#include "back-bdb2.h"
+/* LDBM backend specific entry info -- visible only to the cache */
+struct ldbm_entry_info {
+ /*
+ * These items are specific to the LDBM backend and should
+ * be hidden.
+ */
+ int lei_state; /* for the cache */
+#define CACHE_ENTRY_UNDEFINED 0
+#define CACHE_ENTRY_CREATING 1
+#define CACHE_ENTRY_READY 2
+#define CACHE_ENTRY_DELETED 3
+
+ int lei_refcnt; /* # threads ref'ing this entry */
+ Entry *lei_lrunext; /* for cache lru list */
+ Entry *lei_lruprev;
+};
+#define LEI(e) ((struct ldbm_entry_info *) ((e)->e_private))
+
static int cache_delete_entry_internal(struct cache *cache, Entry *e);
#ifdef LDAP_DEBUG
static void lru_print(struct cache *cache);
#endif
-void
-bdb2i_cache_set_state( struct cache *cache, Entry *e, int state )
+static int
+cache_entry_private_init( Entry*e )
{
- /* set cache mutex */
- ldap_pvt_thread_mutex_lock( &cache->c_mutex );
+ assert( e->e_private == NULL );
- e->e_state = state;
+ if( e->e_private != NULL ) {
+ /* this should never happen */
+ return 1;
+ }
- /* free cache mutex */
- ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+ e->e_private = ch_calloc(1, sizeof(struct ldbm_entry_info));
+
+ return 0;
}
-#ifdef not_used
-static void
-cache_return_entry( struct cache *cache, Entry *e )
+static int
+cache_entry_private_destroy( Entry*e )
{
- /* set cache mutex */
- ldap_pvt_thread_mutex_lock( &cache->c_mutex );
-
- if ( --e->e_refcnt == 0 && e->e_state == ENTRY_STATE_DELETED ) {
- entry_free( e );
- }
+ assert( e->e_private );
- /* free cache mutex */
- ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+ free( e->e_private );
+ e->e_private = NULL;
+ return 0;
}
-#endif
-static void
-cache_return_entry_rw( struct cache *cache, Entry *e, int rw )
+void
+bdb2i_cache_return_entry_rw( struct cache *cache, Entry *e, int rw )
{
- Debug( LDAP_DEBUG_TRACE, "====> cache_return_entry_%s\n",
- rw ? "w" : "r", 0, 0);
-
/* set cache mutex */
ldap_pvt_thread_mutex_lock( &cache->c_mutex );
- entry_rdwr_unlock(e, rw);
+ assert( e->e_private );
+
+ LEI(e)->lei_refcnt--;
+
+ if ( LEI(e)->lei_state == CACHE_ENTRY_CREATING ) {
+ Debug( LDAP_DEBUG_TRACE,
+ "====> bdb2i_cache_return_entry_%s( %ld ): created (%d)\n",
+ rw ? "w" : "r", e->e_id, LEI(e)->lei_refcnt );
+
+ LEI(e)->lei_state = CACHE_ENTRY_READY;
+
+ } else if ( LEI(e)->lei_state == CACHE_ENTRY_DELETED ) {
+ if( LEI(e)->lei_refcnt > 0 ) {
+ Debug( LDAP_DEBUG_TRACE,
+ "====> bdb2i_cache_return_entry_%s( %ld ): delete pending (%d)\n",
+ rw ? "w" : "r", e->e_id, LEI(e)->lei_refcnt );
- if ( --e->e_refcnt == 0 && e->e_state == ENTRY_STATE_DELETED ) {
- entry_free( e );
+ } else {
+ Debug( LDAP_DEBUG_TRACE,
+ "====> bdb2i_cache_return_entry_%s( %ld ): deleted (%d)\n",
+ rw ? "w" : "r", e->e_id, LEI(e)->lei_refcnt );
+
+ cache_entry_private_destroy( e );
+ entry_free( e );
+ }
+
+ } else {
+ Debug( LDAP_DEBUG_TRACE,
+ "====> bdb2i_cache_return_entry_%s( %ld ): returned (%d)\n",
+ rw ? "w" : "r", e->e_id, LEI(e)->lei_refcnt);
}
/* free cache mutex */
ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
}
-void
-bdb2i_cache_return_entry_r( struct cache *cache, Entry *e )
-{
- cache_return_entry_rw(cache, e, 0);
-}
-
-void
-bdb2i_cache_return_entry_w( struct cache *cache, Entry *e )
-{
- cache_return_entry_rw(cache, e, 1);
-}
-
-
#define LRU_DELETE( cache, e ) { \
- if ( e->e_lruprev != NULL ) { \
- e->e_lruprev->e_lrunext = e->e_lrunext; \
+ if ( LEI(e)->lei_lruprev != NULL ) { \
+ LEI(LEI(e)->lei_lruprev)->lei_lrunext = LEI(e)->lei_lrunext; \
} else { \
- cache->c_lruhead = e->e_lrunext; \
+ (cache)->c_lruhead = LEI(e)->lei_lrunext; \
} \
- if ( e->e_lrunext != NULL ) { \
- e->e_lrunext->e_lruprev = e->e_lruprev; \
+ if ( LEI(e)->lei_lrunext != NULL ) { \
+ LEI(LEI(e)->lei_lrunext)->lei_lruprev = LEI(e)->lei_lruprev; \
} else { \
- cache->c_lrutail = e->e_lruprev; \
+ (cache)->c_lrutail = LEI(e)->lei_lruprev; \
} \
}
#define LRU_ADD( cache, e ) { \
- e->e_lrunext = cache->c_lruhead; \
- if ( e->e_lrunext != NULL ) { \
- e->e_lrunext->e_lruprev = e; \
+ LEI(e)->lei_lrunext = (cache)->c_lruhead; \
+ if ( LEI(e)->lei_lrunext != NULL ) { \
+ LEI(LEI(e)->lei_lrunext)->lei_lruprev = (e); \
} \
- cache->c_lruhead = e; \
- e->e_lruprev = NULL; \
- if ( cache->c_lrutail == NULL ) { \
- cache->c_lrutail = e; \
+ (cache)->c_lruhead = (e); \
+ LEI(e)->lei_lruprev = NULL; \
+ if ( (cache)->c_lrutail == NULL ) { \
+ (cache)->c_lrutail = (e); \
} \
}
/*
- * cache_create_entry_lock - create an entry in the cache, and lock it.
+ * bdb2i_cache_add_entry_rw - create and lock an entry in the cache
* returns: 0 entry has been created and locked
* 1 entry already existed
* -1 something bad happened
*/
int
-bdb2i_cache_add_entry_lock(
+bdb2i_cache_add_entry_rw(
struct cache *cache,
Entry *e,
- int state
+ int rw
)
{
- int i, rc;
+ int i;
Entry *ee;
/* set cache mutex */
ldap_pvt_thread_mutex_lock( &cache->c_mutex );
+ assert( e->e_private == NULL );
+
+ if( cache_entry_private_init(e) != 0 ) {
+ /* free cache mutex */
+ ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+
+ Debug( LDAP_DEBUG_ANY,
+ "====> bdb2i_cache_add_entry( %ld ): \"%s\": private init failed!\n",
+ e->e_id, e->e_dn, 0 );
+
+ return( -1 );
+ }
+
if ( avl_insert( &cache->c_dntree, (caddr_t) e,
- entry_dn_cmp, avl_dup_error ) != 0 )
+ (AVL_CMP) entry_dn_cmp, avl_dup_error ) != 0 )
{
Debug( LDAP_DEBUG_TRACE,
- "====> cache_add_entry lock: entry %20s id %lu already in dn cache\n",
- e->e_dn, e->e_id, 0 );
+ "====> bdb2i_cache_add_entry( %ld ): \"%s\": already in dn cache\n",
+ e->e_id, e->e_dn, 0 );
+
+ cache_entry_private_destroy(e);
/* free cache mutex */
ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
/* id tree */
if ( avl_insert( &cache->c_idtree, (caddr_t) e,
- entry_id_cmp, avl_dup_error ) != 0 )
+ (AVL_CMP) entry_id_cmp, avl_dup_error ) != 0 )
{
Debug( LDAP_DEBUG_ANY,
- "====> entry %20s id %lu already in id cache\n",
- e->e_dn, e->e_id, 0 );
+ "====> bdb2i_cache_add_entry( %ld ): \"%s\": already in id cache\n",
+ e->e_id, e->e_dn, 0 );
/* delete from dn tree inserted above */
if ( avl_delete( &cache->c_dntree, (caddr_t) e,
- entry_dn_cmp ) == NULL )
+ (AVL_CMP) entry_dn_cmp ) == NULL )
{
Debug( LDAP_DEBUG_ANY, "====> can't delete from dn cache\n",
0, 0, 0 );
}
+ cache_entry_private_destroy(e);
+
/* free cache mutex */
ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
return( -1 );
}
- e->e_state = state;
- e->e_refcnt = 1;
+ /* put the entry into 'CREATING' state */
+ /* will be marked after when entry is returned */
+ LEI(e)->lei_state = CACHE_ENTRY_CREATING;
+ LEI(e)->lei_refcnt = 1;
/* lru */
LRU_ADD( cache, e );
* first 10 on the tail of the list.
