fix while stopper

BasaltTrainer/while_stopper.py

@@ -9,44 +9,49 @@ else:
 
 
 class WhileStopper:
-
-    is_registered: bool
-    stop_requested: bool
+    _is_registered: bool
+    _stop_requested: bool
 
     def __init__(self) -> None:
-        self.is_registered = False
-        self.stop_requested = False
+        self._is_registered = False
+        self._stop_requested = False
 
     def is_stop_requested(self) -> bool:
-        if not self.is_registered:
-            raise RuntimeError('unexpected stopper status')
+        if not self._is_registered:
+            raise RuntimeError("unexpected stopper status")
 
-        return self.stop_requested
+        return self._stop_requested
 
     def register(self):
-        if self.is_registered:
-            raise RuntimeError('unexpected stopper status')
+        if self._is_registered:
+            raise RuntimeError("unexpected stopper status")
 
-        self.stop_requested = False
+        self._stop_requested = False
         if IS_WINDOWS:
-            win32api.SetConsoleCtrlHandler(self.__win_handler, True)
+            win32api.SetConsoleCtrlHandler(_win_handler, True)
         else:
-            signal.signal(signal.SIGINT, self.__posix_handler)
-        self.is_registered = True
+            signal.signal(signal.SIGINT, _posix_handler)
+        self._is_registered = True
 
     def unregister(self):
-        if not self.is_registered:
-            raise RuntimeError('unexpected stopper status')
+        if not self._is_registered:
+            raise RuntimeError("unexpected stopper status")
 
         if IS_WINDOWS:
-            win32api.SetConsoleCtrlHandler(None, False)
+            win32api.SetConsoleCtrlHandler(_win_handler, False)
         else:
             signal.signal(signal.SIGINT, signal.SIG_DFL)
-        self.is_registered = False
+        self._is_registered = False
 
-    def __win_handler(self, ctrl_type: int) -> bool:
-        self.stop_requested = True
-        return True
 
-    def __posix_handler(self, signal, frame) -> None:
-        self.stop_requested = True
+INSTANCE: WhileStopper = WhileStopper()
+"""The singleton of WhileStopper"""
+
+
+def _win_handler(ctrl_type: int) -> bool:
+    INSTANCE._stop_requested = True
+    return True
+
+
+def _posix_handler(signal, frame) -> None:
+    INSTANCE._stop_requested = True