RSM_GET_SEGMENTID_RANGE(3RSM)RSM_GET_SEGMENTID_RANGE(3RSM)NAMErsm_get_segmentid_range - get segment ID range
SYNOPSIS
cc [ flag... ] file... -lrsm [ library... ]
#include <rsmapi.h>
int rsm_get_segmentid_range(const char *appid,
rsm_memseg_id_t *baseid, uint32_t *length);
DESCRIPTION
RSM segment IDs can be either specified by the application or generated
by the system using the rsm_memseg_export_publish(3RSM) function.
Applications that specify segment IDs require a reserved range of seg‐
ment IDs that they can use. This can be achieved by using rsm_get_seg‐
mentid_range() and by reserving a range of segment IDs in the segment
ID configuration file, /etc/rsm/rsm.segmentid. The rsm_get_segmen‐
tid_range() function can be used by applications to obtain the segment
ID range reserved for them. The appid argument is a null-terminated
string that identifies the application. The baseid argument points to
the location where the starting segment ID of the reserved range is
returned. The length argument points to the location where the number
of reserved segment IDs is returned.
The application can use any value starting at baseid and less than
baseid+length. The application should use an offset within the range of
reserved segment IDs to obtain a segment ID such that if the baseid or
length is modified, it will still be within its reserved range.
It is the responsibility of the system administrator to make sure that
the segment ID ranges are properly administered (such that they are
non-overlapping, the file on various nodes of the cluster have identi‐
cal entries, and so forth.) Entries in the /etc/rsm/rsm.segmentid file
are of the form:
#keyword appid baseid length
reserved SUNWfoo 0x600000 1000
The fields in the file are separated by tabs or blanks. The first
string is a keyword "reserve", followed by the application identifier
(a string without spaces), the baseid (the starting segment ID of the
reserved range in hexadecimal), and the length (the number of segmen‐
tids reserved). Comment lines contain a "#" in the first column. The
file should not contain blank or empty lines. Segment IDs reserved for
the system are defined in the </usr/include/rsm/rsm_common.h> header
and cannot be used by the applications.
RETURN VALUES
Upon successful completion, these functions return 0. Otherwise, an
error value is returned to indicate the error.
ERRORS
The rsm_get_segmentid_range() function can return the following errors:
RSMERR_BAD_ADDR
The address passed is invalid.
RSMERR_BAD_APPID
The appid is not defined in configuration file.
RSMERR_BAD_CONF
The configuration file is not present or not read‐
able, or the configuration file format is incor‐
rect.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌────────────────────┬─────────────────┐
│ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼─────────────────┤
│Interface Stability │ Unstable │
├────────────────────┼─────────────────┤
│MT-Level │ MT-Safe │
└────────────────────┴─────────────────┘
SEE ALSOrsm_memseg_export_publish(3RSM), attributes(5)
May 8, 2003 RSM_GET_SEGMENTID_RANGE(3RSM)