*/
i = 0;
- while ( cache->c_lrutail != NULL && cache->c_lrutail->e_refcnt
- != 0 && i < 10 ) {
+ while ( cache->c_lrutail != NULL &&
+ LEI(cache->c_lrutail)->lei_refcnt != 0 &&
+ i < 10 )
+ {
/* move this in-use entry to the front of the q */
ee = cache->c_lrutail;
LRU_DELETE( cache, ee );
* found at least one to delete - try to get back under
* the max cache size.
*/
- while ( cache->c_lrutail != NULL && cache->c_lrutail->e_refcnt
- == 0 && cache->c_cursize > cache->c_maxsize ) {
+ while ( cache->c_lrutail != NULL &&
+ LEI(cache->c_lrutail)->lei_refcnt == 0 &&
+ cache->c_cursize > cache->c_maxsize )
+ {
e = cache->c_lrutail;
- /* check for active readers/writer lock */
-#ifdef LDAP_DEBUG
- assert(!ldap_pvt_thread_rdwr_active( &e->e_rdwr ));
-#endif
-
/* delete from cache and lru q */
- rc = cache_delete_entry_internal( cache, e );
+ cache_delete_entry_internal( cache, e );
+ cache_entry_private_destroy( e );
+ entry_free( e );
+ }
+ }
+
+ /* free cache mutex */
+ ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+ return( 0 );
+}
+/*
+ * cache_update_entry - update a LOCKED entry which has been deleted.
+ * returns: 0 entry has been created and locked
+ * 1 entry already existed
+ * -1 something bad happened
+ */
+int
+bdb2i_cache_update_entry(
+ struct cache *cache,
+ Entry *e
+)
+{
+ int i;
+ Entry *ee;
+
+ /* set cache mutex */
+ ldap_pvt_thread_mutex_lock( &cache->c_mutex );
+
+ assert( e->e_private );
+
+ if ( avl_insert( &cache->c_dntree, (caddr_t) e,
+ (AVL_CMP) entry_dn_cmp, avl_dup_error ) != 0 )
+ {
+ Debug( LDAP_DEBUG_TRACE,
+ "====> bdb2i_cache_add_entry( %ld ): \"%s\": already in dn cache\n",
+ e->e_id, e->e_dn, 0 );
+
+ /* free cache mutex */
+ ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+ return( 1 );
+ }
+
+ /* id tree */
+ if ( avl_insert( &cache->c_idtree, (caddr_t) e,
+ (AVL_CMP) entry_id_cmp, avl_dup_error ) != 0 )
+ {
+ Debug( LDAP_DEBUG_ANY,
+ "====> bdb2i_cache_update_entry( %ld ): \"%s\": already in id cache\n",
+ e->e_id, e->e_dn, 0 );
+
+ /* delete from dn tree inserted above */
+ if ( avl_delete( &cache->c_dntree, (caddr_t) e,
+ (AVL_CMP) entry_dn_cmp ) == NULL )
+ {
+ Debug( LDAP_DEBUG_ANY, "====> can't delete from dn cache\n",
+ 0, 0, 0 );
+ }
+
+ /* free cache mutex */
+ ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+ return( -1 );
+ }
+
+ /* put the entry into 'CREATING' state */
+ /* will be marked after when entry is returned */
+ LEI(e)->lei_state = CACHE_ENTRY_CREATING;
+
+ /* lru */
+ LRU_ADD( cache, e );
+ if ( ++cache->c_cursize > cache->c_maxsize ) {
+ /*
+ * find the lru entry not currently in use and delete it.
