Basic Async Actor Call (#6183)

* Start trying to figure out where to put fibers

* Pass is_async flag from python to context

* Just running things in fiber works

* Yield implemented, need some debugging to make it work

* It worked!

* Remove debug prints

* Lint

* Revert the clang-format

* Remove unnecessary log

* Remove unncessary import

* Add attribution

* Address comment

* Add test

* Missed a merge conflict

* Make test pass and compile

* Address comment

* Rename async -> asyncio

* Move async test to py3 only

* Fix ignore path

python/ray/includes/common.pxd

@@ -217,7 +217,7 @@ cdef extern from "ray/core_worker/common.h" nogil:
             const unordered_map[c_string, double] &resources,
             const unordered_map[c_string, double] &placement_resources,
             const c_vector[c_string] &dynamic_worker_options,
-            c_bool is_detached)
+            c_bool is_detached, c_bool is_asyncio)
 
 cdef extern from "ray/gcs/gcs_client_interface.h" nogil:
     cdef cppclass CGcsClientOptions "ray::gcs::GcsClientOptions":

python/ray/includes/libcoreworker.pxd

@@ -48,6 +48,12 @@ cdef extern from "ray/core_worker/profiling.h" nogil:
     cdef cppclass CProfileEvent "ray::worker::ProfileEvent":
         void SetExtraData(const c_string &extra_data)
 
+cdef extern from "ray/core_worker/transport/direct_actor_transport.h" nogil:
+    cdef cppclass CFiberEvent "ray::FiberEvent":
+        CFiberEvent()
+        void Wait()
+        void Notify()
+
 cdef extern from "ray/core_worker/core_worker.h" nogil:
     cdef cppclass CCoreWorker "ray::CoreWorker":
         CCoreWorker(const CWorkerType worker_type, const CLanguage language,
@@ -125,3 +131,5 @@ cdef extern from "ray/core_worker/core_worker.h" nogil:
         CRayStatus Delete(const c_vector[CObjectID] &object_ids,
                           c_bool local_only, c_bool delete_creating_tasks)
         c_string MemoryUsageString()
+
+        void YieldCurrentFiber(CFiberEvent &coroutine_done)