Guard the start of the data throttler thread with a lock to prevent multiple launches

platypush/plugins/adafruit/io.py

@@ -2,7 +2,7 @@ import ast
 import statistics
 import time
 
-from threading import Thread
+from threading import Thread, Lock
 from Adafruit_IO import Client
 from Adafruit_IO.errors import ThrottlingError
 
@@ -10,6 +10,8 @@ from platypush.context import get_backend
 from platypush.message import Message
 from platypush.plugins import Plugin, action
 
+data_throttler_lock = Lock()
+
 class AdafruitIoPlugin(Plugin):
     """
     This plugin allows you to interact with the Adafruit IO
@@ -62,9 +64,10 @@ class AdafruitIoPlugin(Plugin):
         self.aio = Client(username=username, key=key)
         self.throttle_seconds = throttle_seconds
 
-        if self.throttle_seconds:
+        if self.throttle_seconds and not data_throttler_lock.locked():
             redis = self._get_redis()
             self.logger.info('Starting Adafruit IO throttler thread')
+            data_throttler_lock.acquire(False)
             self.data_throttler = Thread(target=self._data_throttler())
             self.data_throttler.start()
 
@@ -85,6 +88,7 @@ class AdafruitIoPlugin(Plugin):
             last_processed_batch_timestamp = None
             data = {}
 
+            try:
                 while True:
                     try:
                         new_data = ast.literal_eval(
@@ -111,6 +115,8 @@ class AdafruitIoPlugin(Plugin):
                                     time.sleep(self.throttle_seconds)
 
                         data = {}
+            except Exception as e:
+                self.logger.exception(e)
 
         return run