git.sur5r.net Git - openldap/blob - servers/slapd/back-bdb/cache.c

   1 /* cache.c - routines to maintain an in-core cache of entries */
   2 /* $OpenLDAP$ */
   3 /*
   4  * Copyright 1998-2002 The OpenLDAP Foundation, All Rights Reserved.
   5  * COPYING RESTRICTIONS APPLY, see COPYRIGHT file
   6  */
   7
   8 #include "portable.h"
   9
  10 #include <stdio.h>
  11
  12 #include <ac/errno.h>
  13 #include <ac/string.h>
  14 #include <ac/socket.h>
  15
  16 #include "slap.h"
  17
  18 #include "back-bdb.h"
  19
  20 /* BDB backend specific entry info -- visible only to the cache */
  21 typedef struct bdb_entry_info {
  22         ldap_pvt_thread_rdwr_t  bei_rdwr;       /* reader/writer lock */
  23
  24         /*
  25          * remaining fields require backend cache lock to access
  26          * These items are specific to the BDB backend and should
  27          * be hidden.
  28          */
  29         int             bei_state;      /* for the cache */
  30 #define CACHE_ENTRY_UNDEFINED   0
  31 #define CACHE_ENTRY_CREATING    1
  32 #define CACHE_ENTRY_READY       2
  33 #define CACHE_ENTRY_DELETED     3
  34 #define CACHE_ENTRY_COMMITTED   4
  35
  36         int             bei_refcnt;     /* # threads ref'ing this entry */
  37         Entry   *bei_lrunext;   /* for cache lru list */
  38         Entry   *bei_lruprev;
  39 } EntryInfo;
  40 #undef BEI
  41 #define BEI(e)  ((EntryInfo *) ((e)->e_private))
  42
  43 static int      bdb_cache_delete_entry_internal(Cache *cache, Entry *e);
  44 #ifdef LDAP_DEBUG
  45 static void     bdb_lru_print(Cache *cache);
  46 #endif
  47
  48 static int
  49 bdb_cache_entry_rdwr_lock(Entry *e, int rw)
  50 {
  51 #ifdef NEW_LOGGING
  52         LDAP_LOG(( "cache", LDAP_LEVEL_ENTRY,
  53                    "bdb_cache_entry_rdwr_lock: %s lock on ID %ld\n",
  54                    rw ? "w" : "r", e->e_id ));
  55 #else
  56         Debug( LDAP_DEBUG_ARGS, "entry_rdwr_%slock: ID: %ld\n",
  57                 rw ? "w" : "r", e->e_id, 0);
  58 #endif
  59
  60         if (rw)
  61                 return ldap_pvt_thread_rdwr_wlock(&BEI(e)->bei_rdwr);
  62         else
  63                 return ldap_pvt_thread_rdwr_rlock(&BEI(e)->bei_rdwr);
  64 }
  65
  66 static int
  67 bdb_cache_entry_rdwr_trylock(Entry *e, int rw)
  68 {
  69 #ifdef NEW_LOGGING
  70         LDAP_LOG(( "cache", LDAP_LEVEL_ENTRY,
  71                    "bdb_cache_entry_rdwr_trylock: try %s lock on ID: %ld.\n",
  72                    rw ? "w" : "r", e->e_id ));
  73 #else
  74         Debug( LDAP_DEBUG_ARGS, "entry_rdwr_%strylock: ID: %ld\n",
  75                 rw ? "w" : "r", e->e_id, 0);
  76 #endif
  77
  78         if (rw)
  79                 return ldap_pvt_thread_rdwr_wtrylock(&BEI(e)->bei_rdwr);
  80         else
  81                 return ldap_pvt_thread_rdwr_rtrylock(&BEI(e)->bei_rdwr);
  82 }
  83
  84 static int
  85 bdb_cache_entry_rdwr_unlock(Entry *e, int rw)
  86 {
  87 #ifdef NEW_LOGGING
  88         LDAP_LOG(( "cache", LDAP_LEVEL_ENTRY,
  89                    "bdb_cache_entry_rdwr_unlock: remove %s lock on ID %ld.\n",
  90                    rw ? "w" : "r", e->e_id ));
  91 #else
  92         Debug( LDAP_DEBUG_ARGS, "entry_rdwr_%sunlock: ID: %ld\n",
  93                 rw ? "w" : "r", e->e_id, 0);
  94 #endif
  95
  96         if (rw)
  97                 return ldap_pvt_thread_rdwr_wunlock(&BEI(e)->bei_rdwr);
  98         else
  99                 return ldap_pvt_thread_rdwr_runlock(&BEI(e)->bei_rdwr);
 100 }
 101
 102 static int
 103 bdb_cache_entry_rdwr_init(Entry *e)
 104 {
 105         return ldap_pvt_thread_rdwr_init( &BEI(e)->bei_rdwr );
 106 }
 107
 108 static int
 109 bdb_cache_entry_rdwr_destroy(Entry *e)
 110 {
 111         return ldap_pvt_thread_rdwr_destroy( &BEI(e)->bei_rdwr );
 112 }
 113
 114 static int
 115 bdb_cache_entry_private_init( Entry *e )
 116 {
