static mapping_t* _map_find(epoll_t* epoll, int fd)
{
    size_t i;

    for (i = 0; i < epoll->map_size; i++)
    {
        mapping_t* mapping = &epoll->map[i];

        if (mapping->fd == fd)
            return mapping;
    }

    /* Not found */
    return NULL;
}
static mapping_t* _map_find(epoll_t* epoll, int fd)
{
    size_t i;

    for (i = 0; i < epoll->map_size; i++)
    {
        mapping_t* mapping = &epoll->map[i];

        if (mapping->fd == fd)
            return mapping;
    }

     
    return NULL;
}