Method EnsureInitialized

cpp/src/arrow/filesystem/s3fs.cc:3482–3499

Returns true iff the instance was newly initialized with `options`

  // Returns true iff the instance was newly initialized with `options`
  Result<bool> EnsureInitialized(const S3GlobalOptions& options) {
    // NOTE: The individual accesses are atomic but the entire sequence below is not.
    // The application should serialize calls to InitializeS3() and FinalizeS3()
    // (see docstrings).
    if (is_finalized_.load()) {
      return Status::Invalid("Attempt to initialize S3 after it has been finalized");
    }
    bool newly_initialized = false;
    // EnsureInitialized() can be called concurrently by FileSystemFromUri,
    // therefore we need to serialize initialization (GH-39897).
    std::call_once(initialize_flag_, [&]() {
      bool was_initialized = is_initialized_.exchange(true);
      DCHECK(!was_initialized);
      DoInitialize(options);
      newly_initialized = true;
    });
    return newly_initialized;
  }

  bool IsInitialized() { return !is_finalized_ && is_initialized_; }