};

struct TFE_MonitoringIntGauge0 : TFE_MonitoringGauge<int64_t, 0> {
  using TFE_MonitoringGauge::TFE_MonitoringGauge;
};
struct TFE_MonitoringIntGauge1 : TFE_MonitoringGauge<int64_t, 1> {
  using TFE_MonitoringGauge::TFE_MonitoringGauge;
};
struct TFE_MonitoringIntGauge2 : TFE_MonitoringGauge<int64_t, 2> {
  using TFE_MonitoringGauge::TFE_MonitoringGauge;
};

  virtual Status SetAttrInt(const char* attr_name, int64_t value) = 0;
  virtual Status SetAttrFloat(const char* attr_name, float value) = 0;
  virtual Status SetAttrBool(const char* attr_name, bool value) = 0;
  virtual Status SetAttrType(const char* attr_name, DataType value) = 0;
  virtual Status SetAttrShape(const char* attr_name, const int64_t* dims,
                              const int num_dims) = 0;

                                                  TF_Status* status);
TF_CAPI_EXPORT extern int64_t TFE_TensorHandleNumElements(TFE_TensorHandle* h,
                                                          TF_Status* status);
// This function will block till the operation that produces `h` has completed.
TF_CAPI_EXPORT extern int64_t TFE_TensorHandleDim(TFE_TensorHandle* h,
                                                  int dim_index,

  // `keep_alive_secs` of inactivity.
  virtual Status SetOrUpdateServerDef(const ServerDef& server_def,
                                      bool reset_context, int keep_alive_secs,
                                      int64_t init_timeout_in_ms, int retries,
                                      bool clear_existing_contexts = false) = 0;

  // Initializes context for the local worker and no contexts will be created

  Status DeleteFile(const std::string& fname, TransactionToken* token) override;
  Status DeleteRecursively(const std::string& dirname, TransactionToken* token,
                           int64_t* undeleted_files,
                           int64_t* undeleted_dirs) override;
  Status DeleteDir(const std::string& dirname,
                   TransactionToken* token) override;
  Status RecursivelyCreateDir(const std::string& dirname,

  // Get a list of the names of functions that have been registered.
  virtual std::vector<string> ListFunctionNames() = 0;

  struct CacheStats {
    int64_t kernel_cache_size;
    int64_t device_cache_size;
    std::map<std::string, int64_t> func_kernel_cache_entries;
    int64_t local_rendezvous_cache_active_size;
  };
  virtual CacheStats GetCacheStats() = 0;

Status SetAttrString(AbstractOperation*, const char* attr_name,
                     const char* data, size_t length, ForwardOperation*);
Status SetAttrInt(AbstractOperation*, const char* attr_name, int64_t value,
                  ForwardOperation*);
Status SetAttrFloat(AbstractOperation*, const char* attr_name, float value,
                    ForwardOperation*);

  /// `is_directory`, `delete_file`, and `delete_dir`.
  void (*delete_recursively)(const TF_Filesystem* filesystem, const char* path,
                             uint64_t* undeleted_files,
                             uint64_t* undeleted_dirs, TF_Status* status);

  /// Renames the file given by `src` to that in `dst`.
  ///
  /// Replaces `dst` if it exists. In case of error, both `src` and `dst` keep

#include <vector>

#include "tensorflow/core/platform/types.h"

struct TFE_TensorDebugInfo {
  explicit TFE_TensorDebugInfo(const std::vector<int64_t>& dims)
      : dev_dims(dims) {}

  // Fully-padded, minor-to-major.
  std::vector<int64_t> dev_dims;
};

// gradient registerer to instantiate a GradientFunction.
struct ForwardOperation {
 public:
  string op_name;
  std::vector<AbstractTensorHandle*> inputs;
  std::vector<AbstractTensorHandle*> outputs;
  std::vector<int64_t> skip_input_indices;
  AttrBuilder attrs;
};

using GradientFunctionFactory =
    std::function<GradientFunction*(const ForwardOperation& op)>;

// Map from op name to a `GradientFunctionFactory`.