Method BuildCtrlRegstDescInSameChain

oneflow/core/graph/task_graph.cpp:688–718

}

void TaskGraph::BuildCtrlRegstDescInSameChain() {
  auto GenPhysicalChainId = [](TaskNode* node) {
    // NOTE(chengcheng): different rank cannot use same chain id for bad ctrl link.
    return (node->chain_id() << 31) | (node->machine_id());
  };
  HashMap<int64_t, TaskNode*> physical_chain_id2node;
  // Note that ordered_task_nodes_'s topology order in seperation plan compile is not gerenteed,
  // So add ctrl edge with ordered_task_nodes_ in seperation plan compile may case dead lock.
  for (auto* node : ordered_task_nodes_) {
    if (IsConnectToTickOp(node)) { continue; }
    // NOTE(chengcheng): skip invalid chain id
    if (!IsValidChainId(node->chain_id())) { continue; }
    int64_t physical_chain_id = GenPhysicalChainId(node);
    auto iter = physical_chain_id2node.find(physical_chain_id);
    if (iter == physical_chain_id2node.end()) {
      CHECK(physical_chain_id2node.emplace(physical_chain_id, node).second);
    } else {
      TaskNode* src_node = iter->second;
      TaskNode* dst_node = node;
      std::string ctrl_regst_name;
      bool build_ctrl_edge = src_node->BuildCtrlRegstDescIfNeed(dst_node, &ctrl_regst_name);
      if (build_ctrl_edge) {
        CHECK(!ctrl_regst_name.empty());
        TaskEdge* edge = NewEdge();
        Connect<TaskNode>(src_node, edge, dst_node);
        src_node->BindEdgeWithProducedRegst(edge, ctrl_regst_name);
      }
      iter->second = dst_node;
    }
  }
}

void TaskGraph::GetInplaceOpBlobArgList(
    InplaceObasInfo* obas_info, const HashSet<TaskNode*>& dev_nodes,