Make sure that all hanging threads, backends and services are stopped and their resources cleaned up when the application stops.

platypush/__init__.py

@@ -16,7 +16,7 @@ from .context import register_backends
 from .cron.scheduler import CronScheduler
 from .event.processor import EventProcessor
 from .logger import Logger
-from .message.event import Event, StopEvent
+from .message.event import Event
 from .message.event.application import ApplicationStartedEvent, ApplicationStoppedEvent
 from .message.request import Request
 from .message.response import Response
@@ -80,6 +80,7 @@ class Daemon:
         self.event_processor = EventProcessor()
         self.requests_to_process = requests_to_process
         self.processed_requests = 0
+        self.cron_scheduler = None
 
     @classmethod
     def build_from_cmdline(cls, args):
@@ -135,9 +136,6 @@ class Daemon:
                     self.stop_app()
             elif isinstance(msg, Response):
                 logger.info('Received response: {}'.format(msg))
-            elif isinstance(msg, StopEvent) and msg.targets_me():
-                logger.info('Received STOP event: {}'.format(msg))
-                self.stop_app()
             elif isinstance(msg, Event):
                 if not msg.disable_logging:
                     logger.info('Received event: {}'.format(msg))
@@ -147,9 +145,14 @@ class Daemon:
 
     def stop_app(self):
         """ Stops the backends and the bus """
+        self.bus.post(ApplicationStoppedEvent())
+
         for backend in self.backends.values():
             backend.stop()
+
         self.bus.stop()
+        if self.cron_scheduler:
+            self.cron_scheduler.stop()
 
     def start(self):
         """ Start the daemon """
@@ -175,7 +178,8 @@ class Daemon:
 
         # Start the cron scheduler
         if Config.get_cronjobs():
-            CronScheduler(jobs=Config.get_cronjobs()).start()
+            self.cron_scheduler = CronScheduler(jobs=Config.get_cronjobs())
+            self.cron_scheduler.start()
 
         self.bus.post(ApplicationStartedEvent())
 
@@ -185,9 +189,10 @@ class Daemon:
         except KeyboardInterrupt:
             logger.info('SIGINT received, terminating application')
         finally:
-            self.bus.post(ApplicationStoppedEvent())
             self.stop_app()
 
+        sys.exit(0)
+
 
 def main():
     """

platypush/backend/__init__.py

@@ -22,7 +22,7 @@ from platypush.utils import set_timeout, clear_timeout, \
 from platypush import __version__
 from platypush.event import EventGenerator
 from platypush.message import Message
-from platypush.message.event import Event, StopEvent
+from platypush.message.event import Event
 from platypush.message.request import Request
 from platypush.message.response import Response
 
@@ -62,7 +62,6 @@ class Backend(Thread, EventGenerator):
         self.poll_seconds = float(poll_seconds) if poll_seconds else None
         self.device_id = Config.get('device_id')
         self.thread_id = None
-        self._should_stop = False
         self._stop_event = threading.Event()
         self._kwargs = kwargs
         self.logger = logging.getLogger('platypush:backend:' + get_backend_name_by_class(self.__class__))
@@ -103,10 +102,6 @@ class Backend(Thread, EventGenerator):
             self.stop()
             return
 
-        if isinstance(msg, StopEvent) and msg.targets_me():
-            self.logger.info('Received STOP event on {}'.format(self.__class__.__name__))
-            self._should_stop = True
-        else:
         msg.backend = self   # Augment message to be able to process responses
         self.bus.post(msg)
 
@@ -263,22 +258,19 @@ class Backend(Thread, EventGenerator):
 
     def on_stop(self):
         """ Callback invoked when the process stops """
-        self.unregister_service()
+        pass
 
     def stop(self):
         """ Stops the backend thread by sending a STOP event on its bus """
         def _async_stop():
-            evt = StopEvent(target=self.device_id, origin=self.device_id,
-                            thread_id=self.thread_id)
-
-            self.send_message(evt)
             self._stop_event.set()
+            self.unregister_service()
             self.on_stop()
 
