NAME
    SCI_Group_query - Queries runtime information of an existed group

C Syntax
    #include <sci.h>
    int SCI_Group_query(sci_group_t group, sci_group_query_t query, void *ret_val)

INPUT PARAMETERS
    group
        The group to be queried (IN).
    query
        Specifies the type of query you want to request (IN).
    ret_val
        Specifies the reference parameter for SCI to store as the result of the query. 
        The value of this parameter cannot be NULL (OUT).

DESCRIPTION
    This subroutine is used to query runtime statistics of an existed group. SCI defines
    a set of query types as an enumeration in sci.h.

    For example, you can query the number of back ends in a group using the query value 
    of GROUP_MEMBER_NUM: SCI_Group_query(group, GROUP_MEMBER_NUM, &ret_val);

    In SCI, sci_group_query_t defines the following valid query types:

    GROUP_MEMBER_NUM
        Query the number of back ends in the group
    GROUP_MEMBER
        Query the back end id list in the group
    GROUP_SUCCESSOR_NUM
        Query the number of successors in the group
    GROUP_SUCCESSOR
        Query the successor id list in the group

    For more information, please refer to SCI's online documents.

EXAMPLE
        {
                int be_num, *be_list;
                sci_group_t group;
                ...
                SCI_Group_query(group, GROUP_MEMBER_NUM, &be_num);
                be_list = (int *)malloc(sizeof(int)*be_num);
                SCI_Group_query(group, GROUP_MEMBER, be_list);
        }

ERRORS
    All SCI routines return an error value.

    SCI_ERR_UNINTIALIZED
        Uninitialized SCI execution environment
    SCI_ERR_UNKNOWN_INFO
        Can't set NULL to ret_val
    SCI_ERR_INVALID_CALLER
        Can't be called from back end
    SCI_ERR_GROUP_NOTFOUND
        The group to be freed does not exist

SEE ALSO
    SCI_Query(3)