Fast restart (#5378)

* dont wait so long for queues

* implement stop methods for comms

* set the detection events on exit and return early from processing

* handle the stop event in the broadcast threads

* short circuit the detection process exit code if it already exited

* some logging for stats thread

* just keep the log process alive 1 second after the last log message

* ensure the multiprocessing queues are emptied and closed

* Update frigate/log.py

Co-authored-by: Nicolas Mowen <nickmowen213@gmail.com>

* Update frigate/log.py

Co-authored-by: Nicolas Mowen <nickmowen213@gmail.com>

* mypy fixes

---------

Co-authored-by: Nicolas Mowen <nickmowen213@gmail.com>

frigate/object_detection.py

@@ -88,6 +88,7 @@ def run_detector(
     stop_event = mp.Event()
 
     def receiveSignal(signalNumber, frame):
+        logger.info("Signal to exit detection process...")
         stop_event.set()
 
     signal.signal(signal.SIGTERM, receiveSignal)
@@ -104,7 +105,7 @@ def run_detector(
 
     while not stop_event.is_set():
         try:
-            connection_id = detection_queue.get(timeout=5)
+            connection_id = detection_queue.get(timeout=1)
         except queue.Empty:
             continue
         input_frame = frame_manager.get(
@@ -125,6 +126,8 @@ def run_detector(
 
         avg_speed.value = (avg_speed.value * 9 + duration) / 10
 
+    logger.info("Exited detection process...")
+
 
 class ObjectDetectProcess:
     def __init__(
@@ -144,6 +147,9 @@ class ObjectDetectProcess:
         self.start_or_restart()
 
     def stop(self):
+        # 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)
@@ -151,6 +157,7 @@ class ObjectDetectProcess:
             logging.info("Detection process didnt exit. Force killing...")
             self.detect_process.kill()
             self.detect_process.join()
+        logging.info("Detection process has exited...")
 
     def start_or_restart(self):
         self.detection_start.value = 0.0