         Thread(target=_async_stop).start()
 
     def should_stop(self):
-        return self._should_stop
+        return self._stop_event.is_set()
 
     def wait_stop(self, timeout=None) -> bool:
         return self._stop_event.wait(timeout)

platypush/backend/camera/pi.py

@@ -122,7 +122,7 @@ class CameraPiBackend(Backend):
                 while True:
                     self.camera.wait_recording(2)
             else:
-                while True:
+                while not self.should_stop():
                     connection = self.server_socket.accept()[0].makefile('wb')
                     self.logger.info('Accepted client connection on port {}'.format(self.listen_port))
 

platypush/backend/clipboard.py

@@ -26,6 +26,7 @@ class ClipboardBackend(Backend):
         self._last_text: Optional[str] = None
 
     def run(self):
+        self.logger.info('Started clipboard monitor backend')
         while not self.should_stop():
             text = pyperclip.paste()
             if text and text != self._last_text:
@@ -34,5 +35,6 @@ class ClipboardBackend(Backend):
             self._last_text = text
             time.sleep(0.1)
 
+        self.logger.info('Stopped clipboard monitor backend')
 
 # vim:sw=4:ts=4:et:

platypush/backend/github.py

@@ -165,7 +165,7 @@ class GithubBackend(Backend):
 
     def _events_monitor(self, uri: str, method: str = 'get'):
         def thread():
-            while True:
+            while not self.should_stop():
                 try:
                     events = self._request(uri, method)
                     if not events:

platypush/backend/http/__init__.py

@@ -171,6 +171,7 @@ class HttpBackend(Backend):
 
     def __init__(self, port=_DEFAULT_HTTP_PORT,
                  websocket_port=_DEFAULT_WEBSOCKET_PORT,
+                 bind_address='0.0.0.0',
                  disable_websocket=False, resource_dirs=None,
                  ssl_cert=None, ssl_key=None, ssl_cafile=None, ssl_capath=None,
                  maps=None, run_externally=False, uwsgi_args=None, **kwargs):
@@ -181,6 +182,9 @@ class HttpBackend(Backend):
         :param websocket_port: Listen port for the websocket server (default: 8009)
         :type websocket_port: int
 
+        :param bind_address: Address/interface to bind to (default: 0.0.0.0, accept connection from any IP)
+        :type bind_address: str
+
         :param disable_websocket: Disable the websocket interface (default: False)
         :type disable_websocket: bool
 
@@ -233,6 +237,8 @@ class HttpBackend(Backend):
         self.server_proc = None
         self.disable_websocket = disable_websocket
         self.websocket_thread = None
+        self._websocket_loop = None
+        self.bind_address = bind_address
 
         if resource_dirs:
             self.resource_dirs = {name: os.path.abspath(
@@ -271,10 +277,24 @@ class HttpBackend(Backend):
         if self.server_proc:
             if isinstance(self.server_proc, subprocess.Popen):
                 self.server_proc.kill()
-                self.server_proc.wait()
+                self.server_proc.wait(timeout=10)
+                if self.server_proc.poll() is not None:
+                    self.logger.warning('HTTP server process still alive at termination')
+                else:
+                    self.logger.info('HTTP server process terminated')
             else:
                 self.server_proc.terminate()
-                self.server_proc.join()
+                self.server_proc.join(timeout=10)
+                if self.server_proc.is_alive():
+                    self.server_proc.kill()
+                if self.server_proc.is_alive():
+                    self.logger.warning('HTTP server process still alive at termination')
+                else:
+                    self.logger.info('HTTP server process terminated')
+
+        if self.websocket_thread and self.websocket_thread.is_alive() and self._websocket_loop:
+            self._websocket_loop.stop()
+            self.logger.info('HTTP websocket service terminated')
 
     def _acquire_websocket_lock(self, ws):
         try:
@@ -355,17 +375,17 @@ class HttpBackend(Backend):
         if self.ssl_context:
             websocket_args['ssl'] = self.ssl_context
 
-        loop = get_or_create_event_loop()
+        self._websocket_loop = get_or_create_event_loop()
-        loop.run_until_complete(
+        self._websocket_loop.run_until_complete(
-            websockets.serve(register_websocket, '0.0.0.0', self.websocket_port,
+            websockets.serve(register_websocket, self.bind_address, self.websocket_port,
                              **websocket_args))
-        loop.run_forever()
+        self._websocket_loop.run_forever()
 
     def _start_web_server(self):
         def proc():
             self.logger.info('Starting local web server on port {}'.format(self.port))
             kwargs = {
-                'host': '0.0.0.0',
+                'host': self.bind_address,
                 'port': self.port,
                 'use_reloader': False,
                 'debug': False,

