Change timeout from milliseconds to seconds in ray.wait. (#3706)

* Change timeout from milliseconds to seconds in ray.wait.

* Suppress warning.

* Suppress warning.

* Add prominent warning in API documentation.

python/ray/rllib/evaluation/metrics.py

@@ -32,7 +32,7 @@ def collect_episodes(local_evaluator,
         for a in remote_evaluators
     ]
     collected, _ = ray.wait(
-        pending, num_returns=len(pending), timeout=timeout_seconds * 1000)
+        pending, num_returns=len(pending), timeout=timeout_seconds * 1.0)
     num_metric_batches_dropped = len(pending) - len(collected)
 
     metric_lists = ray.get(collected)

python/ray/rllib/utils/actors.py

@@ -28,7 +28,8 @@ class TaskPool(object):
     def completed(self):
         pending = list(self._tasks)
         if pending:
-            ready, _ = ray.wait(pending, num_returns=len(pending), timeout=10)
+            ready, _ = ray.wait(
+                pending, num_returns=len(pending), timeout=0.01)
             for obj_id in ready:
                 yield (self._tasks.pop(obj_id), self._objects.pop(obj_id))
 

python/ray/rllib/utils/filter.py

@@ -20,7 +20,8 @@ class Filter(object):
         """Creates a new object with same state as self.
 
         Returns:
-            copy (Filter): Copy of self"""
+            A copy of self.
+        """
         raise NotImplementedError
 
     def sync(self, other):