// maximum number of in flight async nodes. Enqueuing of additional async ops
// after the limit is reached blocks until some inflight nodes finishes.
// The effect is bounding the memory held by inflight TensorHandles that are
// referenced by the inflight nodes.
// A recommended value has not been established.
// A value of 0 removes the limit, which is the behavior of TensorFlow 2.11.

                                                  TF_Status* status);

// Creates a new operation - see `TF_NewOperation` for more details.
//
// The lock for `graph` must be held when calling this function.
//
// Unless implementing advanced behavior, like custom gradient functions, you
// most likely need to call `TF_NewOperation` instead.

  void UpdateLRU(const Key& key, const std::shared_ptr<Block>& block,
                 TF_Status* status) ABSL_LOCKS_EXCLUDED(mu_);

  /// Remove all blocks of a file, with mu_ already held.
  void RemoveFile_Locked(const std::string& filename)
      ABSL_EXCLUSIVE_LOCKS_REQUIRED(mu_);

  /// Remove the block `entry` from the block map and LRU list, and update the
  /// cache size accordingly.