Wait on stop event when possible

Generally eliminate the `while True` loops while waiting for a stop
event and prefer to condition the loops on if the stop event is set,
blocking on that where it makes sense.  This generally comes in 3
flavors.  First and simplest, when there is a sleep and the stop event
is the only thing the loop blocks on, instead do a check using
`stop_event.wait(timeout)` to instead block on the stop event for the
designated amount of time. Second, when there is a different event that
is blocking in the loop, condition the loop on `stop_event.is_set()`
rather than breaking when it is set. Finally, when there is a separate
internal condition that requires a counter, have the loop iterate over
the counter and use `if stop_event.wait(timeout)` internal to the loop.

frigate/events.py

@@ -221,11 +221,7 @@ class EventProcessor(threading.Thread):
         return True
 
     def run(self):
-        while True:
-            if self.stop_event.is_set():
-                logger.info(f"Exiting event processor...")
-                break
-
+        while not self.stop_event.is_set():
             try:
                 event_type, camera, event_data = self.event_queue.get(timeout=10)
             except queue.Empty:
@@ -272,6 +268,8 @@ class EventProcessor(threading.Thread):
                 del self.events_in_process[event_data["id"]]
                 self.event_processed_queue.put((event_data["id"], camera))
 
+        logger.info(f"Exiting event processor...")
+
 
 class EventCleanup(threading.Thread):
     def __init__(self, config: FrigateConfig, stop_event):
@@ -398,19 +396,8 @@ class EventCleanup(threading.Thread):
         )
 
     def run(self):
-        counter = 0
-        while True:
-            if self.stop_event.is_set():
-                logger.info(f"Exiting event cleanup...")
-                break
-
-            # only expire events every 5 minutes, but check for stop events every 10 seconds
-            time.sleep(10)
-            counter = counter + 1
-            if counter < 30:
-                continue
-            counter = 0
-
+        # only expire events every 5 minutes
+        while not self.stop_event.wait(300):
             self.expire("clips")
             self.expire("snapshots")
             self.purge_duplicates()
@@ -420,3 +407,5 @@ class EventCleanup(threading.Thread):
                 Event.has_clip == False, Event.has_snapshot == False
             )
             delete_query.execute()
+
+        logger.info(f"Exiting event cleanup...")