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/watchdog.py

@@ -17,14 +17,7 @@ class FrigateWatchdog(threading.Thread):
 
     def run(self):
         time.sleep(10)
-        while True:
-            # wait a bit before checking
-            time.sleep(10)
-
-            if self.stop_event.is_set():
-                logger.info(f"Exiting watchdog...")
-                break
-
+        while not self.stop_event.wait(10):
             now = datetime.datetime.now().timestamp()
 
             # check the detection processes
@@ -38,3 +31,5 @@ class FrigateWatchdog(threading.Thread):
                 elif not detector.detect_process.is_alive():
                     logger.info("Detection appears to have stopped. Exiting frigate...")
                     os.kill(os.getpid(), signal.SIGTERM)
+
+        logger.info(f"Exiting watchdog...")