Method UpdateStatus

cpp/src/arrow/util/task_group.cc:168–175

 protected:
  void UpdateStatus(Status&& st) {
    // Must be called unlocked, only locks on error
    if (ARROW_PREDICT_FALSE(!st.ok())) {
      std::lock_guard<std::mutex> lock(mutex_);
      ok_.store(false, std::memory_order_release);
      status_ &= std::move(st);
    }
  }

  void OneTaskDone() {
    // Can be called unlocked thanks to atomics