Method EndFromProcessThread

cpp/src/arrow/acero/sorted_merge_node.cc:429–450

 private:
  void EndFromProcessThread(arrow::Status st = arrow::Status::OK()) {
    ARROW_CHECK(!cleanup_started);
    for (size_t i = 0; i < input_counter.size(); ++i) {
      ARROW_CHECK(input_counter[i] == output_counter[i])
          << input_counter[i] << " != " << output_counter[i];
    }

#ifdef ARROW_ENABLE_THREADING
    ARROW_UNUSED(
        plan_->query_context()->executor()->Spawn([this, st = std::move(st)]() mutable {
          Defer cleanup([this, &st]() { process_task.MarkFinished(st); });
          if (st.ok()) {
            st = output_->InputFinished(this, batches_produced);
          }
        }));
#else
    process_task.MarkFinished(st);
    if (st.ok()) {
      st = output_->InputFinished(this, batches_produced);
    }
#endif
  }

  bool CheckEnded() {
    bool all_finished = true;