/* cache.c - routines to maintain an in-core cache of entries */
+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 1998-2005 The OpenLDAP Foundation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ */
#include "portable.h"
/* LDBM backend specific entry info -- visible only to the cache */
typedef struct ldbm_entry_info {
- ldap_pvt_thread_rdwr_t lei_rdwr; /* reader/writer lock */
-
/*
- * remaining fields require backend cache lock to access
* These items are specific to the LDBM backend and should
- * be hidden.
+ * be hidden. Backend cache lock required to access.
*/
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
-
+#define CACHE_ENTRY_READY 2
+#define CACHE_ENTRY_DELETED 3
+#define CACHE_ENTRY_COMMITTED 4
+
int lei_refcnt; /* # threads ref'ing this entry */
Entry *lei_lrunext; /* for cache lru list */
Entry *lei_lruprev;
} EntryInfo;
+#undef LEI
#define LEI(e) ((EntryInfo *) ((e)->e_private))
static int cache_delete_entry_internal(Cache *cache, Entry *e);
static void lru_print(Cache *cache);
#endif
-static int
-cache_entry_rdwr_lock(Entry *e, int rw)
-{
- Debug( LDAP_DEBUG_ARGS, "entry_rdwr_%slock: ID: %ld\n",
- rw ? "w" : "r", e->e_id, 0);
-
- if (rw)
- return ldap_pvt_thread_rdwr_wlock(&LEI(e)->lei_rdwr);
- else
- return ldap_pvt_thread_rdwr_rlock(&LEI(e)->lei_rdwr);
-}
-
-static int
-cache_entry_rdwr_trylock(Entry *e, int rw)
-{
- Debug( LDAP_DEBUG_ARGS, "entry_rdwr_%strylock: ID: %ld\n",
- rw ? "w" : "r", e->e_id, 0);
-
- if (rw)
- return ldap_pvt_thread_rdwr_wtrylock(&LEI(e)->lei_rdwr);
- else
- return ldap_pvt_thread_rdwr_rtrylock(&LEI(e)->lei_rdwr);
-}
-
-static int
-cache_entry_rdwr_unlock(Entry *e, int rw)
-{
- Debug( LDAP_DEBUG_ARGS, "entry_rdwr_%sunlock: ID: %ld\n",
- rw ? "w" : "r", e->e_id, 0);
-
- if (rw)
- return ldap_pvt_thread_rdwr_wunlock(&LEI(e)->lei_rdwr);
- else
- return ldap_pvt_thread_rdwr_runlock(&LEI(e)->lei_rdwr);
-}
-
-static int
-cache_entry_rdwr_init(Entry *e)
-{
- return ldap_pvt_thread_rdwr_init( &LEI(e)->lei_rdwr );
-}
-
-static int
-cache_entry_rdwr_destroy(Entry *e)
-{
- return ldap_pvt_thread_rdwr_destroy( &LEI(e)->lei_rdwr );
-}
-
static int
cache_entry_private_init( Entry*e )
{
e->e_private = ch_calloc(1, sizeof(struct ldbm_entry_info));
- if( cache_entry_rdwr_init( e ) != 0 ) {
- free( LEI(e) );
- e->e_private = NULL;
- return 1;
- }
-
return 0;
}
+/*
+ * marks an entry in CREATING state as committed, so it is really returned
+ * to the cache. Otherwise an entry in CREATING state is removed.
