do some core components with async functions?

circuits/core/manager.py

@@ -504,7 +504,7 @@ def unregisterTask(self, g):
         if g in self.root._tasks:
             self.root._tasks.remove(g)
 
-    def waitEvent(self, event, *channels, **kwargs):  # noqa
+    async def waitEvent(self, event, *channels, **kwargs):  # noqa
         # XXX: C901: This has a high McCabe complexity score of 16.
         # TODO: Refactor this method.
 
@@ -567,7 +567,7 @@ def _on_tick(self):
 
     wait = waitEvent
 
-    def callEvent(self, event, *channels, **kwargs):
+    async def callEvent(self, event, *channels, **kwargs):
         """
         Fire the given event to the specified channels and suspend
         execution until it has been dispatched. This method may only
@@ -578,8 +578,9 @@ def callEvent(self, event, *channels, **kwargs):
         been dispatched (see :func:`circuits.core.handlers.handler`).
         """
         value = self.fire(event, *channels)
-        yield from self.waitEvent(event, *event.channels, **kwargs)
-        yield CallValue(value)
+        async for r in self.waitEvent(event, *event.channels, **kwargs):
+            await r  # pass ?
+        return CallValue(value)
 
     call = callEvent
 
@@ -865,7 +866,9 @@ def processTask(self, event, task, parent=None):  # noqa
                 if parent:
                     value = parent.throw(value.extract())
                     if value is not None:
-                        value_generator = (val for val in (value,))
+                        async def value_generator():
+                            return value  # yield?
+                        # value_generator = (val for val in (value,))
                         self.registerTask((event, value_generator, parent))
                 else:
                     raise value.extract()