keep references to background tasks

Author: pschichtel

rasa_vier_cvg/cvg.py

@@ -4,7 +4,7 @@
 import base64
 import logging
 from functools import wraps
-from typing import Any, Awaitable, Callable, Dict, Optional, Text, TypeVar, Coroutine
+from typing import Any, Awaitable, Callable, Dict, Optional, Text, TypeVar, Coroutine, Set
 import warnings
 import aiohttp
 
@@ -52,12 +52,22 @@ def create_recipient_id(reseller_token, project_token, dialog_id) -> Text:
     return base64.b64encode(bytes(json_representation, 'utf-8')).decode('utf-8')
 
 
+class TaskContainer:
+    tasks: Set[asyncio.Task] = set()
+
+    def run(self, coro: Coroutine[Any, Any, None]):
+        task = asyncio.create_task(coro)
+        self.tasks.add(task)
+        task.add_done_callback(self.tasks.discard)
+
+
 class CVGOutput(OutputChannel):
     """Output channel for the Cognitive Voice Gateway"""
 
     on_message: Callable[[UserMessage], Awaitable[Any]]
     base_url: str
     proxy: Optional[str]
+    task_container: TaskContainer = TaskContainer()
 
     @classmethod
     def name(cls) -> Text:
@@ -89,8 +99,7 @@ async def perform():
             status, body = await self._perform_request(path, method, data)
             await process_result(status, body)
 
-        # noinspection PyAsyncCall
-        asyncio.create_task(perform())
+        self.task_container.run(perform())
 
     async def _say(self, dialog_id: str, text: str):
         await self._perform_request("/call/say", method="POST", data={DIALOG_ID_FIELD: dialog_id, "text": text})
@@ -214,6 +223,7 @@ class CVGInput(InputChannel):
     proxy: Optional[str]
     expected_authorization_header_value: str
     blocking_endpoints: bool
+    task_container: TaskContainer = TaskContainer()
 
     @classmethod
     def name(cls) -> Text:
@@ -316,8 +326,7 @@ async def process_request(request: Request, text: Text, must_block: bool):
             if self.blocking_endpoints or must_block:
                 await result
             else:
-                # noinspection PyAsyncCall
-                asyncio.create_task(result)
+                self.task_container.run(result)
 
             return response.empty(204)