(TCP_READ_DEADLINE * time.Second))
		//先读取2个字节头文件长度
		n, err := io.ReadFull(conn, header)
		if err != nil {
			log.Warningf("read header failed, ip:%v reason:%v size:%v", sess.IP, err, n)
			return
		}
		//将2个字节数组转成int16类型, 不丢失精度
		size := binary.BigEndian.Uint16(header)

		// alloc a byte slice for reading
		// 创建一个指定长度的切片，用于存放具体内容
		payload := make([]byte, size)
		//read msg
		n, err = io.ReadFull(conn, payload)
		if err != nil {
			log.Warningf("read payload failed, ip:%v reason:%v size:%v", sess.IP, err, n)
			return
		}

		select {
		//接收的数据，转入in通道
		case in <- payload: //payload queued
			//监听sess_die 通道
		case <-sess_die:
			log.Warning("connection closed by logic, flag:%v ip:%v", sess.Flag, sess.IP)
			return
		}
	}

	// 好像没有处理连接超时, 如果玩家连上游戏后，一直未操作，再次链接时，会是新的连接？难道客户端在许久没有操作的情况下，先发一次ping, 如果有响应，继续操作，如果没响应，则执行重连？

	// 如果玩家已经退出了游戏，但是通过非正常途径退出的，这时，服务器还保留着该session, 当玩家再次登陆时， 原先的连接何时删除

}

// client protocol handle proxy
func proxy_user_request(sess *Session, p []byte) []byte {
	start := time.Now()
	defer utils.PrintPanicStack(sess, p)
	// 解密
	if sess.Flag&SESS_ENCRYPT != 0 {
		sess.Decoder.XORKeyStream(p, p)
	}
	// 封装为reader
	reader := packet.Reader(p)

	// 读客户端数据包序列号(1,2,3...)
	// 客户端发送的数据包必须包含一个自增的序号，必须严格递增
	// 加密后，可避免重放攻击-REPLAY-ATTACK
	seq_id, err := reader.ReadU32()
	if err != nil {
		log.Error("read client timestamp failed:", err)
		sess.Flag |= SESS_KICKED_OUT
		return nil
	}

	// 数据包序列号验证
	if seq_id != sess.PacketCount {
		log.Errorf("illegal packet sequence id:%v should be:%v size:%v", seq_id, sess.PacketCount, len(p)-6)
		sess.Flag |= SESS_KICKED_OUT
		return nil
	}

	// 读协议号
	b, err := reader.ReadS16()
	if err != nil {
		log.Error("read protocol number failed.")
		sess.Flag |= SESS_KICKED_OUT
		return nil
	}

	// 根据协议号断做服务划分
	// 协议号的划分采用分割协议区间, 用户可以自定义多个区间，用于转发到不同的后端服务
	var ret []byte
	if b > MAX_PROTO_NUM {
		if err := forward(sess, p[4:]); err != nil {
			log.Errorf("service id:%v execute failed, error:%v", b, err)
			sess.Flag |= SESS_KICKED_OUT
			return nil
		}
	} else {
		if h := client_handler.Handlers[b]; h != nil {
			ret = h(sess, reader)
		} else {
			log.Errorf("service id:%v not bind", b)
			sess.Flag |= SESS_KICKED_OUT
			return nil
		}
	}

	// 监控协议处理时间
	// 监控数值会发送到statsd,格式为:
	// API.XXX_REQ = 10ms
	elasped := time.Now().Sub(start)
	if b != 0 { // 排除心跳包日志
		log.Trace("[REQ]", client_handler.RCode[b])
		_statter.Timing(1.0, fmt.Sprintf("%v%v", STATSD_PREFIX, client_handler.RCode[b]), elasped)
	}
	return ret
}

// PIPELINE #1: handleClient
// the goroutine is used for reading incoming PACKETS
// each packet is defined as :
// | 2B size |     DATA       |
//
func handleClient(conn *net.TCPConn) {
	defer utils.PrintPanicStack()
	// set socket read buffer
	conn.SetReadBuffer(SO_RCVBUF)
	// set socket write buffer
	conn.SetWriteBuffer(SO_SNDBUF)

