1 /* cache.c - routines to maintain an in-core cache of entries */
3 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
5 * Copyright 2001-2006 The OpenLDAP Foundation.
6 * Portions Copyright 2001-2003 Pierangelo Masarati.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted only as authorized by the OpenLDAP
13 * A copy of this license is available in file LICENSE in the
14 * top-level directory of the distribution or, alternatively, at
15 * <http://www.OpenLDAP.org/license.html>.
18 * This work was initially developed by Pierangelo Masarati for inclusion
19 * in OpenLDAP Software.
25 #include "ac/string.h"
29 #include "back-monitor.h"
32 * The cache maps DNs to Entries.
33 * Each entry, on turn, holds the list of its children in the e_private field.
34 * This is used by search operation to perform onelevel and subtree candidate
37 typedef struct monitor_cache_t {
43 * compares entries based on the dn
50 monitor_cache_t *cc1 = ( monitor_cache_t * )c1;
51 monitor_cache_t *cc2 = ( monitor_cache_t * )c2;
54 * case sensitive, because the dn MUST be normalized
56 return ber_bvcmp( &cc1->mc_ndn, &cc2->mc_ndn );
60 * checks for duplicate entries
67 monitor_cache_t *cc1 = ( monitor_cache_t * )c1;
68 monitor_cache_t *cc2 = ( monitor_cache_t * )c2;
71 * case sensitive, because the dn MUST be normalized
73 return ber_bvcmp( &cc1->mc_ndn, &cc2->mc_ndn ) == 0 ? -1 : 0;
77 * adds an entry to the cache and inits the mutex
91 mp = ( monitor_entry_t *)e->e_private;
93 mc = ( monitor_cache_t * )ch_malloc( sizeof( monitor_cache_t ) );
94 mc->mc_ndn = e->e_nname;
96 ldap_pvt_thread_mutex_lock( &mi->mi_cache_mutex );
97 rc = avl_insert( &mi->mi_cache, ( caddr_t )mc,
98 monitor_cache_cmp, monitor_cache_dup );
99 ldap_pvt_thread_mutex_unlock( &mi->mi_cache_mutex );
105 * locks the entry (no r/w)
114 assert( e->e_private != NULL );
116 mp = ( monitor_entry_t * )e->e_private;
117 ldap_pvt_thread_mutex_lock( &mp->mp_mutex );
123 * tries to lock the entry (no r/w)
126 monitor_cache_trylock(
132 assert( e->e_private != NULL );
134 mp = ( monitor_entry_t * )e->e_private;
135 return ldap_pvt_thread_mutex_trylock( &mp->mp_mutex );
139 * gets an entry from the cache based on the normalized dn
148 monitor_cache_t tmp_mc, *mc;
150 assert( mi != NULL );
151 assert( ndn != NULL );
152 assert( ep != NULL );
156 tmp_mc.mc_ndn = *ndn;
157 ldap_pvt_thread_mutex_lock( &mi->mi_cache_mutex );
158 mc = ( monitor_cache_t * )avl_find( mi->mi_cache,
159 ( caddr_t )&tmp_mc, monitor_cache_cmp );
162 /* entry is returned with mutex locked */
163 monitor_cache_lock( mc->mc_e );
167 ldap_pvt_thread_mutex_unlock( &mi->mi_cache_mutex );
169 return ( *ep == NULL ? -1 : 0 );
173 * gets an entry from the cache based on the normalized dn
177 monitor_cache_remove(
182 monitor_cache_t tmp_mc, *mc;
185 assert( mi != NULL );
186 assert( ndn != NULL );
187 assert( ep != NULL );
191 dnParent( ndn, &pndn );
194 ldap_pvt_thread_mutex_lock( &mi->mi_cache_mutex );
196 tmp_mc.mc_ndn = *ndn;
197 mc = ( monitor_cache_t * )avl_find( mi->mi_cache,
198 ( caddr_t )&tmp_mc, monitor_cache_cmp );
201 monitor_cache_t *pmc;
203 if ( monitor_cache_trylock( mc->mc_e ) ) {
204 ldap_pvt_thread_mutex_unlock( &mi->mi_cache_mutex );
208 tmp_mc.mc_ndn = pndn;
209 pmc = ( monitor_cache_t * )avl_find( mi->mi_cache,
210 ( caddr_t )&tmp_mc, monitor_cache_cmp );
212 monitor_entry_t *mp = (monitor_entry_t *)mc->mc_e->e_private,
213 *pmp = (monitor_entry_t *)pmc->mc_e->e_private;
216 if ( monitor_cache_trylock( pmc->mc_e ) ) {
217 monitor_cache_release( mi, mc->mc_e );
