Method FlushUnlocked

tensorflow/core/kernels/conditional_accumulator_base.cc:168–188

* Try to flush logged, blocked TakeGrad attempts. */

 * Try to flush logged, blocked TakeGrad attempts.
 */
void ConditionalAccumulatorBase::FlushUnlocked() {
  std::vector<CleanUp> clean_up;
  Ref();
  {
    mutex_lock lock(mu_);
    bool changed;
    do {
      changed = TryAttemptLocked(&clean_up);
    } while (changed);
  }
  Unref();
  for (const auto& to_clean : clean_up) {
    if (to_clean.to_deregister != CancellationManager::kInvalidToken) {
      // NOTE(mrry): We can safely ignore the return value of
      // DeregisterCallback because the mutex mu_ ensures that the
      // cleanup action only executes once.
      to_clean.cm->DeregisterCallback(to_clean.to_deregister);
    }
    to_clean.finished();
  }
}

bool ConditionalAccumulatorBase::TakeGradLockedHelper(OpKernelContext* ctx,
                                                      DoneCallback callback) {