drivers/edac: fix edac_device sysfs completion code

With feedback, this patch corrects operation of the kobject release operation
on kobjects, attributes and controls for the edac_device.

Cc: Alan Cox alan@lxorguk.ukuu.org.uk
Signed-off-by: Doug Thompson <dougthompson@xmission.com>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Douglas Thompson 2007-07-19 01:50:29 -07:00 committed by Linus Torvalds
parent 8096cfafbb
commit 1c3631ff1f
4 changed files with 277 additions and 115 deletions

View file

@ -337,6 +337,9 @@ struct mcidev_sysfs_attribute {
*/
struct mem_ctl_info {
struct list_head link; /* for global list of mem_ctl_info structs */
struct module *owner; /* Module owner of this control struct */
unsigned long mtype_cap; /* memory types supported by mc */
unsigned long edac_ctl_cap; /* Mem controller EDAC capabilities */
unsigned long edac_cap; /* configuration capabilities - this is
@ -510,7 +513,6 @@ struct edac_device_block {
/* edac sysfs device control */
struct kobject kobj;
struct completion kobj_complete;
};
/* device instance control structure */
@ -525,7 +527,6 @@ struct edac_device_instance {
/* edac sysfs device control */
struct kobject kobj;
struct completion kobj_complete;
};
@ -537,6 +538,8 @@ struct edac_device_ctl_info {
/* for global list of edac_device_ctl_info structs */
struct list_head link;
struct module *owner; /* Module owner of this control struct */
int dev_idx;
/* Per instance controls for this edac_device */
@ -587,7 +590,7 @@ struct edac_device_ctl_info {
* NMI handlers may be traversing list
*/
struct rcu_head rcu;
struct completion complete;
struct completion removal_complete;
/* sysfs top name under 'edac' directory
* and instance name:
@ -611,7 +614,6 @@ struct edac_device_ctl_info {
* device this structure controls
*/
struct kobject kobj;
struct completion kobj_complete;
};
/* To get from the instance's wq to the beginning of the ctl structure */

View file

@ -48,6 +48,7 @@ static void edac_device_dump_device(struct edac_device_ctl_info *edac_dev)
}
#endif /* CONFIG_EDAC_DEBUG */
/*
* edac_device_alloc_ctl_info()
* Allocate a new edac device control info structure
@ -78,6 +79,7 @@ struct edac_device_ctl_info *edac_device_alloc_ctl_info(
unsigned count;
unsigned instance, block, attr;
void *pvt;
int err;
debugf1("%s() instances=%d blocks=%d\n",
__func__, nr_instances, nr_blocks);
@ -208,6 +210,22 @@ struct edac_device_ctl_info *edac_device_alloc_ctl_info(
/* Mark this instance as merely ALLOCATED */
dev_ctl->op_state = OP_ALLOC;
/*
* Initialize the 'root' kobj for the edac_device controller
*/
err = edac_device_register_sysfs_main_kobj(dev_ctl);
if (err) {
kfree(dev_ctl);
return NULL;
}
/* at this point, the root kobj is valid, and in order to
* 'free' the object, then the function:
* edac_device_unregister_sysfs_main_kobj() must be called
* which will perform kobj unregistration and the actual free
* will occur during the kobject callback operation
*/
return dev_ctl;
}
EXPORT_SYMBOL_GPL(edac_device_alloc_ctl_info);
@ -219,7 +237,7 @@ EXPORT_SYMBOL_GPL(edac_device_alloc_ctl_info);
*/
void edac_device_free_ctl_info(struct edac_device_ctl_info *ctl_info)
{
kfree(ctl_info);
edac_device_unregister_sysfs_main_kobj(ctl_info);
}
EXPORT_SYMBOL_GPL(edac_device_free_ctl_info);
@ -315,22 +333,23 @@ static void complete_edac_device_list_del(struct rcu_head *head)
edac_dev = container_of(head, struct edac_device_ctl_info, rcu);
INIT_LIST_HEAD(&edac_dev->link);
complete(&edac_dev->complete);
