Method Initialize

tensorflow/core/common_runtime/immutable_executor_state.cc:85–265

}

Status ImmutableExecutorState::Initialize() {
  const Graph& graph = *graph_;
  TF_RETURN_IF_ERROR(gview_.Initialize(&graph));

  // Build the information about frames in this subgraph.
  ControlFlowInfo cf_info;
  TF_RETURN_IF_ERROR(BuildControlFlowInfo(&graph, &cf_info));

  for (auto& it : cf_info.unique_frame_names) {
    EnsureFrameInfo(it)->nodes =
        absl::make_unique<std::vector<const NodeItem*>>();
  }
  root_frame_info_ = frame_info_[""].get();

  pending_ids_.resize(gview_.num_nodes());

  // Preprocess every node in the graph to create an instance of op
  // kernel for each node.
  requires_control_flow_ = false;
  for (const Node* n : graph.nodes()) {
    if (IsSink(n)) continue;
    if (IsSwitch(n) || IsMerge(n) || IsEnter(n) || IsExit(n)) {
      requires_control_flow_ = true;
    } else if (IsRecv(n)) {
      // A Recv node from a different device may produce dead tensors from
      // non-local control-flow nodes.
      //
      // TODO(mrry): Track whether control flow was present in the
      // pre-partitioned graph, and enable the caller (e.g.
      // `DirectSession`) to relax this constraint.
      string send_device;
      string recv_device;
      TF_RETURN_IF_ERROR(GetNodeAttr(n->attrs(), "send_device", &send_device));
      TF_RETURN_IF_ERROR(GetNodeAttr(n->attrs(), "recv_device", &recv_device));
      if (send_device != recv_device) {
        requires_control_flow_ = true;
      }
    }

    const int id = n->id();
    const string& frame_name = cf_info.frame_names[id];
    FrameInfo* frame_info = EnsureFrameInfo(frame_name);

    NodeItem* item = gview_.node(id);
    item->node = n;

    item->input_start = frame_info->total_inputs;
    frame_info->total_inputs += n->num_inputs();

    Status s = params_.create_kernel(n->def(), &item->kernel);
    if (!s.ok()) {
      params_.delete_kernel(item->kernel);
      item->kernel = nullptr;
      s = AttachDef(s, *n);
      return s;
    }
    CHECK(item->kernel);
    item->kernel_is_async = (item->kernel->AsAsync() != nullptr);