Support concurrent Actor calls in Ray (#6053)

python/ray/actor.py

@@ -326,6 +326,26 @@ class ActorClass(object):
         """
         return self._remote(args=args, kwargs=kwargs)
 
+    def options(self, **options):
+        """Convenience method for creating an actor with options.
+
+        Same arguments as Actor._remote(), but returns a wrapped actor class
+        that a non-underscore .remote() can be called on.
+
+        Examples:
+            # The following two calls are equivalent.
+            >>> Actor._remote(num_cpus=4, max_concurrency=8, args=[x, y])
+            >>> Actor.options(num_cpus=4, max_concurrency=8).remote(x, y)
+        """
+
+        actor_cls = self
+
+        class ActorOptionWrapper(object):
+            def remote(self, *args, **kwargs):
+                return actor_cls._remote(args=args, kwargs=kwargs, **options)
+
+        return ActorOptionWrapper()
+
     def _remote(self,
                 args=None,
                 kwargs=None,
@@ -335,6 +355,7 @@ class ActorClass(object):
                 object_store_memory=None,
                 resources=None,
                 is_direct_call=None,
+                max_concurrency=None,
                 name=None,
                 detached=False):
         """Create an actor.
@@ -354,6 +375,8 @@ class ActorClass(object):
             resources: The custom resources required by the actor creation
                 task.
             is_direct_call: Use direct actor calls.
+            max_concurrency: The max number of concurrent calls to allow for
+                this actor. This only works with direct actor calls.
             name: The globally unique name for the actor.
             detached: Whether the actor should be kept alive after driver
                 exits.
@@ -365,6 +388,16 @@ class ActorClass(object):
             args = []
         if kwargs is None:
             kwargs = {}
+        if is_direct_call is None:
+            is_direct_call = False
+        if max_concurrency is None:
+            max_concurrency = 1
+
+        if max_concurrency > 1 and not is_direct_call:
+            raise ValueError(
+                "setting max_concurrency requires is_direct_call=True")
+        if max_concurrency < 1:
+            raise ValueError("max_concurrency must be >= 1")
 
         worker = ray.worker.get_global_worker()
         if worker.mode is None:
@@ -452,7 +485,8 @@ class ActorClass(object):
             actor_id = worker.core_worker.create_actor(
                 function_descriptor.get_function_descriptor_list(),
                 creation_args, meta.max_reconstructions, resources,
-                actor_placement_resources, is_direct_call, detached)
+                actor_placement_resources, is_direct_call, max_concurrency,
+                detached)
 
         actor_handle = ActorHandle(
             actor_id,