complete(&edac_dev->removal_complete);
}
/*
* del_edac_device_from_global_list
*
* remove the RCU, setup for a callback call, then wait for the
* callback to occur
* remove the RCU, setup for a callback call,
* then wait for the callback to occur
*/
static void del_edac_device_from_global_list(struct edac_device_ctl_info
*edac_device)
{
list_del_rcu(&edac_device->link);
init_completion(&edac_device->complete);
init_completion(&edac_device->removal_complete);
call_rcu(&edac_device->rcu, complete_edac_device_list_del);
wait_for_completion(&edac_device->complete);
wait_for_completion(&edac_device->removal_complete);
}
/**
@ -542,14 +561,14 @@ struct edac_device_ctl_info *edac_device_del_device(struct device *dev)
/* clear workq processing on this instance */
edac_device_workq_teardown(edac_dev);
/* Tear down the sysfs entries for this instance */
edac_device_remove_sysfs(edac_dev);
/* deregister from global list */
del_edac_device_from_global_list(edac_dev);
mutex_unlock(&device_ctls_mutex);
/* Tear down the sysfs entries for this instance */
edac_device_remove_sysfs(edac_dev);
edac_printk(KERN_INFO, EDAC_MC,
"Removed device %d for %s %s: DEV %s\n",
edac_dev->dev_idx,

View file

@ -1,7 +1,8 @@
/*
* file for managing the edac_device class of devices for EDAC
*
* (C) 2007 SoftwareBitMaker(http://www.softwarebitmaker.com)
* (C) 2007 SoftwareBitMaker (http://www.softwarebitmaker.com)
*
* This file may be distributed under the terms of the
* GNU General Public License.
*
@ -10,6 +11,7 @@
*/
#include <linux/ctype.h>
#include <linux/module.h>
#include "edac_core.h"
#include "edac_module.h"
@ -19,7 +21,6 @@
#define to_edacdev(k) container_of(k, struct edac_device_ctl_info, kobj)
#define to_edacdev_attr(a) container_of(a, struct edacdev_attribute, attr)
/************************** edac_device sysfs code and data **************/
/*
* Set of edac_device_ctl_info attribute store/show functions
@ -103,8 +104,8 @@ static ssize_t edac_device_ctl_poll_msec_store(struct edac_device_ctl_info
/* edac_device_ctl_info specific attribute structure */
struct ctl_info_attribute {
struct attribute attr;
ssize_t(*show) (struct edac_device_ctl_info *, char *);
ssize_t(*store) (struct edac_device_ctl_info *, const char *, size_t);
ssize_t(*show) (struct edac_device_ctl_info *, char *);
ssize_t(*store) (struct edac_device_ctl_info *, const char *, size_t);
};
#define to_ctl_info(k) container_of(k, struct edac_device_ctl_info, kobj)
@ -168,45 +169,76 @@ static struct ctl_info_attribute *device_ctrl_attr[] = {
NULL,
};
/* Main DEVICE kobject release() function */
/*
* edac_device_ctrl_master_release
*
* called when the reference count for the 'main' kobj
* for a edac_device control struct reaches zero
*
* Reference count model:
* One 'main' kobject for each control structure allocated.
* That main kobj is initially set to one AND
* the reference count for the EDAC 'core' module is
* bumped by one, thus added 'keep in memory' dependency.
*
* Each new internal kobj (in instances and blocks) then
* bumps the 'main' kobject.
*
* When they are released their release functions decrement
* the 'main' kobj.
*
* When the main kobj reaches zero (0) then THIS function
* is called which then decrements the EDAC 'core' module.
* When the module reference count reaches zero then the
* module no longer has dependency on keeping the release
* function code in memory and module can be unloaded.
*
* This will support several control objects as well, each
* with its own 'main' kobj.
