Socket upgrade.

src/snek/service/socket.py

@@ -83,6 +83,7 @@ class SocketService(BaseService):
         self.users = {}
         self.subscriptions = {}
         self.last_update = str(datetime.now())
+        self._lock = asyncio.Lock()
 
 
     async def user_availability_service(self):
@@ -139,6 +140,7 @@ class SocketService(BaseService):
             username = safe_get(user, "username", "unknown")
             nick = safe_get(user, "nick") or username
             color = s.user_color
+            async with self._lock:
                 self.sockets.add(s)
                 is_first_connection = False
                 if user_uid not in self.users:
@@ -166,6 +168,7 @@ class SocketService(BaseService):
         if not ws or not channel_uid or not user_uid:
             return False
         try:
+            async with self._lock:
                 existing_socket = None
                 user_sockets = self.users.get(user_uid, set())
                 for sock in user_sockets:
@@ -183,6 +186,24 @@ class SocketService(BaseService):
             logger.warning(f"Failed to subscribe: {safe_str(ex)}")
             return False
 
+    async def unsubscribe(self, ws, channel_uid, user_uid):
+        if not ws or not channel_uid or not user_uid:
+            return False
+        try:
+            async with self._lock:
+                if channel_uid in self.subscriptions:
+                    self.subscriptions[channel_uid].discard(user_uid)
+                    if len(self.subscriptions[channel_uid]) == 0:
+                        del self.subscriptions[channel_uid]
+                for s in self.sockets:
+                    if s and s.ws == ws:
+                        s.subscribed_channels.discard(channel_uid)
+                        break
+            return True
+        except Exception as ex:
+            logger.warning(f"Failed to unsubscribe: {safe_str(ex)}")
+            return False
+
     async def send_to_user(self, user_uid, message):
         if not user_uid or message is None:
             return 0
@@ -250,6 +271,7 @@ class SocketService(BaseService):
     async def delete(self, ws):
         if not ws:
             return
+        async with self._lock:
             sockets_to_remove = [sock for sock in self.sockets if sock and sock.ws == ws]
             for s in sockets_to_remove:
                 self.sockets.discard(s)

src/snek/static/message-list.js

@@ -157,12 +157,10 @@ class MessageList extends HTMLElement {
       threshold: 0,
     });
 
-    // End-of-messages marker
     this.endOfMessages = document.createElement('div');
     this.endOfMessages.classList.add('message-list-bottom');
     this.prepend(this.endOfMessages);
 
-    // Observe existing children and index by uid
     for (const c of this.children) {
       this._observer.observe(c);
       if (c instanceof MessageElement) {
@@ -170,20 +168,30 @@ class MessageList extends HTMLElement {
       }
     }
 
-    // Wire up socket events
-    app.ws.addEventListener("update_message_text", (data) => {
+    this._updateMessageHandler = (data) => {
       if (this.messageMap.has(data.uid)) {
         this.upsertMessage(data);
       }
-    });
-    app.ws.addEventListener("set_typing", (data) => {
+    };
+    this._typingHandler = (data) => {
       if (app._debug) console.debug("set_typing event received:", data);
       this.triggerGlow(data.user_uid, data.color);
-    });
+    };
+
+    app.ws.addEventListener("update_message_text", this._updateMessageHandler);
+    app.ws.addEventListener("set_typing", this._typingHandler);
 
     this.scrollToBottom(true);
   }
 
+  disconnectedCallback() {
+    if (this._observer) {
+      this._observer.disconnect();
+    }
+    app.ws.removeEventListener("update_message_text", this._updateMessageHandler);
+    app.ws.removeEventListener("set_typing", this._typingHandler);
+  }
+
   connectedCallback() {
     this.addEventListener('click', (e) => {
       if (