add the method annotation and a comment explaining what's happening (#13306)

Change-Id: I848cc2f0beaed95340d9de7cca19a50c78d9da9a

python/ray/actor.py

@@ -12,6 +12,7 @@ from ray.util.placement_group import (
 
 from ray import ActorClassID, Language
 from ray._raylet import PythonFunctionDescriptor
+from ray._private.client_mode_hook import client_mode_hook
 from ray import cross_language
 from ray.util.inspect import (
     is_function_or_method,
@@ -22,6 +23,7 @@ from ray.util.inspect import (
 logger = logging.getLogger(__name__)
 
 
+@client_mode_hook
 def method(*args, **kwargs):
     """Annotate an actor method.
 

python/ray/tests/test_actor.py

@@ -650,7 +650,6 @@ def test_actor_inheritance(ray_start_regular_shared):
                 pass
 
 
-@pytest.mark.skipif(client_test_enabled(), reason="ray.method unimplemented")
 def test_multiple_return_values(ray_start_regular_shared):
     @ray.remote
     class Foo:

python/ray/util/client/api.py

@@ -173,6 +173,27 @@ class ClientAPI:
         return self.worker.get_cluster_info(
             ray_client_pb2.ClusterInfoType.NODES)
 
+    def method(self, num_returns=1):
+        """Annotate an actor method
+
+        Args:
+            num_returns: The number of object refs that should be returned by
+                invocations of this actor method.
+        """
+
+        # NOTE: So this follows the same logic as in ray/actor.py::method()
+        # The reason to duplicate it here is to simplify the client mode
+        # redirection logic. As the annotated method gets pickled and sent to
+        # the server from the client it carries this private variable, it
+        # activates the same logic on the server side; so there's no need to
+        # pass anything else. It's inside the class definition that becomes an
+        # actor. Similar annotations would follow the same way.
+        def annotate_method(method):
+            method.__ray_num_returns__ = num_returns
+            return method
+
+        return annotate_method
+
     def cluster_resources(self):
         """Get the current total cluster resources.
 

python/ray/util/client/common.py

@@ -181,10 +181,6 @@ class ClientActorHandle(ClientStub):
     Args:
         actor_ref: A reference to the running actor given to the client. This
           is a serialized version of the actual handle as an opaque token.
-        actor_class: A reference to the ClientActorClass that this actor was
-          instantiated from.
-        _real_actor_handle: Cached copy of the Raylet-side
-          ray.actor.ActorHandle contained in the actor_id ref.
     """
 
     def __init__(self, actor_ref: ClientActorRef):