// Opaque handle to a reader.
typedef struct TFE_MonitoringCounterReader TFE_MonitoringCounterReader;

// Returns a handle to be used for reading values from streamz counter. The
// counter can have been created with any number of labels.
TF_CAPI_EXPORT extern TFE_MonitoringCounterReader*
TFE_MonitoringNewCounterReader(const char* name);

// Reads the value of a counter that was created with 0 labels.

// Causes the calling thread to block till all ops dispatched in this executor
// have been executed. Note that "execution" here refers to kernel execution /
// scheduling of copies, etc. Similar to sync execution, it doesn't guarantee
// that lower level device queues (like GPU streams) have been flushed.
//
// This call may not block for execution of ops enqueued concurrently with this
// call.

                                                TF_Status* status);

// Syncs content of the handle to the filesystem. Blocks waiting for the
// filesystem to indicate that the content has been persisted.
TF_CAPI_EXPORT extern void TF_SyncWritableFile(TF_WritableFileHandle* handle,
                                               TF_Status* status);

  std::vector<TensorHandlePtr> tensors_;
  // Parallel tensors are immutable but compute their shape lazily unless it is
  // provided on construction. The optional has a value if the lazy computation
  // has been completed or the shape was provided on construction.
  mutable absl::optional<std::vector<int64_t>> shape_;
  const TF_DataType dtype_;
};

template <typename DataType>

TF_CAPI_EXPORT extern void TF_DeleteGraph(TF_Graph*);

// Operation being built. The underlying graph must outlive this.
typedef struct TF_OperationDescription TF_OperationDescription;

// Operation that has been added to the graph. Valid until the graph is
// deleted -- in particular adding a new operation to the graph does not
// invalidate old TF_Operation* pointers.
typedef struct TF_Operation TF_Operation;

  }
  const int64_t op_id = next_op_id_++;
  std::vector<TapeTensor> tensors;
  tensors.reserve(output_tensors.size());
  for (const TapeTensor& o : output_tensors) {
    // Note: the tensor can have already been watched and hence be in the tape,
    // so we cannot check that we're inserting it here.
    tensor_tape_[o.GetID()] = op_id;
    tensor_usage_[o.GetID()] = 1;
    tensors.push_back(o);
  }

// things like the available devices, resource manager etc.
// TFE_Context must outlive all tensor handles created using it. In other
// words, TFE_DeleteContext() must be called after all tensor handles have
// been deleted (with TFE_DeleteTensorHandle).
//
// TODO(ashankar): Merge with TF_Session?
typedef struct TFE_Context TFE_Context;

TF_CAPI_EXPORT extern TFE_Context* TFE_NewContext(

  /// succeeded,
  ///    but the read returned a partial block, and the LRU cache contained a
  ///    block at a higher offset (indicating that the partial block should have
  ///    been a full block).
  /// 3) `TF_OUT_OF_RANGE` if the read from the remote filesystem succeeded, but
  ///    the file contents do not extend past `offset` and thus nothing was
  ///    placed in `out`.

  ///
  /// Note: the `buffer` argument is NOT a null terminated string!
  ///
  /// Plugins:
  ///   * Must set `status` to `TF_OK` if exactly `n` bytes have been read.
  ///   * Must set `status` to `TF_OUT_OF_RANGE` if fewer than `n` bytes have
  ///     been read due to EOF.
  ///   * Must return -1 for any other error and must set `status` to any
  ///     other value to provide more information about the error.

// access coordination service functionalities.
TF_CAPI_EXPORT extern TF_CoordinationServiceAgent*
TF_GetCoordinationServiceAgent(TF_OpKernelContext* ctx);

// Returns true if the coordination service agent has been initialized.
TF_CAPI_EXPORT extern bool TF_CoordinationServiceIsInitialized(
    TF_CoordinationServiceAgent* agent);

TF_CAPI_EXPORT extern void TF_CoordinationServiceInsertKeyValue(