Treat actor creation like a regular task. (#1668)

* Treat actor creation like a regular task.

* Small cleanups.

* Change semantics of actor resource handling.

* Bug fix.

* Minor linting

* Bug fix

* Fix jenkins test.

* Fix actor tests

* Some cleanups

* Bug fix

* Fix bug.

* Remove cached actor tasks when a driver is removed.

* Add more info to taskspec in global state API.

* Fix cyclic import bug in tune.

* Fix

* Fix linting.

* Fix linting.

* Don't schedule any tasks (especially actor creaiton tasks) on local schedulers with 0 CPUs.

* Bug fix.

* Add test for 0 CPU case

* Fix linting

* Address comments.

* Fix typos and add comment.

* Add assertion and fix test.

python/ray/workers/default_worker.py

@@ -3,7 +3,6 @@ from __future__ import division
 from __future__ import print_function
 
 import argparse
-import binascii
 import traceback
 
 import ray
@@ -21,32 +20,18 @@ parser.add_argument("--object-store-manager-name", required=True, type=str,
                     help="the object store manager's name")
 parser.add_argument("--local-scheduler-name", required=True, type=str,
                     help="the local scheduler's name")
-parser.add_argument("--actor-id", required=False, type=str,
-                    help="the actor ID of this worker")
-parser.add_argument("--reconstruct", action="store_true",
-                    help=("true if the actor should be started in reconstruct "
-                          "mode"))
 
 
 if __name__ == "__main__":
     args = parser.parse_args()
 
-    # If this worker is not an actor, it cannot be started in reconstruct mode.
-    if args.actor_id is None:
-        assert not args.reconstruct
-
     info = {"node_ip_address": args.node_ip_address,
             "redis_address": args.redis_address,
             "store_socket_name": args.object_store_name,
             "manager_socket_name": args.object_store_manager_name,
             "local_scheduler_socket_name": args.local_scheduler_name}
 
-    if args.actor_id is not None:
-        actor_id = binascii.unhexlify(args.actor_id)
-    else:
-        actor_id = ray.worker.NIL_ACTOR_ID
-
-    ray.worker.connect(info, mode=ray.WORKER_MODE, actor_id=actor_id)
+    ray.worker.connect(info, mode=ray.WORKER_MODE)
 
     error_explanation = """
   This error is unexpected and should not have happened. Somehow a worker