diff options
Diffstat (limited to 'contrib/bind9/lib/dns/cache.c')
| -rw-r--r-- | contrib/bind9/lib/dns/cache.c | 1154 |
1 files changed, 0 insertions, 1154 deletions
diff --git a/contrib/bind9/lib/dns/cache.c b/contrib/bind9/lib/dns/cache.c deleted file mode 100644 index 011dbf7..0000000 --- a/contrib/bind9/lib/dns/cache.c +++ /dev/null @@ -1,1154 +0,0 @@ -/* - * Copyright (C) 2004-2006 Internet Systems Consortium, Inc. ("ISC") - * Copyright (C) 1999-2003 Internet Software Consortium. - * - * Permission to use, copy, modify, and distribute this software for any - * purpose with or without fee is hereby granted, provided that the above - * copyright notice and this permission notice appear in all copies. - * - * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH - * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY - * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, - * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM - * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE - * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR - * PERFORMANCE OF THIS SOFTWARE. - */ - -/* $Id: cache.c,v 1.57.18.16 2006/08/01 01:06:48 marka Exp $ */ - -/*! \file */ - -#include <config.h> - -#include <isc/mem.h> -#include <isc/task.h> -#include <isc/time.h> -#include <isc/timer.h> -#include <isc/util.h> - -#include <dns/cache.h> -#include <dns/db.h> -#include <dns/dbiterator.h> -#include <dns/events.h> -#include <dns/lib.h> -#include <dns/log.h> -#include <dns/masterdump.h> -#include <dns/rdata.h> -#include <dns/rdataset.h> -#include <dns/rdatasetiter.h> -#include <dns/result.h> - -#define CACHE_MAGIC ISC_MAGIC('$', '$', '$', '$') -#define VALID_CACHE(cache) ISC_MAGIC_VALID(cache, CACHE_MAGIC) - -/*! - * Control incremental cleaning. - * DNS_CACHE_MINSIZE is how many bytes is the floor for dns_cache_setcachesize(). - * See also DNS_CACHE_CLEANERINCREMENT - */ -#define DNS_CACHE_MINSIZE 2097152 /*%< Bytes. 2097152 = 2 MB */ -/*! - * Control incremental cleaning. - * CLEANERINCREMENT is how many nodes are examined in one pass. - * See also DNS_CACHE_MINSIZE - */ -#define DNS_CACHE_CLEANERINCREMENT 1000U /*%< Number of nodes. */ - -/*** - *** Types - ***/ - -/* - * A cache_cleaner_t encapsulsates the state of the periodic - * cache cleaning. - */ - -typedef struct cache_cleaner cache_cleaner_t; - -typedef enum { - cleaner_s_idle, /*%< Waiting for cleaning-interval to expire. */ - cleaner_s_busy, /*%< Currently cleaning. */ - cleaner_s_done /*%< Freed enough memory after being overmem. */ -} cleaner_state_t; - -/* - * Convenience macros for comprehensive assertion checking. - */ -#define CLEANER_IDLE(c) ((c)->state == cleaner_s_idle && \ - (c)->resched_event != NULL) -#define CLEANER_BUSY(c) ((c)->state == cleaner_s_busy && \ - (c)->iterator != NULL && \ - (c)->resched_event == NULL) - -/*% - * Accesses to a cache cleaner object are synchronized through - * task/event serialization, or locked from the cache object. - */ -struct cache_cleaner { - isc_mutex_t lock; - /*%< - * Locks overmem_event, overmem. Note: never allocate memory - * while holding this lock - that could lead to deadlock since - * the lock is take by water() which is called from the memory - * allocator. - */ - - dns_cache_t *cache; - isc_task_t *task; - unsigned int cleaning_interval; /*% The cleaning-interval from - named.conf, in seconds. */ - isc_timer_t *cleaning_timer; - isc_event_t *resched_event; /*% Sent by cleaner task to - itself to reschedule */ - isc_event_t *overmem_event; - - dns_dbiterator_t *iterator; - unsigned int increment; /*% Number of names to - clean in one increment */ - cleaner_state_t state; /*% Idle/Busy. */ - isc_boolean_t overmem; /*% The cache