} TFE_CancelCallback;
TF_CAPI_EXPORT extern TFE_CancellationManager* TFE_NewCancellationManager();
TF_CAPI_EXPORT extern bool TFE_CancellationManagerIsCancelled(
    TFE_CancellationManager*);
TF_CAPI_EXPORT extern bool TFE_CancellationManagerIsCancelling(
    TFE_CancellationManager*);
TF_CAPI_EXPORT extern void TFE_CancellationManagerStartCancel(
    TFE_CancellationManager*);

limitations under the License.
==============================================================================*/
#ifndef TENSORFLOW_C_EAGER_C_API_UNIFIED_EXPERIMENTAL_H_
#define TENSORFLOW_C_EAGER_C_API_UNIFIED_EXPERIMENTAL_H_

#include "tensorflow/c/eager/c_api.h"
#include "tensorflow/c/tf_datatype.h"
#include "tensorflow/c/tf_status.h"

#ifdef __cplusplus
extern "C" {
#endif

#define TENSORFLOW_C_EXPERIMENTAL_GRAPPLER_GRAPPLER_H_

#include <stddef.h>
#include <stdint.h>

#include "tensorflow/c/c_api.h"
#include "tensorflow/c/c_api_macros.h"
#include "tensorflow/c/tf_status.h"

// --------------------------------------------------------------------------
// C API for Graph. The API is under active development and eventually
// should allow registering a plugin graph optimizer with TensorFlow.
//
// Conventions:

    tensor_stack.pop_back();
    auto op_id_it = tensor_tape.find(tensor_id);
    if (op_id_it == tensor_tape.end()) {
      continue;
    }
    int64_t op_id = op_id_it->second;
    auto op_it = op_tape->find(op_id);
    auto result_op_it = result.op_tape.find(op_id);
    if (op_id == -1 || op_it == op_tape->end() ||
        result_op_it != result.op_tape.end()) {
      continue;
    }

#ifndef TENSORFLOW_C_EXPERIMENTAL_GRADIENTS_TAPE_TAPE_CONTEXT_H_
#define TENSORFLOW_C_EXPERIMENTAL_GRADIENTS_TAPE_TAPE_CONTEXT_H_

#include "tensorflow/c/eager/abstract_context.h"
#include "tensorflow/c/experimental/gradients/tape/tape_operation.h"

namespace tensorflow {
namespace gradients {
class TapeContext : public AbstractContext {
 public:
  explicit TapeContext(AbstractContext*, Tape*, const GradientRegistry&);

TF_CAPI_EXPORT extern int TF_OperationNumOutputs(TF_Operation* oper);
TF_CAPI_EXPORT extern TF_DataType TF_OperationOutputType(TF_Output oper_out);
TF_CAPI_EXPORT extern int TF_OperationOutputListLength(TF_Operation* oper,
                                                       const char* arg_name,
                                                       TF_Status* status);

#ifndef TENSORFLOW_C_EXPERIMENTAL_GRADIENTS_TAPE_TAPE_OPERATION_H_
#define TENSORFLOW_C_EXPERIMENTAL_GRADIENTS_TAPE_TAPE_OPERATION_H_

#include "tensorflow/c/eager/abstract_operation.h"
#include "tensorflow/c/eager/gradients.h"

namespace tensorflow {
namespace gradients {
class TapeOperation : public AbstractOperation {
 public:
  explicit TapeOperation(AbstractOperation*, Tape*, const GradientRegistry&);
  void Release() override;

#ifndef TENSORFLOW_C_C_API_EXPERIMENTAL_H_
#define TENSORFLOW_C_C_API_EXPERIMENTAL_H_

#include <stddef.h>
#include <stdint.h>

#include "tensorflow/c/c_api.h"
#include "tensorflow/c/c_api_macros.h"
#include "tensorflow/c/eager/c_api.h"

// --------------------------------------------------------------------------
// Experimental C API for TensorFlow.
//
// The API here is subject to changes in the future.

==============================================================================*/

#ifndef TENSORFLOW_C_EAGER_C_API_EXPERIMENTAL_READER_H_
#define TENSORFLOW_C_EAGER_C_API_EXPERIMENTAL_READER_H_

#include "tensorflow/c/eager/c_api.h"

#ifdef __cplusplus
extern "C" {
#endif

// Test only exports of the monitoring Cell Reader API which allows tests to
// read current values from streamz counters defined in other modules.
//

limitations under the License.
==============================================================================*/
#ifndef TENSORFLOW_C_EAGER_C_API_TEST_UTIL_H_
#define TENSORFLOW_C_EAGER_C_API_TEST_UTIL_H_

#include <vector>

#include "tensorflow/c/eager/c_api.h"
#include "tensorflow/c/eager/c_api_experimental.h"
#include "tensorflow/c/tf_datatype.h"
#include "tensorflow/core/platform/logging.h"
#include "tensorflow/core/platform/tstring.h"