[Frontend][Core] Revert "Add shutdown timeout" (#34730 and #36270) (#36628)

Signed-off-by: Mark McLoughlin <markmc@redhat.com>

vllm/v1/engine/utils.py

@@ -3,7 +3,6 @@
 
 import contextlib
 import os
-import threading
 import weakref
 from collections.abc import Callable, Iterator
 from dataclasses import dataclass
@@ -152,12 +151,11 @@ class CoreEngineProcManager:
         finally:
             # Kill other procs if not all are running.
             if self.finished_procs():
-                self.shutdown()
+                self.close()
 
-    def shutdown(self, timeout: float | None = None) -> None:
-        """Shutdown engine core processes with configurable timeout."""
-        if self._finalizer.detach() is not None:
-            shutdown(self.processes, timeout=timeout)
+    def close(self):
+        """Shutdown all procs."""
+        self._finalizer()
 
     def join_first(self):
         """Wait for any process to exit."""
@@ -175,33 +173,6 @@ class CoreEngineProcManager:
         }
 
 
-class SignalCallback:
-    """Safely trigger a callback from signal handler context via a dedicated thread."""
-
-    def __init__(self, callback: Callable[[], None]):
-        self._callback = callback
-        self._event = threading.Event()
-        self._stopped = False
-        self._thread = threading.Thread(
-            target=self._run,
-            daemon=True,
-            name="signal-callback",
-        )
-        self._thread.start()
-
-    def _run(self):
-        self._event.wait()
-        if not self._stopped:
-            self._callback()
-
-    def trigger(self):
-        self._event.set()
-
-    def stop(self):
-        self._stopped = True
-        self._event.set()
-
-
 @contextlib.contextmanager
 def set_device_control_env_var(
     vllm_config: VllmConfig, local_dp_rank: int
@@ -797,7 +768,7 @@ class CoreEngineActorManager:
     def get_run_refs(self):
         return self.run_refs
 
-    def shutdown(self, timeout: float | None = None) -> None:
+    def close(self):
         import ray
 
         for actor in self.local_engine_actors + self.remote_engine_actors: