Using lgrp_children()

The lgrp_children(3LGRP) function takes a cookie that represents the calling thread's snapshot of the lgroup hierarchy and returns the number of child lgroups for the specified lgroup.

#include <sys/lgrp_user.h>
int lgrp_children(lgrp_cookie_t cookie, lgrp_id_t parent,
                  lgrp_id_t *lgrp_array, uint_t lgrp_array_size);

If lgrp_array is not NULL and the value of lgrp_array_size is not zero, the lgrp_children() function fills the array with child lgroup IDs until the array is full or all child lgroup IDs are in the array.

The lgrp_children() function returns EINVAL when the cookie is invalid. The lgrp_children() function returns ESRCH when the specified lgroup ID is not found.