*/
static void edac_device_ctrl_master_release(struct kobject *kobj)
{
struct edac_device_ctl_info *edac_dev;
struct edac_device_ctl_info *edac_dev = to_edacdev(kobj);
edac_dev = to_edacdev(kobj);
debugf1("%s() control index=%d\n", __func__, edac_dev->dev_idx);
debugf1("%s()\n", __func__);
complete(&edac_dev->kobj_complete);
/* decrement the EDAC CORE module ref count */
module_put(edac_dev->owner);
/* free the control struct containing the 'main' kobj
* passed in to this routine
*/
kfree(edac_dev);
}
/* ktype for the main (master) kobject */
static struct kobj_type ktype_device_ctrl = {
.release = edac_device_ctrl_master_release,
.sysfs_ops = &device_ctl_info_ops,
.default_attrs = (struct attribute **)device_ctrl_attr,
};
/**************** edac_device main kobj ctor/dtor code *********************/
/*
* edac_device_register_main_kobj
* edac_device_register_sysfs_main_kobj
*
* perform the high level setup for the new edac_device instance
*
* Return: 0 SUCCESS
* !0 FAILURE
*/
static int edac_device_register_main_kobj(struct edac_device_ctl_info *edac_dev)
int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev)
{
int err = 0;
struct sysdev_class *edac_class;
int err;
debugf1("%s()\n", __func__);
/* get the /sys/devices/system/edac reference */
edac_class = edac_get_edac_class();
if (edac_class == NULL) {
debugf1("%s() no edac_class error=%d\n", __func__, err);
return err;
debugf1("%s() no edac_class error\n", __func__);
err = -ENODEV;
goto err_out;
}
/* Point to the 'edac_class' this instance 'reports' to */
@ -223,42 +255,65 @@ static int edac_device_register_main_kobj(struct edac_device_ctl_info *edac_dev)
debugf1("%s() set name of kobject to: %s\n", __func__, edac_dev->name);
err = kobject_set_name(&edac_dev->kobj, "%s", edac_dev->name);
if (err)
return err;
goto err_out;
/* Record which module 'owns' this control structure
* and bump the ref count of the module
*/
edac_dev->owner = THIS_MODULE;
if (!try_module_get(edac_dev->owner)) {
err = -ENODEV;
goto err_out;
}
/* register */
err = kobject_register(&edac_dev->kobj);
if (err) {
debugf1("%s()Failed to register '.../edac/%s'\n",
__func__, edac_dev->name);
return err;
goto err_kobj_reg;
}
/* At this point, to 'free' the control struct,
* edac_device_unregister_sysfs_main_kobj() must be used
*/
debugf1("%s() Registered '.../edac/%s' kobject\n",
__func__, edac_dev->name);
return 0;
/* Error exit stack */
err_kobj_reg:
module_put(edac_dev->owner);
err_out:
return err;
}
/*
* edac_device_unregister_main_kobj:
* edac_device_unregister_sysfs_main_kobj:
* the '..../edac/<name>' kobject
*/
static void edac_device_unregister_main_kobj(struct edac_device_ctl_info
*edac_dev)
void edac_device_unregister_sysfs_main_kobj(
struct edac_device_ctl_info *edac_dev)
{
debugf0("%s()\n", __func__);
debugf1("%s() name of kobject is: %s\n",
__func__, kobject_name(&edac_dev->kobj));
init_completion(&edac_dev->kobj_complete);
/*
* Unregister the edac device's kobject and
* wait for reference count to reach 0.
* allow for reference count to reach 0 at which point
* the callback will be called to:
* a) module_put() this module
* b) 'kfree' the memory
*/
kobject_unregister(&edac_dev->kobj);
wait_for_completion(&edac_dev->kobj_complete);
}
/*************** edac_dev -> instance information ***********/
/* edac_dev -> instance information */
/*
* Set of low-level instance attribute show functions
@ -285,8 +340,11 @@ static void edac_device_ctrl_instance_release(struct kobject *kobj)
debugf1("%s()\n", __func__);
/* map from this kobj to the main control struct
* and then dec the main kobj count
*/
instance = to_instance(kobj);
complete(&instance->kobj_complete);
kobject_put(&instance->ctl->kobj);
}
/* instance specific attribute structure */
@ -356,7 +414,7 @@ static struct kobj_type ktype_instance_ctrl = {
.default_attrs = (struct attribute **)device_instance_attr,
};
/*************** edac_dev -> instance -> block information *********/
/* edac_dev -> instance -> block information */
/*
* Set of low-level block attribute show functions
@ -381,8 +439,13 @@ static void edac_device_ctrl_block_release(struct kobject *kobj)
debugf1("%s()\n", __func__);
