m4_comment([$Id: env_set_shm_key.so,v 10.28 2004/09/28 15:04:20 bostic Exp $])

define(M4PAGELOCAL, [dbenv_set_shm_key, dbenv_get_shm_key])
include(m4/m4.seealso)

m4_pf_header(m4_ref(dbenv_set_shm_key),
ifelse(M4API, C_API, [dnl
int
DB_ENV-__GT__set_shm_key(DB_ENV *dbenv, long shm_key);
m4_blank
int
DB_ENV-__GT__get_shm_key(DB_ENV *dbenv, long *shm_keyp);
])
ifelse(M4API, CXX_API, [dnl
int
DbEnv::set_shm_key(long shm_key);
m4_blank
int
DbEnv::get_shm_key(long *shm_keyp);
]))

m4_p([dnl
Specify a base segment ID for m4_db environment shared memory regions
created in system memory on VxWorks or systems supporting X/Open-style
shared memory interfaces; for example, UNIX systems supporting
m4_manref(shmget, 2) and related System V IPC interfaces.])

m4_p([dnl
This base segment ID will be used when m4_db shared memory regions are
first created.  It will be incremented a small integer value each time
a new shared memory region is created; that is, if the base ID is 35,
the first shared memory region created will have a segment ID of 35,
and the next one will have a segment ID between 36 and 40 or so.  A
m4_db environment always creates a master shared memory region; an
additional shared memory region for each of the subsystems supported by
the environment (Locking, Logging, Memory Pool and Transaction); plus
an additional shared memory region for each additional memory pool cache
that is supported.  Already existing regions with the same segment IDs
will be removed.  See m4_link(M4RELDIR/ref/env/region, [Shared Memory
Regions]) for more information.])

m4_p([dnl
The intent behind this method is two-fold: without it, applications
have no way to ensure that two m4_db applications don't attempt to use
the same segment IDs when creating different m4_db environments.  In
addition, by using the same segment IDs each time the environment is
created, previously created segments will be removed, and the set of
segments on the system will not grow without bound.])

m4_env_config(dbenv_set_shm_key, [base segment ID], set_shm_key, [the ID])

m4_scope_dbenv(dbenv_set_shm_key)

m4_when_envopen(dbenv_set_shm_key, corrupt)

m4_return(dbenv_set_shm_key, std)

m4_parambegin
m4_param(shm_key, [dnl
The m4_arg(shm_key) parameter is the base segment ID for the database
environment.])
m4_paramend

m4_err(dbenv_set_shm_key,
einval, [the method was called after m4_ref(dbenv_open) was called])

m4_pf_getter(dbenv_get_shm_key, base segment ID,, shm_keyp)

m4_seealso(DbEnv)
m4_page_footer