// Close a session.
//
// Contacts any other processes associated with the session, if applicable.
// May not be called after TF_DeleteSession().
TF_CAPI_EXPORT extern void TF_CloseSession(TF_Session*, TF_Status* status);

// Destroy a session object.
//
// Even if error information is recorded in *status, this call discards all
// local resources associated with the session.  The session may not be used

TF_CAPI_EXPORT extern bool TF_StringStreamNext(TF_StringStream* list,
                                               const char** result);

// Frees the resources associated with given string list. All pointers returned
// by TF_StringStreamNext are invalid after this call.
TF_CAPI_EXPORT extern void TF_StringStreamDone(TF_StringStream* list);

TF_CAPI_EXPORT extern char* TF_FunctionDebugString(TF_Function* func,
                                                   size_t* len);

// On success, dequeues a tensor from a TF-managed FifoQueue given by
// `tensor_id`, associated with `session`. There must be a graph node named
// "fifo_queue_dequeue_<tensor_id>", to be executed by this API call.

// Caller must call TF_DeleteTensor() over the returned tensor. If the queue is

  // FetchJVP for it would return `tangent`.
  void Watch(int64_t tensor_id, Gradient* tangent);

  // Removes the gradient associated with tensor_id. Should be called when the
  // Tensor associated with `tensor_id` is deleted.
  void DeleteGradient(int64_t tensor_id);

  // Runs forward autodiff. Should be called whenever a new operation is

TF_CAPI_EXPORT extern bool TFE_CancellationManagerTryDeregisterCallback(
    TFE_CancellationManager*, TFE_CancellationToken token);
TF_CAPI_EXPORT extern void TFE_DeleteCancellationManager(
    TFE_CancellationManager*);

// Associates the given `cancellation_manager` with `op`, so that invoking
// `TFE_CancellationManagerStartCancel(cancellation_manager)` will cancel the
// execution of `op`.
typedef struct TFE_CancellationManager TFE_CancellationManager;

/// This is the interop header between core TensorFlow and modular filesystem
/// plugins (see initial RFC https://github.com/tensorflow/community/pull/101).
///
/// Both core TensorFlow and every plugin will use this header. The associated
/// `.cc` file is only used by core TensorFlow to implement checking needed for
/// plugin registration and ensuring API and ABI compatibility. Plugin authors