POOL_CONF_ALLOC(3POOL) Pool Configuration Manipulation Library Functions


NAME


pool_conf_alloc, pool_conf_close, pool_conf_commit, pool_conf_export,
pool_conf_free, pool_conf_info, pool_conf_location, pool_conf_open,
pool_conf_remove, pool_conf_rollback, pool_conf_status, pool_conf_update,
pool_conf_validate - manipulate resource pool configurations

SYNOPSIS


cc [ flag... ] file... -lpool [ library... ]
#include <pool.h>

pool_conf_t *pool_conf_alloc(void);


int pool_conf_close(pool_conf_t *conf);


int pool_conf_commit(pool_conf_t *conf, int active);


int pool_conf_export(pool_conf_t *conf, const char *location,
pool_export_format_t format);


void pool_conf_free(pool_conf_t *conf);


char *pool_conf_info(const pool_conf_t *conf, int flags);


const char *pool_conf_location(pool_conf_t *conf);


int pool_conf_open(pool_conf_t *conf, const char *location,
int flags);


int pool_conf_remove(pool_conf_t *conf);


int pool_conf_rollback(pool_conf_t *conf);


pool_conf_state_t pool_conf_status(const pool_conf_t *conf);


int pool_conf_update(const pool_conf_t *conf, int *changed);


int pool_conf_validate(pool_conf_t *conf,
pool_valid_level_t level);


DESCRIPTION


These functions enable the access and creation of configuration files
associated with the pools facility. Since the pool configuration is an
opaque type, an initial configuration is obtained with pool_conf_alloc()
and released with pool_conf_free() when the configuration is no longer of
interest. The conf argument for each function refers to the target
configuration to which the operation applies.


The pool_conf_close() function closes the given configuration, releasing
associated resources.


The pool_conf_commit() function commits changes made to the given
pool_conf_t to permanent storage. If the active flag is non-zero, the
state of the system will be configured to match that described in the
supplied pool_conf_t. If configuring the system fails, pool_conf_commit()
will attempt to restore the system to its previous state.


The pool_conf_export() function saves the given configuration to the
specified location. The only currently supported value of format is
POX_NATIVE, which is the format native to libpool, the output of which
can be used as input to pool_conf_open().


The pool_conf_info() function returns a string describing the entire
configuration. The string is allocated with malloc(3C). The caller is
responsible for freeing the returned string. If the flags option is non-
zero, the string returned also describes the sub-elements (if any)
contained in the configuration.


The pool_conf_location() function returns the location string provided to
pool_conf_open() for the given pool_conf_t.


The pool_conf_open() function creates a pool_conf_t given a location at
which the configuration is stored. The valid flags are a bitmap of the
following:

PO_RDONLY
Open for reading only.


PO_RDWR
Open read-write.


PO_CREAT
Create a configuration at the given location if it does not
exist. If it does, truncate it.


PO_DISCO
Perform `discovery'. This option only makes sense when used
in conjunction with PO_CREAT, and causes the returned
pool_conf_t to contain the resources and components
currently active on the system.

The use of this flag is deprecated. PO_CREAT always performs
discovery. If supplied, this flag is ignored.


PO_UPDATE
Use when opening the dynamic state file, which is the
configuration at pool_dynamic_location(3POOL), to ensure
that the contents of the dynamic state file are updated to
represent the current state of the system.

The use of this flag is deprecated. The dynamic state is
always current and does not require updating. If supplied,
this flag is ignored.


A call to pool_conf_open() with the pool dynamic location and write
permission will hang if the dynamic location has already been opened for
writing.


The pool_conf_remove() function removes the configuration's permanent
storage. If the configuration is still open, it is first closed.


The pool_conf_rollback() function restores the configuration state to
that held in the configuration's permanent storage. This will either be
the state last successfully committed (using pool_conf_commit()) or the
state when the configuration was opened if there have been no
successfully committed changes since then.


The pool_conf_status() function returns the status of a configuration,
which can be one of the following values:

POF_INVALID
The configuration is not in a suitable state for use.


POF_VALID
The configuration is in a suitable state for use.


The pool_conf_update() function updates the library snapshot of kernel
state. If changed is non-null, it is updated to identify which types of
configuration elements changed during the update. To check for change,
treat the changed value as a bitmap of possible element types.


A change is defined for the different element classes as follows:

POU_SYSTEM
A property on the system element has been created,
modified, or removed.


POU_POOL
A property on a pool element has been created, modified, or
removed. A pool has changed a resource association.


POU_PSET
A property on a pset element has been created, modified, or
removed. A pset's resource composition has changed.


POU_CPU
A property on a CPU element has been created, modified, or
removed.


The pool_conf_validate() function checks the validity of the contents of
the given configuration. The validation can be at several (increasing)
levels of strictness:

POV_LOOSE
Performs basic internal syntax validation.