is in an overmem state. */ - isc_boolean_t replaceiterator; -}; - -/*% - * The actual cache object. - */ - -struct dns_cache { - /* Unlocked. */ - unsigned int magic; - isc_mutex_t lock; - isc_mutex_t filelock; - isc_mem_t *mctx; - - /* Locked by 'lock'. */ - int references; - int live_tasks; - dns_rdataclass_t rdclass; - dns_db_t *db; - cache_cleaner_t cleaner; - char *db_type; - int db_argc; - char **db_argv; - - /* Locked by 'filelock'. */ - char * filename; - /* Access to the on-disk cache file is also locked by 'filelock'. */ -}; - -/*** - *** Functions - ***/ - -static isc_result_t -cache_cleaner_init(dns_cache_t *cache, isc_taskmgr_t *taskmgr, - isc_timermgr_t *timermgr, cache_cleaner_t *cleaner); - -static void -cleaning_timer_action(isc_task_t *task, isc_event_t *event); - -static void -incremental_cleaning_action(isc_task_t *task, isc_event_t *event); - -static void -cleaner_shutdown_action(isc_task_t *task, isc_event_t *event); - -static void -overmem_cleaning_action(isc_task_t *task, isc_event_t *event); - -/*% - * Work out how many nodes can be cleaned in the time between two - * requests to the nameserver. Smooth the resulting number and use - * it as a estimate for the number of nodes to be cleaned in the next - * iteration. - */ -static void -adjust_increment(cache_cleaner_t *cleaner, unsigned int remaining, - isc_time_t *start) -{ - isc_time_t end; - isc_uint64_t usecs; - isc_uint64_t new; - unsigned int pps = dns_pps; - unsigned int interval; - unsigned int names; - - /* - * Tune for minumum of 100 packets per second (pps). - */ - if (pps < 100) - pps = 100; - - isc_time_now(&end); - - interval = 1000000 / pps; /* Interval between packets in usecs. */ - if (interval == 0) - interval = 1; - - INSIST(cleaner->increment >= remaining); - names = cleaner->increment - remaining; - usecs = isc_time_microdiff(&end, start); - - isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE, - ISC_LOG_DEBUG(1), "adjust_increment interval=%u " - "names=%u usec=%" ISC_PLATFORM_QUADFORMAT "u", - interval, names, usecs); - - if (usecs == 0) { - /* - * If we cleaned all the nodes in unmeasurable time - * double the number of nodes to be cleaned next time. - */ - if (names == cleaner->increment) { - cleaner->increment *= 2; - if (cleaner->increment > DNS_CACHE_CLEANERINCREMENT) - cleaner->increment = DNS_CACHE_CLEANERINCREMENT; - isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, - DNS_LOGMODULE_CACHE, ISC_LOG_DEBUG(1), - "%p:new cleaner->increment = %u\n", - cleaner, cleaner->increment); - } - return; - } - - new = (names * interval); - new /= (usecs * 2); - if (new == 0) - new = 1; - - /* Smooth */ - new = (new + cleaner->increment * 7) / 8; - - if (new > DNS_CACHE_CLEANERINCREMENT) - new = DNS_CACHE_CLEANERINCREMENT; - - cleaner->increment = (unsigned int)new; - - isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE, - ISC_LOG_DEBUG(1), "%p:new cleaner->increment = %u\n", - cleaner, cleaner->increment); -} - -static inline isc_result_t -cache_create_db(dns_cache_t *cache, dns_db_t **db) { - return (dns_db_create(cache->mctx, cache->db_type, dns_rootname, - dns_dbtype_cache, cache->rdclass, - cache->db_argc, cache->db_argv, db)); -} - -isc_result_t -dns_cache_create(isc_mem_t *mctx, isc_taskmgr_t *taskmgr, - isc_timermgr_t *timermgr, dns_rdataclass_t rdclass, - const char *db_type, unsigned int db_argc, char **db_argv, - dns_cache_t **cachep) -{ - isc_result_t result; - dns_cache_t *cache; - int i; - - REQUIRE(cachep != NULL); - REQUIRE(*cachep == NULL); - REQUIRE(mctx != NULL); - - cache = isc_mem_get(mctx, sizeof(*cache)); - if (cache == NULL) - return (ISC_R_NOMEMORY); - - cache->mctx = NULL; - isc_mem_attach(mctx, &cache->mctx); - - result = isc_mutex_init(&cache->lock); - if (result != ISC_R_SUCCESS) - goto cleanup_mem; - - result = isc_mutex_init(&cache->filelock); - if (result != ISC_R_SUCCESS) - goto cleanup_lock; - - cache->references = 1; - cache->live_tasks = 0; - cache->rdclass = rdclass; - - cache->db_type = isc_mem_strdup(mctx, db_type); - if (cache->db_type == NULL) { - result = ISC_R_NOMEMORY; - goto cleanup_filelock; - } - - cache->db_argc = db_argc; - if (cache->db_argc == 0) - cache->db_argv = NULL; - else { - cache->db_argv = isc_mem_get(mctx, - cache->db_argc * sizeof(char *)); - if (cache->db_argv == NULL) { - result = ISC_R_NOMEMORY; - goto cleanup_dbtype; - } - for (i = 0; i < cache->db_argc; i++) - cache->db_argv[i] = NULL; - for (i = 0; i < cache->db_argc; i++) { - cache->db_argv[i] = isc_mem_strdup(mctx, db_argv[i]); - if (cache->db_argv[i] == NULL) { - result = ISC_R_NOMEMORY; - goto cleanup_dbargv; - } - } - } - - cache->db = NULL; - result = cache_create_db(cache, &cache->db); - if (result != ISC_R_SUCCESS) - goto cleanup_dbargv; - - cache->filename = NULL; - - cache->magic = CACHE_MAGIC; - - result = cache_cleaner_init(cache, taskmgr, timermgr, &cache->cleaner); - if (result != ISC_R_SUCCESS) - goto cleanup_db; - - *cachep = cache; - return (ISC_R_SUCCESS); - - cleanup_db: - dns_db_detach(&cache->db); - cleanup_dbargv: - for (i = 0; i < cache->db_argc; i++) - if (cache->db_argv[i] != NULL) - isc_mem_free(mctx, cache->db_argv[i]); - if (cache->db_argv != NULL) - isc_mem_put(mctx, cache->db_argv, - cache->db_argc * sizeof(char *)); - cleanup_dbtype: - isc_mem_free(mctx, cache->db_type); - cleanup_filelock: - DESTROYLOCK(&cache->filelock); - cleanup_lock: - DESTROYLOCK(&cache->lock); - cleanup_mem: - isc_mem_put(mctx, cache, sizeof(*cache)); - isc_mem_detach(&mctx); - return (result); -} - -static void -cache_free(dns_cache_t *cache) { - isc_mem_t *mctx; - int i; - - REQUIRE(VALID_CACHE(cache)); - REQUIRE(cache->references == 0); - - isc_mem_setwater(cache->mctx, NULL, NULL, 0, 0); - - if (cache->cleaner.task != NULL) - isc_task_detach(&cache->cleaner.task); - - if (cache->cleaner.overmem_event != NULL) - isc_event_free(&cache->cleaner.overmem_event); - - if (cache->cleaner.resched_event != NULL) - isc_event_free(&cache->cleaner.resched_event); - - if (cache->cleaner.iterator != NULL) - dns_dbiterator_destroy(&cache->cleaner.iterator); - - DESTROYLOCK(&cache->cleaner.lock); - - if (cache->filename) { - isc_mem_free(cache->mctx, cache->filename); - cache->filename = NULL; - } - - if (cache->db != NULL) - dns_db_detach(&cache->db); - - if (cache->db_argv != NULL) { - for (i = 0; i < cache->db_argc; i++) - if (cache->db_argv[i] != NULL) - isc_mem_free(cache->mctx, cache->db_argv[i]); - isc_mem_put(cache->mctx, cache->db_argv, - cache->db_argc * sizeof(char *)); - } - - if (cache->db_type != NULL) - isc_mem_free(cache->mctx, cache->db_type); - - DESTROYLOCK(&cache->lock); - DESTROYLOCK(&cache->filelock); - cache->magic = 0; - mctx = cache->mctx; - isc_mem_put(cache->mctx, cache, sizeof(*cache)); - isc_mem_detach(&mctx); -} - - -void -dns_cache_attach(dns_cache_t *cache, dns_cache_t **targetp) { - - REQUIRE(VALID_CACHE(cache)); - REQUIRE(targetp != NULL && *targetp == NULL); - - LOCK(&cache->lock); - cache->references++; - UNLOCK(&cache->lock); - - *targetp = cache; -} - -void -dns_cache_detach(dns_cache_t **cachep) { - dns_cache_t *cache; - isc_boolean_t free_cache = ISC_FALSE; - - REQUIRE(cachep != NULL); - cache = *cachep; - REQUIRE(VALID_CACHE(cache)); - - LOCK(&cache->lock); - REQUIRE(cache->references > 0); - cache->references--; - if (cache->references == 0) { - cache->cleaner.overmem = ISC_FALSE; - free_cache = ISC_TRUE; - } - - *cachep = NULL; - - if (free_cache) { - /* - * When the cache is shut down, dump it to a file if one is - * specified. - */ - isc_result_t result = dns_cache_dump(cache); - if (result != ISC_R_SUCCESS) - isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, - DNS_LOGMODULE_CACHE, ISC_LOG_WARNING, - "error dumping cache: %s ", - isc_result_totext(result)); - - /* - * If the cleaner task exists, let it free the cache. - */ - if (cache->live_tasks > 0) { - isc_task_shutdown(cache->cleaner.task); - free_cache = ISC_FALSE; - } - } - - UNLOCK(&cache->lock); - - if (free_cache) - cache_free(cache); -} - -void -dns_cache_attachdb(dns_cache_t *cache, dns_db_t **dbp) { - REQUIRE(VALID_CACHE(cache)); - REQUIRE(dbp != NULL && *dbp == NULL); - REQUIRE(cache->db != NULL); - - LOCK(&cache->lock); - dns_db_attach(cache->db, dbp); - UNLOCK(&cache->lock); - -} - -isc_result_t -dns_cache_setfilename(dns_cache_t *cache, const char *filename) { - char *newname; - - REQUIRE(VALID_CACHE(cache)); - REQUIRE(filename != NULL); - - newname = isc_mem_strdup(cache->mctx, filename); - if (newname == NULL) - return (ISC_R_NOMEMORY); - - LOCK(&cache->filelock); - if (cache->filename) - isc_mem_free(cache->mctx, cache->filename); - cache->filename = newname; - UNLOCK(&cache->filelock); - - return (ISC_R_SUCCESS); -} - -isc_result_t -dns_cache_load(dns_cache_t *cache) { - isc_result_t result; - - REQUIRE(VALID_CACHE(cache)); - - if (cache->filename == NULL) - return (ISC_R_SUCCESS); - - LOCK(&cache->filelock); - result = dns_db_load(cache->db, cache->filename); - UNLOCK(&cache->filelock); - - return (result); -} - -isc_result_t -dns_cache_dump(dns_cache_t *cache) { - isc_result_t result; - - REQUIRE(VALID_CACHE(cache)); - - if (cache->filename == NULL) - return (ISC_R_SUCCESS); - - LOCK(&cache->filelock); - result = dns_master_dump(cache->mctx, cache->db, NULL, - &dns_master_style_cache, cache->filename); - UNLOCK(&cache->filelock); - - return (result); -} - -void -dns_cache_setcleaninginterval(dns_cache_t *cache, unsigned int t) { - isc_interval_t interval; - isc_result_t result; - - LOCK(&cache->lock); - - /* - * It may be the case that the cache has already shut down. - * If so, it has no timer. - */ - if (cache->cleaner.cleaning_timer == NULL) - goto unlock; - - cache->cleaner.cleaning_interval = t; - - if (t == 0) { - result = isc_timer_reset(cache->cleaner.cleaning_timer, - isc_timertype_inactive, - NULL, NULL, ISC_TRUE); - } else { - isc_interval_set(&interval, cache->cleaner.cleaning_interval, - 0); - result = isc_timer_reset(cache->cleaner.cleaning_timer, - isc_timertype_ticker, - NULL, &interval, ISC_FALSE); - } - if (result != ISC_R_SUCCESS) - isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, - DNS_LOGMODULE_CACHE, ISC_LOG_WARNING, - "could not set cache cleaning interval: %s", - isc_result_totext(result)); - - unlock: - UNLOCK(&cache->lock); -} - -/* - * Initialize the cache cleaner object at *cleaner. - * Space for the object must be allocated by the caller. - */ - -static isc_result_t -cache_cleaner_init(dns_cache_t *cache, isc_taskmgr_t *taskmgr, - isc_timermgr_t *timermgr, cache_cleaner_t *cleaner) -{ - isc_result_t result; - - result = isc_mutex_init(&cleaner->lock); - if (result != ISC_R_SUCCESS) - goto fail; - - cleaner->increment = DNS_CACHE_CLEANERINCREMENT; - cleaner->state = cleaner_s_idle; - cleaner->cache = cache; - cleaner->iterator = NULL; - cleaner->overmem = ISC_FALSE; - cleaner->replaceiterator = ISC_FALSE; - - cleaner->task = NULL; - cleaner->cleaning_timer = NULL; - cleaner->resched_event = NULL; - cleaner->overmem_event = NULL; - - result = dns_db_createiterator(cleaner->cache->db, ISC_FALSE, - &cleaner->iterator); - if (result != ISC_R_SUCCESS) - goto cleanup; - - if (taskmgr != NULL && timermgr != NULL) { - result = isc_task_create(taskmgr, 1, &cleaner->task); - if (result != ISC_R_SUCCESS) { - UNEXPECTED_ERROR(__FILE__, __LINE__, - "isc_task_create() failed: %s", - dns_result_totext(result)); - result = ISC_R_UNEXPECTED; - goto cleanup; - } - cleaner->cache->live_tasks++; - isc_task_setname(cleaner->task, "cachecleaner", cleaner); - - result = isc_task_onshutdown(cleaner->task, - cleaner_shutdown_action, cache); - if (result != ISC_R_SUCCESS) { - UNEXPECTED_ERROR(__FILE__, __LINE__, - "cache cleaner: " - "isc_task_onshutdown() failed: %s", - dns_result_totext(result)); - goto cleanup; - } - - cleaner->cleaning_interval = 0; /* Initially turned off. */ - result = isc_timer_create(timermgr, isc_timertype_inactive, - NULL, NULL, - cleaner->task, - cleaning_timer_action, cleaner, - &cleaner->cleaning_timer); - if (result != ISC_R_SUCCESS) { - UNEXPECTED_ERROR(__FILE__, __LINE__, - "isc_timer_create() failed: %s", - dns_result_totext(result)); - result = ISC_R_UNEXPECTED; - goto cleanup; - } - - cleaner->resched_event = - isc_event_allocate(cache->mctx, cleaner, - DNS_EVENT_CACHECLEAN, - incremental_cleaning_action, - cleaner, sizeof(isc_event_t)); - if (cleaner->resched_event == NULL) { - result = ISC_R_NOMEMORY; - goto cleanup; - } - - cleaner->overmem_event = - isc_event_allocate(cache->mctx, cleaner, - DNS_EVENT_CACHEOVERMEM, - overmem_cleaning_action, - cleaner, sizeof(isc_event_t)); - if (cleaner->overmem_event == NULL) { - result = ISC_R_NOMEMORY; - goto cleanup; - } - } - - return (ISC_R_SUCCESS); - - cleanup: - if (cleaner->overmem_event != NULL) - isc_event_free(&cleaner->overmem_event); - if (cleaner->resched_event != NULL) - isc_event_free(&cleaner->resched_event); - if (cleaner->cleaning_timer != NULL) - isc_timer_detach(&cleaner->cleaning_timer); - if (cleaner->task != NULL) - isc_task_detach(&cleaner->task); - if (cleaner->iterator != NULL) - dns_dbiterator_destroy(&cleaner->iterator); - DESTROYLOCK(&cleaner->lock); - fail: - return (result); -} - -static void -begin_cleaning(cache_cleaner_t *cleaner) { - isc_result_t result = ISC_R_SUCCESS; - - REQUIRE(CLEANER_IDLE(cleaner)); - - /* - * Create an iterator, if it does not already exist, and - * position it at the beginning of the cache. - */ - if (cleaner->iterator == NULL) - result = dns_db_createiterator(cleaner->cache->db, ISC_FALSE, - &cleaner->iterator); - if (result != ISC_R_SUCCESS) - isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, - DNS_LOGMODULE_CACHE, ISC_LOG_WARNING, - "cache cleaner could not create " - "iterator: %s", isc_result_totext(result)); - else { - dns_dbiterator_setcleanmode(cleaner->iterator, ISC_TRUE); - result = dns_dbiterator_first(cleaner->iterator); - } - if (result != ISC_R_SUCCESS) { - /* - * If the result is ISC_R_NOMORE, the database is empty, - * so there is nothing to be cleaned. - */ - if (result != ISC_R_NOMORE && cleaner->iterator != NULL) { - UNEXPECTED_ERROR(__FILE__, __LINE__, - "cache cleaner: " - "dns_dbiterator_first() failed: %s", - dns_result_totext(result)); - dns_dbiterator_destroy(&cleaner->iterator); - } else if (cleaner->iterator != NULL) { - result = dns_dbiterator_pause(cleaner->iterator); - RUNTIME_CHECK(result == ISC_R_SUCCESS); - } - } else { - /* - * Pause the iterator to free its lock. - */ - result = dns_dbiterator_pause(cleaner->iterator); - RUNTIME_CHECK(result == ISC_R_SUCCESS); - - isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, - DNS_LOGMODULE_CACHE, ISC_LOG_DEBUG(1), - "begin cache cleaning, mem inuse %lu", - (unsigned long)isc_mem_inuse(cleaner->cache->mctx)); - cleaner->state = cleaner_s_busy; - isc_task_send(cleaner->task, &cleaner->resched_event); - } - - return; -} - -static void -end_cleaning(cache_cleaner_t *cleaner, isc_event_t *event) { - isc_result_t result; - - REQUIRE(CLEANER_BUSY(cleaner)); - REQUIRE(event != NULL); - - result = dns_dbiterator_pause(cleaner->iterator); - if (result != ISC_R_SUCCESS) - dns_dbiterator_destroy(&cleaner->iterator); - - dns_cache_setcleaninginterval(cleaner->cache, - cleaner->cleaning_interval); - - isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE, - ISC_LOG_DEBUG(1), "end cache cleaning, mem inuse %lu", - (unsigned long)isc_mem_inuse(cleaner->cache->mctx)); - - cleaner->state = cleaner_s_idle; - cleaner->resched_event = event; -} - -/* - * This is run once for every cache-cleaning-interval as defined in named.conf. - */ -static void -cleaning_timer_action(isc_task_t *task, isc_event_t *event) { - cache_cleaner_t *cleaner = event->ev_arg; - - UNUSED(task); - - INSIST(task == cleaner->task); - INSIST(event->ev_type == ISC_TIMEREVENT_TICK); - - isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE, - ISC_LOG_DEBUG(1), "cache cleaning timer fired, " - "cleaner state = %d", cleaner->state); - - if (cleaner->state == cleaner_s_idle) - begin_cleaning(cleaner); - - isc_event_free(&event); -} - -/* - * This is called when the cache either surpasses its upper limit - * or shrinks beyond its lower limit. - */ -static void -overmem_cleaning_action(isc_task_t *task, isc_event_t *event) { - cache_cleaner_t *cleaner = event->ev_arg; - isc_boolean_t want_cleaning = ISC_FALSE; - - UNUSED(task); - - INSIST(task == cleaner->task); - INSIST(event->ev_type == DNS_EVENT_CACHEOVERMEM); - INSIST(cleaner->overmem_event == NULL); - - isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE, - ISC_LOG_DEBUG(1), "overmem_cleaning_action called, " - "overmem = %d, state = %d", cleaner->overmem, - cleaner->state); - - LOCK(&cleaner->lock); - - if (cleaner->overmem) { - if (cleaner->state == cleaner_s_idle) - want_cleaning = ISC_TRUE; - } else { - if (cleaner->state == cleaner_s_busy) - /* - * end_cleaning() can't be called here because - * then both cleaner->overmem_event and - * cleaner->resched_event will point to this - * event. Set the state to done, and then - * when the incremental_cleaning_action() event - * is posted, it will handle the end_cleaning. - */ - cleaner->state = cleaner_s_done; - } - - cleaner->overmem_event = event; - - UNLOCK(&cleaner->lock); - - if (want_cleaning) - begin_cleaning(cleaner); -} - -/* - * Do incremental cleaning. - */ -static void -incremental_cleaning_action(isc_task_t *task, isc_event_t *event) { - cache_cleaner_t *cleaner = event->ev_arg; - isc_result_t result; - unsigned int n_names; - isc_time_t start; - - UNUSED(task); - - INSIST(task == cleaner->task); - INSIST(event->ev_type == DNS_EVENT_CACHECLEAN); - - if (cleaner->state == cleaner_s_done) { - cleaner->state = cleaner_s_busy; - end_cleaning(cleaner, event); - LOCK(&cleaner->cache->lock); - LOCK(&cleaner->lock); - if (cleaner->replaceiterator) { - dns_dbiterator_destroy(&cleaner->iterator); - (void) dns_db_createiterator(cleaner->cache->db, - ISC_FALSE, - &cleaner->iterator); - cleaner->replaceiterator = ISC_FALSE; - } - UNLOCK(&cleaner->lock); - UNLOCK(&cleaner->cache->lock); - return; - } - - INSIST(CLEANER_BUSY(cleaner)); - - n_names = cleaner->increment; - - REQUIRE(DNS_DBITERATOR_VALID(cleaner->iterator)); - - isc_time_now(&start); - while (n_names-- > 0) { - dns_dbnode_t *node = NULL; - - result = dns_dbiterator_current(cleaner->iterator, &node, - NULL); - if (result != ISC_R_SUCCESS) { - UNEXPECTED_ERROR(__FILE__, __LINE__, - "cache cleaner: dns_dbiterator_current() " - "failed: %s", dns_result_totext(result)); - - adjust_increment(cleaner, n_names, &start); - end_cleaning(cleaner, event); - return; - } - - /* - * The node was not needed, but was required by - * dns_dbiterator_current(). Give up its reference. - */ - dns_db_detachnode(cleaner->cache->db, &node); - - /* - * Step to the next node. - */ - result = dns_dbiterator_next(cleaner->iterator); - - if (result != ISC_R_SUCCESS) { - /* - * Either the end was reached (ISC_R_NOMORE) or - * some error was signaled. If the cache is still - * overmem and no error was encountered, - * keep trying to clean it, otherwise stop cleaning. - */ - if (result != ISC_R_NOMORE) - UNEXPECTED_ERROR(__FILE__, __LINE__, - "cache cleaner: " - "dns_dbiterator_next() " - "failed: %s", - dns_result_totext(result)); - else if (cleaner->overmem) { - result = dns_dbiterator_first(cleaner-> - iterator); - if (result == ISC_R_SUCCESS) { - isc_log_write(dns_lctx, - DNS_LOGCATEGORY_DATABASE, - DNS_LOGMODULE_CACHE, - ISC_LOG_DEBUG(1), - "cache cleaner: " - "still overmem, " - "reset and try again"); - continue; - } - } - - adjust_increment(cleaner, n_names, &start); - end_cleaning(cleaner, event); - return; - } - } - - adjust_increment(cleaner, 0U, &start); - - /* - * We have successfully performed a cleaning increment but have - * not gone through the entire cache. Free the iterator locks - * and reschedule another batch. If it fails, just try to continue - * anyway. - */ - result = dns_dbiterator_pause(cleaner->iterator); - RUNTIME_CHECK(result == ISC_R_SUCCESS); - - isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_CACHE, - ISC_LOG_DEBUG(1), "cache cleaner: checked %u nodes, " - "mem inuse %lu, sleeping", cleaner->increment, - (unsigned long)isc_mem_inuse(cleaner->cache->mctx)); - - isc_task_send(task, &event); - INSIST(CLEANER_BUSY(cleaner)); - return; -} - -/* - * Do immediate cleaning. - */ -isc_result_t -dns_cache_clean(dns_cache_t *cache, isc_stdtime_t now) { - isc_result_t result; - dns_dbiterator_t *iterator = NULL; - - REQUIRE(VALID_CACHE(cache)); - - result = dns_db_createiterator(cache->db, ISC_FALSE, &iterator); - if (result != ISC_R_SUCCESS) - return result; - - result = dns_dbiterator_first(iterator); - - while (result == ISC_R_SUCCESS) { - dns_dbnode_t *node = NULL; - result = dns_dbiterator_current(iterator, &node, - (dns_name_t *)NULL); - if (result != ISC_R_SUCCESS) - break; - - /* - * Check TTLs, mark expired rdatasets stale. - */ - result = dns_db_expirenode(cache->db, node, now); - if (result != ISC_R_SUCCESS) { - UNEXPECTED_ERROR(__FILE__, __LINE__, - "cache cleaner: dns_db_expirenode() " - "failed: %s", - dns_result_totext(result)); - /* - * Continue anyway. - */ - } - - /* - * This is where the actual freeing takes place. - */ - dns_db_detachnode(cache->db, &node); - - result = dns_dbiterator_next(iterator); - } - - dns_dbiterator_destroy(&iterator); - - if (result == ISC_R_NOMORE) - result = ISC_R_SUCCESS; - - return (result); -} - -static void -water(void *arg, int mark) { - dns_cache_t *cache = arg; - isc_boolean_t overmem = ISC_TF(mark == ISC_MEM_HIWATER); - - REQUIRE(VALID_CACHE(cache)); - - LOCK(&cache->cleaner.lock); - - dns_db_overmem(cache->db, overmem); - cache->cleaner.overmem = overmem; - - if (cache->cleaner.overmem_event != NULL) - isc_task_send(cache->cleaner.task, - &cache->cleaner.overmem_event); - - UNLOCK(&cache->cleaner.lock); -} - -void -dns_cache_setcachesize(dns_cache_t *cache, isc_uint32_t size) { - isc_uint32_t lowater; - isc_uint32_t hiwater; - - REQUIRE(VALID_CACHE(cache)); - - /* - * Impose a minumum cache size; pathological things happen if there - * is too little room. - */ - if (size != 0 && size < DNS_CACHE_MINSIZE) - size = DNS_CACHE_MINSIZE; - - hiwater = size - (size >> 