[MemryX] Clean shutdown of detector process (#21035)

* update code for clean exit

* ruff format

* remove unused time import

* update stop_event handling

* remove hasattr check

frigate/detectors/plugins/memryx.py

@@ -2,7 +2,6 @@ import glob
 import logging
 import os
 import shutil
-import time
 import urllib.request
 import zipfile
 from queue import Queue
@@ -55,6 +54,9 @@ class MemryXDetector(DetectionApi):
             )
             return
 
+        # Initialize stop_event as None, will be set later by set_stop_event()
+        self.stop_event = None
+
         model_cfg = getattr(detector_config, "model", None)
 
         # Check if model_type was explicitly set by the user
@@ -363,27 +365,44 @@ class MemryXDetector(DetectionApi):
     def process_input(self):
         """Input callback function: wait for frames in the input queue, preprocess, and send to MX3 (return)"""
         while True:
+            # Check if shutdown is requested
+            if self.stop_event and self.stop_event.is_set():
+                logger.debug("[process_input] Stop event detected, returning None")
+                return None
             try:
-                # Wait for a frame from the queue (blocking call)
-                frame = self.capture_queue.get(
-                    block=True
-                )  # Blocks until data is available
+                # Wait for a frame from the queue with timeout to check stop_event periodically
+                frame = self.capture_queue.get(block=True, timeout=0.5)
 
                 return frame
 
             except Exception as e:
-                logger.info(f"[process_input] Error processing input: {e}")
-                time.sleep(0.1)  # Prevent busy waiting in case of error
+                # Silently handle queue.Empty timeouts (expected during normal operation)
+                # Log any other unexpected exceptions
+                if "Empty" not in str(type(e).__name__):
+                    logger.warning(f"[process_input] Unexpected error: {e}")
+                # Loop continues and will check stop_event at the top
 
     def receive_output(self):
         """Retrieve processed results from MemryX output queue + a copy of the original frame"""
-        connection_id = (
-            self.capture_id_queue.get()
+        try:
+            # Get connection ID with timeout
+            connection_id = self.capture_id_queue.get(
+                block=True, timeout=1.0
             )  # Get the corresponding connection ID
             detections = self.output_queue.get()  # Get detections from MemryX
 
             return connection_id, detections
 
+        except Exception as e:
+            # On timeout or stop event, return None
+            if self.stop_event and self.stop_event.is_set():
+                logger.debug("[receive_output] Stop event detected, exiting")
+            # Silently handle queue.Empty timeouts, they're expected during normal operation
+            elif "Empty" not in str(type(e).__name__):
+                logger.warning(f"[receive_output] Error receiving output: {e}")
+
+            return None, None
+
     def post_process_yolonas(self, output):
         predictions = output[0]
 
@@ -831,6 +850,19 @@ class MemryXDetector(DetectionApi):
                 f"{self.memx_model_type} is currently not supported for memryx. See the docs for more info on supported models."
             )
 
+    def set_stop_event(self, stop_event):
+        """Set the stop event for graceful shutdown."""
+        self.stop_event = stop_event
+
+    def shutdown(self):
+        """Gracefully shutdown the MemryX accelerator"""
+        try:
+            if hasattr(self, "accl") and self.accl is not None:
+                self.accl.shutdown()
+                logger.info("MemryX accelerator shutdown complete")
+        except Exception as e:
+            logger.error(f"Error during MemryX shutdown: {e}")
+
     def detect_raw(self, tensor_input: np.ndarray):
         """Removed synchronous detect_raw() function so that we only use async"""
         return 0

frigate/object_detection/base.py

@@ -43,6 +43,7 @@ class BaseLocalDetector(ObjectDetector):
         self,
         detector_config: BaseDetectorConfig = None,
         labels: str = None,
+        stop_event: MpEvent = None,
     ):
         self.fps = EventsPerSecond()
         if labels is None:
@@ -60,6 +61,10 @@ class BaseLocalDetector(ObjectDetector):
 
         self.detect_api = create_detector(detector_config)
 
+        # If the detector supports stop_event, pass it
+        if hasattr(self.detect_api, "set_stop_event") and stop_event:
+            self.detect_api.set_stop_event(stop_event)
+
     def _transform_input(self, tensor_input: np.ndarray) -> np.ndarray:
         if self.input_transform:
             tensor_input = np.transpose(tensor_input, self.input_transform)
@@ -240,6 +245,10 @@ class AsyncDetectorRunner(FrigateProcess):
         while not self.stop_event.is_set():
             connection_id, detections = self._detector.async_receive_output()
 
+            # Handle timeout case (queue.Empty) - just continue
+            if connection_id is None:
+                continue
+
             if not self.send_times:
                 # guard; shouldn't happen if send/recv are balanced
                 continue
@@ -266,21 +275,38 @@ class AsyncDetectorRunner(FrigateProcess):
 
         self._frame_manager = SharedMemoryFrameManager()
         self._publisher = ObjectDetectorPublisher()
-        self._detector = AsyncLocalObjectDetector(detector_config=self.detector_config)
+        self._detector = AsyncLocalObjectDetector(
+            detector_config=self.detector_config, stop_event=self.stop_event
+        )
 
         for name in self.cameras:
             self.create_output_shm(name)
 
-        t_detect = threading.Thread(target=self._detect_worker, daemon=True)
-        t_result = threading.Thread(target=self._result_worker, daemon=True)
+        t_detect = threading.Thread(target=self._detect_worker, daemon=False)
+        t_result = threading.Thread(target=self._result_worker, daemon=False)
         t_detect.start()
         t_result.start()
 
+        try:
             while not self.stop_event.is_set():
                 time.sleep(0.5)
 
+            logger.info(
+                "Stop event detected, waiting for detector threads to finish..."
+            )
+
+            # Wait for threads to finish processing
+            t_detect.join(timeout=5)
+            t_result.join(timeout=5)
+
+            # Shutdown the AsyncDetector
+            self._detector.detect_api.shutdown()
+
             self._publisher.stop()
-        logger.info("Exited async detection process...")
+        except Exception as e:
+            logger.error(f"Error during async detector shutdown: {e}")
+        finally:
+            logger.info("Exited Async detection process...")
 
 
 class ObjectDetectProcess:
@@ -308,7 +334,7 @@ class ObjectDetectProcess:
         # if the process has already exited on its own, just return
         if self.detect_process and self.detect_process.exitcode:
             return
-        self.detect_process.terminate()
+
         logging.info("Waiting for detection process to exit gracefully...")
         self.detect_process.join(timeout=30)
         if self.detect_process.exitcode is None: