C API: Slight re-organization of code that deletes input tensors.

This change itself is a no-op. However, my plan is to change the
API contract with the TF_Session*Run functions in a follow up
change so that they do NOT take ownership of the input tensor values.

This just makes it slightly easier to do so.
Change: 138646376

1 files changed, 29 insertions, 25 deletions

diff --git a/tensorflow/c/c_api.cc b/tensorflow/c/c_api.cc
index ced231396a..35fef4f741 100644
--- a/tensorflow/c/c_api.cc
+++ b/tensorflow/c/c_api.cc
@@ -443,25 +443,25 @@ static bool TF_Run_Inputs(
     std::vector<std::pair<tensorflow::string, Tensor>>* input_pairs,
     TF_Status* status) {
   const int ninputs = input_pairs->size();
-  bool ok = true;
   for (int i = 0; i < ninputs; ++i) {
     TF_Tensor* src = c_inputs[i];
-    if (ok) {
-      if (c_inputs[i]->dtype != TF_STRING) {
-        (*input_pairs)[i].second = tensorflow::TensorCApi::MakeTensor(
-            src->dtype, src->shape, src->buffer);
-      } else {
-        // TF_STRING tensors require copying since Tensor class expects
-        // a sequence of string objects.
-        ok = tensorflow::TF_Tensor_DecodeStrings(src, &(*input_pairs)[i].second,
-                                                 status);
-        // Must keep looping through all c_inputs even if there is an error
-        // so that TF_DeleteTensor() is called unconditionally on all c_inputs.
-      }
+    if (c_inputs[i]->dtype != TF_STRING) {
+      (*input_pairs)[i].second = tensorflow::TensorCApi::MakeTensor(
+          src->dtype, src->shape, src->buffer);
+    } else if (!tensorflow::TF_Tensor_DecodeStrings(
+                   src, &(*input_pairs)[i].second, status)) {
+      // TF_STRING tensors require copying since Tensor class expects
+      // a sequence of string objects.
+      return false;
     }
-    TF_DeleteTensor(src);
   }
-  return ok;
+  return true;
+}
+
+static void TF_DeleteTensors(TF_Tensor* const* tensors, int num) {
+  for (int i = 0; i < num; ++i) {
+    TF_DeleteTensor(tensors[i]);
+  }
 }
 
 static void TF_Run_Helper(
@@ -542,7 +542,9 @@ void TF_Run(TF_DeprecatedSession* s, const TF_Buffer* run_options,
             TF_Buffer* run_metadata, TF_Status* status) {
   TF_Run_Setup(noutputs, c_outputs, status);
   std::vector<std::pair<tensorflow::string, Tensor>> input_pairs(ninputs);
-  if (!TF_Run_Inputs(c_inputs, &input_pairs, status)) return;
+  const bool ok = TF_Run_Inputs(c_inputs, &input_pairs, status);
+  TF_DeleteTensors(c_inputs, ninputs);
+  if (!ok) return;
   for (int i = 0; i < ninputs; ++i) {
     input_pairs[i].first = c_input_names[i];
   }
@@ -603,7 +605,9 @@ void TF_PRun(TF_DeprecatedSession* s, const char* handle,
              TF_Status* status) {
   TF_Run_Setup(noutputs, c_outputs, status);
   std::vector<std::pair<tensorflow::string, Tensor>> input_pairs(ninputs);
-  if (!TF_Run_Inputs(c_inputs, &input_pairs, status)) return;
+  const bool ok = TF_Run_Inputs(c_inputs, &input_pairs, status);
+  TF_DeleteTensors(c_inputs, ninputs);
+  if (!ok) return;
   for (int i = 0; i < ninputs; ++i) {
     input_pairs[i].first = c_input_names[i];
   }
@@ -1695,9 +1699,7 @@ void TF_SessionRun(TF_Session* session, const TF_Buffer* run_options,
   // directly, instead of requiring us to serialize to a GraphDef and
   // call Session::Extend().
   if (!ExtendSessionGraphHelper(session, status)) {
-    for (int i = 0; i < ninputs; ++i) {
-      TF_DeleteTensor(input_values[i]);
-    }
+    TF_DeleteTensors(input_values, ninputs);
     return;
   }
 
@@ -1705,7 +1707,9 @@ void TF_SessionRun(TF_Session* session, const TF_Buffer* run_options,
 
   // Convert from TF_Port and TF_Tensor to a string and Tensor.
   std::vector<std::pair<tensorflow::string, Tensor>> input_pairs(ninputs);
-  if (!TF_Run_Inputs(input_values, &input_pairs, status)) return;
+  const bool ok = TF_Run_Inputs(input_values, &input_pairs, status);
+  TF_DeleteTensors(input_values, ninputs);
+  if (!ok) return;
   for (int i = 0; i < ninputs; ++i) {
     input_pairs[i].first = PortName(inputs[i]);
   }
@@ -1771,9 +1775,7 @@ void TF_SessionPRun(TF_Session* session, const char* handle,
   // directly, instead of requiring us to serialize to a GraphDef and
   // call Session::Extend().
   if (!ExtendSessionGraphHelper(session, status)) {
-    for (int i = 0; i < ninputs; ++i) {
-      TF_DeleteTensor(input_values[i]);
-    }
+    TF_DeleteTensors(input_values, ninputs);
     return;
   }
 
@@ -1781,7 +1783,9 @@ void TF_SessionPRun(TF_Session* session, const char* handle,
 
   // Convert from TF_Port and TF_Tensor to a string and Tensor.
   std::vector<std::pair<tensorflow::string, Tensor>> input_pairs(ninputs);
-  if (!TF_Run_Inputs(input_values, &input_pairs, status)) return;
+  const bool ok = TF_Run_Inputs(input_values, &input_pairs, status);
+  TF_DeleteTensors(input_values, ninputs);
+  if (!ok) return;
   for (int i = 0; i < ninputs; ++i) {
     input_pairs[i].first = PortName(inputs[i]);
   }