[Fedora-directory-commits] ldapserver/ldap/servers/plugins/dna dna.c, 1.6, 1.7
Nathan Kinder (nkinder)
fedora-directory-commits at redhat.com
Thu Jul 31 16:22:27 UTC 2008
Author: nkinder
Update of /cvs/dirsec/ldapserver/ldap/servers/plugins/dna
In directory cvs-int.fedora.redhat.com:/tmp/cvs-serv20120
Modified Files:
dna.c
Log Message:
Resolves: 457329
Summary: Make better use of cached DNA config information
Index: dna.c
===================================================================
RCS file: /cvs/dirsec/ldapserver/ldap/servers/plugins/dna/dna.c,v
retrieving revision 1.6
retrieving revision 1.7
diff -u -r1.6 -r1.7
--- dna.c 30 Jul 2008 18:17:26 -0000 1.6
+++ dna.c 31 Jul 2008 16:22:25 -0000 1.7
@@ -695,7 +695,7 @@
Distributed ranges Helpers
****************************************************/
-static int dna_fix_maxval(Slapi_DN *dn, PRUint64 *cur, PRUint64 *max)
+static int dna_fix_maxval(struct configEntry *config_entry, PRUint64 *cur)
{
/* TODO: check the main partition to see if another range
* is available, and set the new local configuration
@@ -707,8 +707,13 @@
return LDAP_OPERATIONS_ERROR;
}
-static void dna_notice_allocation(Slapi_DN *dn, PRUint64 new)
+static void dna_notice_allocation(struct configEntry *config_entry, PRUint64 new)
{
+ /* update our cached config entry with the newly allocated
+ * value.
+ */
+ config_entry->nextval = new;
+
/* TODO: check if we passed a new chunk threshold and update
* the shared configuration on the public partition.
*/
@@ -794,13 +799,11 @@
than config and startup
****************************************************/
-/* we do search all values between newval and maxval asking the
+/* we do search all values between nextval and maxval asking the
* server to sort them, then we check the first free spot and
* use it as newval */
static int dna_first_free_value(struct configEntry *config_entry,
- PRUint64 *newval,
- PRUint64 maxval,
- PRUint64 increment)
+ PRUint64 *newval)
{
Slapi_Entry **entries = NULL;
Slapi_PBlock *pb = NULL;
@@ -816,7 +819,7 @@
prefix = config_entry->prefix;
type = config_entry->type;
- tmpval = *newval;
+ tmpval = config_entry->nextval;
attrs[0] = type;
attrs[1] = NULL;
@@ -834,7 +837,7 @@
filter = slapi_ch_smprintf("(&%s(&(%s>=%s%llu)(%s<=%s%llu)))",
config_entry->filter,
type, prefix?prefix:"", tmpval,
- type, prefix?prefix:"", maxval);
+ type, prefix?prefix:"", config_entry->maxval);
if (NULL == filter) {
ldap_control_free(ctrls[0]);
slapi_ch_free((void **)&ctrls);
@@ -870,6 +873,7 @@
if (NULL == entries || NULL == entries[0]) {
/* no values means we already have a good value */
+ *newval = tmpval;
status = LDAP_SUCCESS;
goto cleanup;
}
@@ -904,10 +908,10 @@
if (tmpval != sval)
break;
- if (maxval < sval)
+ if (config_entry->maxval < sval)
break;
- tmpval += increment;
+ tmpval += config_entry->interval;
}
*newval = tmpval;
@@ -924,201 +928,107 @@
/*
* Perform ldap operationally atomic increment
* Return the next value to be assigned
- * Method:
- * 1. retrieve entry
- * 2. do increment operations
- * 3. remove current value, add new value in one operation
- * 4. if failed, and less than 3 times, goto 1
*/
static int dna_get_next_value(struct configEntry *config_entry,