	// for reading the 2-Byte header
	header := make([]byte, 2)
	// the input channel for agent()
	in := make(chan []byte)
	defer func() {
		close(in) // session will close
	}()

	// create a new session object for the connection
	// and record it's IP address
	var sess Session
	host, port, err := net.SplitHostPort(conn.RemoteAddr().String())
	if err != nil {
		log.Error("cannot get remote address:", err)
		return
	}
	sess.IP = net.ParseIP(host)
	log.Infof("new connection from:%v port:%v", host, port)

	// session die signal, will be triggered by agent()
	sess.Die = make(chan struct{})

	// create a write buffer
	out := new_buffer(conn, sess.Die)
	go out.start()

	// start agent for PACKET processing
	wg.Add(1)
	go agent(&sess, in, out)

	// read loop
	for {
		// solve dead link problem:
		// physical disconnection without any communcation between client and server
		// will cause the read to block FOREVER, so a timeout is a rescue.
		conn.SetReadDeadline(time.Now().Add(TCP_READ_DEADLINE * time.Second))

		// read 2B header
		n, err := io.ReadFull(conn, header)
		if err != nil {
			log.Warningf("read header failed, ip:%v reason:%v size:%v", sess.IP, err, n)
			return
		}
		size := binary.BigEndian.Uint16(header)

		// alloc a byte slice of the size defined in the header for reading data
		payload := make([]byte, size)
		n, err = io.ReadFull(conn, payload)
		if err != nil {
			log.Warningf("read payload failed, ip:%v reason:%v size:%v", sess.IP, err, n)
			return
		}

		// deliver the data to the input queue of agent()
		select {
		case in <- payload: // payload queued
		case <-sess.Die:
			log.Warningf("connection closed by logic, flag:%v ip:%v", sess.Flag, sess.IP)
			return
		}
	}
}

func agent(sess *Session, in chan []byte, out *Buffer, sess_die chan bool) {
	defer wg.Done()
	defer utils.PrintPanicStack()

	// init session
	//存储玩家异步消息, 让消息超过时, 会阻塞，等待等读取,
	//那么如果一直是满的时，玩家好久没上线
	//别的玩家发过来的消息会一直发送不过去, 这时会长期阻塞，怎么解决, 发送方设置超时,当许久没发送成功后，弹出对方信箱已满?
	//  ...... 这里是异步消息，还是离线消息？
	sess.MQ = make(chan []byte, DEFAULT_MQ_SIZE)
	sess.ConnectTime = time.Now()
	sess.LastPacketTime = time.Now()

	// minute timer
	min_timer := time.After(time.Minute)

	// cleanup work
	defer func() {
		close(sess_die)
		//  当session关闭时，连接游戏后段的流需要关闭
		if sess.Stream != nil {
			sess.Stream.CloseSend()
		}
	}()

	// >> the main message loop <<
	for {
		select {
		case msg, ok := <-in: // packet from network
			if !ok {
				return
			}

			//数据包个数++
			sess.PacketCount++
			//更新接收数据包的时间
			sess.PacketTime = time.Now()

			//处理用户请求
			if result := proxy_user_request(sess, msg); result != nil {
				//将结果发送出去
				out.send(sess, result)
			}
			//当处理完之后，将数据包时间设置成上个数据包时间
			sess.LastPacketTime = sess.PacketTime
			//如果异步通道有消息? (内部发送过来的消息）
		case frame := <-sess.MQ:
			switch frame.Type {
			case spp.Game_Message:
				out.send(sess, frame.Message)
				//如果是关闭命令, 则设置关闭状态， (用于后台管理)
			case spp.Game_Kick:
				sess.Flag |= SESS_KICKED_OUT
			}
		case <-min_timer: //minutes timer
			//定时器工作, 用于检测用户行为，防治玩家作弊
			timer_work(sess, out)
			min_timer = time.After(time.Minute)
		case <-die: // server is shuting down...
			sess.Flag |= SESS_KICKED_OUT
		}

		// see if the player should be kicked out.
		if sess.Flag&SESS_KICKED_OUT != 0 {
			return
		}
	}
}