Function fdt_fd_new

components/dfs/dfs_v2/src/dfs.c:298–342

* @ingroup group_fs_file_descriptor * * @brief Allocate a new file descriptor in the file descriptor table * * @param[in,out] fdt Pointer to the file descriptor table to allocate from * * @return int The allocated file descriptor index if successful (>= 0), * -RT_ENOSYS if filesystem lock failed, * -1 if allocation failed (no empty slots or memory allocation failed) */

 *         -1 if allocation failed (no empty slots or memory allocation failed)
 */
int fdt_fd_new(struct dfs_fdtable *fdt)
{
    int idx = -1;

    /* lock filesystem */
    if (dfs_file_lock() != RT_EOK)
    {
        return -RT_ENOSYS;
    }

    /* find an empty fd entry */
    idx = _fdt_fd_alloc(fdt, (fdt == &_fdtab) ? DFS_STDIO_OFFSET : 0);
    /* can't find an empty fd entry */
    if (idx < 0)
    {
        LOG_E("DFS fd new is failed! Could not found an empty fd entry.");
    }
    else if (!fdt->fds[idx])
    {
        struct dfs_file *file;

        file = dfs_file_create();

        if (file)
        {
            fdt->fds[idx] = file;

            LOG_D("allocate a new fd @ %d", idx);
        }
        else
        {
            fdt->fds[idx] = RT_NULL;
            idx = -1;
        }
    }
    else
    {
        LOG_E("DFS not found an empty fds entry.");
        idx = -1;
    }

    dfs_file_unlock();

    return idx;
}

/**
 * @brief Release a file descriptor from the file descriptor table