From 71184c0ef42dfe4ad530c095af868fda472f63da Mon Sep 17 00:00:00 2001
From: Nicolas Mowen <nickmowen213@gmail.com>
Date: Sun, 18 Feb 2024 10:06:43 -0700
Subject: [PATCH] Use select for time sensitive polls

---
 frigate/comms/detections_updater.py | 14 +++++++++-----
 frigate/comms/inter_process.py      |  7 ++++++-
 frigate/object_processing.py        |  4 +---
 frigate/output/output.py            |  6 ++----
 frigate/record/maintainer.py        |  4 +++-
 5 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/frigate/comms/detections_updater.py b/frigate/comms/detections_updater.py
index d1624dc93..6a6de4c7b 100644
--- a/frigate/comms/detections_updater.py
+++ b/frigate/comms/detections_updater.py
@@ -22,7 +22,6 @@ class DetectionTypeEnum(str, Enum):
 
 
 class DetectionProxyRunner(threading.Thread):
-
     def __init__(self, context: zmq.Context[zmq.Socket]) -> None:
         threading.Thread.__init__(self)
         self.name = "detection_proxy"
@@ -105,13 +104,18 @@ class DetectionSubscriber:
         self.socket.setsockopt_string(zmq.SUBSCRIBE, topic.value)
         self.socket.connect(f"tcp://127.0.0.1:{port}")
 
-    def get_data(self) -> Optional[tuple[str, any]]:
+    def get_data(self, timeout: float = None) -> Optional[tuple[str, any]]:
         """Returns detections or None if no update."""
         try:
-            topic = DetectionTypeEnum[self.socket.recv_string(flags=zmq.NOBLOCK)]
-            return (topic, self.socket.recv_pyobj())
+            has_update, _, _ = zmq.select([self.socket], [], [], timeout)
+
+            if has_update:
+                topic = DetectionTypeEnum[self.socket.recv_string(flags=zmq.NOBLOCK)]
+                return (topic, self.socket.recv_pyobj())
         except zmq.ZMQError:
-            return (None, None)
+            pass
+
+        return (None, None)
 
     def stop(self) -> None:
         self.socket.close()
diff --git a/frigate/comms/inter_process.py b/frigate/comms/inter_process.py
index bcf99738f..6a8929194 100644
--- a/frigate/comms/inter_process.py
+++ b/frigate/comms/inter_process.py
@@ -32,8 +32,13 @@ class InterProcessCommunicator(Communicator):
         self.reader_thread.start()
 
     def read(self) -> None:
-        while not self.stop_event.wait(0.1):
+        while not self.stop_event.is_set():
             while True:  # load all messages that are queued
+                has_message, _, _ = zmq.select([self.socket], [], [], 1)
+
+                if not has_message:
+                    break
+
                 try:
                     (topic, value) = self.socket.recv_pyobj(flags=zmq.NOBLOCK)
 
diff --git a/frigate/object_processing.py b/frigate/object_processing.py
index 6146f54a3..68cac4ec0 100644
--- a/frigate/object_processing.py
+++ b/frigate/object_processing.py
@@ -521,9 +521,7 @@ class CameraState:
                     ):
                         max_target_box = self.ptz_autotracker_thread.ptz_autotracker.tracked_object_metrics[
                             self.name
-                        ][
-                            "max_target_box"
-                        ]
+                        ]["max_target_box"]
                         side_length = max_target_box * (
                             max(
                                 self.camera_config.detect.width,
diff --git a/frigate/output/output.py b/frigate/output/output.py
index 85ea586a7..e717463b1 100644
--- a/frigate/output/output.py
+++ b/frigate/output/output.py
@@ -4,7 +4,6 @@ import logging
 import multiprocessing as mp
 import signal
 import threading
-import time
 from typing import Optional
 from wsgiref.simple_server import make_server
 
@@ -75,10 +74,9 @@ def output_frames(
     websocket_thread.start()
 
     while not stop_event.is_set():
-        (topic, data) = detection_subscriber.get_data()
+        (topic, data) = detection_subscriber.get_data(timeout=10)
 
         if not topic:
-            time.sleep(0.1)
             continue
 
         (
@@ -128,7 +126,7 @@ def output_frames(
         previous_frames[camera] = frame_time
 
     while True:
-        (topic, data) = detection_subscriber.get_data()
+        (topic, data) = detection_subscriber.get_data(timeout=0)
 
         if not topic:
             break
diff --git a/frigate/record/maintainer.py b/frigate/record/maintainer.py
index 52f357894..2715dec89 100644
--- a/frigate/record/maintainer.py
+++ b/frigate/record/maintainer.py
@@ -450,7 +450,9 @@ class RecordingMaintainer(threading.Thread):
             stale_frame_count_threshold = 10
             # empty the object recordings info queue
             while True:
-                (topic, data) = self.detection_subscriber.get_data()
+                (topic, data) = self.detection_subscriber.get_data(
+                    timeout=QUEUE_READ_TIMEOUT
+                )
 
                 if not topic:
                     break