fix(scheduler): make scheduler init idempotent to prevent duplicate task runs

agent/tools/scheduler/integration.py

@@ -3,6 +3,7 @@ Integration module for scheduler with AgentBridge
 """
 
 import os
+import threading
 from typing import Optional
 from config import conf
 from common.log import logger
@@ -13,20 +14,36 @@ from bridge.reply import Reply, ReplyType
 # Global scheduler service instance
 _scheduler_service = None
 _task_store = None
+# Module-level lock to guard idempotent initialization across threads
+_init_lock = threading.Lock()
 
 
 def init_scheduler(agent_bridge) -> bool:
     """
-    Initialize scheduler service
+    Initialize scheduler service (idempotent).
+
+    Safe to call multiple times and from multiple threads: only the first
+    successful call creates the singleton ``SchedulerService`` + background
+    scanning thread. Subsequent calls return immediately.
 
     Args:
         agent_bridge: AgentBridge instance
 
     Returns:
-        True if initialized successfully
+        True if scheduler is initialized (newly created or already running)
     """
     global _scheduler_service, _task_store
 
+    # Fast path: already initialized and running
+    if _scheduler_service is not None and getattr(_scheduler_service, "running", False):
+        return True
+
+    with _init_lock:
+        # Re-check under the lock to avoid races where multiple threads
+        # passed the fast-path check before any of them acquired the lock.
+        if _scheduler_service is not None and getattr(_scheduler_service, "running", False):
+            return True
+
         try:
             from agent.tools.scheduler.task_store import TaskStore
             from agent.tools.scheduler.scheduler_service import SchedulerService
@@ -35,7 +52,8 @@ def init_scheduler(agent_bridge) -> bool:
             workspace_root = expand_path(conf().get("agent_workspace", "~/cow"))
             store_path = os.path.join(workspace_root, "scheduler", "tasks.json")
 
-        # Create task store
+            # Create task store (reuse if already created)
+            if _task_store is None:
                 _task_store = TaskStore(store_path)
                 logger.debug(f"[Scheduler] Task store initialized: {store_path}")
 

bridge/agent_initializer.py

@@ -5,6 +5,7 @@ Agent Initializer - Handles agent initialization logic
 import os
 import asyncio
 import datetime
+import threading
 import time
 from typing import Optional, List
 
@@ -13,6 +14,9 @@ from agent.tools import ToolManager
 from common.log import logger
 from common.utils import expand_path
 
+# Module-level lock to serialize scheduler init across concurrent sessions
+_scheduler_init_lock = threading.Lock()
+
 
 class AgentInitializer:
     """
@@ -406,7 +410,14 @@ class AgentInitializer:
         return tools
     
     def _initialize_scheduler(self, tools: List, session_id: Optional[str] = None):
-        """Initialize scheduler service if needed"""
+        """Initialize scheduler service if needed.
+
+        Serialize the check-and-set under a module-level lock so concurrent
+        first-time session inits cannot each create a new SchedulerService
+        (which would leak background scanning threads).
+        """
+        if not self.agent_bridge.scheduler_initialized:
+            with _scheduler_init_lock:
                 if not self.agent_bridge.scheduler_initialized:
                     try:
                         from agent.tools.scheduler.integration import init_scheduler