[Core][Frontend] Bound duplex output delivery and reject cancelled audio (#7644)

Signed-off-by: Nolen Liang <nliang@nvidia.com>
Signed-off-by: bcsdhjew <nliang@nvidia.com>

tests/entrypoints/openai/test_duplex_session_attachment.py

@@ -9,6 +9,8 @@ import json
 
 import pytest
 
+from vllm_omni.engine.duplex.delivery import DuplexOutputBuffer
+from vllm_omni.engine.duplex.events import AudioDelta, ResponseDone
 from vllm_omni.entrypoints.duplex.session_attachment import (
     DuplexEventJournal,
     DuplexJournalGapError,
@@ -22,6 +24,36 @@ from vllm_omni.entrypoints.duplex.session_attachment import (
 pytestmark = [pytest.mark.core_model, pytest.mark.cpu]
 
 
+@pytest.mark.asyncio
+@pytest.mark.parametrize("journal", [False, True])
+async def test_audio_invalidated_while_waiting_for_send_is_not_sequenced_or_journaled(mocker, journal: bool):
+    registry = DuplexSessionAttachmentRegistry(replay_ttl_s=60.0, replay_max_bytes_per_session=4096)
+    output = DuplexOutputBuffer(max_bytes=4096, max_events=8)
+    sent: list[dict[str, object]] = []
+    accepted = mocker.Mock()
+
+    await registry.create("s", send=mocker.AsyncMock(side_effect=sent.append), close=mocker.AsyncMock())
+    audio = AudioDelta(session_id="s", response_id="r", epoch=0, delta="AAAA")
+    output.put(audio)
+    assert await output.get() is audio
+    state = registry._sessions["s"]
+    async with state.outbound_lock:
+        delivery = asyncio.create_task(
+            registry.send_event(
+                "s", audio.to_realtime(), journal=journal, on_accepted=accepted, event_guard=lambda: output.guard(audio)
+            )
+        )
+        await asyncio.sleep(0)
+        assert not delivery.done()
+        output.invalidate("r", through_epoch=0)
+    assert await delivery is None
+    accepted.assert_not_called()
+    done = ResponseDone(response_id="r", response={"status": "cancelled"})
+    await registry.send_event("s", done.to_realtime())
+    assert [(entry["type"], entry["server_event_seq"]) for entry in sent] == [("response.done", 1)]
+    assert [entry.payload["event_id"] for entry in state.journal.replay_after(0)] == [done.event_id]
+
+
 class _Clock:
     def __init__(self) -> None:
         self.value = 0.0