Method RunOnce

python/pyarrow/src/arrow/python/helpers.cc:313–335

  template <typename Func>
  void RunOnce(Func&& func) {
    auto do_init = [&]() {
      OwnedRef module;
      if (ImportModule(module_name, &module).ok()) {
#ifndef Py_GIL_DISABLED
        // Since ImportModule can release the GIL, another thread could have
        // already initialized the static data.
        if (initialized) {
          return;
        }
#endif
        func(module);
      }
    };
#ifdef Py_GIL_DISABLED
    std::call_once(initialized, do_init);
#else
    if (!initialized) {
      do_init();
      initialized = true;
    }
#endif
  }
};

static PyObject* uuid_UUID = nullptr;