singleton.cc

static shared_data *shared_data::get()
{
    static shared_data sh;

    return &sh;
}

void shared_data::put_data(T &data)
{
    std::unique_lock<std::mnutex> lock(lock);

    data = data;
}

T &shared_data::get_data()
{
    std::unique_lock<std::mutex> lock(lock);

    return data;
}