218 ldap_pvt_thread_mutex_unlock( &mi->mi_cache_mutex );
222 for ( entryp = &pmp->mp_children; *entryp != NULL; ) {
223 monitor_entry_t *next = (monitor_entry_t *)(*entryp)->e_private;
225 *entryp = next->mp_next;
230 entryp = &next->mp_next;
233 if ( entryp != NULL ) {
234 Debug( LDAP_DEBUG_ANY,
235 "monitor_cache_remove(\"%s\"): "
236 "not in parent's list\n",
240 /* either succeeded, and the entry is no longer
241 * in its parent's list, or failed, and the
242 * entry is neither mucked with nor returned */
243 monitor_cache_release( mi, pmc->mc_e );
245 if ( entryp == NULL ) {
246 monitor_cache_t *tmpmc;
248 tmp_mc.mc_ndn = *ndn;
249 tmpmc = avl_delete( &mi->mi_cache,
250 ( caddr_t )&tmp_mc, monitor_cache_cmp );
251 assert( tmpmc == mc );
257 /* NOTE: we destroy the mutex, but otherwise
258 * leave the private data around; specifically,
259 * callbacks need be freed by someone else */
261 ldap_pvt_thread_mutex_destroy( &mp->mp_mutex );
263 mp->mp_children = NULL;
267 monitor_cache_release( mi, mc->mc_e );
270 ldap_pvt_thread_mutex_unlock( &mi->mi_cache_mutex );
272 return ( *ep == NULL ? -1 : 0 );
276 * If the entry exists in cache, it is returned in locked status;
277 * otherwise, if the parent exists, if it may generate volatile
278 * descendants an attempt to generate the required entry is
279 * performed and, if successful, the entry is returned
282 monitor_cache_dn2entry(
289 monitor_info_t *mi = (monitor_info_t *)op->o_bd->be_private;
291 struct berval p_ndn = BER_BVNULL;
295 assert( mi != NULL );
296 assert( ndn != NULL );
297 assert( ep != NULL );
298 assert( matched != NULL );
302 if ( !dnIsSuffix( ndn, &op->o_bd->be_nsuffix[ 0 ] ) ) {
306 rc = monitor_cache_get( mi, ndn, ep );
307 if ( !rc && *ep != NULL ) {
311 /* try with parent/ancestors */
312 if ( BER_BVISNULL( ndn ) ) {
313 BER_BVSTR( &p_ndn, "" );
316 dnParent( ndn, &p_ndn );
319 rc = monitor_cache_dn2entry( op, rs, &p_ndn, &e_parent, matched );
320 if ( rc || e_parent == NULL ) {
324 mp = ( monitor_entry_t * )e_parent->e_private;
326 if ( mp->mp_flags & MONITOR_F_VOLATILE_CH ) {
327 /* parent entry generates volatile children */
328 rc = monitor_entry_create( op, rs, ndn, e_parent, ep );
332 monitor_cache_lock( *ep );
333 monitor_cache_release( mi, e_parent );
343 * releases the lock of the entry; if it is marked as volatile, it is
347 monitor_cache_release(
353 assert( mi != NULL );
355 assert( e->e_private != NULL );
357 mp = ( monitor_entry_t * )e->e_private;
359 if ( mp->mp_flags & MONITOR_F_VOLATILE ) {
360 monitor_cache_t *mc, tmp_mc;
362 /* volatile entries do not return to cache */
363 ldap_pvt_thread_mutex_lock( &mi->mi_cache_mutex );
364 tmp_mc.mc_ndn = e->e_nname;
365 mc = avl_delete( &mi->mi_cache,
366 ( caddr_t )&tmp_mc, monitor_cache_cmp );
367 ldap_pvt_thread_mutex_unlock( &mi->mi_cache_mutex );
372 ldap_pvt_thread_mutex_unlock( &mp->mp_mutex );
373 ldap_pvt_thread_mutex_destroy( &mp->mp_mutex );
381 ldap_pvt_thread_mutex_unlock( &mp->mp_mutex );
387 monitor_entry_destroy( void *v_mc )
389 monitor_cache_t *mc = (monitor_cache_t *)v_mc;
391 if ( mc->mc_e != NULL ) {
394 assert( mc->mc_e->e_private != NULL );
396 mp = ( monitor_entry_t * )mc->mc_e->e_private;
399 monitor_callback_t *cb;
401 for ( cb = mp->mp_cb; cb != NULL; ) {
402 monitor_callback_t *next = cb->mc_next;
405 cb->mc_free( mc->mc_e, cb->mc_private );
407 ch_free( mp->mp_cb );
413 ldap_pvt_thread_mutex_destroy( &mp->mp_mutex );
416 mc->mc_e->e_private = NULL;
417 entry_free( mc->mc_e );
424 monitor_cache_destroy(
427 if ( mi->mi_cache ) {
428 avl_free( mi->mi_cache, monitor_entry_destroy );