Move main_event_loop and main_event_loop_pid initialization from Asyn…

…cToSync.__init__ to AsyncToSync.__call__

asgiref/sync.py

@@ -153,7 +153,12 @@ def __init__(
             self.__self__ = self.awaitable.__self__  # type: ignore[union-attr]
         except AttributeError:
             pass
-        if force_new_loop:
+        self.force_new_loop = force_new_loop
+
+    def __call__(self, *args: _P.args, **kwargs: _P.kwargs) -> _R:
+        __traceback_hide__ = True  # noqa: F841
+
+        if self.force_new_loop:
             # They have asked that we always run in a new sub-loop.
             self.main_event_loop = None
         else:
@@ -173,10 +178,7 @@ def __init__(
                     )
                 else:
                     self.main_event_loop = None
-
-    def __call__(self, *args: _P.args, **kwargs: _P.kwargs) -> _R:
-        __traceback_hide__ = True  # noqa: F841
-
+
         # You can't call AsyncToSync from a thread with a running event loop
         try:
             event_loop = asyncio.get_running_loop()