3); /* Approximately 7/8ths. */ - lowater = size - (size >> 2); /* Approximately 3/4ths. */ - - /* - * If the cache was overmem and cleaning, but now with the new limits - * it is no longer in an overmem condition, then the next - * isc_mem_put for cache memory will do the right thing and trigger - * water(). - */ - - if (size == 0 || hiwater == 0 || lowater == 0) - /* - * Disable cache memory limiting. - */ - isc_mem_setwater(cache->mctx, water, cache, 0, 0); - else - /* - * Establish new cache memory limits (either for the first - * time, or replacing other limits). - */ - isc_mem_setwater(cache->mctx, water, cache, hiwater, lowater); -} - -/* - * The cleaner task is shutting down; do the necessary cleanup. - */ -static void -cleaner_shutdown_action(isc_task_t *task, isc_event_t *event) { - dns_cache_t *cache = event->ev_arg; - isc_boolean_t should_free = ISC_FALSE; - - UNUSED(task); - - INSIST(task == cache->cleaner.task); - INSIST(event->ev_type == ISC_TASKEVENT_SHUTDOWN); - - if (CLEANER_BUSY(&cache->cleaner)) - end_cleaning(&cache->cleaner, event); - else - isc_event_free(&event); - - LOCK(&cache->lock); - - cache->live_tasks--; - INSIST(cache->live_tasks == 0); - - if (cache->references == 0) - should_free = ISC_TRUE; - - /* - * By detaching the timer in the context of its task, - * we are guaranteed that there will be no further timer - * events. - */ - if (cache->cleaner.cleaning_timer != NULL) - isc_timer_detach(&cache->cleaner.cleaning_timer); - - /* Make sure we don't reschedule anymore. */ - (void)isc_task_purge(task, NULL, DNS_EVENT_CACHECLEAN, NULL); - - UNLOCK(&cache->lock); - - if (should_free) - cache_free(cache); -} - -isc_result_t -dns_cache_flush(dns_cache_t *cache) { - dns_db_t *db = NULL; - isc_result_t result; - - result = cache_create_db(cache, &db); - if (result != ISC_R_SUCCESS) - return (result); - - LOCK(&cache->lock); - LOCK(&cache->cleaner.lock); - if (cache->cleaner.state == cleaner_s_idle) { - if (cache->cleaner.iterator != NULL) - dns_dbiterator_destroy(&cache->cleaner.iterator); - (void) dns_db_createiterator(db, ISC_FALSE, - &cache->cleaner.iterator); - } else { - if (cache->cleaner.state == cleaner_s_busy) - cache->cleaner.state = cleaner_s_done; - cache->cleaner.replaceiterator = ISC_TRUE; - } - dns_db_detach(&cache->db); - cache->db = db; - UNLOCK(&cache->cleaner.lock); - UNLOCK(&cache->lock); - - return (ISC_R_SUCCESS); -} - -isc_result_t -dns_cache_flushname(dns_cache_t *cache, dns_name_t *name) { - isc_result_t result; - dns_rdatasetiter_t *iter = NULL; - dns_dbnode_t *node = NULL; - dns_db_t *db = NULL; - - LOCK(&cache->lock); - if (cache->db != NULL) - dns_db_attach(cache->db, &db); - UNLOCK(&cache->lock); - if (db == NULL) - return (ISC_R_SUCCESS); - result = dns_db_findnode(cache->db, name, ISC_FALSE, &node); - if (result == ISC_R_NOTFOUND) { - result = ISC_R_SUCCESS; - goto cleanup_db; - } - if (result != ISC_R_SUCCESS) - goto cleanup_db; - - result = dns_db_allrdatasets(cache->db, node, NULL, - (isc_stdtime_t)0, &iter); - if (result != ISC_R_SUCCESS) - goto cleanup_node; - - for (result = dns_rdatasetiter_first(iter); - result == ISC_R_SUCCESS; - result = dns_rdatasetiter_next(iter)) - { - dns_rdataset_t rdataset; - dns_rdataset_init(&rdataset); - - dns_rdatasetiter_current(iter, &rdataset); - result = dns_db_deleterdataset(cache->db, node, NULL, - rdataset.type, rdataset.covers); - dns_rdataset_disassociate(&rdataset); - if (result != ISC_R_SUCCESS && result != DNS_R_UNCHANGED) - break; - } - if (result == ISC_R_NOMORE) - result = ISC_R_SUCCESS; - - dns_rdatasetiter_destroy(&iter); - - cleanup_node: - dns_db_detachnode(cache->db, &node); - - cleanup_db: - dns_db_detach(&db); - return (result); -} |
