Added `StoppableThread` common interface.

platypush/common/__init__.py

@@ -4,6 +4,8 @@ import os
 
 from platypush.utils.manifest import Manifest
 
+from ._types import StoppableThread
+
 logger = logging.getLogger('platypush')
 
 
@@ -26,9 +28,20 @@ class ExtensionWithManifest:
         self._manifest = self.get_manifest()
 
     def get_manifest(self) -> Manifest:
-        manifest_file = os.path.join(os.path.dirname(inspect.getfile(self.__class__)), 'manifest.yaml')
-        assert os.path.isfile(manifest_file), (
-            'The extension {} has no associated manifest.yaml'.format(self.__class__.__name__)
+        manifest_file = os.path.join(
+            os.path.dirname(inspect.getfile(self.__class__)), 'manifest.yaml'
+        )
+        assert os.path.isfile(
+            manifest_file
+        ), 'The extension {} has no associated manifest.yaml'.format(
+            self.__class__.__name__
         )
 
         return Manifest.from_file(manifest_file)
+
+
+__all__ = [
+    'ExtensionWithManifest',
+    'StoppableThread',
+    'exec_wrapper',
+]

platypush/common/_types.py

@@ -0,0 +1,12 @@
+from abc import ABC, abstractmethod
+from threading import Thread
+
+
+class StoppableThread(Thread, ABC):
+    """
+    Base interface for stoppable threads.
+    """
+
+    @abstractmethod
+    def stop(self):
+        ...