platypush/backend/light/hue.py

@@ -1,5 +1,3 @@
-import time
-
 from threading import Thread
 
 from platypush.backend import Backend
@@ -80,12 +78,13 @@ class LightHueBackend(Backend):
                 except Exception as e:
                     self.logger.exception(e)
                 finally:
-                    time.sleep(self.poll_seconds)
+                    self.wait_stop(self.poll_seconds)
 
         return _thread
 
     def run(self):
         super().run()
+        self.logger.info('Starting Hue lights backend')
 
         while not self.should_stop():
             try:
@@ -94,7 +93,9 @@ class LightHueBackend(Backend):
                 poll_thread.join()
             except Exception as e:
                 self.logger.exception(e)
-                time.sleep(self.poll_seconds)
+                self.wait_stop(self.poll_seconds)
+
+        self.logger.info('Stopped Hue lights backend')
 
 
 # vim:sw=4:ts=4:et:

platypush/backend/local/__init__.py

@@ -1,20 +1,16 @@
-import json
 import os
 import time
-import threading
 
 from .. import Backend
 
 from platypush.message import Message
-from platypush.message.event import StopEvent
-from platypush.message.request import Request
 from platypush.message.response import Response
 
 
 class LocalBackend(Backend):
     """
-    Sends and receive messages on two distinct local FIFOs, one for
+    Sends and receive messages on two distinct local FIFOs, one for the requests and one for the responses.
-    the requests and one for the responses.
+    This is a legacy backend that should only be used for testing purposes.
 
     You can use this backend either to send local commands to push through
     Pusher (or any other script), or debug. You can even send command on the
@@ -41,8 +37,7 @@ class LocalBackend(Backend):
         try: os.mkfifo(self.response_fifo)
         except FileExistsError as e: pass
 
-
+    def send_message(self, msg, **kwargs):
-    def send_message(self, msg):
         fifo = self.response_fifo \
             if isinstance(msg, Response) or self._request_context \
             else self.request_fifo

platypush/backend/mqtt.py

@@ -334,17 +334,17 @@ class MqttBackend(Backend):
 
         self.add_listeners(*self.listeners_conf)
 
-    def stop(self):
+    def on_stop(self):
         self.logger.info('Received STOP event on the MQTT backend')
 
         for ((host, port, _), listener) in self._listeners.items():
             try:
-                listener.loop_stop()
+                listener.stop()
-                listener.disconnect()
             except Exception as e:
                 # noinspection PyProtectedMember
                 self.logger.warning('Could not stop listener {host}:{port}: {error}'.
                                     format(host=host, port=port, error=str(e)))
 
+        self.logger.info('MQTT backend terminated')
 
 # vim:sw=4:ts=4:et:

platypush/backend/music/mopidy.py

@@ -224,6 +224,8 @@ class MusicMopidyBackend(Backend):
             self._connected_event.clear()
             self._ws = None
             self.logger.warning('Mopidy websocket connection closed')
+
+            if not self.should_stop():
                 self._retry_connect()
 
         return hndl
@@ -252,5 +254,12 @@ class MusicMopidyBackend(Backend):
         self.logger.info('Started tracking Mopidy events backend on {}:{}'.format(self.host, self.port))
         self._connect()
 
+    def on_stop(self):
+        self.logger.info('Received STOP event on the Mopidy backend')
+        if self._ws:
+            self._ws.close()
+
+        self.logger.info('Mopidy backend terminated')
+
 
 # vim:sw=4:ts=4:et:

platypush/backend/music/snapcast.py

@@ -1,4 +1,5 @@
 import json
+import select
 import socket
 import threading
 import time
@@ -94,9 +95,16 @@ class MusicSnapcastBackend(Backend):
 
     @classmethod
     def _recv(cls, sock):
+        sock.setblocking(0)
         buf = b''
+
         while buf[-2:] != cls._SOCKET_EOL:
+            ready = select.select([sock], [], [], 0.5)
+            if ready[0]:
                 buf += sock.recv(1)
+            else:
+                return
+
         return json.loads(buf.decode().strip())
 
     @classmethod
@@ -150,6 +158,8 @@ class MusicSnapcastBackend(Backend):
                     sock = self._connect(host, port)
                     msgs = self._recv(sock)
 
+                    if msgs is None:
+                        continue
                     if not isinstance(msgs, list):
                         msgs = [msgs]
 
@@ -157,6 +167,7 @@ class MusicSnapcastBackend(Backend):
                         self.logger.debug('Received message on {host}:{port}: {msg}'.
                                           format(host=host, port=port, msg=msg))
 