char **next_value_ret)
{
Slapi_PBlock *pb = NULL;
- char *old_value = NULL;
- Slapi_Entry *e = NULL;
- Slapi_DN *dn = NULL;
- char *attrlist[4];
- int attempts;
+ LDAPMod mod_replace;
+ LDAPMod *mods[2];
+ char *replace_val[2];
+ char next_value[16];
+ PRUint64 setval = 0;
+ PRUint64 nextval = 0;
int ret;
slapi_log_error(SLAPI_LOG_TRACE, DNA_PLUGIN_SUBSYSTEM,
"--> dna_get_next_value\n");
- /* get pre-requisites to search */
- dn = slapi_sdn_new_dn_byref(config_entry->dn);
- attrlist[0] = DNA_NEXTVAL;
- attrlist[1] = DNA_MAXVAL;
- attrlist[2] = DNA_INTERVAL;
- attrlist[3] = NULL;
-
-
- /* the operation is constructed such that race conditions
- * to increment the value are detected and avoided - one wins,
- * one loses - however, there is no need for the server to compete
- * with itself so we lock here
- */
-
+ /* get the lock to prevent contention with other threads over
+ * the next new value for this range. */
slapi_lock_mutex(config_entry->new_value_lock);
- for (attempts = 0; attempts < 3; attempts++) {
+ /* get the first value */
+ ret = dna_first_free_value(config_entry, &setval);
+ if (LDAP_SUCCESS != ret)
+ goto done;
- LDAPMod mod_add;
- LDAPMod mod_delete;
- LDAPMod *mods[3];
- char *delete_val[2];
- char *add_val[2];
- char new_value[16];
- char *interval;
- char *max_value;
- PRUint64 increment = 1; /* default increment */
- PRUint64 setval = 0;
- PRUint64 newval = 0;
- PRUint64 maxval = -1;
-
- /* do update */
- ret = slapi_search_internal_get_entry(dn, attrlist, &e,
- getPluginID());
+ /* try for a new range or fail */
+ if (setval > config_entry->maxval) {
+ ret = dna_fix_maxval(config_entry, &setval);
if (LDAP_SUCCESS != ret) {
- ret = LDAP_OPERATIONS_ERROR;
- goto done;
- }
-
- old_value = slapi_entry_attr_get_charptr(e, DNA_NEXTVAL);
- if (NULL == old_value) {
- ret = LDAP_OPERATIONS_ERROR;
+ slapi_log_error(SLAPI_LOG_FATAL, DNA_PLUGIN_SUBSYSTEM,
+ "dna_get_next_value: no more IDs available!!\n");
goto done;
}
- setval = strtoul(old_value, 0, 0);
-
- max_value = slapi_entry_attr_get_charptr(e, DNA_MAXVAL);
- if (max_value) {
- maxval = strtoul(max_value, 0, 0);
- slapi_ch_free_string(&max_value);
- }
-
- /* if not present the default is 1 */
- interval = slapi_entry_attr_get_charptr(e, DNA_INTERVAL);
- if (NULL != interval) {
- increment = strtoul(interval, 0, 0);
- }
-
- slapi_entry_free(e);
- e = NULL;
-
- /* check the value is actually in range */
-
- /* verify the new value is actually free and get the first
- * one free if not*/
- ret = dna_first_free_value(config_entry, &setval, maxval, increment);
+ /* get the first value from our newly extended range */
+ ret = dna_first_free_value(config_entry, &setval);
if (LDAP_SUCCESS != ret)
goto done;
+ }
- /* try for a new range or fail */
- if (setval > maxval) {
- ret = dna_fix_maxval(dn, &setval, &maxval);
- if (LDAP_SUCCESS != ret) {
- slapi_log_error(SLAPI_LOG_FATAL, DNA_PLUGIN_SUBSYSTEM,
- "dna_get_next_value: no more IDs available!!\n");
- goto done;
- }
+ /* ensure that we haven't gone past the end of our range */
+ if (setval > config_entry->maxval) {
+ ret = LDAP_OPERATIONS_ERROR;
+ goto done;
+ }
