Fix concurrent read and errors by using Mutex

extractor/chat/chatRelayClientHandler.go

@@ -67,7 +67,11 @@ func (c *Client) Write() {
 }
 
 func (c *Client) Close() {
+	_, ok := <-c.send
+
+	if ok {
 		close(c.send)
+	}
 	c.Conn.Close()
 }
 

extractor/chat/chatRelayClientMessageHandler.go

@@ -6,14 +6,12 @@ import (
 
 func ClientMessageHandler(client *Client, msg string) {
 	splitMsg := strings.Split(msg, " ")
-
 	if len(splitMsg) == 2 && splitMsg[0] == "JOIN" {
 		client.send <- "OK"
 		client.FollowingStreamers[splitMsg[1]] = true
 		FollowStreamer(splitMsg[1])
 		return
-	}
-
-	client.send <- "Invalid request"
+	} else {
 		client.Close()
+	}
 }

extractor/chat/chatRelayClientSorter.go

@@ -1,24 +1,41 @@
 package chat
 
-type ClientMap map[*Client]bool
+import (
+	"sync"
+)
 
-var ClientHandler = ClientMap{}
-
-func (c ClientMap) AddClient(client *Client) {
-	c[client] = true
+type ClientMap struct {
+	Clients map[*Client]bool
+	sync.Mutex
 }
 
-func (c ClientMap) DeleteClient(ID string) {
-	for client := range c {
+var ClientHandler = ClientMap{
+	Clients: map[*Client]bool{},
+	Mutex:   sync.Mutex{},
+}
+
+func (c *ClientMap) AddClient(client *Client) {
+	c.Lock()
+	c.Clients[client] = true
+	c.Unlock()
+}
+
+func (c *ClientMap) DeleteClient(ID string) {
+	c.Lock()
+
+	for client := range c.Clients {
 		if client.ID == ID {
-			delete(c, client)
+			delete(c.Clients, client)
 		}
 	}
+	c.Unlock()
 }
 
-func (c ClientMap) FindClientsByStreamer(streamer string) []*Client {
+func (c *ClientMap) FindClientsByStreamer(streamer string) []*Client {
+	c.Lock()
+
 	var clients []*Client
-	for client := range c {
+	for client := range c.Clients {
 		// check if the client is following the given streamer
 		for s, _ := range client.FollowingStreamers {
 			if s == streamer {
@@ -27,5 +44,6 @@ func (c ClientMap) FindClientsByStreamer(streamer string) []*Client {
 			}
 		}
 	}
+	c.Unlock()
 	return clients
 }

extractor/chat/twitchChat.go

@@ -178,11 +178,13 @@ func SendMessage(msg string) error {
 
 // function to check and remove unused streamers from server map
 func RemoveUnusedStreamers() {
+	ClientHandler.Lock()
 	for streamer := range streamersFollowing {
 		found := false
 		// iterate over each client and their streamer map
-		for client, _ := range ClientHandler {
-			if client.FollowingStreamers[streamer] == true {
+
+		for client, _ := range ClientHandler.Clients {
+			if client.FollowingStreamers[streamer] {
 				found = true
 				break
 			}
@@ -193,4 +195,5 @@ func RemoveUnusedStreamers() {
 			sendMessage("PART #" + streamer)
 		}
 	}
+	ClientHandler.Unlock()
 }