+                        # noinspection PyTypeChecker
                         evt = self._parse_msg(host=host, msg=msg)
                         if evt:
                             self.bus.post(evt)
@@ -191,5 +202,17 @@ class MusicSnapcastBackend(Backend):
             for host in self.hosts:
                 self._threads[host].join()
 
+        self.logger.info('Snapcast backend terminated')
+
+    def on_stop(self):
+        self.logger.info('Received STOP event on the Snapcast backend')
+        for host, sock in self._socks.items():
+            if sock:
+                try:
+                    sock.close()
+                except Exception as e:
+                    self.logger.warning('Could not close Snapcast connection to {}: {}: {}'.format(
+                        host, type(e), str(e)))
+
 
 # vim:sw=4:ts=4:et:

platypush/backend/pushbullet/__init__.py

@@ -127,8 +127,10 @@ class PushbulletBackend(Backend):
             self.listener = None
 
     def on_stop(self):
+        self.logger.info('Received STOP event on the Pushbullet backend')
         super().on_stop()
-        return self.close()
+        self.close()
+        self.logger.info('Pushbullet backend terminated')
 
     def on_error(self, e):
         self.logger.exception(e)

platypush/backend/redis.py

@@ -53,10 +53,13 @@ class RedisBackend(Backend):
     # noinspection PyBroadException
     def get_message(self, queue_name=None):
         queue = queue_name or self.queue
-        msg = self.redis.blpop(queue)[1].decode('utf-8')
+        data = self.redis.blpop(queue, timeout=1)
+        if data is None:
+            return
 
+        msg = data[1].decode()
         try:
-            msg = Message.build(json.loads(msg))
+            msg = Message.build(msg)
         except:
             try:
                 import ast
@@ -78,11 +81,16 @@ class RedisBackend(Backend):
         while not self.should_stop():
             try:
                 msg = self.get_message()
+                if not msg:
+                    continue
+
                 self.logger.info('Received message on the Redis backend: {}'.
                                  format(msg))
                 self.on_message(msg)
             except Exception as e:
                 self.logger.exception(e)
 
+        self.logger.info('Redis backend terminated')
+
 
 # vim:sw=4:ts=4:et:

platypush/backend/sensor/ir/zeroborg/__init__.py

@@ -31,11 +31,10 @@ class SensorIrZeroborgBackend(Backend):
         self.zb.Init()
         self.logger.info('Initialized Zeroborg infrared sensor backend')
 
-
     def run(self):
         super().run()
 
-        while True:
+        while not self.should_stop():
             try:
                 self.zb.GetIrMessage()
                 if self.zb.HasNewIrMessage():
@@ -47,7 +46,7 @@ class SensorIrZeroborgBackend(Backend):
                     self.last_message = message
                     self.last_message_timestamp = time.time()
             except OSError as e:
-                self.logger.warning('Failed reading IR sensor status')
+                self.logger.warning('Failed reading IR sensor status: {}: {}'.format(type(e), str(e)))
 
             if self.last_message_timestamp and \
                     time.time() - self.last_message_timestamp > self.no_message_timeout:
@@ -57,6 +56,4 @@ class SensorIrZeroborgBackend(Backend):
                 self.last_message = None
                 self.last_message_timestamp = None
 
-
 # vim:sw=4:ts=4:et:
-

platypush/backend/tcp.py

@@ -39,7 +39,7 @@ class TcpBackend(Backend):
             msg = b''
             prev_ch = None
 
-            while True:
+            while not self.should_stop():
                 if processed_bytes > self._MAX_REQ_SIZE:
                     self.logger.warning('Ignoring message longer than {} bytes from {}'
                                         .format(self._MAX_REQ_SIZE, address[0]))
@@ -95,6 +95,8 @@ class TcpBackend(Backend):
 
         serv_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         serv_sock.bind((self.bind_address, self.port))
+        serv_sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        serv_sock.settimeout(0.5)
 
         self.logger.info('Initialized TCP backend on port {} with bind address {}'.
                          format(self.port, self.bind_address))
@@ -102,9 +104,15 @@ class TcpBackend(Backend):
         serv_sock.listen(self.listen_queue)
 
         while not self.should_stop():
+            try:
                 (sock, address) = serv_sock.accept()
+            except socket.timeout:
+                continue
+
             self.logger.info('Accepted connection from client {}'.format(address[0]))
             self._process_client(sock, address)
 
