Method CreateBodyFuncCallNode

tensorflow/core/common_runtime/lower_while_op.cc:296–321

}

Status LowerWhileHelper::CreateBodyFuncCallNode() {
  for (Node* switch_node : switch_nodes_) {
    body_call_builder_.Input(NodeOut(switch_node, 1));
  }
  body_call_builder_.Device(while_op_->requested_device());
  TF_RETURN_IF_ERROR(body_call_builder_.Finalize(graph_, &body_call_node_));
  // Add a control edge to make sure the Const nodes in the body function
  // are in the same frame as the rest of the function, otherwise
  // `BuildControlFlowInfo` throws an error.
  // TODO(srbs): The choice of input at index 0 seems arbitrary(is it?) however
  // this is how tf.while_loop does it. Can this affect performance if the 0th
  // node is not the first one to be ready? Can we speed that case up using some
  // sort of multi-input Merge?
  Node* body_control_node_;
  string op_type = "Identity";
  if (IsRefType(switch_nodes_[0]->output_type(1))) {
    op_type = "RefIdentity";
  }
  TF_RETURN_IF_ERROR(NodeBuilder(NewName("loop_body_control"), op_type,
                                 graph_->op_registry(), &debug_info_)
                         .Input(NodeOut(switch_nodes_[0], 1))
                         .Device(while_op_->requested_device())
                         .Finalize(graph_, &body_control_node_));
  graph_->AddControlEdge(body_control_node_, body_call_node_);
  return Status::OK();
}

Status LowerWhileHelper::CreateExitNodes() {
  std::vector<NodeOut> outputs;