Method SpawnAddsAndCancel

cpp/src/arrow/util/thread_pool_test.cc:521–524

  }

  void SpawnAddsAndCancel(ThreadPool* pool, int nadds, AddTaskFunc add_func,
                          StopSource* stop_source) {
    DoSpawnAdds(pool, nadds, std::move(add_func), stop_source->token(), stop_source);
  }

  void DoSpawnAddsThreaded(ThreadPool* pool, int nthreads, int nadds,
                           AddTaskFunc add_func,