+        self.logger.info('TCP backend terminated')
+
 
 # vim:sw=4:ts=4:et:

platypush/backend/websocket.py

@@ -56,6 +56,7 @@ class WebsocketBackend(Backend):
         self.bind_address = bind_address
         self.client_timeout = client_timeout
         self.active_websockets = set()
+        self._loop = None
 
         self.ssl_context = get_ssl_server_context(ssl_cert=ssl_cert,
                                                   ssl_key=ssl_key,
@@ -104,7 +105,7 @@ class WebsocketBackend(Backend):
                               format(websocket.remote_address[0]))
 
             try:
-                while True:
+                while not self.should_stop():
                     if self.client_timeout:
                         msg = await asyncio.wait_for(websocket.recv(),
                                                      timeout=self.client_timeout)
@@ -142,12 +143,19 @@ class WebsocketBackend(Backend):
         if self.ssl_context:
             websocket_args['ssl'] = self.ssl_context
 
-        loop = get_or_create_event_loop()
+        self._loop = get_or_create_event_loop()
         server = websockets.serve(serve_client, self.bind_address, self.port,
                                   **websocket_args)
 
-        loop.run_until_complete(server)
+        self._loop.run_until_complete(server)
-        loop.run_forever()
+        self._loop.run_forever()
+
+    def on_stop(self):
+        self.logger.info('Received STOP event on the websocket backend')
+        if self._loop:
+            self._loop.stop()
+
+        self.logger.info('Websocket backend terminated')
 
 
 # vim:sw=4:ts=4:et:

platypush/bus/__init__.py

@@ -2,11 +2,10 @@ import logging
 import threading
 import time
 
-from queue import Queue
+from queue import Queue, Empty
 from typing import Callable, Type
 
-from platypush.config import Config
+from platypush.message.event import Event
-from platypush.message.event import Event, StopEvent
 
 logger = logging.getLogger('platypush:bus')
 
@@ -21,6 +20,7 @@ class Bus(object):
         self.on_message = on_message
         self.thread_id = threading.get_ident()
         self.event_handlers = {}
+        self._should_stop = threading.Event()
 
     def post(self, msg):
         """ Sends a message to the bus """
@@ -28,15 +28,13 @@ class Bus(object):
 
     def get(self):
         """ Reads one message from the bus """
-        return self.bus.get()
+        try:
+            return self.bus.get(timeout=0.1)
+        except Empty:
+            return
 
     def stop(self):
-        """ Stops the bus by sending a STOP event """
+        self._should_stop.set()
-        evt = StopEvent(target=Config.get('device_id'),
-                        origin=Config.get('device_id'),
-                        thread_id=self.thread_id)
-
-        self.post(evt)
 
     def _msg_executor(self, msg):
         def event_handler(event: Event, handler: Callable[[Event], None]):
@@ -62,18 +60,22 @@ class Bus(object):
 
         return executor
 
+    def should_stop(self):
+        return self._should_stop.is_set()
+
     def poll(self):
         """
         Reads messages from the bus until either stop event message or KeyboardInterrupt
         """
-
         if not self.on_message:
             logger.warning('No message handlers installed, cannot poll')
             return
 
-        stop = False
+        while not self.should_stop():
-        while not stop:
             msg = self.get()
+            if msg is None:
+                continue
+
             timestamp = msg.timestamp if hasattr(msg, 'timestamp') else msg.get('timestamp')
             if timestamp and time.time() - timestamp > self._MSG_EXPIRY_TIMEOUT:
                 logger.debug('{} seconds old message on the bus expired, ignoring it: {}'.
@@ -82,9 +84,7 @@ class Bus(object):
 
             threading.Thread(target=self._msg_executor(msg)).start()
 
-            if isinstance(msg, StopEvent) and msg.targets_me():
+        logger.info('Bus service stoppped')
-                logger.info('Received STOP event on the bus')
-                stop = True
 
     def register_handler(self, event_type: Type[Event], handler: Callable[[Event], None]) -> Callable[[], None]:
         """

platypush/bus/redis.py

@@ -32,9 +32,11 @@ class RedisBus(Bus):
     def get(self):
         """ Reads one message from the Redis queue """
         msg = None
-
         try:
-            msg = self.redis.blpop(self.redis_queue)
+            if self.should_stop():
+                return
+
+            msg = self.redis.blpop(self.redis_queue, timeout=1)
             if not msg or msg[1] is None:
                 return
 
