Start AudioStream _run task after the FFI handle is assigned (#742)

Author: apoorva-01

livekit-rtc/livekit/rtc/audio_stream.py

@@ -125,9 +125,6 @@ def __init__(
             self._processor = noise_cancellation
             self._processor_auto_close = auto_close_noise_cancellation
 
-        self._task = self._loop.create_task(self._run())
-        self._task.add_done_callback(task_done_logger)
-
         stream: Any = None
         if "participant" in kwargs:
             stream = self._create_owned_stream_from_participant(
@@ -138,6 +135,11 @@ def __init__(
         self._ffi_handle = FfiHandle(stream.handle.id)
         self._info = stream.info
 
+        # Start _run only after _ffi_handle is set, so a failure above doesn't orphan
+        # a task that dereferences an unassigned _ffi_handle.
+        self._task = self._loop.create_task(self._run())
+        self._task.add_done_callback(task_done_logger)
+
         if self._track is not None:
             self._track._register_audio_stream(self)
 

livekit-rtc/tests/test_audio_stream_init.py

@@ -0,0 +1,53 @@
+# Copyright 2026 LiveKit, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Regression tests for AudioStream.__init__ error handling."""
+
+from __future__ import annotations
+
+import asyncio
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from livekit import rtc
+
+
+async def test_failed_stream_creation_does_not_orphan_run_task() -> None:
+    """If owned-stream creation fails, __init__ must not leave a running _run task.
+
+    _run dereferences self._ffi_handle, which is only assigned once stream creation
+    succeeds. Scheduling the task before that assignment leaves an orphaned task that
+    raises AttributeError from the event loop, uncatchable by the caller.
+    """
+    track = MagicMock(spec=rtc.Track)
+    before = asyncio.all_tasks()
+
+    with patch.object(
+        rtc.AudioStream,
+        "_create_owned_stream",
+        side_effect=RuntimeError("track already closed"),
+    ):
+        with pytest.raises(RuntimeError, match="track already closed"):
+            rtc.AudioStream(track)
+
+    orphaned = [
+        t
+        for t in asyncio.all_tasks() - before
+        if getattr(t.get_coro(), "__qualname__", "") == "AudioStream._run"
+    ]
+    for t in orphaned:
+        t.cancel()
+
+    assert not orphaned