diff --git a/litellm/litellm_core_utils/logging_worker.py b/litellm/litellm_core_utils/logging_worker.py index 5ccc5632646..2f8e7bdccea 100644 --- a/litellm/litellm_core_utils/logging_worker.py +++ b/litellm/litellm_core_utils/logging_worker.py @@ -484,9 +484,13 @@ class LoggingWorker: so it correctly handles items that have been dequeued but whose callback hasn't finished yet — ``queue.empty()`` would return True in that window and cause us to skip the wait. + + ``start()`` runs first so a queue left behind by a previous event loop + is carried onto this one and drained here instead of joined forever. """ if self._queue is None: return + self.start() await self._queue.join() async def clear_queue(self): diff --git a/tests/test_litellm/litellm_core_utils/test_logging_worker.py b/tests/test_litellm/litellm_core_utils/test_logging_worker.py index 1553e788472..2bb93a58531 100644 --- a/tests/test_litellm/litellm_core_utils/test_logging_worker.py +++ b/tests/test_litellm/litellm_core_utils/test_logging_worker.py @@ -180,6 +180,53 @@ class TestLoggingWorker: assert sorted(fired) == ["first", "second"] + @pytest.mark.parametrize("stranded", ["still_queued", "dequeued_never_started"]) + def test_flush_on_new_loop_drains_tasks_stranded_on_previous_loop(self, stranded): + """ + Regression: ``flush()`` from a new event loop used to ``join()`` the queue bound to the + previous loop, whose unfinished counter nothing on the new loop ever decrements. The first + such flush hung until pytest-timeout killed it and every later one raised + ``RuntimeError: ... is bound to a different event loop`` from the queue's Event. + """ + worker = LoggingWorker(timeout=1.0, max_queue_size=10) + callback = AsyncMock() + + async def enqueue_on_first_loop(): + if stranded == "still_queued": + worker._ensure_queue() + worker.enqueue(callback()) + return + worker.ensure_initialized_and_enqueue(callback()) + + asyncio.run(enqueue_on_first_loop()) + assert worker._queue is not None + expected_shape = (1, 0) if stranded == "still_queued" else (0, 1) + assert (worker._queue.qsize(), len(worker._unstarted_dequeued_tasks())) == expected_shape + assert callback.await_count == 0, "precondition: the callback never ran before the first loop closed" + + async def flush_twice_on_second_loop(): + await asyncio.wait_for(worker.flush(), timeout=5) + await asyncio.wait_for(worker.flush(), timeout=5) + + asyncio.run(flush_twice_on_second_loop()) + + assert callback.await_count == 1 + + def test_flush_starts_a_worker_when_the_queue_has_none(self): + """``flush()`` must drain a queue that exists on the current loop without a running worker.""" + worker = LoggingWorker(timeout=1.0, max_queue_size=10) + callback = AsyncMock() + + async def enqueue_then_flush(): + worker._ensure_queue() + worker.enqueue(callback()) + assert worker._worker_task is None, "precondition: nothing is draining the queue yet" + await asyncio.wait_for(worker.flush(), timeout=3) + + asyncio.run(enqueue_then_flush()) + + assert callback.await_count == 1 + def test_flush_on_exit_swallows_cancellation_and_drains_remaining(self): """A callback raising CancelledError must not abort the atexit flush of later events.""" worker = LoggingWorker(timeout=1.0, max_queue_size=10)