event handlers are now executed in separate tasks

src/pipecat/utils/base_object.py

@@ -4,6 +4,7 @@
 # SPDX-License-Identifier: BSD 2-Clause License
 #
 
+import asyncio
 import inspect
 from abc import ABC
 from typing import Optional
@@ -17,8 +18,15 @@ class BaseObject(ABC):
     def __init__(self, *, name: Optional[str] = None):
         self._id: int = obj_id()
         self._name = name or f"{self.__class__.__name__}#{obj_count(self)}"
+
+        # Registered event handlers.
         self._event_handlers: dict = {}
 
+        # Set of tasks being executed. When a task finishes running it gets
+        # automatically removed from the set. When we cleanup we wait for all
+        # event tasks still being executed.
+        self._event_tasks = set()
+
     @property
     def id(self) -> int:
         return self._id
@@ -27,6 +35,12 @@ class BaseObject(ABC):
     def name(self) -> str:
         return self._name
 
+    async def cleanup(self):
+        if self._event_tasks:
+            event_names, tasks = zip(*self._event_tasks)
+            logger.debug(f"{self} wating on event handlers to finish {list(event_names)}...")
+            await asyncio.wait(tasks)
+
     def event_handler(self, event_name: str):
         def decorator(handler):
             self.add_event_handler(event_name, handler)
@@ -45,6 +59,16 @@ class BaseObject(ABC):
         self._event_handlers[event_name] = []
 
     async def _call_event_handler(self, event_name: str, *args, **kwargs):
+        # Create the task.
+        task = asyncio.create_task(self._run_task(event_name, *args, **kwargs))
+
+        # Add it to our list of event tasks.
+        self._event_tasks.add((event_name, task))
+
+        # Remove the task from the event tasks list when the task completes.
+        task.add_done_callback(self._event_task_finished)
+
+    async def _run_task(self, event_name: str, *args, **kwargs):
         try:
             for handler in self._event_handlers[event_name]:
                 if inspect.iscoroutinefunction(handler):
@@ -54,5 +78,10 @@ class BaseObject(ABC):
         except Exception as e:
             logger.exception(f"Exception in event handler {event_name}: {e}")
 
+    def _event_task_finished(self, task: asyncio.Task):
+        tuple_to_remove = next((t for t in self._event_tasks if t[1] == task), None)
+        if tuple_to_remove:
+            self._event_tasks.discard(tuple_to_remove)
+
     def __str__(self):
         return self.name