From bf7368f7a02db5055de09be13ac3ba0143749598 Mon Sep 17 00:00:00 2001
From: "A. Unique TensorFlower" <gardener@tensorflow.org>
Date: Mon, 22 Jul 2019 13:25:39 -0700
Subject: [PATCH] Return eager tensors from the training_eager.* methods
 instead of numpy scalars. This also moves the conversion to numpy() to the
 end of the dist strat strategy execution function in the v2 loops.

PiperOrigin-RevId: 259393774
---
 tensorflow/python/keras/engine/training.py    | 18 ++++++++++++++++--
 .../python/keras/engine/training_eager.py     |  9 ++-------
 .../python/keras/engine/training_v2_utils.py  | 19 +++++++++----------
 3 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/tensorflow/python/keras/engine/training.py b/tensorflow/python/keras/engine/training.py
index cdc06daae6a..718f3a582cf 100644
--- a/tensorflow/python/keras/engine/training.py
+++ b/tensorflow/python/keras/engine/training.py
@@ -946,9 +946,14 @@ class Model(network.Network):
       ValueError: In case of invalid user-provided arguments.
     """
     if self._run_distributed:
-      return training_v2_utils.train_on_batch(
+      outputs = training_v2_utils.train_on_batch(
           self, x, y=y, sample_weight=sample_weight,
           class_weight=class_weight, reset_metrics=reset_metrics)
+      outputs = [
+          training_v2_utils._non_none_constant_value(v) for v in outputs]  # pylint: disable=protected-access
+      if len(outputs) == 1:
+        outputs = outputs[0]
+      return outputs
 
     self._assert_compile_was_called()
     # If at this point we are in the replica context, then it is okay to execute
@@ -974,6 +979,8 @@ class Model(network.Network):
           y,
           sample_weights=sample_weights,
           output_loss_metrics=self._output_loss_metrics)
+      outputs = [
+          training_v2_utils._non_none_constant_value(v) for v in outputs]  # pylint: disable=protected-access
     else:
       x = training_utils.ModelInputs(x).as_list()
       ins = x + (y or []) + (sample_weights or [])
@@ -1031,9 +1038,14 @@ class Model(network.Network):
         ValueError: In case of invalid user-provided arguments.
     """
     if self._run_distributed:
-      return training_v2_utils.test_on_batch(
+      outputs = training_v2_utils.test_on_batch(
           self, x, y=y, sample_weight=sample_weight,
           reset_metrics=reset_metrics)
+      outputs = [
+          training_v2_utils._non_none_constant_value(v) for v in outputs]  # pylint: disable=protected-access
+      if len(outputs) == 1:
+        outputs = outputs[0]
+      return outputs
 
     self._assert_compile_was_called()
     if (self._distribution_strategy and
@@ -1053,6 +1065,8 @@ class Model(network.Network):
           y,
           sample_weights=sample_weights,
           output_loss_metrics=self._output_loss_metrics)
+      outputs = [
+          training_v2_utils._non_none_constant_value(v) for v in outputs]  # pylint: disable=protected-access
     else:
       x = training_utils.ModelInputs(x).as_list()
       inputs = x + (y or []) + (sample_weights or [])
diff --git a/tensorflow/python/keras/engine/training_eager.py b/tensorflow/python/keras/engine/training_eager.py
index 6cbc6851a8e..c019238f48e 100644
--- a/tensorflow/python/keras/engine/training_eager.py
+++ b/tensorflow/python/keras/engine/training_eager.py
@@ -307,12 +307,7 @@ def train_on_batch(model,
   total_loss = nest.flatten(total_loss)
   results = total_loss + output_losses + metrics_results
 
-  return [_non_none_constant_value(v) for v in results]
-
-
-def _non_none_constant_value(v):
-  constant_value = tensor_util.constant_value(v)
-  return constant_value if constant_value is not None else v
+  return results
 
 
 def test_on_batch(model,
@@ -365,4 +360,4 @@ def test_on_batch(model,
   total_loss = nest.flatten(total_loss)
   results = total_loss + output_losses + metrics_results
 
-  return [_non_none_constant_value(v) for v in results]
+  return results
diff --git a/tensorflow/python/keras/engine/training_v2_utils.py b/tensorflow/python/keras/engine/training_v2_utils.py
index 982ef2a71a1..e609559e5e8 100644
--- a/tensorflow/python/keras/engine/training_v2_utils.py
+++ b/tensorflow/python/keras/engine/training_v2_utils.py
@@ -70,19 +70,22 @@ def _make_execution_function(model, mode):
         strategy, outputs, with_loss_tensor=(mode != ModeKeys.PREDICT))
     return all_outputs
 
-  if model.run_eagerly:
-    execution_function = distributed_function
-  else:
+  if not model.run_eagerly:
     distributed_function = def_function.function(
         distributed_function, autograph=False)
 
-    def execution_function(input_fn):
-      # `numpy` translates Tensors to values in Eager mode.
-      return [out.numpy() for out in distributed_function(input_fn)]
+  def execution_function(input_fn):
+    # `numpy` translates Tensors to values in Eager mode.
+    return [out.numpy() for out in distributed_function(input_fn)]
 
   return execution_function
 
 
+def _non_none_constant_value(v):
+  constant_value = tensor_util.constant_value(v)
+  return constant_value if constant_value is not None else v
+
+
 def _prepare_feed_values(model, inputs, mode):
   """Prepare feed values to the model execution function.
 
@@ -232,8 +235,6 @@ def train_on_batch(
   if reset_metrics:
     model.reset_metrics()
 
-  if len(outputs) == 1:
-    return outputs[0]
   return outputs
 
 
@@ -295,8 +296,6 @@ def test_on_batch(model, x, y=None, sample_weight=None, reset_metrics=True):
   if reset_metrics:
     model.reset_metrics()
 
-  if len(outputs) == 1:
-    return outputs[0]
   return outputs