Fix some bugs causing Travis test failures. (#839)

* Fix bug in which worker has no actor_class attribute.

* Remove case where we check if processes are defunct.

python/ray/actor.py

@@ -6,6 +6,7 @@ import cloudpickle as pickle
 import hashlib
 import inspect
 import json
+import time
 import traceback
 
 import ray.local_scheduler
@@ -215,7 +216,8 @@ def reconstruct_actor_state(actor_id, worker):
         print("Loading actor state from checkpoint {}"
               .format(checkpoint_index))
         # Wait for the actor to have been defined.
-        worker._wait_for_actor()
+        while not hasattr(worker, "actor_class"):
+            time.sleep(0.001)
         # TODO(rkn): Restoring from the checkpoint may fail, so this should be
         # in a try-except block and we should give a good error message.
         worker.actors[actor_id] = (

python/ray/test/test_utils.py

@@ -4,7 +4,6 @@ from __future__ import print_function
 
 import json
 import os
-import psutil
 import redis
 import time
 
@@ -115,18 +114,12 @@ def _pid_alive(pid):
         pid: The pid to check.
 
     Returns:
-        This returns false if the process is dead or defunct. Otherwise, it
-            returns true.
+        This returns false if the process is dead. Otherwise, it returns true.
     """
     try:
         os.kill(pid, 0)
     except OSError:
         return False
-    else:
-        if psutil.Process(pid).status() == psutil.STATUS_ZOMBIE:
-            return False
-        else:
-            return True
 
 
 def wait_for_pid_to_exit(pid, timeout=20):