/* get the container of the kobj */
block = to_block(kobj);
complete(&block->kobj_complete);
/* map from 'block kobj' to 'block->instance->controller->main_kobj'
* now 'release' the block kobject
*/
kobject_put(&block->instance->ctl->kobj);
}
/* block specific attribute structure */
@ -447,49 +510,60 @@ static struct kobj_type ktype_block_ctrl = {
.default_attrs = (struct attribute **)device_block_attr,
};
/************** block ctor/dtor code ************/
/* block ctor/dtor code */
/*
* edac_device_create_block
*/
static int edac_device_create_block(struct edac_device_ctl_info *edac_dev,
struct edac_device_instance *instance,
int idx)
struct edac_device_block *block)
{
int i;
int err;
struct edac_device_block *block;
struct edac_dev_sysfs_block_attribute *sysfs_attrib;
struct kobject *main_kobj;
block = &instance->blocks[idx];
debugf1("%s() Instance '%s' block[%d] '%s'\n",
__func__, instance->name, idx, block->name);
debugf1("%s() Instance '%s' block '%s'\n",
__func__, instance->name, block->name);
/* init this block's kobject */
memset(&block->kobj, 0, sizeof(struct kobject));
block->kobj.parent = &instance->kobj;
block->kobj.ktype = &ktype_block_ctrl;
block->instance = instance;
err = kobject_set_name(&block->kobj, "%s", block->name);
if (err)
return err;
/* bump the main kobject's reference count for this controller
* and this instance is dependant on the main
*/
main_kobj = kobject_get(&edac_dev->kobj);
if (!main_kobj) {
err = -ENODEV;
goto err_out;
}
/* Add this block's kobject */
err = kobject_register(&block->kobj);
if (err) {
debugf1("%s()Failed to register instance '%s'\n",
debugf1("%s() Failed to register instance '%s'\n",
__func__, block->name);
return err;
kobject_put(main_kobj);
err = -ENODEV;
goto err_out;
}
/* If there are driver level block attributes, then added them
* to the block kobject
*/
sysfs_attrib = block->block_attributes;
if (sysfs_attrib != NULL) {
if (sysfs_attrib) {
for (i = 0; i < block->nr_attribs; i++) {
err = sysfs_create_file(&block->kobj,
(struct attribute *) &sysfs_attrib[i]);
(struct attribute *) sysfs_attrib);
if (err)
goto err_on_attrib;
@ -499,30 +573,41 @@ static int edac_device_create_block(struct edac_device_ctl_info *edac_dev,
return 0;
/* Error unwind stack */
err_on_attrib:
kobject_unregister(&block->kobj);
err_out:
return err;
}
/*
* edac_device_delete_block(edac_dev,j);
* edac_device_delete_block(edac_dev,block);
*/
static void edac_device_delete_block(struct edac_device_ctl_info *edac_dev,
struct edac_device_instance *instance,
int idx)
struct edac_device_block *block)
{
struct edac_device_block *block;
struct edac_dev_sysfs_block_attribute *sysfs_attrib;
int i;
block = &instance->blocks[idx];
/* if this block has 'attributes' then we need to iterate over the list
* and 'remove' the attributes on this block
*/
sysfs_attrib = block->block_attributes;
if (sysfs_attrib && block->nr_attribs) {
for (i = 0; i < block->nr_attribs; i++) {
sysfs_remove_file(&block->kobj,
(struct attribute *) sysfs_attrib);
}
}
/* unregister this block's kobject */
init_completion(&block->kobj_complete);
/* unregister this block's kobject, SEE:
* edac_device_ctrl_block_release() callback operation
*/
kobject_unregister(&block->kobj);
wait_for_completion(&block->kobj_complete);
}
/************** instance ctor/dtor code ************/
/* instance ctor/dtor code */
/*
* edac_device_create_instance
@ -534,6 +619,7 @@ static int edac_device_create_instance(struct edac_device_ctl_info *edac_dev,
int i, j;
int err;
struct edac_device_instance *instance;
struct kobject *main_kobj;
instance = &edac_dev->instances[idx];
@ -543,16 +629,28 @@ static int edac_device_create_instance(struct edac_device_ctl_info *edac_dev,
/* set this new device under the edac_device main kobject */
instance->kobj.parent = &edac_dev->kobj;
instance->kobj.ktype = &ktype_instance_ctrl;
instance->ctl = edac_dev;
err = kobject_set_name(&instance->kobj, "%s", instance->name);
if (err)
return err;
goto err_out;
/* bump the main kobject's reference count for this controller
* and this instance is dependant on the main
*/
main_kobj = kobject_get(&edac_dev->kobj);
