+
+/* Used by hdb_dn2idl when loading the EntryInfo for all the children
+ * of a given node
+ */
+int hdb_cache_load(
+ struct bdb_info *bdb,
+ EntryInfo *ei,
+ EntryInfo **res )
+{
+ EntryInfo *ei2;
+ int rc;
+
+ /* See if we already have this one */
+ bdb_cache_entryinfo_lock( ei->bei_parent );
+ ei2 = (EntryInfo *)avl_find( ei->bei_parent->bei_kids, ei, bdb_rdn_cmp );
+ bdb_cache_entryinfo_unlock( ei->bei_parent );
+
+ if ( !ei2 ) {
+ /* Not found, add it */
+ struct berval bv;
+
+ /* bei_rdn was not malloc'd before, do it now */
+ ber_dupbv( &bv, &ei->bei_rdn );
+ ei->bei_rdn = bv;
+
+ rc = bdb_entryinfo_add_internal( bdb, ei, res );
+ bdb_cache_entryinfo_unlock( ei->bei_parent );
+ ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
+ } else {
+ /* Found, return it */
+ *res = ei2;
+ return 0;
+ }
+ return rc;
+}
+#endif
+
+/* This is best-effort only. If all entries in the cache are
+ * busy, they will all be kept. This is unlikely to happen
+ * unless the cache is very much smaller than the working set.
+ */
+static void
+bdb_cache_lru_purge( struct bdb_info *bdb )
+{
+ DB_LOCK lock, *lockp;
+ EntryInfo *elru, *elnext = NULL;
+ int islocked;
+ ID eicount, ecount;
+ ID count, efree, eifree = 0;
+#ifdef LDAP_DEBUG
+ int iter;
+#endif
+
+ /* Wait for the mutex; we're the only one trying to purge. */
+ ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_lru_mutex );
+
+ if ( bdb->bi_cache.c_cursize > bdb->bi_cache.c_maxsize ) {
+ efree = bdb->bi_cache.c_cursize - bdb->bi_cache.c_maxsize;
+ efree += bdb->bi_cache.c_minfree;
+ } else {
+ efree = 0;
+ }
+
+ /* maximum number of EntryInfo leaves to cache. In slapcat
+ * we always free all leaf nodes.
+ */
+
+ if ( slapMode & SLAP_TOOL_READONLY ) {
+ eifree = bdb->bi_cache.c_leaves;
+ } else if ( bdb->bi_cache.c_eimax &&
+ bdb->bi_cache.c_leaves > bdb->bi_cache.c_eimax ) {
+ eifree = bdb->bi_cache.c_minfree * 10;
+ if ( eifree >= bdb->bi_cache.c_leaves )
+ eifree /= 2;
+ }
+
+ if ( !efree && !eifree ) {
+ ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_lru_mutex );
+ bdb->bi_cache.c_purging = 0;
+ return;
+ }
+
+ if ( bdb->bi_cache.c_txn ) {
+ lockp = &lock;
+ } else {
+ lockp = NULL;
+ }
+
+ count = 0;
+ eicount = 0;
+ ecount = 0;
+#ifdef LDAP_DEBUG
+ iter = 0;
+#endif
+
+ /* Look for an unused entry to remove */
+ for ( elru = bdb->bi_cache.c_lruhead; elru; elru = elnext ) {
+ elnext = elru->bei_lrunext;
+
+ if ( bdb_cache_entryinfo_trylock( elru ))
+ goto bottom;
+
+ /* This flag implements the clock replacement behavior */
+ if ( elru->bei_state & ( CACHE_ENTRY_REFERENCED )) {
+ elru->bei_state &= ~CACHE_ENTRY_REFERENCED;
+ bdb_cache_entryinfo_unlock( elru );
+ goto bottom;
+ }
+
+ /* If this node is in the process of linking into the cache,
+ * or this node is being deleted, skip it.
+ */
+ if (( elru->bei_state & ( CACHE_ENTRY_NOT_LINKED |
+ CACHE_ENTRY_DELETED | CACHE_ENTRY_LOADING |
+ CACHE_ENTRY_ONELEVEL )) ||
+ elru->bei_finders > 0 ) {
+ bdb_cache_entryinfo_unlock( elru );
+ goto bottom;
+ }
+
+ if ( bdb_cache_entryinfo_trylock( elru->bei_parent )) {
+ bdb_cache_entryinfo_unlock( elru );
+ goto bottom;
+ }
+
+ /* entryinfo is locked */
+ islocked = 1;
+
+ /* If we can successfully writelock it, then
+ * the object is idle.
+ */
+ if ( bdb_cache_entry_db_lock( bdb,
+ bdb->bi_cache.c_txn, elru, 1, 1, lockp ) == 0 ) {
+
+ /* Free entry for this node if it's present */
+ if ( elru->bei_e ) {
+ ecount++;
+
+ /* the cache may have gone over the limit while we
+ * weren't looking, so double check.
+ */
+ if ( !efree && ecount > bdb->bi_cache.c_maxsize )
+ efree = bdb->bi_cache.c_minfree;
+
+ if ( count < efree ) {
+ elru->bei_e->e_private = NULL;
+#ifdef SLAP_ZONE_ALLOC
+ bdb_entry_return( bdb, elru->bei_e, elru->bei_zseq );
+#else
+ bdb_entry_return( elru->bei_e );