fix: subclasses cannot access name-mangled mangled loop attr (#436)

* feat: speed up SmartTask and SmartFuture init

* fix: cannot access name-mangled __loop

a_sync/_smart.py

@@ -6,6 +6,7 @@
 """
 
 import asyncio
+import contextvars
 import logging
 import warnings
 import weakref
@@ -197,7 +198,7 @@ def __init__(
         if key:
             self._key = key
         self._waiters = weakref.WeakSet()
-        self.add_done_callback(SmartFuture._self_done_cleanup_callback)
+        self._callbacks.append((SmartFuture._self_done_cleanup_callback, contextvars.copy_context()))
 
     def __repr__(self):
         return f"<{type(self).__name__} key={self._key} waiters={self.num_waiters} {self._state}>"
@@ -298,7 +299,7 @@ def __init__(
         """
         asyncio.Task.__init__(self, coro, loop=loop, name=name)
         self._waiters: Set["asyncio.Task[T]"] = set()
-        self.add_done_callback(SmartTask._self_done_cleanup_callback)
+        self._callbacks.append((SmartTask._self_done_cleanup_callback, contextvars.copy_context()))
 
 
 def smart_task_factory(

a_sync/primitives/locks/prio_semaphore.pyx

@@ -351,7 +351,7 @@ cdef class _AbstractPrioritySemaphoreContextManager(Semaphore):
         while self._parent._Semaphore__value <= 0:
             if self._AbstractPrioritySemaphoreContextManager__waiters is None:
                 self._AbstractPrioritySemaphoreContextManager__waiters = deque()
-            fut = (self.__loop or self._c_get_loop()).create_future()
+            fut = self._c_get_loop().create_future()
             self._AbstractPrioritySemaphoreContextManager__waiters.append(fut)
             self._parent._potential_lost_waiters.append(fut)
             try: