Fix #61 freeze/broken pipe after some idle time

samsungctl/remote_websocket.py

@@ -1,8 +1,9 @@
 import base64
 import json
 import logging
-import socket
+import threading
 import time
+import select
 
 from . import exceptions
 
@@ -26,9 +27,12 @@ def __init__(self, config):
                                 self._serialize_string(config["name"]))
 
         self.connection = websocket.create_connection(url, config["timeout"])
-
         self._read_response()
 
+        ## Keep long-lived connection alive by spawning a thread
+        thread = threading.Thread(target=self._keep_alive, daemon=True)
+        thread.start()
+
     def __enter__(self):
         return self
 
@@ -73,6 +77,18 @@ def _read_response(self):
 
         logging.debug("Access granted.")
 
+    def _keep_alive(self):
+        while True:
+            r, w, e = select.select((self.connection.sock, ), (), ())
+            if not (self.connection and self.connection.connected):
+                # stop if connection was already closed
+                # while blocking in select function above
+                logging.debug("keep alive thread terminating.")
+                return
+            if r:
+                _ = self.connection.recv()
+                logging.debug("data received.")
+
     @staticmethod
     def _serialize_string(string):
         if isinstance(string, str):