Don't instantiate new CurrentThreadScheduler._Local with each schedul…

…er instance

rx/concurrency/currentthreadscheduler.py

@@ -36,16 +36,16 @@ class CurrentThreadScheduler(SchedulerBase):
     You never want to schedule timeouts using the CurrentThreadScheduler since
     that will block the current thread while waiting.
     """
-
-    _global: MutableMapping[threading.Thread, 'CurrentThreadScheduler'] = WeakKeyDictionary()
-
     class _Local(threading.local):
         __slots__ = 'idle', 'queue'
 
         def __init__(self):
             self.idle: bool = True
             self.queue: PriorityQueue[ScheduledItem[typing.TState]] = PriorityQueue()
 
+    _local = _Local()
+    _global: MutableMapping[threading.Thread, 'CurrentThreadScheduler'] = WeakKeyDictionary()
+
     def __new__(cls) -> 'CurrentThreadScheduler':
         """Ensure that each thread has at most a single instance."""
 
@@ -59,8 +59,7 @@ def __new__(cls) -> 'CurrentThreadScheduler':
     def __init__(self) -> None:
         """Creates a scheduler that schedules work as soon as possible
         on the current thread."""
-
-        self._local = CurrentThreadScheduler._Local()
+        super().__init__()
 
     def schedule(self,
                  action: typing.ScheduledAction,
@@ -114,7 +113,7 @@ def schedule_absolute(self, duetime: typing.AbsoluteTime,
 
         si: ScheduledItem[typing.TState] = ScheduledItem(self, state, action, duetime)
 
-        local: CurrentThreadScheduler._Local = self._local
+        local: CurrentThreadScheduler._Local = CurrentThreadScheduler._local
         local.queue.enqueue(si)
         if local.idle:
             local.idle = False
@@ -134,7 +133,7 @@ def schedule_required(self) -> bool:
         False; otherwise, if the trampoline is not active, then it
         returns True.
         """
-        return self._local.idle
+        return CurrentThreadScheduler._local.idle
 
     def ensure_trampoline(self, action):
         """Method for testing the CurrentThreadScheduler."""