[P/D] Add a shutdown method to the Connector API (#22699)

Signed-off-by: chaunceyjiang <chaunceyjiang@gmail.com>

vllm/v1/executor/multiproc_executor.py

@@ -1,7 +1,6 @@
 # SPDX-License-Identifier: Apache-2.0
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 import multiprocessing
-import os
 import pickle
 import queue
 import signal
@@ -507,6 +506,7 @@ class WorkerProc:
         return cast(list[WorkerProcHandle], ready_proc_handles)
 
     def shutdown(self):
+        self.worker.shutdown()
         self.rpc_broadcast_mq = None
         self.worker_response_mq = None
         destroy_model_parallel()
@@ -536,7 +536,7 @@ class WorkerProc:
         # tuple[Connection, Connection]
         reader, ready_writer = kwargs.pop("ready_pipe")
         death_pipe = kwargs.pop("death_pipe", None)
-
+        shutdown_event = threading.Event()
         # Start death monitoring thread if death_pipe is provided
         if death_pipe is not None:
 
@@ -548,7 +548,7 @@ class WorkerProc:
                     # Parent process has exited, terminate this worker
                     logger.info("Parent process exited, terminating worker")
                     # Send signal to self to trigger clean shutdown
-                    os.kill(os.getpid(), signal.SIGTERM)
+                    shutdown_event.set()
                 except Exception as e:
                     logger.warning("Death monitoring error: %s", e)
 
@@ -576,7 +576,7 @@ class WorkerProc:
             ready_writer.close()
             ready_writer = None
 
-            worker.worker_busy_loop()
+            worker.worker_busy_loop(cancel=shutdown_event)
 
         except Exception:
             # NOTE: if an Exception arises in busy_loop, we send
@@ -586,6 +586,8 @@ class WorkerProc:
 
             if ready_writer is not None:
                 logger.exception("WorkerProc failed to start.")
+            elif shutdown_event.is_set():
+                logger.info("WorkerProc shutting down.")
             else:
                 logger.exception("WorkerProc failed.")
 
@@ -637,11 +639,11 @@ class WorkerProc:
             output = self.async_output_queue.get()
             self.enqueue_output(output)
 
-    def worker_busy_loop(self):
+    def worker_busy_loop(self, cancel: Optional[threading.Event] = None):
         """Main busy loop for Multiprocessing Workers"""
         while True:
-            method, args, kwargs, output_rank = self.rpc_broadcast_mq.dequeue()
-
+            method, args, kwargs, output_rank = self.rpc_broadcast_mq.dequeue(
+                cancel=cancel)
             try:
                 if isinstance(method, str):
                     func = getattr(self.worker, method)