[Log] Wire stat loggers into AsyncOmniEngine to match AsyncLLM (#2551)

Signed-off-by: gcanlin <canlinguosdu@gmail.com>

tests/engine/test_async_omni_engine_do_log_stats.py

@@ -0,0 +1,56 @@
+"""Guard tests for AsyncOmniEngine.do_log_stats edge cases.
+
+These are pure-Python tests that bypass __init__ and only exercise the
+no-op branches of do_log_stats, so no stage cores / threads are needed.
+"""
+
+import asyncio
+
+import pytest
+
+from vllm_omni.engine.async_omni_engine import AsyncOmniEngine
+
+pytestmark = [pytest.mark.core_model, pytest.mark.cpu]
+
+
+def _make_bare_engine() -> AsyncOmniEngine:
+    # Bypass __init__ so we don't spin up stage cores; we only need the
+    # attributes do_log_stats touches.
+    return AsyncOmniEngine.__new__(AsyncOmniEngine)
+
+
+@pytest.mark.asyncio
+async def test_do_log_stats_noop_when_manager_missing():
+    engine = _make_bare_engine()
+    engine.logger_manager = None
+    engine.orchestrator_loop = None
+    await engine.do_log_stats()  # should silently return
+
+
+@pytest.mark.asyncio
+async def test_do_log_stats_noop_when_loop_missing():
+    engine = _make_bare_engine()
+
+    class _Manager:
+        def log(self) -> None:  # pragma: no cover - must not be called
+            raise AssertionError("log() should not be called without a loop")
+
+    engine.logger_manager = _Manager()
+    engine.orchestrator_loop = None
+    await engine.do_log_stats()
+
+
+@pytest.mark.asyncio
+async def test_do_log_stats_noop_when_loop_not_running():
+    engine = _make_bare_engine()
+
+    class _Manager:
+        def log(self) -> None:  # pragma: no cover - must not be called
+            raise AssertionError("log() should not be called on a stopped loop")
+
+    dead_loop = asyncio.new_event_loop()
+    dead_loop.close()
+
+    engine.logger_manager = _Manager()
+    engine.orchestrator_loop = dead_loop
+    await engine.do_log_stats()