Update app.py

app.py

@@ -257,6 +257,11 @@ if generate_all:
 
     workers = [WorkerThread(jobs, results) for _ in range(num_concurrent_calls)]
 
+    # Start all worker threads
+    for worker in workers:
+        worker.start()
+
+    # Join all worker threads
     for worker in workers:
         worker.join()