+ * Makes e_private be destroyed at the following cache_return_entry_w,
+ * but lets the entry untouched (owned by someone else)
+ */
+void
+cache_entry_commit( Entry *e )
+{
+ assert( e );
+ assert( e->e_private );
+ assert( LEI(e)->lei_state == CACHE_ENTRY_CREATING );
+ /* assert( LEI(e)->lei_refcnt == 1 ); */
+
+ LEI(e)->lei_state = CACHE_ENTRY_COMMITTED;
+}
+
static int
cache_entry_private_destroy( Entry*e )
{
assert( e->e_private );
- cache_entry_rdwr_destroy( e );
-
free( e->e_private );
e->e_private = NULL;
return 0;
cache_return_entry_rw( Cache *cache, Entry *e, int rw )
{
ID id;
- int refcnt;
+ int refcnt, freeit = 1;
+
+ if ( slapMode != SLAP_SERVER_MODE ) {
+ return;
+ }
/* set cache mutex */
ldap_pvt_thread_mutex_lock( &cache->c_mutex );
assert( e->e_private );
- cache_entry_rdwr_unlock(e, rw);
-
id = e->e_id;
refcnt = --LEI(e)->lei_refcnt;
- if ( LEI(e)->lei_state == CACHE_ENTRY_CREATING ) {
+ /*
+ * if the entry is returned when in CREATING state, it is deleted
+ * but not freed because it may belong to someone else (do_add,
+ * for instance)
+ */
+ if ( LEI(e)->lei_state == CACHE_ENTRY_CREATING ) {
+ cache_delete_entry_internal( cache, e );
+ freeit = 0;
+ /* now the entry is in DELETED state */
+ }
+
+ if ( LEI(e)->lei_state == CACHE_ENTRY_COMMITTED ) {
LEI(e)->lei_state = CACHE_ENTRY_READY;
/* free cache mutex */
} else {
cache_entry_private_destroy( e );
- entry_free( e );
+ if ( freeit ) {
+ entry_free( e );
+ }
/* free cache mutex */
ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
}
if ( avl_insert( &cache->c_dntree, (caddr_t) e,
- (AVL_CMP) entry_dn_cmp, avl_dup_error ) != 0 )
+ entry_dn_cmp, avl_dup_error ) != 0 )
{
/* free cache mutex */
ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
/* id tree */
if ( avl_insert( &cache->c_idtree, (caddr_t) e,
- (AVL_CMP) entry_id_cmp, avl_dup_error ) != 0 )
+ entry_id_cmp, avl_dup_error ) != 0 )
{
Debug( LDAP_DEBUG_ANY,
"====> 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,
- (AVL_CMP) entry_dn_cmp ) == NULL )
+ entry_dn_cmp ) == NULL )
{
Debug( LDAP_DEBUG_ANY, "====> can't delete from dn cache\n",
0, 0, 0 );
return( -1 );
}
- cache_entry_rdwr_lock( e, rw );
-
/* put the entry into 'CREATING' state */
/* will be marked after when entry is returned */
LEI(e)->lei_state = CACHE_ENTRY_CREATING;
assert( e->e_private );
if ( avl_insert( &cache->c_dntree, (caddr_t) e,
- (AVL_CMP) entry_dn_cmp, avl_dup_error ) != 0 )
+ entry_dn_cmp, avl_dup_error ) != 0 )
{
Debug( LDAP_DEBUG_TRACE,
"====> cache_update_entry( %ld ): \"%s\": already in dn cache\n",
/* id tree */
if ( avl_insert( &cache->c_idtree, (caddr_t) e,
- (AVL_CMP) entry_id_cmp, avl_dup_error ) != 0 )
+ entry_id_cmp, avl_dup_error ) != 0 )
{
Debug( LDAP_DEBUG_ANY,
"====> cache_update_entry( %ld ): \"%s\": already in id cache\n",
/* delete from dn tree inserted above */
if ( avl_delete( &cache->c_dntree, (caddr_t) e,
- (AVL_CMP) entry_dn_cmp ) == NULL )
+ entry_dn_cmp ) == NULL )
{
Debug( LDAP_DEBUG_ANY, "====> can't delete from dn cache\n",
0, 0, 0 );
return( -1 );
}
-
/* put the entry into 'CREATING' state */
/* will be marked after when entry is returned */
LEI(e)->lei_state = CACHE_ENTRY_CREATING;
return( 0 );
}
-/*
- * cache_find_entry_dn2id - find an entry in the cache, given dn
- */
-
ID
-cache_find_entry_dn2id(
+cache_find_entry_ndn2id(
Backend *be,
Cache *cache,
- char *dn
+ struct berval *ndn
)
{
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 );
+ /* this function is always called with normalized DN */
+ e.e_nname = *ndn;
try_again:
/* set cache mutex */
ldap_pvt_thread_mutex_lock( &cache->c_mutex );
if ( (ep = (Entry *) avl_find( cache->c_dntree, (caddr_t) &e,
- (AVL_CMP) entry_dn_cmp )) != NULL )
+ entry_dn_cmp )) != NULL )
{
int state;
count++;
* we do not need to lock the entry if we only
* check the state, refcnt, LRU, and id.
*/
-
assert( ep->e_private );
/* save id */
ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
Debug(LDAP_DEBUG_TRACE,
- "====> cache_find_entry_dn2id(\"%s\"): %ld (not ready) %d\n",
- dn, id, state);
+ "====> cache_find_entry_ndn2id(\"%s\"): %ld (not ready) %d\n",
+ ndn->bv_val, id, state);
ldap_pvt_thread_yield();
goto try_again;
/* lru */
LRU_DELETE( cache, ep );
LRU_ADD( cache, ep );
-
+
/* free cache mutex */
ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
Debug(LDAP_DEBUG_TRACE,
- "====> cache_find_entry_dn2id(\"%s\"): %ld (%d tries)\n",
- dn, id, count);
+ "====> cache_find_entry_ndn2id(\"%s\"): %ld (%d tries)\n",
+ ndn->bv_val, id, count);
} else {
/* free cache mutex */
ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
-
id = NOID;
}
- free(e.e_ndn);
-
return( id );
}
ldap_pvt_thread_mutex_lock( &cache->c_mutex );
if ( (ep = (Entry *) avl_find( cache->c_idtree, (caddr_t) &e,
- (AVL_CMP) entry_id_cmp )) != NULL )
+ entry_id_cmp )) != NULL )
{
int state;
ID ep_id;
* entry is deleted or not fully created yet
*/
if ( state != CACHE_ENTRY_READY ) {
-
assert(state != CACHE_ENTRY_UNDEFINED);
/* free cache mutex */
goto try_again;
}
- /* acquire reader lock */
- if ( cache_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.
- */
-
- /* free cache mutex */
- ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
-
- Debug(LDAP_DEBUG_TRACE,
- "====> cache_find_entry_id( %ld ): %ld (busy) %d\n",
- id, ep_id, state);
-
- ldap_pvt_thread_yield();
- goto try_again;
- }
-
/* lru */
LRU_DELETE( cache, ep );
LRU_ADD( cache, ep );
-
+
LEI(ep)->lei_refcnt++;
/* free cache mutex */
Entry *e
)
{
- int rc = 0; /* return code */
+ int rc = 0; /* return code */
/* dn tree */
- if ( avl_delete( &cache->c_dntree, (caddr_t) e, (AVL_CMP) entry_dn_cmp )
- == NULL )
+ if ( avl_delete( &cache->c_dntree, (caddr_t) e, entry_dn_cmp ) == NULL )
{
rc = -1;
}
/* id tree */
- if ( avl_delete( &cache->c_idtree, (caddr_t) e, (AVL_CMP) entry_id_cmp )
- == NULL )
+ if ( avl_delete( &cache->c_idtree, (caddr_t) e, entry_id_cmp ) == NULL )
{
rc = -1;
}
return( 0 );
}
-#ifdef SLAP_CLEANUP
-
void
cache_release_all( Cache *cache )
{
Debug( LDAP_DEBUG_TRACE, "====> cache_release_all\n", 0, 0, 0 );
- while ( (e = cache->c_lrutail) != NULL && LEI(e)->lei_refcnt == 0 ) {
- assert(!ldap_pvt_thread_rdwr_active(&LEI(e)->lei_rdwr));
+ while ( (e = cache->c_lrutail) != NULL && LEI(e)->lei_refcnt == 0 ) {
/* delete from cache and lru q */
/* XXX do we need rc ? */
rc = cache_delete_entry_internal( cache, e );
ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
}
-#endif /* SLAP_CLEANUP */
-
#ifdef LDAP_DEBUG
-
static void
lru_print( Cache *cache )
{
e->e_dn, e->e_id, LEI(e)->lei_refcnt );
}
}
-
#endif
-
projects / openldap / blobdiff