POV_STRICT
Performs a more thorough syntax validation and internal
consistency checks.


POV_RUNTIME
Performs an estimate of whether attempting to commit the
given configuration on the system would succeed or fail.
It is optimistic in that a successful validation does not
guarantee a subsequent commit operation will be
successful; it is conservative in that a failed validation
indicates that a subsequent commit operation on the
current system will always fail.


RETURN VALUES


Upon successful completion, pool_conf_alloc() returns an initialized
pool_conf_t pointer. Otherwise it returns NULL and pool_error(3POOL)
returns the pool-specific error value.


Upon successful completion, pool_conf_close(), pool_conf_commit(),
pool_conf_export(), pool_conf_open(), pool_conf_remove(),
pool_conf_rollback(), pool_conf_update(), and pool_conf_validate() return
0. Otherwise they return -1 and pool_error() returns the pool-specific
error value.


The pool_conf_status() function returns either POF_INVALID or POF_VALID.

ERRORS


The pool_conf_alloc() function will fail if:

POE_SYSTEM
There is not enough memory available to allocate the
configuration. Check errno for the specific system
error code.


POE_INVALID_CONF
The configuration is invalid.


The pool_conf_close() function will fail if:

POE_BADPARAM
The supplied configuration's status is not POF_VALID.


POE_SYSTEM
The configuration's permanent store cannot be closed.
Check errno for the specific system error code.


The pool_conf_commit() function will fail if:

POE_BADPARAM
The supplied configuration's status is not POF_VALID
or the active flag is non-zero and the system could
not be modified.


POE_SYSTEM
The permanent store could not be updated. Check errno
for the specific system error code.


POE_INVALID_CONF
The configuration is not valid for this system.


POE_ACCESS
The configuration was not opened with the correct
permissions.


POE_DATASTORE
The update of the permanent store has failed and the
contents could be corrupted. Check for a .bak file at
the datastore location if manual recovery is
required.


The pool_conf_export() function will fail if:

POE_BADPARAM
The supplied configuration's status is not POF_VALID or
the requested export format is not supported.


POE_DATASTORE
The creation of the export file failed. A file might
have been created at the specified location but the
contents of the file might not be correct.


The pool_conf_info() function will fail if:

POE_BADPARAM
The supplied configuration's status is not POF_VALID
or flags is neither 0 nor 1.


POE_SYSTEM
There is not enough memory available to allocate the
buffer used to build the information string. Check
errno for the specific system error code.


POE_INVALID_CONF
The configuration is invalid.


The pool_conf_location() function will fail if:

POE_BADPARAM
The supplied configuration's status is not POF_VALID.


The pool_conf_open() function will fail if:

POE_BADPARAM
The supplied configuration's status is already
POF_VALID.


POE_SYSTEM
There is not enough memory available to store the
supplied location, or the pools facility is not
active. Check errno for the specific system error
code.


POE_INVALID_CONF
The configuration to be opened is at
pool_dynamic_location(3POOL) and the configuration is
not valid for this system.


The pool_conf_remove() function will fail if:

POE_BADPARAM
The supplied configuration's status is not POF_VALID.


POE_SYSTEM
The configuration's permanent storage could not be
removed. Check errno for the specific system error code.


The pool_conf_rollback() function will fail if:

POE_BADPARAM
The supplied configuration's status is not POF_VALID.


POE_SYSTEM
The permanent store could not be accessed. Check errno
for the specific system error code.


The pool_conf_update() function will fail if:

POE_BADPARAM
The supplied configuration's status is not POF_VALID
or the configuration is not the dynamic
configuration.


POE_DATASTORE
The kernel snapshot cannot be correctly unpacked.


POE_INVALID_CONF
The configuration contains uncommitted transactions.


POE_SYSTEM
A system error occurred during snapshot retrieval and
update.


The pool_conf_validate() function will fail if:

POE_BADPARAM
The supplied configuration's status is not POF_VALID.


POE_INVALID_CONF
The configuration is invalid.


EXAMPLES


Example 1: Create the configuration at the specified location.



#include <pool.h>
#include <stdio.h>

...

pool_conf_t *pool_conf;
pool_conf = pool_conf_alloc();
char *input_location = "/tmp/poolconf.example";

if (pool_conf_open(pool_conf, input_location,
PO_RDONLY) < 0) {
fprintf(stderr, "Opening pool configuration %s
failed\n", input_location);
}


ATTRIBUTES


See attributes(5) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|CSI | Enabled |
+--------------------+-----------------+
|Interface Stability | Uncommitted |
+--------------------+-----------------+
|MT-Level | Safe |
+--------------------+-----------------+

SEE ALSO


libpool(3LIB), pool_error(3POOL), attributes(5)


August 3, 2009 POOL_CONF_ALLOC(3POOL)