Merge pull request #87 from sony/fix/20190510_dali-data-iterator

Align the latest changes of DALI pkg

imagenet-classification/dali_data_iterator.py

@@ -106,6 +106,8 @@ def __init__(self,
 
         # We need data about the batches (like shape information),
         # so we need to run a single batch as part of setup to get that info
+        for p in self._pipes:
+            p._run()
         self._first_batch = None
         self._first_batch = self.next()
 
@@ -120,8 +122,6 @@ def __next__(self):
             # raise StopIteration
         # Gather outputs
         outputs = []
-        for p in self._pipes:
-            p._prefetch()
         for p in self._pipes:
             outputs.append(p._share_outputs())
         for i in range(self._num_gpus):
@@ -172,7 +172,7 @@ def __next__(self):
 
         for p in self._pipes:
             p._release_outputs()
-            p._start_run()
+            p._run()
 
         copy_db_index = self._current_data_batch
         # Change index for double buffering