[Fix] Wire the detokenizer soft watchdog into the multi-http-worker event loop (#31392)

python/sglang/srt/managers/multi_tokenizer_mixin.py

@@ -381,12 +381,13 @@ class MultiHttpWorkerDetokenizerMixin:
     def multi_http_worker_event_loop(self: DetokenizerManager):
         """The event loop that handles requests, for multi multi-http-worker mode"""
         self.socket_mapping = SocketMapping()
+        # Watchdog wiring mirrors DetokenizerManager.event_loop: the watchdog is
+        # paused while waiting for input and fed once per processed message.
         while True:
+            with self.soft_watchdog.disable():
                 recv_obj = sock_recv(self.recv_from_scheduler)
             output = self._request_dispatcher(recv_obj)
-            if output is None:
-                continue
-
+            if output is not None:
                 # Fan out the output back to the originating tokenizer worker(s).
                 # In multi-detokenizer mode the upstream MultiDetokenizerRouter may
                 # forward either batched or single requests, so handle both shapes.
@@ -404,6 +405,7 @@ class MultiHttpWorkerDetokenizerMixin:
                     raise ValueError(
                         f"multi_http_worker_event_loop got unexpected req type {type(recv_obj)}"
                     )
+            self.soft_watchdog.feed()
 
 
 class MultiTokenizerRouter: