Method ProcessNonThreaded

cpp/src/arrow/acero/asof_join_node.cc:1467–1497

#ifndef ARROW_ENABLE_THREADING
  bool ProcessNonThreaded() {
    while (!process_task_.is_finished()) {
      Result<std::shared_ptr<RecordBatch>> result = ProcessInner();

      if (result.ok()) {
        auto out_rb = *result;
        if (!out_rb) break;
        ExecBatch out_b(*out_rb);
        out_b.index = batches_produced_++;
        DEBUG_SYNC(this, "produce batch ", out_b.index, ":", DEBUG_MANIP(std::endl),
                   out_rb->ToString(), DEBUG_MANIP(std::endl));
        Status st = output_->InputReceived(this, std::move(out_b));
        if (!st.ok()) {
          // this isn't really from a thread,
          // but we call through to this for consistency
          EndFromSingleThread(std::move(st));
          return false;
        }
      } else {
        // this isn't really from a thread,
        // but we call through to this for consistency
        EndFromSingleThread(result.status());
        return false;
      }
    }
    auto& lhs = *state_.at(0);
    if (lhs.Finished() && !process_task_.is_finished()) {
      EndFromSingleThread(Status::OK());
    }
    return true;
  }

  void EndFromSingleThread(Status st = Status::OK()) {
    process_task_.MarkFinished(st);