From: Kurt Zeilenga <kurt@openldap.org>
Date: Wed, 10 Feb 1999 20:36:53 +0000 (+0000)
Subject: Port cache add vs update bug fix from devel without new
X-Git-Tag: OPENLDAP_REL_ENG_1_2_0~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=eccd72e5d6cb0c1deeda009c199ed02c92c9ed54;p=thirdparty%2Fopenldap.git

Port cache add vs update bug fix from devel without new
cache managed entry locking.  The cache managed entry locking
should be imported as soon as possible.
---

diff --git a/build/version b/build/version
index 86658ea30a..a473fbbb52 100644
--- a/build/version
+++ b/build/version
@@ -1 +1 @@
-1.2.0-Engineering
+1.2.0-Release
diff --git a/servers/slapd/back-ldbm/add.c b/servers/slapd/back-ldbm/add.c
index 052b23c6a9..cdda78edb0 100644
--- a/servers/slapd/back-ldbm/add.c
+++ b/servers/slapd/back-ldbm/add.c
@@ -149,7 +149,7 @@ ldbm_back_add(
 	 * This should only fail if the entry already exists.
 	 */
 
-	if ( cache_add_entry_lock( &li->li_cache, e, ENTRY_STATE_CREATING ) != 0 ) {
+	if ( cache_add_entry( &li->li_cache, e, ENTRY_STATE_CREATING ) != 0 ) {
 		if( p != NULL) {
 			/* free parent and writer lock */
 			cache_return_entry_w( &li->li_cache, p ); 
diff --git a/servers/slapd/back-ldbm/cache.c b/servers/slapd/back-ldbm/cache.c
index 46d8c655b6..8cfdeeaac0 100644
--- a/servers/slapd/back-ldbm/cache.c
+++ b/servers/slapd/back-ldbm/cache.c
@@ -59,22 +59,6 @@ cache_set_state( struct cache *cache, Entry *e, int state )
 	ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
 }
 
-#ifdef not_used
-static void
-cache_return_entry( struct cache *cache, 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 );
-	}
-
-	/* free cache mutex */
-	ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
-}
-#endif
-
 static void
 cache_return_entry_rw( struct cache *cache, Entry *e, int rw )
 {
@@ -133,13 +117,13 @@ cache_return_entry_w( struct cache *cache, Entry *e )
 }
 
 /*
- * cache_create_entry_lock - create an entry in the cache, and lock it.
+ * cache_create_entry - create an entry in the cache, and lock it.
  * returns:	0	entry has been created and locked
  *		1	entry already existed
  *		-1	something bad happened
  */
 int
-cache_add_entry_lock(
+cache_add_entry(
     struct cache	*cache,
     Entry		*e,
     int			state
@@ -230,6 +214,102 @@ cache_add_entry_lock(
 	return( 0 );
 }
 
+/*
+ * cache_update_entry - update an entry in the cache
+ * returns:	0	entry has been created and locked
+ *		1	entry already existed
+ *		-1	something bad happened
+ */
+int
+cache_update_entry(
+    struct cache	*cache,
+    Entry		*e
+)
+{
+	int	i, rc;
+	Entry	*ee;
+
+	/* set cache mutex */
+	ldap_pvt_thread_mutex_lock( &cache->c_mutex );
+
+	if ( avl_insert( &cache->c_dntree, (caddr_t) e,
+		cache_entrydn_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 );
+
+		/* free cache mutex */
+		ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+		return( 1 );
+	}
+
+	/* id tree */
+	if ( avl_insert( &cache->c_idtree, (caddr_t) e,
+		cache_entryid_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 );
+
+		/* delete from dn tree inserted above */
+		if ( avl_delete( &cache->c_dntree, (caddr_t) e,
+			cache_entrydn_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 );
+	}
+
+	e->e_state = 0;
+
+	/* 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 && cache->c_lrutail->e_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 && cache->c_lrutail->e_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 );
+
+			entry_free( e );
+		}
+	}
+
+	/* free cache mutex */
+	ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+	return( 0 );
+}
+
 /*
  * cache_find_entry_dn2id - find an entry in the cache, given dn
  */
diff --git a/servers/slapd/back-ldbm/id2entry.c b/servers/slapd/back-ldbm/id2entry.c
index ae5e18868e..115dc0a2fe 100644
--- a/servers/slapd/back-ldbm/id2entry.c
+++ b/servers/slapd/back-ldbm/id2entry.c
@@ -45,7 +45,6 @@ id2entry_add( Backend *be, Entry *e )
 	ldap_pvt_thread_mutex_unlock( &entry2str_mutex );
 
 	ldbm_cache_close( be, db );
-	(void) cache_add_entry_lock( &li->li_cache, e, 0 );
 
 	Debug( LDAP_DEBUG_TRACE, "<= id2entry_add %d\n", rc, 0, 0 );
 
@@ -153,7 +152,7 @@ id2entry( Backend *be, ID id, int rw )
 	}
 
 	e->e_id = id;
-	(void) cache_add_entry_lock( &li->li_cache, e, 0 );
+	(void) cache_add_entry( &li->li_cache, e, 0 );
 
 	Debug( LDAP_DEBUG_TRACE, "<= id2entry_%s( %ld ) (disk)\n",
 		rw ? "w" : "r", id, 0 );
diff --git a/servers/slapd/back-ldbm/modrdn.c b/servers/slapd/back-ldbm/modrdn.c
index cf2e9751aa..4bff9e72cf 100644
--- a/servers/slapd/back-ldbm/modrdn.c
+++ b/servers/slapd/back-ldbm/modrdn.c
@@ -145,6 +145,7 @@ ldbm_back_modrdn(
 	free( e->e_ndn );
 	e->e_dn = new_dn;
 	e->e_ndn = new_ndn;
+	(void) cache_update_entry( &li->li_cache, e );
 
 	/* XXX
 	 * At some point here we need to update the attribute values in
diff --git a/servers/slapd/back-ldbm/proto-back-ldbm.h b/servers/slapd/back-ldbm/proto-back-ldbm.h
index 2f6d4a11a4..603325d27d 100644
--- a/servers/slapd/back-ldbm/proto-back-ldbm.h
+++ b/servers/slapd/back-ldbm/proto-back-ldbm.h
@@ -35,7 +35,8 @@ void attr_index_config LDAP_P(( struct ldbminfo *li, char *fname, int lineno,
 void cache_set_state LDAP_P(( struct cache *cache, Entry *e, int state ));
 void cache_return_entry_r LDAP_P(( struct cache *cache, Entry *e ));
 void cache_return_entry_w LDAP_P(( struct cache *cache, Entry *e ));
-int cache_add_entry_lock LDAP_P(( struct cache *cache, Entry *e, int state ));
+int cache_add_entry LDAP_P(( struct cache *cache, Entry *e, int state ));
+int cache_update_entry LDAP_P(( struct cache *cache, Entry *e ));
 ID cache_find_entry_dn2id LDAP_P(( Backend *be, struct cache *cache, char *dn ));
 Entry * cache_find_entry_id LDAP_P(( struct cache *cache, ID id, int rw ));
 int cache_delete_entry LDAP_P(( struct cache *cache, Entry *e ));