solve quit/connection close race

irc/client.go

@@ -19,6 +19,7 @@ type Client struct {
 	ctime       time.Time
 	flags       map[UserMode]bool
 	friends     map[*Client]uint
+	hasQuit     bool
 	hops        uint
 	hostname    string
 	idleTimer   *time.Timer
@@ -46,12 +47,16 @@ func NewClient(server *Server, conn net.Conn) *Client {
 		socket:   NewSocket(conn),
 	}
 
-	client.loginTimer = time.AfterFunc(LOGIN_TIMEOUT, client.connectionClosed)
+	client.loginTimer = time.AfterFunc(LOGIN_TIMEOUT, client.connectionTimeout)
 	go client.readCommands()
 
 	return client
 }
 
+//
+// socket read gorountine
+//
+
 func (client *Client) readCommands() {
 	for line := range client.socket.Read() {
 		msg, err := ParseCommand(line)
@@ -68,12 +73,46 @@ func (client *Client) readCommands() {
 		client.server.commands <- msg
 	}
 
-	client.server.toDestroy <- client
+	client.connectionClosed()
+}
+
+func (client *Client) connectionClosed() {
+	msg := &QuitCommand{
+		message: "connection closed",
+	}
+	msg.SetClient(client)
+	client.server.commands <- msg
+}
+
+//
+// idle timer goroutine
+//
+
+func (client *Client) connectionIdle() {
+	client.server.idle <- client
+}
+
+//
+// quit timer goroutine
+//
+
+func (client *Client) connectionTimeout() {
+	msg := &QuitCommand{
+		message: "connection timeout",
+	}
+	msg.SetClient(client)
+	client.server.commands <- msg
+}
+
+//
+// server goroutine
+//
+
+func (client *Client) Active() {
+	client.atime = time.Now()
 }
 
 func (client *Client) Touch() {
-	client.atime = time.Now()
-
 	if client.quitTimer != nil {
 		client.quitTimer.Stop()
 	}
@@ -95,24 +134,11 @@ func (client *Client) Idle() {
 	}
 }
 
-func (client *Client) connectionIdle() {
+func (client *Client) Register() {
-	client.server.idle <- client
+	client.phase = Normal
-}
+	client.loginTimer.Stop()
-
+	client.AddFriend(client)
-func (client *Client) connectionTimeout() {
+	client.Touch()
-	msg := &QuitCommand{
-		message: "connection timeout",
-	}
-	msg.SetClient(client)
-	client.server.commands <- msg
-}
-
-func (client *Client) connectionClosed() {
-	msg := &QuitCommand{
-		message: "connection closed",
-	}
-	msg.SetClient(client)
-	client.server.commands <- msg
 }
 
 func (client *Client) Destroy() {
@@ -225,6 +251,13 @@ func (client *Client) ChangeNickname(nickname string) {
 }
 
 func (client *Client) Quit(message string) {
+	if client.hasQuit {
+		return
+	}
+	client.hasQuit = true
+	client.Reply(RplError(client.server, client.Nick()))
+	client.Destroy()
+
 	if len(client.friends) > 0 {
 		reply := RplQuit(client, message)
 		for friend := range client.friends {
@@ -234,7 +267,4 @@ func (client *Client) Quit(message string) {
 			friend.Reply(reply)
 		}
 	}
-
-	client.Reply(RplError(client.server, client))
-	client.socket.Close()
 }

irc/reply.go

@@ -238,8 +238,8 @@ func RplQuit(client *Client, message string) Reply {
 	return NewStringReply(client, QUIT, ":%s", message)
 }
 
-func RplError(server *Server, target Identifier) Reply {
+func RplError(server *Server, message string) Reply {
-	return NewStringReply(server, ERROR, target.Nick())
+	return NewStringReply(server, ERROR, message)
 }
 
 func RplInviteMsg(channel *Channel, inviter *Client) Reply {

irc/server.go

@@ -24,7 +24,6 @@ type Server struct {
 	name      string
 	operators map[string]string
 	password  string
-	toDestroy chan *Client
 }
 
 func NewServer(config *Config) *Server {
@@ -39,7 +38,6 @@ func NewServer(config *Config) *Server {
 		name:      config.Name,
 		operators: make(map[string]string),
 		password:  config.Password,
-		toDestroy: make(chan *Client),
 	}
 
 	for _, opConf := range config.Operators {
@@ -59,9 +57,6 @@ func (server *Server) ReceiveCommands() {
 		case conn := <-server.conns:
 			NewClient(server, conn)
 
-		case client := <-server.toDestroy:
-			client.Destroy()
-
 		case client := <-server.idle:
 			client.Idle()
 
@@ -75,7 +70,7 @@ func (server *Server) ReceiveCommands() {
 			case Authorization:
 				authCmd, ok := cmd.(AuthServerCommand)
 				if !ok {
-					client.socket.Close()
+					client.Quit("unexpected command")
 					continue
 				}
 				authCmd.HandleAuthServer(server)
@@ -83,7 +78,7 @@ func (server *Server) ReceiveCommands() {
 			case Registration:
 				regCmd, ok := cmd.(RegServerCommand)
 				if !ok {
-					client.socket.Close()
+					client.Quit("unexpected command")
 					continue
 				}
 				regCmd.HandleRegServer(server)
@@ -94,7 +89,15 @@ func (server *Server) ReceiveCommands() {
 					client.Reply(ErrUnknownCommand(server, cmd.Code()))
 					continue
 				}
-				client.Touch()
+				switch srvCmd.(type) {
+				case *PingCommand, *PongCommand:
+					client.Touch()
+				case *QuitCommand:
+					// no-op
+				default:
+					client.Active()
+					client.Touch()
+				}
 				srvCmd.HandleServer(server)
 			}
 		}
@@ -184,10 +187,7 @@ func (s *Server) GenerateGuestNick() string {
 
 func (s *Server) tryRegister(c *Client) {
 	if c.HasNick() && c.HasUsername() {
-		c.phase = Normal
+		c.Register()
-		c.loginTimer.Stop()
-		c.AddFriend(c)
-
 		c.Reply(RplWelcome(s, c))
 		c.Reply(RplYourHost(s))
 		c.Reply(RplCreated(s))
@@ -270,6 +270,10 @@ func (m *PassCommand) HandleAuthServer(s *Server) {
 	client.phase = Registration
 }
 
+func (msg *QuitCommand) HandleAuthServer(server *Server) {
+	msg.Client().Quit(msg.message)
+}
+
 //
 // registration commands
 //
@@ -319,6 +323,10 @@ func (msg *UserCommand) HandleRegServer2(server *Server) {
 	server.tryRegister(client)
 }
 
+func (msg *QuitCommand) HandleRegServer(server *Server) {
+	msg.Client().Quit(msg.message)
+}
+
 //
 // normal commands
 //