From e10ddb343c859d951600767f3f07766653d38ac7 Mon Sep 17 00:00:00 2001
From: Blake Blackshear <blakeb@blakeshome.com>
Date: Sat, 4 Feb 2023 08:58:45 -0600
Subject: [PATCH] additional shutdown optimizations (#5380)

---
 frigate/app.py              | 17 ++++++++++-------
 frigate/object_detection.py |  8 ++++++--
 frigate/video.py            | 20 ++++++++++++--------
 3 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/frigate/app.py b/frigate/app.py
index 1e5140603..c5cc8411a 100644
--- a/frigate/app.py
+++ b/frigate/app.py
@@ -416,10 +416,15 @@ class FrigateApp:
         logger.info(f"Stopping...")
         self.stop_event.set()
 
-        # Set the events for the camera processor processes because
-        # they may be waiting on the event coming out of the detection process
-        for name in self.config.cameras.keys():
-            self.detection_out_events[name].set()
+        for detector in self.detectors.values():
+            detector.stop()
+
+        # Empty the detection queue and set the events for all requests
+        while not self.detection_queue.empty():
+            connection_id = self.detection_queue.get(timeout=1)
+            self.detection_out_events[connection_id].set()
+        self.detection_queue.close()
+        self.detection_queue.join_thread()
 
         self.dispatcher.stop()
         self.detected_frames_processor.join()
@@ -431,9 +436,6 @@ class FrigateApp:
         self.frigate_watchdog.join()
         self.db.stop()
 
-        for detector in self.detectors.values():
-            detector.stop()
-
         while len(self.detection_shms) > 0:
             shm = self.detection_shms.pop()
             shm.close()
@@ -445,6 +447,7 @@ class FrigateApp:
             self.video_output_queue,
             self.detected_frames_queue,
             self.recordings_info_queue,
+            self.log_queue,
         ]:
             while not queue.empty():
                 queue.get_nowait()
diff --git a/frigate/object_detection.py b/frigate/object_detection.py
index 206c47839..129fd6b26 100644
--- a/frigate/object_detection.py
+++ b/frigate/object_detection.py
@@ -180,12 +180,13 @@ class ObjectDetectProcess:
 
 
 class RemoteObjectDetector:
-    def __init__(self, name, labels, detection_queue, event, model_config):
+    def __init__(self, name, labels, detection_queue, event, model_config, stop_event):
         self.labels = labels
         self.name = name
         self.fps = EventsPerSecond()
         self.detection_queue = detection_queue
         self.event = event
+        self.stop_event = stop_event
         self.shm = mp.shared_memory.SharedMemory(name=self.name, create=False)
         self.np_shm = np.ndarray(
             (1, model_config.height, model_config.width, 3),
@@ -200,11 +201,14 @@ class RemoteObjectDetector:
     def detect(self, tensor_input, threshold=0.4):
         detections = []
 
+        if self.stop_event.is_set():
+            return detections
+
         # copy input to shared memory
         self.np_shm[:] = tensor_input[:]
         self.event.clear()
         self.detection_queue.put(self.name)
-        result = self.event.wait(timeout=10.0)
+        result = self.event.wait(timeout=5.0)
 
         # if it timed out
         if result is None:
diff --git a/frigate/video.py b/frigate/video.py
index 1b64b21a4..ca200fd53 100755
--- a/frigate/video.py
+++ b/frigate/video.py
@@ -160,6 +160,7 @@ def capture_frames(
     fps: mp.Value,
     skipped_fps: mp.Value,
     current_frame: mp.Value,
+    stop_event: mp.Event,
 ):
 
     frame_size = frame_shape[0] * frame_shape[1]
@@ -177,6 +178,9 @@ def capture_frames(
         try:
             frame_buffer[:] = ffmpeg_process.stdout.read(frame_size)
         except Exception as e:
+            # shutdown has been initiated
+            if stop_event.is_set():
+                break
             logger.error(f"{camera_name}: Unable to read frames from ffmpeg process.")
 
             if ffmpeg_process.poll() != None:
@@ -340,6 +344,7 @@ class CameraWatchdog(threading.Thread):
             self.frame_shape,
             self.frame_queue,
             self.camera_fps,
+            self.stop_event,
         )
         self.capture_thread.start()
 
@@ -368,13 +373,16 @@ class CameraWatchdog(threading.Thread):
 
 
 class CameraCapture(threading.Thread):
-    def __init__(self, camera_name, ffmpeg_process, frame_shape, frame_queue, fps):
+    def __init__(
+        self, camera_name, ffmpeg_process, frame_shape, frame_queue, fps, stop_event
+    ):
         threading.Thread.__init__(self)
         self.name = f"capture:{camera_name}"
         self.camera_name = camera_name
         self.frame_shape = frame_shape
         self.frame_queue = frame_queue
         self.fps = fps
+        self.stop_event = stop_event
         self.skipped_fps = EventsPerSecond()
         self.frame_manager = SharedMemoryFrameManager()
         self.ffmpeg_process = ffmpeg_process
@@ -392,6 +400,7 @@ class CameraCapture(threading.Thread):
             self.fps,
             self.skipped_fps,
             self.current_frame,
+            self.stop_event,
         )
 
 
@@ -461,7 +470,7 @@ def track_camera(
         motion_contour_area,
     )
     object_detector = RemoteObjectDetector(
-        name, labelmap, detection_queue, result_connection, model_config
+        name, labelmap, detection_queue, result_connection, model_config, stop_event
     )
 
     object_tracker = ObjectTracker(config.detect)
@@ -723,9 +732,6 @@ def process_frames(
                         object_filters,
                     )
                 )
-                # if frigate is exiting
-                if stop_event.is_set():
-                    return
 
             #########
             # merge objects, check for clipped objects and look again up to 4 times
@@ -790,9 +796,7 @@ def process_frames(
                             refining = True
                         else:
                             selected_objects.append(obj)
-                        # if frigate is exiting
-                        if stop_event.is_set():
-                            return
+
                 # set the detections list to only include top, complete objects
                 # and new detections
                 detections = selected_objects