fix race data related to reading bridge state

Makefile

@@ -6,6 +6,9 @@ mumble-discord-bridge: $(GOFILES)
 dev: $(GOFILES)
 	goreleaser build --skip-validate --rm-dist && sudo ./dist/mumble-discord-bridge_linux_amd64/mumble-discord-bridge
 
+dev-race: $(GOFILES)
+	go run -race *.go
+
 dev-profile: $(GOFILES)
 	goreleaser build --skip-validate --rm-dist && sudo ./dist/mumble-discord-bridge_linux_amd64/mumble-discord-bridge -cpuprofile cpu.prof
 

bridge.go

@@ -35,6 +35,9 @@ type BridgeState struct {
 	// Wait for bridge to exit cleanly
 	WaitExit *sync.WaitGroup
 
+	// Bridge State Mutex
+	BridgeMutex sync.Mutex
+
 	// Bridge connection
 	Connected bool
 
@@ -189,7 +192,9 @@ func (b *BridgeState) startBridge() {
 		}
 	}()
 
+	b.BridgeMutex.Lock()
 	b.Connected = true
+	b.BridgeMutex.Unlock()
 
 	// Hold until cancelled or external die request
 	select {
@@ -200,7 +205,10 @@ func (b *BridgeState) startBridge() {
 		cancel()
 	}
 
+	b.BridgeMutex.Lock()
 	b.Connected = false
+	b.BridgeMutex.Unlock()
+
 	wg.Wait()
 	log.Println("Terminating Bridge")
 	b.MumbleUsersMutex.Lock()
@@ -221,6 +229,7 @@ func (b *BridgeState) discordStatusUpdate() {
 			b.DiscordSession.UpdateListeningStatus("an error pinging mumble")
 		} else {
 			b.MumbleUsersMutex.Lock()
+			b.BridgeMutex.Lock()
 			b.MumbleUserCount = resp.ConnectedUsers
 			if b.Connected {
 				b.MumbleUserCount = b.MumbleUserCount - 1
@@ -234,6 +243,7 @@ func (b *BridgeState) discordStatusUpdate() {
 					status = fmt.Sprintf("%v users in Mumble\n", b.MumbleUserCount)
 				}
 			}
+			b.BridgeMutex.Unlock()
 			b.MumbleUsersMutex.Unlock()
 			b.DiscordSession.UpdateListeningStatus(status)
 		}
@@ -257,6 +267,7 @@ func (b *BridgeState) AutoBridge() {
 
 		b.MumbleUsersMutex.Lock()
 		b.DiscordUsersMutex.Lock()
+		b.BridgeMutex.Lock()
 
 		if !b.Connected && b.MumbleUserCount > 0 && len(b.DiscordUsers) > 0 {
 			log.Println("users detected in mumble and discord, bridging")
@@ -267,6 +278,7 @@ func (b *BridgeState) AutoBridge() {
 			b.BridgeDie <- true
 		}
 
+		b.BridgeMutex.Unlock()
 		b.MumbleUsersMutex.Unlock()
 		b.DiscordUsersMutex.Unlock()
 	}

discord-handlers.go

@@ -49,11 +49,13 @@ func (l *DiscordListener) guildCreate(s *discordgo.Session, event *discordgo.Gui
 			l.Bridge.DiscordUsersMutex.Unlock()
 
 			// If connected to mumble inform users of Discord users
+			l.Bridge.BridgeMutex.Lock()
 			if l.Bridge.Connected && !l.Bridge.BridgeConfig.MumbleDisableText {
 				l.Bridge.MumbleClient.Do(func() {
 					l.Bridge.MumbleClient.Self.Channel.Send(fmt.Sprintf("%v has joined Discord\n", u.Username), false)
 				})
 			}
+			l.Bridge.BridgeMutex.Unlock()
 
 		}
 	}
@@ -85,10 +87,14 @@ func (l *DiscordListener) messageCreate(s *discordgo.Session, m *discordgo.Messa
 		return
 	}
 
+	l.Bridge.BridgeMutex.Lock()
+	bridgeConnected := l.Bridge.Connected
+	l.Bridge.BridgeMutex.Unlock()
+
 	if strings.HasPrefix(m.Content, prefix+" link") {
 		// Look for the message sender in that guild's current voice states.
 		for _, vs := range g.VoiceStates {
-			if l.Bridge.Connected {
+			if bridgeConnected {
 				l.Bridge.DiscordSession.ChannelMessageSend(m.ChannelID, "Bridge already running, unlink first")
 				return
 			}
@@ -103,7 +109,7 @@ func (l *DiscordListener) messageCreate(s *discordgo.Session, m *discordgo.Messa
 
 	if strings.HasPrefix(m.Content, prefix+" unlink") {
 		// Look for the message sender in that guild's current voice states.
-		if !l.Bridge.Connected {
+		if !bridgeConnected {
 			l.Bridge.DiscordSession.ChannelMessageSend(m.ChannelID, "Bridge is not currently running")
 			return
 		}
@@ -118,7 +124,7 @@ func (l *DiscordListener) messageCreate(s *discordgo.Session, m *discordgo.Messa
 
 	if strings.HasPrefix(m.Content, prefix+" refresh") {
 		// Look for the message sender in that guild's current voice states.
-		if !l.Bridge.Connected {
+		if !bridgeConnected {
 			l.Bridge.DiscordSession.ChannelMessageSend(m.ChannelID, "Bridge is not currently running")
 			return
 		}
@@ -195,11 +201,13 @@ func (l *DiscordListener) voiceUpdate(s *discordgo.Session, event *discordgo.Voi
 						seen:     true,
 						dm:       dm,
 					}
+					l.Bridge.BridgeMutex.Lock()
 					if l.Bridge.Connected && !l.Bridge.BridgeConfig.MumbleDisableText {
 						l.Bridge.MumbleClient.Do(func() {
 							l.Bridge.MumbleClient.Self.Channel.Send(fmt.Sprintf("%v has joined Discord\n", u.Username), false)
 						})
 					}
+					l.Bridge.BridgeMutex.Unlock()
 				} else {
 					du := l.Bridge.DiscordUsers[vs.UserID]
 					du.seen = true
@@ -213,11 +221,13 @@ func (l *DiscordListener) voiceUpdate(s *discordgo.Session, event *discordgo.Voi
 		for id := range l.Bridge.DiscordUsers {
 			if !l.Bridge.DiscordUsers[id].seen {
 				log.Println("User left Discord channel " + l.Bridge.DiscordUsers[id].username)
+				l.Bridge.BridgeMutex.Lock()
 				if l.Bridge.Connected && !l.Bridge.BridgeConfig.MumbleDisableText {
 					l.Bridge.MumbleClient.Do(func() {
 						l.Bridge.MumbleClient.Self.Channel.Send(fmt.Sprintf("%v has left Discord channel\n", l.Bridge.DiscordUsers[id].username), false)
 					})
 				}
+				l.Bridge.BridgeMutex.Unlock()
 				delete(l.Bridge.DiscordUsers, id)
 			}
 		}

discord.go

@@ -24,7 +24,6 @@ type DiscordDuplex struct {
 	Bridge *BridgeState
 
 	discordMutex   sync.Mutex
-	discordMixerMutex sync.Mutex
 	fromDiscordMap map[uint32]fromDiscord
 }
 
@@ -87,6 +86,7 @@ func (dd *DiscordDuplex) discordSendPCM(ctx context.Context, wg *sync.WaitGroup,
 				continue
 			}
 
+			dd.Bridge.DiscordVoice.RWMutex.RLock()
 			if !dd.Bridge.DiscordVoice.Ready || dd.Bridge.DiscordVoice.OpusSend == nil {
 				if lastReady {
 					OnError(fmt.Sprintf("Discordgo not ready for opus packets. %+v : %+v", dd.Bridge.DiscordVoice.Ready, dd.Bridge.DiscordVoice.OpusSend), nil)
@@ -96,13 +96,15 @@ func (dd *DiscordDuplex) discordSendPCM(ctx context.Context, wg *sync.WaitGroup,
 					})
 					lastReady = false
 				}
-				continue
 			} else if !lastReady {
 				fmt.Println("Discordgo ready to send opus packets")
 				lastReady = true
 				readyTimeout.Stop()
-			}
+			} else {
 				dd.Bridge.DiscordVoice.OpusSend <- opus
+			}
+			dd.Bridge.DiscordVoice.RWMutex.RUnlock()
+
 		} else {
 			if streaming {
 				dd.Bridge.DiscordVoice.Speaking(false)
@@ -123,6 +125,7 @@ func (dd *DiscordDuplex) discordReceivePCM(ctx context.Context, wg *sync.WaitGro
 	wg.Add(1)
 
 	for {
+		dd.Bridge.DiscordVoice.RWMutex.RLock()
 		if !dd.Bridge.DiscordVoice.Ready || dd.Bridge.DiscordVoice.OpusRecv == nil {
 			if lastReady {
 				OnError(fmt.Sprintf("Discordgo not to receive opus packets. %+v : %+v", dd.Bridge.DiscordVoice.Ready, dd.Bridge.DiscordVoice.OpusSend), nil)
@@ -138,6 +141,7 @@ func (dd *DiscordDuplex) discordReceivePCM(ctx context.Context, wg *sync.WaitGro
 			lastReady = true
 			readyTimeout.Stop()
 		}
+		dd.Bridge.DiscordVoice.RWMutex.RUnlock()
 
 		var ok bool
 		var p *discordgo.Packet

main.go

@@ -40,7 +40,7 @@ func main() {
 	mumblePassword := flag.String("mumble-password", lookupEnvOrString("MUMBLE_PASSWORD", ""), "MUMBLE_PASSWORD, mumble password, optional")
 	mumbleInsecure := flag.Bool("mumble-insecure", lookupEnvOrBool("MUMBLE_INSECURE", false), " MUMBLE_INSECURE, mumble insecure, optional")
 	mumbleCertificate := flag.String("mumble-certificate", lookupEnvOrString("MUMBLE_CERTIFICATE", ""), "MUMBLE_CERTIFICATE, client certificate to use when connecting to the Mumble server")
-	mumbleChannel := flag.String("mumble-channel", lookupEnvOrString("MUMBLE_CHANNEL", ""), "MUMBLE_CHANNEL, mumble channel to start in, using '/' to seperate nested channels, optional")
+	mumbleChannel := flag.String("mumble-channel", lookupEnvOrString("MUMBLE_CHANNEL", ""), "MUMBLE_CHANNEL, mumble channel to start in, using '/' to separate nested channels, optional")
 	mumbleDisableText := flag.Bool("mumble-disable-text", lookupEnvOrBool("MUMBLE_DISABLE_TEXT", false), "MUMBLE_DISABLE_TEXT, disable sending text to mumble, (default false)")
 	discordToken := flag.String("discord-token", lookupEnvOrString("DISCORD_TOKEN", ""), "DISCORD_TOKEN, discord bot token, required")
 	discordGID := flag.String("discord-gid", lookupEnvOrString("DISCORD_GID", ""), "DISCORD_GID, discord gid, required")
@@ -197,9 +197,11 @@ func main() {
 	log.Println("OS Signal. Bot shutting down")
 
 	// Wait or the bridge to exit cleanly
+	Bridge.BridgeMutex.Lock()
 	if Bridge.Connected {
 		//TODO BridgeDie occasionally panics on send to closed channel
 		Bridge.BridgeDie <- true
 		Bridge.WaitExit.Wait()
 	}
+	Bridge.BridgeMutex.Unlock()
 }

mumble-handlers.go

@@ -43,22 +43,23 @@ func (l *MumbleListener) mumbleUserChange(e *gumble.UserChangeEvent) {
 			e.User.Send("Mumble-Discord-Bridge v" + version)
 
 			// Tell the user who is connected to discord
+			l.Bridge.DiscordUsersMutex.Lock()
 			if len(l.Bridge.DiscordUsers) == 0 {
 				e.User.Send("No users connected to Discord")
 			} else {
 				s := "Connected to Discord: "
 
 				arr := []string{}
-				l.Bridge.DiscordUsersMutex.Lock()
 				for u := range l.Bridge.DiscordUsers {
 					arr = append(arr, l.Bridge.DiscordUsers[u].username)
 				}
 
 				s = s + strings.Join(arr[:], ",")
 
-				l.Bridge.DiscordUsersMutex.Unlock()
 				e.User.Send(s)
 			}
+			l.Bridge.DiscordUsersMutex.Unlock()
+
 		}
 
 		// Send discord a notice