修改枷锁方式

backend/SystemUpdater/Core/utils.py

@@ -620,26 +620,30 @@ def get_package_label(pkg):
     name = getattr(pkg.candidate, "summary", "")
     return capitalize_first_word(name)
 
+#安装时禁止关机 进行加锁
 def LockedPreventShutdown():
     global locked
 
+    #加锁后直接返回
     if locked:
         return
-
+    #锁目录是否存在 不存在时 创建
     if not os.path.exists(FILELOCK_PATH):
         os.makedirs(FILELOCK_PATH)
 
     with open(os.path.join(FILELOCK_PATH, SHUTDOWN_BLOCK_FILELOCK), "w+") as pidfile:
         try:
-                locked = True
             fcntl.flock(pidfile, fcntl.LOCK_EX | fcntl.LOCK_NB)
+            locked = True
             logging.info("Has been locked.")
+        #多次加锁就会出现异常
         except Exception as e:
             logging.error(e)
             locked = False
             logging.error("file cannot be locked.")
             return False
 
+#解锁禁止关机 
 def unLockedEnableShutdown():
     global locked