Convert config updating and video/audio queues to use zmq (#9893)

* Add config pub / sub pattern

* remove recording from feature metrics

* remove audio and feature metrics

* Check for updates from all cameras

* remove birdseye from camera metrics

* remove motion and detection camera metrics

* Ensure that all processes are stopped

* Stop communicators

* Detections

* Cleanup video output queue

* Use select for time sensitive polls

* Use ipc instead of tcp

frigate/comms/inter_process.py

@@ -1,7 +1,6 @@
 """Facilitates communication between processes."""
 
 import multiprocessing as mp
-import os
 import threading
 from multiprocessing.synchronize import Event as MpEvent
 from typing import Callable
@@ -9,17 +8,15 @@ from typing import Callable
 import zmq
 
 from frigate.comms.dispatcher import Communicator
-from frigate.const import PORT_INTER_PROCESS_COMM
+
+SOCKET_REP_REQ = "ipc:///tmp/cache/comms"
 
 
 class InterProcessCommunicator(Communicator):
     def __init__(self) -> None:
-        INTER_PROCESS_COMM_PORT = (
-            os.environ.get("INTER_PROCESS_COMM_PORT") or PORT_INTER_PROCESS_COMM
-        )
         self.context = zmq.Context()
         self.socket = self.context.socket(zmq.REP)
-        self.socket.bind(f"tcp://127.0.0.1:{INTER_PROCESS_COMM_PORT}")
+        self.socket.bind(SOCKET_REP_REQ)
         self.stop_event: MpEvent = mp.Event()
 
     def publish(self, topic: str, payload: str, retain: bool) -> None:
@@ -32,8 +29,13 @@ class InterProcessCommunicator(Communicator):
         self.reader_thread.start()
 
     def read(self) -> None:
-        while not self.stop_event.wait(0.5):
+        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)
 
@@ -57,10 +59,9 @@ class InterProcessRequestor:
     """Simplifies sending data to InterProcessCommunicator and getting a reply."""
 
     def __init__(self) -> None:
-        port = os.environ.get("INTER_PROCESS_COMM_PORT") or PORT_INTER_PROCESS_COMM
         self.context = zmq.Context()
         self.socket = self.context.socket(zmq.REQ)
-        self.socket.connect(f"tcp://127.0.0.1:{port}")
+        self.socket.connect(SOCKET_REP_REQ)
 
     def send_data(self, topic: str, data: any) -> any:
         """Sends data and then waits for reply."""