Function CreateVariable

tensorflow/c/eager/c_api_test.cc:1426–1469

BENCHMARK(BM_ExecuteFunction)->Arg(0)->Arg(1);

TFE_TensorHandle* CreateVariable(TFE_Context* ctx, float value,
                                 TF_Status* status) {
  // Create the variable handle.
  TFE_Op* op = TFE_NewOp(ctx, "VarHandleOp", status);
  if (TF_GetCode(status) != TF_OK) return nullptr;
  TFE_OpSetAttrType(op, "dtype", TF_FLOAT);
  TFE_OpSetAttrShape(op, "shape", {}, 0, status);
  TFE_OpSetAttrString(op, "container", "", 0);
  TFE_OpSetAttrString(op, "shared_name", "", 0);
  if (TF_GetCode(status) != TF_OK) return nullptr;
  TFE_TensorHandle* var_handle = nullptr;
  int num_retvals = 1;
  TFE_Execute(op, &var_handle, &num_retvals, status);
  TFE_DeleteOp(op);
  if (TF_GetCode(status) != TF_OK) return nullptr;
  CHECK_EQ(1, num_retvals);

  // Assign 'value' to it.
  op = TFE_NewOp(ctx, "AssignVariableOp", status);
  if (TF_GetCode(status) != TF_OK) return nullptr;
  TFE_OpSetAttrType(op, "dtype", TF_FLOAT);
  TFE_OpAddInput(op, var_handle, status);

  // Convert 'value' to a TF_Tensor then a TFE_TensorHandle.
  std::unique_ptr<TF_Tensor, decltype(&TF_DeleteTensor)> t(
      TF_AllocateTensor(TF_FLOAT, nullptr, 0, sizeof(value)), TF_DeleteTensor);
  memcpy(TF_TensorData(t.get()), &value, TF_TensorByteSize(t.get()));

  std::unique_ptr<TFE_TensorHandle, decltype(&TFE_DeleteTensorHandle)>
      value_handle(TFE_NewTensorHandle(t.get(), status),
                   TFE_DeleteTensorHandle);
  if (TF_GetCode(status) != TF_OK) return nullptr;

  TFE_OpAddInput(op, value_handle.get(), status);
  if (TF_GetCode(status) != TF_OK) return nullptr;

  num_retvals = 0;
  TFE_Execute(op, nullptr, &num_retvals, status);
  TFE_DeleteOp(op);
  if (TF_GetCode(status) != TF_OK) return nullptr;
  CHECK_EQ(0, num_retvals);

  return var_handle;
}

TEST(CAPI, Variables) {
  // Variables use resource handles, so this is really a test for resource