复查修复(三): 调度与扫描

- scan: .tmp/.part 过滤 + list_files 分批遍历(消除 10 万条截断误判)
- Scheduler: 持锁只做标记, 锁外异步执行任务(长任务不再冻结调度)
- cron 范围/步进边界校验;FTP 下载后大小校验防静默截断

core/scheduler.py

@@ -103,16 +103,27 @@ class ScheduledTask:
                 result.extend(self._parse_cron_part(sub.strip(), min_val, max_val))
             return result
 
-        # 处理范围: "1-5"
+        # 处理范围: "1-5"（校验边界，越界返回空）
         if '-' in part:
-            start, end = part.split('-')
-            return list(range(int(start), int(end) + 1))
+            try:
+                start, end = part.split('-')
+                start, end = int(start), int(end)
+                if not (min_val <= start <= end <= max_val):
+                    return []
+                return list(range(start, end + 1))
+            except ValueError:
+                return []
 
         # 处理步进: "*/5"
         if '/' in part:
             base, step = part.split('/')
             base_list = self._parse_cron_part(base or '*', min_val, max_val)
-            step = int(step)
+            try:
+                step = int(step)
+                if step <= 0:
+                    return []
+            except ValueError:
+                return []
             return base_list[::step]
 
         # 单个值
@@ -301,18 +312,23 @@ class Scheduler:
         logger.info("定时任务调度器已停止")
 
     def _run_loop(self):
-        """运行循环"""
+        """运行循环（持锁只做标记，锁外异步执行任务，避免长任务冻结调度）"""
         while self._running:
             try:
                 now = datetime.now()
 
+                due = []
                 with self._lock:
                     for name, task in self.tasks.items():
                         if task.should_run_now():
-                            # 使用线程池执行任务
-                            from concurrent.futures import ThreadPoolExecutor
-                            with ThreadPoolExecutor(max_workers=1) as executor:
-                                executor.submit(task.run)
+                            due.append(task)
+
+                # 锁外异步执行，不阻塞后续任务的调度
+                for task in due:
+                    try:
+                        threading.Thread(target=task.run, daemon=True).start()
+                    except Exception as e:
+                        logger.error(f"调度任务 {task.name} 启动失败: {e}")
 
                 time.sleep(self.check_interval)