Class LIFOManager

tensorflow/core/grappler/costs/virtual_scheduler.h:184–200

The LIFOManager schedules nodes by returning the last one added to the scheduler. A node is executed and then its ready outputs are newly added to the scheduler, so the LIFOManager will return outputs to a node following that node's execution.

// the scheduler, so the LIFOManager will return outputs to a node following
// that node's execution.
class LIFOManager : public ReadyNodeManager {
 public:
  LIFOManager() : ReadyNodeManager() {}
  ~LIFOManager() override {}
  void AddNode(const NodeDef* node) override { nodes_.push_back(node); }
  const NodeDef* GetCurrNode() override;
  void RemoveCurrNode() override;
  bool Empty() const override { return nodes_.empty(); }

 private:
  std::list<const NodeDef*> nodes_;
  // Keep track of the current node being executed by saving its position.
  // Necessary because nodes may be added to the end of the list while a node is
  // executing, and we want to remove the correct node (the one that is
  // executing) rather than the new ones being added.
  std::list<const NodeDef*>::iterator curr_pos_ = nodes_.end();
};

// Abstract class that maintains a heap/priority queue for scheduling ready
// nodes. Derived class needs to implement the Greater() function which returns