 117         assert( e->e_private == NULL );
 118
 119         if( e->e_private != NULL ) {
 120                 /* this should never happen */
 121                 return 1;
 122         }
 123
 124         e->e_private = ch_calloc(1, sizeof(struct bdb_entry_info));
 125
 126         if( bdb_cache_entry_rdwr_init( e ) != 0 ) {
 127                 free( BEI(e) );
 128                 e->e_private = NULL;
 129                 return 1;
 130         }
 131
 132         return 0;
 133 }
 134
 135 /*
 136  * marks an entry in CREATING state as committed, so it is really returned
 137  * to the cache. Otherwise an entry in CREATING state is removed.
 138  * Makes e_private be destroyed at the following cache_return_entry_w,
 139  * but lets the entry untouched (owned by someone else)
 140  */
 141 void
 142 bdb_cache_entry_commit( Entry *e )
 143 {
 144         assert( e );
 145         assert( e->e_private );
 146         assert( BEI(e)->bei_state == CACHE_ENTRY_CREATING );
 147         /* assert( BEI(e)->bei_refcnt == 1 ); */
 148
 149         BEI(e)->bei_state = CACHE_ENTRY_COMMITTED;
 150 }
 151
 152 static int
 153 bdb_cache_entry_private_destroy( Entry *e )
 154 {
 155         assert( e->e_private );
 156
 157         bdb_cache_entry_rdwr_destroy( e );
 158
 159         free( e->e_private );
 160         e->e_private = NULL;
 161         return 0;
 162 }
 163
 164 void
 165 bdb_cache_return_entry_rw( Cache *cache, Entry *e, int rw )
 166 {
 167         ID id;
 168         int refcnt, freeit = 1;
 169
 170         /* set cache mutex */
 171         ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
 172
 173         assert( e->e_private );
 174
 175         bdb_cache_entry_rdwr_unlock(e, rw);
 176
 177         id = e->e_id;
 178         refcnt = --BEI(e)->bei_refcnt;
 179
 180         /*
 181          * if the entry is returned when in CREATING state, it is deleted
 182          * but not freed because it may belong to someone else (do_add,
 183          * for instance)
 184          */
 185         if (  BEI(e)->bei_state == CACHE_ENTRY_CREATING ) {
 186                 ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
 187                 bdb_cache_delete_entry_internal( cache, e );
 188                 ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
 189                 freeit = 0;
 190                 /* now the entry is in DELETED state */
 191         }
 192
 193         if ( BEI(e)->bei_state == CACHE_ENTRY_COMMITTED ) {
 194                 BEI(e)->bei_state = CACHE_ENTRY_READY;
 195
 196                 /* free cache mutex */
 197                 ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 198
 199 #ifdef NEW_LOGGING
 200                 LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
 201                            "bdb_cache_return_entry_rw: return (%ld):%s, refcnt=%d\n",
 202                            id, rw ? "w" : "r", refcnt ));
 203 #else
 204                 Debug( LDAP_DEBUG_TRACE,
 205                         "====> bdb_cache_return_entry_%s( %ld ): created (%d)\n",
 206                         rw ? "w" : "r", id, refcnt );
 207 #endif
 208
 209
 210         } else if ( BEI(e)->bei_state == CACHE_ENTRY_DELETED ) {
 211                 if( refcnt > 0 ) {
 212                         /* free cache mutex */
 213                         ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 214
 215 #ifdef NEW_LOGGING
 216                         LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
 217                                    "bdb_cache_return_entry_rw: %ld, delete pending (%d).\n",
 218                                    id, refcnt ));
 219 #else
 220                         Debug( LDAP_DEBUG_TRACE,
 221                                 "====> bdb_cache_return_entry_%s( %ld ): delete pending (%d)\n",
 222                                 rw ? "w" : "r", id, refcnt );
