fix: make coordinator shutdown signal handling idempotent

scripts/multi_process_launcher.py

@@ -84,6 +84,7 @@ class Coordinator:
         self.num_workers = num_workers or max(2, cpu_count())
         self.workers: List[WorkerProcess] = []
         self.running = False
+        self._stopping = False
         self.enable_agent = enable_agent
     
     def _get_shard_key(self, acc_id: str, from_id: str) -> int:
@@ -153,11 +154,17 @@ class Coordinator:
     
     def _signal_handler(self, signum, frame):
         """信号处理"""
+        if self._stopping:
+            return
+        self._stopping = True
         logger.info(f"收到信号 {signum}，正在停止所有工作进程...")
         self.stop()
     
     def stop(self):
         """停止所有工作进程"""
+        if self._stopping and not self.running and not any(w.process and w.process.is_alive() for w in self.workers):
+            return
+        self._stopping = True
         self.running = False
         
         for worker in self.workers: