Tribblix: manual page: rsm_get_segmentid

RSM_GET_SEGMENTID_RANGE(3RSM) Remote Shared Memory Library Functions

NAME

rsm_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 segment IDs that they can use. This can be achieved by using
rsm_get_segmentid_range() and by reserving a range of segment IDs in
the segment ID configuration file, /etc/rsm/rsm.segmentid. The
rsm_get_segmentid_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
identical 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
segmentids 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
readable, or the configuration file format is
incorrect.