if (!main_kobj) {
err = -ENODEV;
goto err_out;
}
/* Formally register this instance's kobject */
err = kobject_register(&instance->kobj);
if (err != 0) {
debugf2("%s() Failed to register instance '%s'\n",
__func__, instance->name);
return err;
kobject_put(main_kobj);
goto err_out;
}
debugf1("%s() now register '%d' blocks for instance %d\n",
@ -560,11 +658,14 @@ static int edac_device_create_instance(struct edac_device_ctl_info *edac_dev,
/* register all blocks of this instance */
for (i = 0; i < instance->nr_blocks; i++) {
err = edac_device_create_block(edac_dev, instance, i);
err = edac_device_create_block(edac_dev, instance,
&instance->blocks[i]);
if (err) {
/* If any fail, remove all previous ones */
for (j = 0; j < i; j++)
edac_device_delete_block(edac_dev, instance, j);
return err;
edac_device_delete_block(edac_dev,
&instance->blocks[j]);
goto err_release_instance_kobj;
}
}
@ -572,6 +673,13 @@ static int edac_device_create_instance(struct edac_device_ctl_info *edac_dev,
__func__, idx, instance->name);
return 0;
/* error unwind stack */
err_release_instance_kobj:
kobject_unregister(&instance->kobj);
err_out:
return err;
}
/*
@ -581,19 +689,19 @@ static int edac_device_create_instance(struct edac_device_ctl_info *edac_dev,
static void edac_device_delete_instance(struct edac_device_ctl_info *edac_dev,
int idx)
{
int i;
struct edac_device_instance *instance;
int i;
instance = &edac_dev->instances[idx];
/* unregister all blocks in this instance */
for (i = 0; i < instance->nr_blocks; i++)
edac_device_delete_block(edac_dev, instance, i);
edac_device_delete_block(edac_dev, &instance->blocks[i]);
/* unregister this instance's kobject */
init_completion(&instance->kobj_complete);
/* unregister this instance's kobject, SEE:
* edac_device_ctrl_instance_release() for callback operation
*/
kobject_unregister(&instance->kobj);
wait_for_completion(&instance->kobj_complete);
}
/*
@ -635,39 +743,69 @@ static void edac_device_delete_instances(struct edac_device_ctl_info *edac_dev)
edac_device_delete_instance(edac_dev, i);
}
/******************* edac_dev sysfs ctor/dtor code *************/
/* edac_dev sysfs ctor/dtor code */
/*
* edac_device_add_sysfs_attributes
* edac_device_add_main_sysfs_attributes
* add some attributes to this instance's main kobject
*/
static int edac_device_add_sysfs_attributes(
static int edac_device_add_main_sysfs_attributes(
struct edac_device_ctl_info *edac_dev)
{
int err;
struct edac_dev_sysfs_attribute *sysfs_attrib;
int err = 0;
/* point to the start of the array and iterate over it
* adding each attribute listed to this mci instance's kobject
*/
sysfs_attrib = edac_dev->sysfs_attributes;
while (sysfs_attrib->attr.name != NULL) {
err = sysfs_create_file(&edac_dev->kobj,
if (sysfs_attrib) {
/* iterate over the array and create an attribute for each
* entry in the list
*/
while (sysfs_attrib->attr.name != NULL) {
err = sysfs_create_file(&edac_dev->kobj,
(struct attribute*) sysfs_attrib);
if (err)
return err;
if (err)
goto err_out;
sysfs_attrib++;
sysfs_attrib++;
}
}
return 0;
err_out:
return err;
}
/*
* edac_device_remove_main_sysfs_attributes
* remove any attributes to this instance's main kobject
*/
static void edac_device_remove_main_sysfs_attributes(
struct edac_device_ctl_info *edac_dev)
{
struct edac_dev_sysfs_attribute *sysfs_attrib;
/* if there are main attributes, defined, remove them. First,
* point to the start of the array and iterate over it
* removing each attribute listed from this device's instance's kobject
*/
sysfs_attrib = edac_dev->sysfs_attributes;
if (sysfs_attrib) {
while (sysfs_attrib->attr.name != NULL) {
sysfs_remove_file(&edac_dev->kobj,
(struct attribute *) sysfs_attrib);
sysfs_attrib++;
}
}
}
/*
* edac_device_create_sysfs() Constructor
*
* Create a new edac_device kobject instance,
* accept a created edac_device control structure
* and 'export' it to sysfs. The 'main' kobj should already have been
* created. 'instance' and 'block' kobjects should be registered
* along with any 'block' attributes from the low driver. In addition,
* the main attributes (if any) are connected to the main kobject of
* the control structure.
