[V1] Make AsyncLLMEngine v1-v0 opaque (#11383)

Signed-off-by: Ricky Xu <xuchen727@hotmail.com>

vllm/engine/async_llm_engine.py

@@ -1256,3 +1256,10 @@ class AsyncLLMEngine(EngineClient):
             self.engine.model_executor.stop_profile()
         else:
             self.engine.model_executor._run_workers("stop_profile")
+
+
+# TODO(v1): Remove this class proxy when V1 goes default.
+if envs.VLLM_USE_V1:
+    from vllm.v1.engine.async_llm import AsyncLLM
+
+    AsyncLLMEngine = AsyncLLM  # type: ignore

vllm/entrypoints/openai/api_server.py

@@ -27,6 +27,7 @@ from typing_extensions import assert_never
 import vllm.envs as envs
 from vllm.config import ModelConfig
 from vllm.engine.arg_utils import AsyncEngineArgs
+from vllm.engine.async_llm_engine import AsyncLLMEngine  # type: ignore
 from vllm.engine.multiprocessing.client import MQLLMEngineClient
 from vllm.engine.multiprocessing.engine import run_mp_engine
 from vllm.engine.protocol import EngineClient
@@ -66,11 +67,6 @@ from vllm.utils import (FlexibleArgumentParser, get_open_zmq_ipc_path,
                         is_valid_ipv6_address)
 from vllm.version import __version__ as VLLM_VERSION
 
-if envs.VLLM_USE_V1:
-    from vllm.v1.engine.async_llm import AsyncLLMEngine  # type: ignore
-else:
-    from vllm.engine.async_llm_engine import AsyncLLMEngine  # type: ignore
-
 TIMEOUT_KEEP_ALIVE = 5  # seconds
 
 prometheus_multiproc_dir: tempfile.TemporaryDirectory

vllm/v1/engine/async_llm.py

@@ -98,7 +98,7 @@ class AsyncLLM(EngineClient):
         start_engine_loop: bool = True,
         usage_context: UsageContext = UsageContext.ENGINE_CONTEXT,
         stat_loggers: Optional[Dict[str, StatLoggerBase]] = None,
-    ) -> "AsyncLLMEngine":
+    ) -> "AsyncLLM":
         """Create an AsyncLLM from the EngineArgs."""
 
         # Create the engine configs.
@@ -386,7 +386,3 @@ class AsyncLLM(EngineClient):
     @property
     def dead_error(self) -> BaseException:
         return Exception()  # TODO: implement
-
-
-# Retain V0 name for backwards compatibility.
-AsyncLLMEngine = AsyncLLM