 223 #endif
 224
 225                 } else {
 226                         bdb_cache_entry_private_destroy( e );
 227                         if ( freeit ) {
 228                                 bdb_entry_return( e );
 229                         }
 230
 231                         /* free cache mutex */
 232                         ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 233
 234 #ifdef NEW_LOGGING
 235                         LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
 236                                    "bdb_cache_return_entry_rw: (%ld): deleted (%d)\n",
 237                                    id, refcnt ));
 238 #else
 239                         Debug( LDAP_DEBUG_TRACE,
 240                                 "====> bdb_cache_return_entry_%s( %ld ): deleted (%d)\n",
 241                                 rw ? "w" : "r", id, refcnt );
 242 #endif
 243                 }
 244
 245         } else {
 246                 /* free cache mutex */
 247                 ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 248
 249 #ifdef NEW_LOGGING
 250                 LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
 251                            "bdb_cache_return_entry_rw: ID %ld:%s returned (%d)\n",
 252                            id, rw ? "w": "r", refcnt ));
 253 #else
 254                 Debug( LDAP_DEBUG_TRACE,
 255                         "====> bdb_cache_return_entry_%s( %ld ): returned (%d)\n",
 256                         rw ? "w" : "r", id, refcnt);
 257 #endif
 258         }
 259 }
 260
 261 #define LRU_DELETE( cache, e ) do { \
 262         if ( BEI(e)->bei_lruprev != NULL ) { \
 263                 BEI(BEI(e)->bei_lruprev)->bei_lrunext = BEI(e)->bei_lrunext; \
 264         } else { \
 265                 (cache)->c_lruhead = BEI(e)->bei_lrunext; \
 266         } \
 267         if ( BEI(e)->bei_lrunext != NULL ) { \
 268                 BEI(BEI(e)->bei_lrunext)->bei_lruprev = BEI(e)->bei_lruprev; \
 269         } else { \
 270                 (cache)->c_lrutail = BEI(e)->bei_lruprev; \
 271         } \
 272 } while(0)
 273
 274 #define LRU_ADD( cache, e ) do { \
 275         BEI(e)->bei_lrunext = (cache)->c_lruhead; \
 276         if ( BEI(e)->bei_lrunext != NULL ) { \
 277                 BEI(BEI(e)->bei_lrunext)->bei_lruprev = (e); \
 278         } \
 279         (cache)->c_lruhead = (e); \
 280         BEI(e)->bei_lruprev = NULL; \
 281         if ( (cache)->c_lrutail == NULL ) { \
 282                 (cache)->c_lrutail = (e); \
 283         } \
 284 } while(0)
 285
 286 /*
 287  * cache_add_entry_rw - create and lock an entry in the cache
 288  * returns:     0       entry has been created and locked
 289  *              1       entry already existed
 290  *              -1      something bad happened
 291  */
 292 int
 293 bdb_cache_add_entry_rw(
 294     Cache       *cache,
 295     Entry       *e,
 296     int         rw
 297 )
 298 {
 299         int     i, rc;
 300         Entry   *ee;
 301
 302 #ifdef NEW_LOGGING
 303         LDAP_LOG(( "cache", LDAP_LEVEL_ENTRY,
 304                    "bdb_cache_add_entry_rw: add (%s):%s to cache\n",
 305                    e->e_dn, rw ? "w" : "r" ));
 306 #endif
 307         /* set cache mutex */
 308         ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
 309
 310         assert( e->e_private == NULL );
 311
 312         if( bdb_cache_entry_private_init(e) != 0 ) {
 313                 /* free cache mutex */
 314                 ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
 315
 316 #ifdef NEW_LOGGING
 317                 LDAP_LOG(( "cache", LDAP_LEVEL_ERR,
 318                            "bdb_cache_add_entry_rw: add (%s):%ld private init failed!\n",
 319                            e->e_dn, e->e_id ));
 320 #else
 321                 Debug( LDAP_DEBUG_ANY,
 322                         "====> bdb_cache_add_entry( %ld ): \"%s\": private init failed!\n",
 323                     e->e_id, e->e_dn, 0 );
 324 #endif
 325
 326
 327                 return( -1 );
 328         }
 329
 330         if ( avl_insert( &cache->c_dntree, (caddr_t) e,
 331                 (AVL_CMP) entry_dn_cmp, avl_dup_error ) != 0 )
 332         {
 333                 /* free cache mutex */
 334                 ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 335
 336 #ifdef NEW_LOGGING
 337                 LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
 338                            "bdb_cache_add_entry: (%s):%ld already in cache.\n",
 339                            e->e_dn, e->e_id ));
 340 #else
 341                 Debug( LDAP_DEBUG_TRACE,
 342                         "====> bdb_cache_add_entry( %ld ): \"%s\": already in dn cache\n",
 343                     e->e_id, e->e_dn, 0 );
 344 #endif
 345
 346                 bdb_cache_entry_private_destroy(e);
 347
 348                 return( 1 );
 349         }
 350
 351         /* id tree */
 352         if ( avl_insert( &cache->c_idtree, (caddr_t) e,
 353                 (AVL_CMP) entry_id_cmp, avl_dup_error ) != 0 )
 354         {
 355 #ifdef NEW_LOGGING
 356                 LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
 357                            "bdb_cache_add_entry: (%s):%ls already in cache.\n",
 358                            e->e_dn, e->e_id ));
 359 #else
 360                 Debug( LDAP_DEBUG_ANY,
 361                         "====> bdb_cache_add_entry( %ld ): \"%s\": already in id cache\n",
 362                     e->e_id, e->e_dn, 0 );
 363 #endif
 364
 365                 /* delete from dn tree inserted above */
 366                 if ( avl_delete( &cache->c_dntree, (caddr_t) e,
 367                         (AVL_CMP) entry_dn_cmp ) == NULL )
 368                 {
 369 #ifdef NEW_LOGGING
 370                         LDAP_LOG(( "cache", LDAP_LEVEL_INFO,
 371                                    "bdb_cache_add_entry: can't delete (%s) from cache.\n",
 372                                    e->e_dn ));
 373 #else
 374                         Debug( LDAP_DEBUG_ANY, "====> can't delete from dn cache\n",
 375                             0, 0, 0 );
 376 #endif
 377                 }
 378
 379                 bdb_cache_entry_private_destroy(e);
 380
 381                 /* free cache mutex */
 382                 ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 383                 return( -1 );
 384         }
 385
 386         bdb_cache_entry_rdwr_lock( e, rw );
 387
 388         /* put the entry into 'CREATING' state */
 389         /* will be marked after when entry is returned */
 390         BEI(e)->bei_state = CACHE_ENTRY_CREATING;
 391         BEI(e)->bei_refcnt = 1;
 392
 393         ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
 394         /* lru */
 395         LRU_ADD( cache, e );
 396         if ( ++cache->c_cursize > cache->c_maxsize ) {
 397                 /*
 398                  * find the lru entry not currently in use and delete it.
 399                  * in case a lot of entries are in use, only look at the
 400                  * first 10 on the tail of the list.
 401                  */
 402                 i = 0;
 403                 while ( cache->c_lrutail != NULL &&
 404                         BEI(cache->c_lrutail)->bei_refcnt != 0 &&
 405                         i < 10 )
 406                 {
 407                         /* move this in-use entry to the front of the q */
 408                         ee = cache->c_lrutail;
 409                         LRU_DELETE( cache, ee );
 410                         LRU_ADD( cache, ee );
 411                         i++;
 412                 }
 413
 414                 /*
 415                  * found at least one to delete - try to get back under
 416                  * the max cache size.
 417                  */
 418                 while ( cache->c_lrutail != NULL &&
 419                         BEI(cache->c_lrutail)->bei_refcnt == 0 &&
 420                         cache->c_cursize > cache->c_maxsize )
 421                 {
 422                         e = cache->c_lrutail;
 423
 424                         /* delete from cache and lru q */
 425                         /* XXX do we need rc ? */
 426                         rc = bdb_cache_delete_entry_internal( cache, e );
 427                         bdb_cache_entry_private_destroy( e );
 428                         bdb_entry_return( e );
 429                 }
 430         }
 431
 432         /* free cache mutex */
 433         ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
 434         ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 435         return( 0 );
 436 }
 437
 438 /*
 439  * cache_update_entry - update a LOCKED entry which has been deleted.
 440  * returns:     0       entry has been created and locked
 441  *              1       entry already existed
 442  *              -1      something bad happened
 443  */
 444 int
 445 bdb_cache_update_entry(
 446     Cache       *cache,
 447     Entry               *e
 448 )
 449 {
 450         int     i, rc;
 451         Entry   *ee;
 452
 453         /* set cache mutex */
 454         ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
 455
 456         assert( e->e_private );
 457
 458         if ( avl_insert( &cache->c_dntree, (caddr_t) e,
 459                 (AVL_CMP) entry_dn_cmp, avl_dup_error ) != 0 )
 460         {
 461 #ifdef NEW_LOGGING
 462                 LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
 463                            "bdb_cache_update_entry: (%s):%ld already in dn cache\n",
 464                            e->e_dn, e->e_id ));
 465 #else
 466                 Debug( LDAP_DEBUG_TRACE,
 467                         "====> bdb_cache_update_entry( %ld ): \"%s\": already in dn cache\n",
 468                     e->e_id, e->e_dn, 0 );
 469 #endif
 470
 471                 /* free cache mutex */
 472                 ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 473                 return( 1 );
 474         }
 475
 476         /* id tree */
 477         if ( avl_insert( &cache->c_idtree, (caddr_t) e,
 478                 (AVL_CMP) entry_id_cmp, avl_dup_error ) != 0 )
 479         {
 480 #ifdef NEW_LOGGING
 481                 LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
 482                            "bdb_cache_update_entry: (%s)%ld already in id cache\n",
 483                            e->e_dn, e->e_id ));
 484 #else
 485                 Debug( LDAP_DEBUG_ANY,
 486                         "====> bdb_cache_update_entry( %ld ): \"%s\": already in id cache\n",
 487                     e->e_id, e->e_dn, 0 );
 488 #endif
 489
 490                 /* delete from dn tree inserted above */
 491                 if ( avl_delete( &cache->c_dntree, (caddr_t) e,
 492                         (AVL_CMP) entry_dn_cmp ) == NULL )
 493                 {
 494 #ifdef NEW_LOGGING
 495                         LDAP_LOG(( "cache", LDAP_LEVEL_INFO,
 496                                    "bdb_cache_update_entry: can't delete (%s)%ld from dn cache.\n",
 497                                    e->e_dn, e->e_id ));
 498 #else
 499                         Debug( LDAP_DEBUG_ANY, "====> can't delete from dn cache\n",
 500                             0, 0, 0 );
 501 #endif
 502                 }
 503
 504                 /* free cache mutex */
 505                 ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 506                 return( -1 );
 507         }
 508
 509
 510         /* put the entry into 'CREATING' state */
 511         /* will be marked after when entry is returned */
 512         BEI(e)->bei_state = CACHE_ENTRY_CREATING;
 513
 514         ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
 515         /* lru */
 516         LRU_ADD( cache, e );
 517         if ( ++cache->c_cursize > cache->c_maxsize ) {
 518                 /*
 519                  * find the lru entry not currently in use and delete it.
 520                  * in case a lot of entries are in use, only look at the
 521                  * first 10 on the tail of the list.
 522                  */
 523                 i = 0;
 524                 while ( cache->c_lrutail != NULL &&
 525                         BEI(cache->c_lrutail)->bei_refcnt != 0 &&
 526                         i < 10 )
 527                 {
 528                         /* move this in-use entry to the front of the q */
 529                         ee = cache->c_lrutail;
 530                         LRU_DELETE( cache, ee );
 531                         LRU_ADD( cache, ee );
 532                         i++;
 533                 }
 534
 535                 /*
 536                  * found at least one to delete - try to get back under
 537                  * the max cache size.
 538                  */
 539                 while ( cache->c_lrutail != NULL &&
 540                         BEI(cache->c_lrutail)->bei_refcnt == 0 &&
 541                         cache->c_cursize > cache->c_maxsize )
 542                 {
 543                         e = cache->c_lrutail;
 544
 545                         /* delete from cache and lru q */
 546                         /* XXX do we need rc ? */
 547                         rc = bdb_cache_delete_entry_internal( cache, e );
 548                         bdb_cache_entry_private_destroy( e );
 549                         bdb_entry_return( e );
 550                 }
 551         }
 552
 553         /* free cache mutex */
 554         ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
 555         ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 556         return( 0 );
 557 }
 558
 559 ID
 560 bdb_cache_find_entry_ndn2id(
 561         Backend         *be,
 562     Cache       *cache,
 563     struct berval       *ndn
 564 )
 565 {
 566         Entry           e, *ep;
 567         ID                      id;
 568         int count = 0;
 569
 570         /* this function is always called with normalized DN */
 571         e.e_nname = *ndn;
 572
 573 try_again:
 574         /* set cache mutex */
 575         ldap_pvt_thread_rdwr_rlock( &cache->c_rwlock );
 576
 577         if ( (ep = (Entry *) avl_find( cache->c_dntree, (caddr_t) &e,
 578                 (AVL_CMP) entry_dn_cmp )) != NULL )
 579         {
 580                 int state;
 581                 count++;
 582
 583                 /*
 584                  * ep now points to an unlocked entry
 585                  * we do not need to lock the entry if we only
 586                  * check the state, refcnt, LRU, and id.
 587                  */
 588
 589                 assert( ep->e_private );
 590
 591                 /* save id */
 592                 id = ep->e_id;
 593                 state = BEI(ep)->bei_state;
 594
 595                 /*
 596                  * entry is deleted or not fully created yet
 597                  */
 598                 if ( state != CACHE_ENTRY_READY ) {
 599                         assert(state != CACHE_ENTRY_UNDEFINED);
 600
 601                         /* free cache mutex */
 602                         ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 603
 604 #ifdef NEW_LOGGING
 605                         LDAP_LOG(( "cache", LDAP_LEVEL_INFO,
 606                                    "bdb_cache_find_entry_dn2id: (%s) %ld not ready: %d\n",
 607                                    ndn->bv_val, id, state ));
 608 #else
 609                         Debug(LDAP_DEBUG_TRACE,
 610                                 "====> bdb_cache_find_entry_dn2id(\"%s\"): %ld (not ready) %d\n",
 611                                 ndn->bv_val, id, state);
 612 #endif
 613
 614
 615                         ldap_pvt_thread_yield();
 616                         goto try_again;
 617                 }
 618
 619                 ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 620
 621                 ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
 622
 623                 /* lru */
 624                 LRU_DELETE( cache, ep );
 625                 LRU_ADD( cache, ep );
 626
 627                 /* free cache mutex */
 628                 ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
 629
 630 #ifdef NEW_LOGGING
 631                 LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
 632                            "bdb_cache_find_entry_dn2id: (%s): %ld %d tries\n",
 633                            ndn->bv_val, id, count ));
 634 #else
 635                 Debug(LDAP_DEBUG_TRACE,
 636                         "====> bdb_cache_find_entry_dn2id(\"%s\"): %ld (%d tries)\n",
 637                         ndn->bv_val, id, count);
 638 #endif
 639
 640         } else {
 641                 /* free cache mutex */
 642                 ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 643
 644                 id = NOID;
 645         }
 646
 647         return( id );
 648 }
 649
 650 /*
 651  * cache_find_entry_id - find an entry in the cache, given id
 652  */
 653
 654 Entry *
 655 bdb_cache_find_entry_id(
 656         Cache   *cache,
 657         ID                              id,
 658         int                             rw
 659 )
 660 {
 661         Entry   e;
 662         Entry   *ep;
 663         int     count = 0;
 664
 665         e.e_id = id;
 666
 667 try_again:
 668         /* set cache mutex */
 669         ldap_pvt_thread_rdwr_rlock( &cache->c_rwlock );
 670
 671         if ( (ep = (Entry *) avl_find( cache->c_idtree, (caddr_t) &e,