*
* Return:
* 0 Success
@ -678,23 +816,13 @@ int edac_device_create_sysfs(struct edac_device_ctl_info *edac_dev)
int err;
struct kobject *edac_kobj = &edac_dev->kobj;
/* register this instance's main kobj with the edac class kobj */
err = edac_device_register_main_kobj(edac_dev);
if (err)
return err;
debugf0("%s() idx=%d\n", __func__, edac_dev->dev_idx);
/* If the low level driver requests some sysfs entries
* then go create them here
*/
if (edac_dev->sysfs_attributes != NULL) {
err = edac_device_add_sysfs_attributes(edac_dev);
if (err) {
debugf0("%s() failed to add sysfs attribs\n",
__func__);
goto err_unreg_object;
}
/* go create any main attributes callers wants */
err = edac_device_add_main_sysfs_attributes(edac_dev);
if (err) {
debugf0("%s() failed to add sysfs attribs\n", __func__);
goto err_out;
}
/* create a symlink from the edac device
@ -705,17 +833,24 @@ int edac_device_create_sysfs(struct edac_device_ctl_info *edac_dev)
if (err) {
debugf0("%s() sysfs_create_link() returned err= %d\n",
__func__, err);
goto err_unreg_object;
goto err_remove_main_attribs;
}
/* Create the first level instance directories
* In turn, the nested blocks beneath the instances will
* be registered as well
*/
err = edac_device_create_instances(edac_dev);
if (err) {
debugf0("%s() edac_device_create_instances() "
"returned err= %d\n", __func__, err);
goto err_remove_link;
}
debugf0("%s() calling create-instances, idx=%d\n",
__func__, edac_dev->dev_idx);
/* Create the first level instance directories */
err = edac_device_create_instances(edac_dev);
if (err)
goto err_remove_link;
return 0;
/* Error unwind stack */
@ -723,26 +858,28 @@ int edac_device_create_sysfs(struct edac_device_ctl_info *edac_dev)
/* remove the sym link */
sysfs_remove_link(&edac_dev->kobj, EDAC_DEVICE_SYMLINK);
err_unreg_object:
edac_device_unregister_main_kobj(edac_dev);
err_remove_main_attribs:
edac_device_remove_main_sysfs_attributes(edac_dev);
err_out:
return err;
}
/*
* edac_device_remove_sysfs() destructor
*
* remove a edac_device instance
* given an edac_device struct, tear down the kobject resources
*/
void edac_device_remove_sysfs(struct edac_device_ctl_info *edac_dev)
{
debugf0("%s()\n", __func__);
edac_device_delete_instances(edac_dev);
/* remove any main attributes for this device */
edac_device_remove_main_sysfs_attributes(edac_dev);
/* remove the sym link */
/* remove the device sym link */
sysfs_remove_link(&edac_dev->kobj, EDAC_DEVICE_SYMLINK);
/* unregister the instance's main kobj */
edac_device_unregister_main_kobj(edac_dev);
/* walk the instance/block kobject tree, deconstructing it */
edac_device_delete_instances(edac_dev);
}

View file

@ -37,6 +37,10 @@ extern int edac_mc_get_panic_on_ue(void);
extern int edac_get_poll_msec(void);
extern int edac_mc_get_poll_msec(void);
extern int edac_device_register_sysfs_main_kobj(
struct edac_device_ctl_info *edac_dev);
extern void edac_device_unregister_sysfs_main_kobj(
struct edac_device_ctl_info *edac_dev);
extern int edac_device_create_sysfs(struct edac_device_ctl_info *edac_dev);
extern void edac_device_remove_sysfs(struct edac_device_ctl_info *edac_dev);
extern struct sysdev_class *edac_get_edac_class(void);