Fix stop_stream: add lock and emit response

app.py

@@ -385,11 +385,12 @@ def start_stream(n_steps=8, cfg=0.0, fps=30, clamp=True):
 
 def stop_stream():
     global stream_thread, stream_running
-    if stream_thread is not None:
-        stream_thread.stop()
-        stream_thread.join(timeout=1.0)
-        stream_thread = None
-    stream_running = False
+    with stream_lock:
+        if stream_thread is not None:
+            stream_thread.stop()
+            stream_thread.join(timeout=1.0)
+            stream_thread = None
+        stream_running = False
 
 @socketio.on_error_default
 def default_error_handler(e):
@@ -462,7 +463,14 @@ def handle_action(data):
 @socketio.on('stop_stream')
 def handle_stop_stream():
     print('Stopping stream')
-    stop_stream()
+    try:
+        stop_stream()
+        emit('stream_stopped', {'status': 'ok'})
+    except Exception as e:
+        print(f"Error stopping stream: {e}")
+        import traceback
+        traceback.print_exc()
+        emit('error', {'message': f'Failed to stop stream: {str(e)}'})
 
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