@@ -54,5 +56,9 @@ class RedisBus(Bus):
         """ Sends a message to the Redis queue """
         return self.redis.rpush(self.redis_queue, str(msg))
 
+    def stop(self):
+        super().stop()
+        self.redis.close()
+
 
 # vim:sw=4:ts=4:et:

platypush/cron/scheduler.py

@@ -1,11 +1,10 @@
 import enum
 import logging
+import threading
 import time
 
 import croniter
 
-from threading import Thread
-
 from platypush.procedure import Procedure
 from platypush.utils import is_functional_cron
 
@@ -20,12 +19,13 @@ class CronjobState(enum.IntEnum):
     ERROR = 4
 
 
-class Cronjob(Thread):
+class Cronjob(threading.Thread):
     def __init__(self, name, cron_expression, actions):
         super().__init__()
         self.cron_expression = cron_expression
         self.name = name
         self.state = CronjobState.IDLE
+        self._should_stop = threading.Event()
 
         if isinstance(actions, dict) or isinstance(actions, list):
             self.actions = Procedure.build(name=name + '__Cron', _async=False, requests=actions)
@@ -35,6 +35,9 @@ class Cronjob(Thread):
     def run(self):
         self.state = CronjobState.WAIT
         self.wait()
+        if self.should_stop():
+            return
+
         self.state = CronjobState.RUNNING
 
         try:
@@ -56,7 +59,7 @@ class Cronjob(Thread):
         now = int(time.time())
         cron = croniter.croniter(self.cron_expression, now)
         next_run = int(cron.get_next())
-        time.sleep(next_run - now)
+        self._should_stop.wait(next_run - now)
 
     def should_run(self):
         now = int(time.time())
@@ -64,12 +67,19 @@ class Cronjob(Thread):
         next_run = int(cron.get_next())
         return now == next_run
 
+    def stop(self):
+        self._should_stop.set()
 
-class CronScheduler(Thread):
+    def should_stop(self):
+        return self._should_stop.is_set()
+
+
+class CronScheduler(threading.Thread):
     def __init__(self, jobs):
         super().__init__()
         self.jobs_config = jobs
         self._jobs = {}
+        self._should_stop = threading.Event()
         logger.info('Cron scheduler initialized with {} jobs'.
                     format(len(self.jobs_config.keys())))
 
@@ -90,10 +100,18 @@ class CronScheduler(Thread):
 
         return self._jobs[name]
 
+    def stop(self):
+        for job in self._jobs.values():
+            job.stop()
+        self._should_stop.set()
+
+    def should_stop(self):
+        return self._should_stop.is_set()
+
     def run(self):
         logger.info('Running cron scheduler')
 
-        while True:
+        while not self.should_stop():
             for (job_name, job_config) in self.jobs_config.items():
                 job = self._get_job(name=job_name, config=job_config)
                 if job.state == CronjobState.IDLE:
@@ -101,5 +119,7 @@ class CronScheduler(Thread):
 
             time.sleep(0.5)
 
+        logger.info('Terminating cron scheduler')
+
 
 # vim:sw=4:ts=4:et:

platypush/message/event/__init__.py

@@ -2,7 +2,6 @@ import copy
 import json
 import random
 import re
-import threading
 import time
 
 from datetime import date
@@ -199,29 +198,6 @@ class EventMatchResult(object):
         self.parsed_args = {} if not parsed_args else parsed_args
 
 
-# XXX Should be a stop Request, not an Event
-class StopEvent(Event):
-    """ StopEvent message. When received on a Bus, it will terminate the
-    listening thread having the specified ID. Useful to keep listeners in
-    sync and make them quit when the application terminates """
-
-    def __init__(self, target, origin, thread_id, id=None, **kwargs):
-        """ Constructor.
-        :param target: Target node
-        :param origin: Origin node
-        :param thread_id: thread_iden() to be terminated if listening on the bus
-        :param id: Event ID (default: auto-generated)
-        :param kwargs: Extra key-value arguments
-        """
-
-        super().__init__(target=target, origin=origin, id=id,
-                         thread_id=thread_id, **kwargs)
-
-    def targets_me(self):
-        """ Returns true if the stop event is for the current thread """
-        return self.args['thread_id'] == threading.get_ident()
-
-
 def flatten(args):
     if isinstance(args, dict):
         for (key, value) in args.items():