Fix review issues: race condition in invokeWithTimeout and mutex queue entry

- Add settled flag to invokeWithTimeout to prevent double-settling
- Create mutex queue entry with wrapped resolve before pushing to queue

Co-authored-by: xCyanGrizzly <53275238+xCyanGrizzly@users.noreply.github.com>

worker/src/tdlib/download.ts

@@ -88,18 +88,29 @@ export async function invokeWithTimeout<T>(
   timeoutMs = INVOKE_TIMEOUT_MS
 ): Promise<T> {
   return new Promise<T>((resolve, reject) => {
+    let settled = false;
+
     const timer = setTimeout(() => {
-      reject(new Error(`TDLib invoke timed out after ${timeoutMs}ms for ${request._}`));
+      if (!settled) {
+        settled = true;
+        reject(new Error(`TDLib invoke timed out after ${timeoutMs}ms for ${request._}`));
+      }
     }, timeoutMs);
 
     (client.invoke(request) as Promise<T>)
       .then((result) => {
-        clearTimeout(timer);
-        resolve(result);
+        if (!settled) {
+          settled = true;
+          clearTimeout(timer);
+          resolve(result);
+        }
       })
       .catch((err) => {
-        clearTimeout(timer);
-        reject(err);
+        if (!settled) {
+          settled = true;
+          clearTimeout(timer);
+          reject(err);
+        }
       });
   });
 }

worker/src/util/mutex.ts

@@ -27,10 +27,6 @@ export async function withTdlibMutex<T>(
   if (locked) {
     log.info({ waiting: label, holder }, "Waiting for TDLib mutex");
     await new Promise<void>((resolve, reject) => {
-      const entry = { resolve, reject, label };
-      queue.push(entry);
-
-      // Timeout: reject if we've been waiting too long
       const timer = setTimeout(() => {
         const idx = queue.indexOf(entry);
         if (idx !== -1) {
@@ -42,12 +38,15 @@ export async function withTdlibMutex<T>(
         }
       }, MUTEX_WAIT_TIMEOUT_MS);
 
-      // Wrap resolve to clear the timer
-      const origResolve = entry.resolve;
-      entry.resolve = () => {
-        clearTimeout(timer);
-        origResolve();
+      const entry = {
+        resolve: () => {
+          clearTimeout(timer);
+          resolve();
+        },
+        reject,
+        label,
       };
+      queue.push(entry);
     });
   }