Enable Diffusion Image models asynchronous output (#4981)

Signed-off-by: zzh <943967662@qq.com>
Co-authored-by: dengyunyang <584797741@qq.com>

tests/platforms/test_record_device_event.py

@@ -0,0 +1,79 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+"""Unit tests for OmniPlatform.record_device_event implementations."""
+
+import pytest
+
+pytestmark = [pytest.mark.core_model, pytest.mark.cpu]
+
+
+class TestOmniPlatformRecordDeviceEventInterface:
+    """Test that the base OmniPlatform returns None (safe no-op fallback)."""
+
+    def test_base_class_returns_none(self):
+        from vllm_omni.platforms.interface import OmniPlatform
+
+        assert OmniPlatform.record_device_event() is None
+
+
+class TestCudaOmniPlatformRecordDeviceEvent:
+    """Test CudaOmniPlatform.record_device_event with mocked torch.Event."""
+
+    def test_records_event_successfully(self, mocker):
+        from vllm_omni.platforms.cuda.platform import CudaOmniPlatform
+
+        mock_event = mocker.MagicMock()
+        mocker.patch("torch.Event", return_value=mock_event)
+
+        result = CudaOmniPlatform.record_device_event()
+        assert result is mock_event
+        mock_event.record.assert_called_once()
+
+    def test_returns_none_on_failure(self, mocker):
+        from vllm_omni.platforms.cuda.platform import CudaOmniPlatform
+
+        mocker.patch("torch.Event", side_effect=RuntimeError("no CUDA"))
+
+        result = CudaOmniPlatform.record_device_event()
+        assert result is None
+
+
+class TestNPUOmniPlatformRecordDeviceEvent:
+    """Test NPUOmniPlatform.record_device_event with mocked torch.npu."""
+
+    def test_returns_none_on_failure(self, mocker):
+        """When torch.npu.current_stream().synchronize() fails, return None."""
+        try:
+            from vllm_omni.platforms.npu.platform import NPUOmniPlatform
+        except ModuleNotFoundError:
+            pytest.skip("vllm_ascend not available")
+
+        mock_torch = mocker.MagicMock()
+        mock_torch.npu.current_stream.return_value.synchronize.side_effect = RuntimeError("no NPU")
+        mocker.patch("vllm_omni.platforms.npu.platform.torch", mock_torch)
+
+        result = NPUOmniPlatform.record_device_event()
+        assert result is None
+
+    def test_synchronizes_stream_then_records_event(self, mocker):
+        """NPU should sync stream first, then create and record an Event."""
+        try:
+            from vllm_omni.platforms.npu.platform import NPUOmniPlatform
+        except ModuleNotFoundError:
+            pytest.skip("vllm_ascend not available")
+
+        mock_event = mocker.MagicMock()
+        mock_stream = mocker.MagicMock()
+        mock_torch = mocker.MagicMock()
+        mock_torch.npu.current_stream.return_value = mock_stream
+        mock_torch.npu.Event.return_value = mock_event
+        mocker.patch("vllm_omni.platforms.npu.platform.torch", mock_torch)
+
+        result = NPUOmniPlatform.record_device_event()
+
+        # Stream should be synced first (HCCL ordering)
+        mock_stream.synchronize.assert_called_once()
+        # Then event should be created and recorded
+        mock_torch.npu.Event.assert_called_once()
+        mock_event.record.assert_called_once()
+        assert result is mock_event