fix 单例加锁，防止init方法时间过长导致多次init

app/utils/singleton.py

@@ -1,4 +1,5 @@
 import abc
+import threading
 
 
 class Singleton(abc.ABCMeta, type):
@@ -7,12 +8,14 @@ class Singleton(abc.ABCMeta, type):
     """
 
     _instances: dict = {}
+    _lock = threading.Lock()
 
     def __call__(cls, *args, **kwargs):
         key = (cls, args, frozenset(kwargs.items()))
-        if key not in cls._instances:
-            cls._instances[key] = super().__call__(*args, **kwargs)
-        return cls._instances[key]
+        with cls._lock:
+            if key not in cls._instances:
+                cls._instances[key] = super().__call__(*args, **kwargs)
+            return cls._instances[key]
 
 
 class AbstractSingleton(abc.ABC, metaclass=Singleton):