disable add on parallel

Author: ryanontheinside

src/streamdiffusion/config.py

@@ -124,6 +124,9 @@ def _extract_wrapper_params(config: Dict[str, Any]) -> Dict[str, Any]:
         'normalize_prompt_weights': config.get('normalize_prompt_weights', True),
         'normalize_seed_weights': config.get('normalize_seed_weights', True),
         'enable_pytorch_fallback': config.get('enable_pytorch_fallback', False),
+        # Concurrency options
+        'controlnet_max_parallel': config.get('controlnet_max_parallel'),
+        'controlnet_block_add_when_parallel': config.get('controlnet_block_add_when_parallel', True),
     }
     if 'controlnets' in config and config['controlnets']:
         param_map['use_controlnet'] = True

src/streamdiffusion/stream_parameter_updater.py

@@ -1004,6 +1004,22 @@ def _update_controlnet_config(self, desired_config: List[Dict[str, Any]]) -> Non
 
             if existing_index is None:
                 # Add new controlnet
+                # Respect wrapper/init configuration: block adds when parallel enabled
+                try:
+                    block_add = bool(getattr(self.stream, 'controlnet_block_add_when_parallel', True))
+                except Exception:
+                    block_add = True
+                concurrency_active = False
+                try:
+                    cn_module = getattr(self.stream, '_controlnet_module', None)
+                    if cn_module is not None:
+                        max_par = int(getattr(cn_module, '_max_parallel_controlnets', 0))
+                        concurrency_active = max_par > 1
+                except Exception:
+                    concurrency_active = False
+                if block_add and concurrency_active:
+                    logger.warning(f"_update_controlnet_config: Add blocked by configuration while parallel ControlNet is active; skipping add for {model_id}")
+                    continue
                 logger.info(f"_update_controlnet_config: Adding ControlNet {model_id}")
                 try:
                     # Prefer module path: construct ControlNetConfig

src/streamdiffusion/wrapper.py

@@ -110,6 +110,9 @@ def __init__(
         # IPAdapter options
         use_ipadapter: bool = False,
         ipadapter_config: Optional[Union[Dict[str, Any], List[Dict[str, Any]]]] = None,
+        # Concurrency options
+        controlnet_max_parallel: Optional[int] = None,
+        controlnet_block_add_when_parallel: bool = True,
     ):
         """
         Initializes the StreamDiffusionWrapper.
@@ -198,6 +201,9 @@ def __init__(
         self.enable_pytorch_fallback = enable_pytorch_fallback
         self.use_ipadapter = use_ipadapter
         self.ipadapter_config = ipadapter_config
+        # Concurrency settings
+        self.controlnet_max_parallel = controlnet_max_parallel
+        self.controlnet_block_add_when_parallel = controlnet_block_add_when_parallel
 
         if mode == "txt2img":
             if cfg_type != "none":
@@ -1482,6 +1488,17 @@ def _load_model(
                 from streamdiffusion.modules.controlnet_module import ControlNetModule, ControlNetConfig
                 cn_module = ControlNetModule(device=self.device, dtype=self.dtype)
                 cn_module.install(stream)
+                # Apply configured max parallel if provided
+                try:
+                    if self.controlnet_max_parallel is not None:
+                        setattr(cn_module, '_max_parallel_controlnets', int(self.controlnet_max_parallel))
+                except Exception:
+                    pass
+                # Expose add-blocking policy on stream
+                try:
+                    setattr(stream, 'controlnet_block_add_when_parallel', bool(self.controlnet_block_add_when_parallel))
+                except Exception:
+                    pass
                 # Normalize to list of configs
                 configs = controlnet_config if isinstance(controlnet_config, list) else [controlnet_config]
                 for cfg in configs: