]> git.sur5r.net Git - openldap/blobdiff - servers/slapd/back-bdb/idl.c
don't dereference NULL pointers
[openldap] / servers / slapd / back-bdb / idl.c
index 9e55ef3ca3b44a6f6a595e5d070f51e82f4bc6f0..ff85ecee5cdbe683e8bf819ea54f4011bc23717a 100644 (file)
@@ -2,7 +2,7 @@
 /* $OpenLDAP$ */
 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
  *
- * Copyright 2000-2006 The OpenLDAP Foundation.
+ * Copyright 2000-2008 The OpenLDAP Foundation.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
 
 #define IDL_CMP(x,y)   ( x < y ? -1 : ( x > y ? 1 : 0 ) )
 
-#define IDL_LRU_DELETE( bdb, e ) do {                                  \
-       if ( e->idl_lru_prev != NULL ) {                                \
-               e->idl_lru_prev->idl_lru_next = e->idl_lru_next;        \
-       } else {                                                        \
-               bdb->bi_idl_lru_head = e->idl_lru_next;                 \
-       }                                                               \
-       if ( e->idl_lru_next != NULL ) {                                \
-               e->idl_lru_next->idl_lru_prev = e->idl_lru_prev;        \
-       } else {                                                        \
-               bdb->bi_idl_lru_tail = e->idl_lru_prev;                 \
-       }                                                               \
-} while ( 0 )
-
-#define IDL_LRU_ADD( bdb, e ) do {                                     \
-       e->idl_lru_next = bdb->bi_idl_lru_head;                         \
-       if ( e->idl_lru_next != NULL ) {                                \
-               e->idl_lru_next->idl_lru_prev = (e);                    \
-       }                                                               \
-       (bdb)->bi_idl_lru_head = (e);                                   \
-       e->idl_lru_prev = NULL;                                         \
-       if ( (bdb)->bi_idl_lru_tail == NULL ) {                         \
-               (bdb)->bi_idl_lru_tail = (e);                           \
-       }                                                               \
+#define IDL_LRU_DELETE( bdb, e ) do { \
+       if ( (e) == (bdb)->bi_idl_lru_head ) { \
+               if ( (e)->idl_lru_next == (bdb)->bi_idl_lru_head ) { \
+                       (bdb)->bi_idl_lru_head = NULL; \
+               } else { \
+                       (bdb)->bi_idl_lru_head = (e)->idl_lru_next; \
+               } \
+       } \
+       if ( (e) == (bdb)->bi_idl_lru_tail ) { \
+               if ( (e)->idl_lru_prev == (bdb)->bi_idl_lru_tail ) { \
+                       assert( (bdb)->bi_idl_lru_head == NULL ); \
+                       (bdb)->bi_idl_lru_tail = NULL; \
+               } else { \
+                       (bdb)->bi_idl_lru_tail = (e)->idl_lru_prev; \
+               } \
+       } \
+       (e)->idl_lru_next->idl_lru_prev = (e)->idl_lru_prev; \
+       (e)->idl_lru_prev->idl_lru_next = (e)->idl_lru_next; \
 } while ( 0 )
 
 static int
@@ -317,10 +312,7 @@ bdb_idl_cache_get(
        if ( matched_idl_entry != NULL ) {
                if ( matched_idl_entry->idl && ids )
                        BDB_IDL_CPY( ids, matched_idl_entry->idl );
-               ldap_pvt_thread_mutex_lock( &bdb->bi_idl_tree_lrulock );
-               IDL_LRU_DELETE( bdb, matched_idl_entry );
-               IDL_LRU_ADD( bdb, matched_idl_entry );
-               ldap_pvt_thread_mutex_unlock( &bdb->bi_idl_tree_lrulock );
+               matched_idl_entry->idl_flags |= CACHE_ENTRY_REFERENCED;
                if ( matched_idl_entry->idl )
                        rc = LDAP_SUCCESS;
                else
@@ -340,7 +332,7 @@ bdb_idl_cache_put(
        int                     rc )
 {
        bdb_idl_cache_entry_t idl_tmp;
-       bdb_idl_cache_entry_t *ee;
+       bdb_idl_cache_entry_t *ee, *eprev;
 
        if ( rc == DB_NOTFOUND || BDB_IDL_IS_ZERO( ids ))
                return;
@@ -355,6 +347,7 @@ bdb_idl_cache_put(
 
        ee->idl_lru_prev = NULL;
        ee->idl_lru_next = NULL;
+       ee->idl_flags = 0;
        ber_dupbv( &ee->kstr, &idl_tmp.kstr );
        ldap_pvt_thread_rdwr_wlock( &bdb->bi_idl_tree_rwlock );
        if ( avl_insert( &bdb->bi_idl_tree, (caddr_t) ee,
@@ -367,11 +360,34 @@ bdb_idl_cache_put(
                return;
        }
        ldap_pvt_thread_mutex_lock( &bdb->bi_idl_tree_lrulock );
-       IDL_LRU_ADD( bdb, ee );
+       /* LRU_ADD */
+       if ( bdb->bi_idl_lru_head ) {
+               assert( bdb->bi_idl_lru_tail != NULL );
+               assert( bdb->bi_idl_lru_head->idl_lru_prev != NULL );
+               assert( bdb->bi_idl_lru_head->idl_lru_next != NULL );
+
+               ee->idl_lru_next = bdb->bi_idl_lru_head;
+               ee->idl_lru_prev = bdb->bi_idl_lru_head->idl_lru_prev;
+               bdb->bi_idl_lru_head->idl_lru_prev->idl_lru_next = ee;
+               bdb->bi_idl_lru_head->idl_lru_prev = ee;
+       } else {
+               ee->idl_lru_next = ee->idl_lru_prev = ee;
+               bdb->bi_idl_lru_tail = ee;
+       }
+       bdb->bi_idl_lru_head = ee;
+
        if ( ++bdb->bi_idl_cache_size > bdb->bi_idl_cache_max_size ) {
-               int i = 0;
-               while ( bdb->bi_idl_lru_tail != NULL && i < 10 ) {
-                       ee = bdb->bi_idl_lru_tail;
+               int i;
+               ee = bdb->bi_idl_lru_tail;
+               for ( i = 0; ee != NULL && i < 10; i++, ee = eprev ) {
+                       eprev = ee->idl_lru_prev;
+                       if ( eprev == ee ) {
+                               eprev = NULL;
+                       }
+                       if ( ee->idl_flags & CACHE_ENTRY_REFERENCED ) {
+                               ee->idl_flags ^= CACHE_ENTRY_REFERENCED;
+                               continue;
+                       }
                        if ( avl_delete( &bdb->bi_idl_tree, (caddr_t) ee,
                                    bdb_idl_entry_cmp ) == NULL ) {
                                Debug( LDAP_DEBUG_ANY, "=> bdb_idl_cache_put: "
@@ -385,8 +401,10 @@ bdb_idl_cache_put(
                        ch_free( ee->idl );
                        ch_free( ee );
                }
+               bdb->bi_idl_lru_tail = eprev;
+               assert( bdb->bi_idl_lru_tail != NULL
+                       || bdb->bi_idl_lru_head == NULL );
        }
-
        ldap_pvt_thread_mutex_unlock( &bdb->bi_idl_tree_lrulock );
        ldap_pvt_thread_rdwr_wunlock( &bdb->bi_idl_tree_rwlock );
 }
@@ -484,7 +502,7 @@ int
 bdb_idl_fetch_key(
        BackendDB       *be,
        DB                      *db,
-       DB_TXN          *tid,
+       DB_TXN          *txn,
        DBT                     *key,
        ID                      *ids,
        DBC                     **saved_cursor,
@@ -557,7 +575,7 @@ bdb_idl_fetch_key(
 
        /* If we're not reusing an existing cursor, get a new one */
        if( opflag != DB_NEXT ) {
-               rc = db->cursor( db, tid, &cursor, bdb->bi_db_opflags );
+               rc = db->cursor( db, txn, &cursor, bdb->bi_db_opflags );
                if( rc != 0 ) {
                        Debug( LDAP_DEBUG_ANY, "=> bdb_idl_fetch_key: "
                                "cursor failed: %s (%d)\n", db_strerror(rc), rc, 0 );
@@ -696,10 +714,6 @@ bdb_idl_insert_key(
 
        assert( id != NOID );
 
-       if ( bdb->bi_idl_cache_size ) {
-               bdb_idl_cache_del( bdb, db, key );
-       }
-
        DBTzero( &data );
        data.size = sizeof( ID );
        data.ulen = data.size;
@@ -872,6 +886,12 @@ fail:
                cursor->c_close( cursor );
                return rc;
        }
+       /* If key was added (didn't already exist) and using IDL cache,
+        * update key in IDL cache.
+        */
+       if ( !rc && bdb->bi_idl_cache_max_size ) {
+               bdb_idl_cache_add_id( bdb, db, key, id );
+       }
        rc = cursor->c_close( cursor );
        if( rc != 0 ) {
                Debug( LDAP_DEBUG_ANY, "=> bdb_idl_insert_key: "
@@ -904,7 +924,7 @@ bdb_idl_delete_key(
        }
        assert( id != NOID );
 
-       if ( bdb->bi_idl_cache_max_size ) {
+       if ( bdb->bi_idl_cache_size ) {
                bdb_idl_cache_del( bdb, db, key );
        }