From 46245e851f228ba1f1e75bbe07265773fcbee371 Mon Sep 17 00:00:00 2001
From: Fabio Manganiello <fabio@manganiello.tech>
Date: Tue, 15 Aug 2023 02:06:13 +0200
Subject: [PATCH] Synchronize with the currently running stop thread (if any)
 in `Backend.wait_stop`.

---
 platypush/backend/__init__.py | 53 ++++++++++++++++++++++++++---------
 1 file changed, 39 insertions(+), 14 deletions(-)

diff --git a/platypush/backend/__init__.py b/platypush/backend/__init__.py
index 92929b77f0..c8b0ea65d6 100644
--- a/platypush/backend/__init__.py
+++ b/platypush/backend/__init__.py
@@ -6,28 +6,28 @@ import time
 from threading import Thread, Event as ThreadEvent, get_ident
 from typing import Optional, Dict
 
+from platypush import __version__
 from platypush.bus import Bus
 from platypush.common import ExtensionWithManifest
 from platypush.config import Config
 from platypush.context import get_backend
+from platypush.event import EventGenerator
+from platypush.message import Message
+from platypush.message.event import Event
 from platypush.message.event.zeroconf import (
     ZeroconfServiceAddedEvent,
     ZeroconfServiceRemovedEvent,
 )
-from platypush.utils import (
-    set_timeout,
-    clear_timeout,
-    get_redis_queue_name_by_message,
-    get_backend_name_by_class,
-)
-
-from platypush import __version__
-from platypush.event import EventGenerator
-from platypush.message import Message
-from platypush.message.event import Event
 from platypush.message.request import Request
 from platypush.message.response import Response
-from platypush.utils import get_redis
+from platypush.utils import (
+    clear_timeout,
+    get_backend_name_by_class,
+    get_redis,
+    get_redis_queue_name_by_message,
+    get_remaining_timeout,
+    set_timeout,
+)
 
 
 class Backend(Thread, EventGenerator, ExtensionWithManifest):
@@ -69,6 +69,7 @@ class Backend(Thread, EventGenerator, ExtensionWithManifest):
         self.device_id = Config.get('device_id')
         self.thread_id = None
         self._stop_event = ThreadEvent()
+        self._stop_thread: Optional[Thread] = None
         self._kwargs = kwargs
         self.logger = logging.getLogger(
             'platypush:backend:' + get_backend_name_by_class(self.__class__)
@@ -300,14 +301,38 @@ class Backend(Thread, EventGenerator, ExtensionWithManifest):
             self._stop_event.set()
             self.unregister_service()
             self.on_stop()
+            self._stop_thread = None
 
-        Thread(target=_async_stop).start()
+        if not (self._stop_thread and self._stop_thread.is_alive()):
+            self._stop_thread = Thread(target=_async_stop)
+            self._stop_thread.start()
 
     def should_stop(self):
+        """
+        :return: True if the backend thread should be stopped, False otherwise.
+        """
         return self._stop_event.is_set()
 
     def wait_stop(self, timeout=None) -> bool:
-        return self._stop_event.wait(timeout)
+        """
+        Waits for the backend thread to stop.
+
+        :param timeout: The maximum time to wait for the backend thread to stop (default: None)
+        :return: True if the backend thread has stopped, False otherwise.
+        """
+        start = time.time()
+
+        if self._stop_thread:
+            try:
+                self._stop_thread.join(
+                    get_remaining_timeout(timeout=timeout, start=start)
+                )
+            except AttributeError:
+                pass
+
+        return self._stop_event.wait(
+            get_remaining_timeout(timeout=timeout, start=start)
+        )
 
     def get_message_response(self, msg):
         queue = get_redis_queue_name_by_message(msg)