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Code Issues Releases Wiki Activity

Pulling rt15958 into HEAD.

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This commit is contained in:
Shane Kerr 2006-04-26 12:03:08 +00:00
parent 47f9dd025a
commit 602784c4ce
1 changed files with 43 additions and 21 deletions
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62
lib/dns/acache.c
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@ -14,7 +14,7 @@
* PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: acache.c,v 1.11 2005/11/30 03:33:48 marka Exp $ */
/* $Id: acache.c,v 1.12 2006/04/26 12:03:08 shane Exp $ */
#include <config.h>
@ -132,6 +132,8 @@ struct acache_cleaner {
unsigned int cleaning_interval; /* The cleaning-interval
from named.conf,
in seconds. */
isc_stdtime_t last_cleanup_time; /* The time when the last
cleanup task completed */
isc_timer_t *cleaning_timer;
isc_event_t *resched_event; /* Sent by cleaner task to
@ -523,6 +525,7 @@ acache_cleaner_init(dns_acache_t *acache, isc_timermgr_t *timermgr,
}
cleaner->cleaning_interval = 0; /* Initially turned off. */
isc_stdtime_get(&cleaner->last_cleanup_time);
result = isc_timer_create(timermgr, isc_timertype_inactive,
NULL, NULL,
acache->task,
@ -636,6 +639,8 @@ end_cleaning(acache_cleaner_t *cleaner, isc_event_t *event) {
}
dns_acache_detachentry(&cleaner->current_entry);
isc_stdtime_get(&cleaner->last_cleanup_time);
UNLOCK(&acache->lock);
dns_acache_setcleaninginterval(cleaner->acache,
@ -647,13 +652,6 @@ end_cleaning(acache_cleaner_t *cleaner, isc_event_t *event) {
cleaner->ncleaned,
(unsigned long)isc_mem_inuse(cleaner->acache->mctx));
if (cleaner->overmem) {
isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE,
DNS_LOGMODULE_ACACHE, ISC_LOG_NOTICE,
"acache is still in overmem state "
"after cleaning");
}
cleaner->ncleaned = 0;
cleaner->state = cleaner_s_idle;
cleaner->resched_event = event;
@ -684,11 +682,8 @@ acache_cleaning_timer_action(isc_task_t *task, isc_event_t *event) {
/* The caller must hold entry lock. */
static inline isc_boolean_t
entry_stale(acache_cleaner_t *cleaner, dns_acacheentry_t *entry,
isc_stdtime_t now)
isc_stdtime32_t now32, unsigned int interval)
{
unsigned int interval = cleaner->cleaning_interval;
isc_stdtime32_t now32;
/*
* If the callback has been canceled, we definitely do not need the
* entry.
@ -696,25 +691,28 @@ entry_stale(acache_cleaner_t *cleaner, dns_acacheentry_t *entry,
if (entry->callback == NULL)
return (ISC_TRUE);
isc_stdtime_convert32(now, &now32);
if (interval > cleaner->cleaning_interval)
interval = cleaner->cleaning_interval;
if (entry->lastused + interval < now32)
return (ISC_TRUE);
/*
* If the acache is in an overmem state, probabilistically decide if
* If the acache is in the overmem state, probabilistically decide if
* the entry should be purged, based on the time passed from its last
* use and the cleaning interval.
*/
if (cleaner->overmem) {
unsigned int passed =
now32 - entry->lastused; /* <= interval */
isc_uint32_t val, r;
isc_uint32_t val;
isc_random_get(&val);
r = val % interval;
if (r < passed)
if (passed > interval / 2)
return (ISC_TRUE);
isc_random_get(&val);
if (passed > interval / 4)
return (ISC_TF(val % 4 == 0));
return (ISC_TF(val % 8 == 0));
}
return (ISC_FALSE);
@ -729,7 +727,9 @@ acache_incremental_cleaning_action(isc_task_t *task, isc_event_t *event) {
dns_acache_t *acache = cleaner->acache;
dns_acacheentry_t *entry, *next = NULL;
int n_entries;
isc_stdtime32_t now32, last32;
isc_stdtime_t now;
unsigned int interval;
INSIST(DNS_ACACHE_VALID(acache));
INSIST(task == acache->task);
@ -746,10 +746,14 @@ acache_incremental_cleaning_action(isc_task_t *task, isc_event_t *event) {
n_entries = cleaner->increment;
isc_stdtime_get(&now);
isc_stdtime_convert32(now, &now32);
LOCK(&acache->lock);
entry = cleaner->current_entry;
isc_stdtime_convert32(cleaner->last_cleanup_time, &last32);
INSIST(now32 > last32);
interval = now32 - last32;
while (n_entries-- > 0) {
isc_boolean_t is_stale = ISC_FALSE;
@ -760,7 +764,7 @@ acache_incremental_cleaning_action(isc_task_t *task, isc_event_t *event) {
ACACHE_LOCK(&entry->lock, isc_rwlocktype_write);
is_stale = entry_stale(cleaner, entry, now);
is_stale = entry_stale(cleaner, entry, now32, interval);
if (is_stale) {
ISC_LIST_UNLINK(acache->entries, entry, link);
unlink_dbentries(acache, entry);
@ -777,6 +781,24 @@ acache_incremental_cleaning_action(isc_task_t *task, isc_event_t *event) {
dns_acache_detachentry(&entry);
if (next == NULL) {
if (cleaner->overmem) {
entry = ISC_LIST_HEAD(acache->entries);
if (entry != NULL) {
/*
* If we are still in the overmem
* state, keep cleaning.
*/
isc_log_write(dns_lctx,
DNS_LOGCATEGORY_DATABASE,
DNS_LOGMODULE_ACACHE,
ISC_LOG_DEBUG(1),
"acache cleaner: "
"still overmem, "
"reset and try again");
continue;
}
}
UNLOCK(&acache->lock);
end_cleaning(cleaner, event);
return;