Method StartStep

tensorflow/core/distributed_runtime/master_session.cc:1721–1765

}

Status MasterSession::StartStep(const BuildGraphOptions& opts, bool is_partial,
                                ReffedClientGraph** out_rcg, int64* out_count) {
  const uint64 hash = HashBuildGraphOptions(opts);
  {
    mutex_lock l(mu_);
    // TODO(suharshs): We cache partial run graphs and run graphs separately
    // because there is preprocessing that needs to only be run for partial
    // run calls.
    RCGMap* m = is_partial ? &partial_run_graphs_ : &run_graphs_;
    auto iter = m->find(hash);
    if (iter == m->end()) {
      // We have not seen this subgraph before. Build the subgraph and
      // cache it.
      VLOG(1) << "Unseen hash " << hash << " for "
              << BuildGraphOptionsString(opts) << " is_partial = " << is_partial
              << "\n";
      std::unique_ptr<ClientGraph> client_graph;
      TF_RETURN_IF_ERROR(execution_state_->BuildGraph(opts, &client_graph));
      WorkerCacheInterface* worker_cache = get_worker_cache();
      /*auto entry = new ReffedClientGraph(
          handle_, opts, std::move(client_graph), session_opts_,
          stats_publisher_factory_, is_partial, worker_cache,
          !should_delete_worker_sessions_);*/
      ReffedClientGraph *entry = nullptr;
      if (env_->run_graph_mode || env_->run_graph_mode_lite) {
        entry = new ReffedClientGraphV2(
            handle_, opts, std::move(client_graph), session_opts_,
            stats_publisher_factory_, execution_state_.get(), is_partial,
            worker_cache, env_, !should_delete_worker_sessions_);
        LOG(INFO) << "Use ReffedClientGraphV2 for partition and run  graph.";
      } else {
        entry = new ReffedClientGraph(
            handle_, opts, std::move(client_graph), session_opts_,
            stats_publisher_factory_, execution_state_.get(), is_partial,
            worker_cache, env_, !should_delete_worker_sessions_);
      }
      iter = m->insert({hash, entry}).first;
      VLOG(1) << "Preparing to execute new graph";
    }
    *out_rcg = iter->second;
    (*out_rcg)->Ref();
    *out_count = (*out_rcg)->get_and_increment_execution_count();
  }
  return Status::OK();
}

void MasterSession::ClearRunsTable(std::vector<ReffedClientGraph*>* to_unref,
                                   RCGMap* rcg_map) {