+ * in case a lot of entries are in use, only look at the
+ * first 10 on the tail of the list.
+ */
+ i = 0;
+ while ( cache->c_lrutail != NULL &&
+ LEI(cache->c_lrutail)->lei_refcnt != 0 &&
+ i < 10 )
+ {
+ /* move this in-use entry to the front of the q */
+ ee = cache->c_lrutail;
+ LRU_DELETE( cache, ee );
+ LRU_ADD( cache, ee );
+ i++;
+ }
+
+ /*
+ * found at least one to delete - try to get back under
+ * the max cache size.
+ */
+ while ( cache->c_lrutail != NULL &&
+ LEI(cache->c_lrutail)->lei_refcnt == 0 &&
+ cache->c_cursize > cache->c_maxsize )
+ {
+ e = cache->c_lrutail;
+
+ /* delete from cache and lru q */
+ cache_delete_entry_internal( cache, e );
+ cache_entry_private_destroy( e );
entry_free( e );
}
}
}
/*
- * cache_find_entry_dn2id - find an entry in the cache, given dn
+ * bdb2i_cache_find_entry_dn2id - find an entry in the cache, given dn
*/
ID
char *dn
)
{
- struct ldbminfo *li = (struct ldbminfo *) be->be_private;
Entry e, *ep;
ID id;
+ int count = 0;
+
+ e.e_dn = dn;
+ e.e_ndn = ch_strdup( dn );
+ (void) dn_normalize_case( e.e_ndn );
+try_again:
/* set cache mutex */
ldap_pvt_thread_mutex_lock( &cache->c_mutex );
- e.e_dn = dn;
- e.e_ndn = dn_normalize_case( ch_strdup( dn ) );
-
if ( (ep = (Entry *) avl_find( cache->c_dntree, (caddr_t) &e,
- entry_dn_cmp )) != NULL )
+ (AVL_CMP) entry_dn_cmp )) != NULL )
{
+ int state;
+ count++;
+
/*
* ep now points to an unlocked entry
* we do not need to lock the entry if we only
* check the state, refcnt, LRU, and id.
*/
- free(e.e_ndn);
- Debug(LDAP_DEBUG_TRACE, "====> cache_find_entry_dn2id: found dn: %s\n",
- dn, 0, 0);
+ assert( ep->e_private );
+
+ /* save id */
+ id = ep->e_id;
+ state = LEI(ep)->lei_state;
/*
* entry is deleted or not fully created yet
*/
- if ( ep->e_state == ENTRY_STATE_DELETED ||
- ep->e_state == ENTRY_STATE_CREATING )
- {
+ if ( state != CACHE_ENTRY_READY ) {
+ assert(state != CACHE_ENTRY_UNDEFINED);
+
/* free cache mutex */
ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
- return( NOID );
+
+ Debug(LDAP_DEBUG_TRACE,
+ "====> bdb2i_cache_find_entry_dn2id(\"%s\"): %ld (not ready) %d\n",
+ dn, id, state);
+
+ ldap_pvt_thread_yield();
+ goto try_again;
}
/* lru */
LRU_DELETE( cache, ep );
LRU_ADD( cache, ep );
- /* save id */
- id = ep->e_id;
+ /* free cache mutex */
+ ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+
+ Debug(LDAP_DEBUG_TRACE,
+ "====> bdb2i_cache_find_entry_dn2id(\"%s\"): %ld (%d tries)\n",
+ dn, id, count);
+ } else {
/* free cache mutex */
ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
- return( id );
+ id = NOID;
}
free(e.e_ndn);
- /* free cache mutex */
- ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
-
- return( NOID );
+ return( id );
}
/*
{
Entry e;
Entry *ep;
+ int count=0;
e.e_id = id;
ldap_pvt_thread_mutex_lock( &cache->c_mutex );
if ( (ep = (Entry *) avl_find( cache->c_idtree, (caddr_t) &e,
- entry_id_cmp )) != NULL )
+ (AVL_CMP) entry_id_cmp )) != NULL )
{
- Debug(LDAP_DEBUG_TRACE,
- "====> cache_find_entry_dn2id: found id: %ld rw: %d\n",
- id, rw, 0);
+ int state;
+
+ assert( ep->e_private );
+
+ state = LEI(ep)->lei_state;
/*
* entry is deleted or not fully created yet
*/
- if ( ep->e_state == ENTRY_STATE_DELETED ||
- ep->e_state == ENTRY_STATE_CREATING )
- {
- /* free cache mutex */
- ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
- return( NULL );
- }
+ if ( state != CACHE_ENTRY_READY ) {
+ ID ep_id = ep->e_id;
- /* acquire reader lock */
- if ( entry_rdwr_trylock(ep, rw) == LDAP_PVT_THREAD_EBUSY ) {
- /* could not acquire entry lock...
