static std::mutex all_images_lock;
static std::map<std::string, std::shared_ptr<const Image>> all_images;
static std::map<std::string, std::thread> update_threads;
static std::mutex all_images_lock;
static std::map<std::string, std::shared_ptr<const Image>> all_images;
static std::map<std::string, std::thread> update_threads;