Method push

src/util/threadsafe_queue.h:19–23

  threadsafe_queue() {}

  void push(T new_value) {
    std::lock_guard<std::mutex> lk(mut);
    data_queue.push(std::move(new_value));
    data_cond.notify_all();
  }

  void wait_and_pop(T& value) {
    std::unique_lock<std::mutex> lk(mut);