- /* verify the new value is actually free and get the first
- * one free if not */
- ret = dna_first_free_value(config_entry, &setval, maxval, increment);
- if (LDAP_SUCCESS != ret)
- goto done;
- }
+ nextval = setval + config_entry->interval;
- if (setval > maxval) {
- ret = LDAP_OPERATIONS_ERROR;
+ /* try for a new range or fail */
+ if (nextval > config_entry->maxval) {
+ ret = dna_fix_maxval(config_entry, &nextval);
+ if (LDAP_SUCCESS != ret) {
+ slapi_log_error(SLAPI_LOG_FATAL, DNA_PLUGIN_SUBSYSTEM,
+ "dna_get_next_value: no more IDs available!!\n");
goto done;
}
+ }
- newval = setval + increment;
-
- /* try for a new range or fail */
- if (newval > maxval) {
- ret = dna_fix_maxval(dn, &newval, &maxval);
- if (LDAP_SUCCESS != ret) {
- slapi_log_error(SLAPI_LOG_FATAL, DNA_PLUGIN_SUBSYSTEM,
- "dna_get_next_value: no more IDs available!!\n");
- goto done;
- }
- }
-
- /* try to set the new value */
+ /* try to set the new next value in the config entry */
+ snprintf(next_value, sizeof(next_value),"%llu", nextval);
- sprintf(new_value, "%llu", newval);
+ /* set up our replace modify operation */
+ replace_val[0] = next_value;
+ replace_val[1] = 0;
+ mod_replace.mod_op = LDAP_MOD_REPLACE;
+ mod_replace.mod_type = DNA_NEXTVAL;
+ mod_replace.mod_values = replace_val;
+ mods[0] = &mod_replace;
+ mods[1] = 0;
- delete_val[0] = old_value;
- delete_val[1] = 0;
+ pb = slapi_pblock_new();
+ if (NULL == pb) {
+ ret = LDAP_OPERATIONS_ERROR;
+ goto done;
+ }
- mod_delete.mod_op = LDAP_MOD_DELETE;
- mod_delete.mod_type = DNA_NEXTVAL;
- mod_delete.mod_values = delete_val;
+ slapi_modify_internal_set_pb(pb, config_entry->dn,
+ mods, 0, 0, getPluginID(), 0);
- add_val[0] = new_value;
- add_val[1] = 0;
+ slapi_modify_internal_pb(pb);
- mod_add.mod_op = LDAP_MOD_ADD;
- mod_add.mod_type = DNA_NEXTVAL;
- mod_add.mod_values = add_val;
+ slapi_pblock_get(pb, SLAPI_PLUGIN_INTOP_RESULT, &ret);
- mods[0] = &mod_delete;
- mods[1] = &mod_add;
- mods[2] = 0;
+ slapi_pblock_destroy(pb);
+ pb = NULL;
- pb = slapi_pblock_new();
- if (NULL == pb) {
+ if (LDAP_SUCCESS == ret) {
+ *next_value_ret = slapi_ch_smprintf("%llu", setval);
+ if (NULL == *next_value_ret) {
ret = LDAP_OPERATIONS_ERROR;
goto done;
}
- slapi_modify_internal_set_pb(pb, config_entry->dn,
- mods, 0, 0, getPluginID(), 0);
-
- slapi_modify_internal_pb(pb);
-
- slapi_pblock_get(pb, SLAPI_PLUGIN_INTOP_RESULT, &ret);
-
- slapi_pblock_destroy(pb);
- pb = NULL;
- slapi_ch_free_string(&interval);
- slapi_ch_free_string(&old_value);
-
- if (LDAP_SUCCESS == ret) {
- *next_value_ret = slapi_ch_smprintf("%llu", setval);
- if (NULL == *next_value_ret) {
- ret = LDAP_OPERATIONS_ERROR;
- goto done;
- }
-
- dna_notice_allocation(dn, newval);
- goto done;
- }
-
- if (LDAP_NO_SUCH_ATTRIBUTE != ret) {
- /* not the result of a race
- to change the value
- */
- goto done;
- }
+ /* update our cached config */
+ dna_notice_allocation(config_entry, nextval);
}
done:
slapi_unlock_mutex(config_entry->new_value_lock);
- if (LDAP_SUCCESS != ret)
- slapi_ch_free_string(&old_value);
-
- if (dn)
- slapi_sdn_free(&dn);
-
- if (e)
- slapi_entry_free(e);
-
if (pb)
slapi_pblock_destroy(pb);
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