- * owner cannot free as we have the cache locked.
- * so, unlock the cache, yield, and try again.
- */
+ assert(state != CACHE_ENTRY_UNDEFINED);
/* free cache mutex */
ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+
+ Debug(LDAP_DEBUG_TRACE,
+ "====> bdb2i_cache_find_entry_id( %ld ): %ld (not ready) %d\n",
+ id, ep_id, state);
+
ldap_pvt_thread_yield();
goto try_again;
}
LRU_DELETE( cache, ep );
LRU_ADD( cache, ep );
- ep->e_refcnt++;
+ LEI(ep)->lei_refcnt++;
/* free cache mutex */
ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+ Debug(LDAP_DEBUG_TRACE,
+ "====> bdb2i_cache_find_entry_id( %ld ) \"%s\" (found) (%d tries)\n",
+ id, ep->e_dn, count);
+
return( ep );
}
{
int rc;
- Debug( LDAP_DEBUG_TRACE, "====> cache_delete_entry:\n", 0, 0, 0 );
-
/* set cache mutex */
ldap_pvt_thread_mutex_lock( &cache->c_mutex );
- /* XXX check for writer lock - should also check no readers pending */
-#ifdef LDAP_DEBUG
- assert(ldap_pvt_thread_rdwr_writers( &e->e_rdwr ) == 1);
-#endif
+ assert( e->e_private );
+
+ Debug( LDAP_DEBUG_TRACE, "====> bdb2i_cache_delete_entry( %ld )\n",
+ e->e_id, 0, 0 );
rc = cache_delete_entry_internal( cache, e );
int rc = 0; /* return code */
/* dn tree */
- if ( avl_delete( &cache->c_dntree, (caddr_t) e, entry_dn_cmp )
+ if ( avl_delete( &cache->c_dntree, (caddr_t) e, (AVL_CMP) entry_dn_cmp )
== NULL )
{
rc = -1;
}
/* id tree */
- if ( avl_delete( &cache->c_idtree, (caddr_t) e, entry_id_cmp )
+ if ( avl_delete( &cache->c_idtree, (caddr_t) e, (AVL_CMP) entry_id_cmp )
== NULL )
{
rc = -1;
/*
* flag entry to be freed later by a call to cache_return_entry()
*/
- e->e_state = ENTRY_STATE_DELETED;
+ LEI(e)->lei_state = CACHE_ENTRY_DELETED;
return( 0 );
}
Entry *e;
fprintf( stderr, "LRU queue (head to tail):\n" );
- for ( e = cache->c_lruhead; e != NULL; e = e->e_lrunext ) {
- fprintf( stderr, "\tdn %20s id %lu refcnt %d\n", e->e_dn,
- e->e_id, e->e_refcnt );
+ for ( e = cache->c_lruhead; e != NULL; e = LEI(e)->lei_lrunext ) {
+ fprintf( stderr, "\tdn \"%20s\" id %ld refcnt %d\n",
+ e->e_dn, e->e_id, LEI(e)->lei_refcnt );
}
fprintf( stderr, "LRU queue (tail to head):\n" );
- for ( e = cache->c_lrutail; e != NULL; e = e->e_lruprev ) {
- fprintf( stderr, "\tdn %20s id %lu refcnt %d\n", e->e_dn,
- e->e_id, e->e_refcnt );
+ for ( e = cache->c_lrutail; e != NULL; e = LEI(e)->lei_lruprev ) {
+ fprintf( stderr, "\tdn \"%20s\" id %ld refcnt %d\n",
+ e->e_dn, e->e_id, LEI(e)->lei_refcnt );
}
}
projects / openldap / blobdiff