// threadpool, so that we avoid the possibility of running the runner_ in the
  // threadpool of GPU event mgr, as that can trigger more callbacks to be
  // scheduled on that same threadpool, causing a deadlock in cases where the
  // caller of event_mgr->ThenExecute() blocks on the completion of the callback
  // (as in the case of ConstOp kernel creation on GPU, which involves copying a
  // CPU tensor to GPU).

    const TFE_CancelCallback* c_callback, const char* callback_name) {
  tensorflow::CancelCallback callback = [callback = c_callback->callback,
                                         context = c_callback->context]() {
    callback(context);
  };
  return tensorflow::unwrap(cancellation_manager)
      ->RegisterCallbackWithErrorLogging(token, callback, callback_name);
}