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:

See Also

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