 672                 (AVL_CMP) entry_id_cmp )) != NULL )
 673         {
 674                 int state;
 675                 ID      ep_id;
 676
 677                 count++;
 678
 679                 assert( ep->e_private );
 680
 681                 ep_id = ep->e_id;
 682                 state = BEI(ep)->bei_state;
 683
 684                 /*
 685                  * entry is deleted or not fully created yet
 686                  */
 687                 if ( state != CACHE_ENTRY_READY ) {
 688
 689                         assert(state != CACHE_ENTRY_UNDEFINED);
 690
 691                         /* free cache mutex */
 692                         ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 693
 694 #ifdef NEW_LOGGING
 695                         LDAP_LOG(( "cache", LDAP_LEVEL_INFO,
 696                                    "bdb_cache_find_entry_id: (%ld)->%ld not ready (%d).\n",
 697                                    id, ep_id, state ));
 698
 699 #else
 700                         Debug(LDAP_DEBUG_TRACE,
 701                                 "====> bdb_cache_find_entry_id( %ld ): %ld (not ready) %d\n",
 702                                 id, ep_id, state);
 703 #endif
 704
 705                         ldap_pvt_thread_yield();
 706                         goto try_again;
 707                 }
 708
 709                 /* acquire reader lock */
 710                 if ( bdb_cache_entry_rdwr_trylock(ep, rw) == LDAP_PVT_THREAD_EBUSY ) {
 711                         /* could not acquire entry lock...
 712                          * owner cannot free as we have the cache locked.
 713                          * so, unlock the cache, yield, and try again.
 714                          */
 715
 716                         /* free cache mutex */
 717                         ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 718
 719 #ifdef NEW_LOGGING
 720                         LDAP_LOG(( "cache", LDAP_LEVEL_INFO,
 721                                    "bdb_cache_find_entry_id: %ld -> %ld (busy) %d.\n",
 722                                    id, ep_id, state ));
 723 #else
 724                         Debug(LDAP_DEBUG_TRACE,
 725                                 "====> bdb_cache_find_entry_id( %ld ): %ld (busy) %d\n",
 726                                 id, ep_id, state);
 727 #endif
 728
 729                         ldap_pvt_thread_yield();
 730                         goto try_again;
 731                 }
 732
 733                 ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 734                 ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
 735                 /* lru */
 736                 LRU_DELETE( cache, ep );
 737                 LRU_ADD( cache, ep );
 738
 739                 BEI(ep)->bei_refcnt++;
 740
 741                 /* free cache mutex */
 742                 ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
 743
 744 #ifdef NEW_LOGGING
 745                 LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
 746                            "bdb_cache_find_entry_id: %ld -> %s  found %d tries.\n",
 747                            ep_id, ep->e_dn, count ));
 748 #else
 749                 Debug(LDAP_DEBUG_TRACE,
 750                         "====> bdb_cache_find_entry_id( %ld ) \"%s\" (found) (%d tries)\n",
 751                         ep_id, ep->e_dn, count);
 752 #endif
 753
 754
 755                 return( ep );
 756         }
 757
 758         /* free cache mutex */
 759         ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 760
 761         return( NULL );
 762 }
 763
 764 /*
 765  * cache_delete_entry - delete the entry e from the cache.  the caller
 766  * should have obtained e (increasing its ref count) via a call to one
 767  * of the cache_find_* routines.  the caller should *not* call the
 768  * cache_return_entry() routine prior to calling cache_delete_entry().
 769  * it performs this function.
 770  *
 771  * returns:     0       e was deleted ok
 772  *              1       e was not in the cache
 773  *              -1      something bad happened
 774  */
 775 int
 776 bdb_cache_delete_entry(
 777     Cache       *cache,
 778     Entry               *e
 779 )
 780 {
 781         int     rc;
 782
 783         /* set cache mutex */
 784         ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
 785
 786         assert( e->e_private );
 787
 788 #ifdef NEW_LOGGING
 789         LDAP_LOG(( "cache", LDAP_LEVEL_ENTRY,
 790                    "bdb_cache_delete_entry: delete %ld.\n", e->e_id ));
 791 #else
 792         Debug( LDAP_DEBUG_TRACE, "====> bdb_cache_delete_entry( %ld )\n",
 793                 e->e_id, 0, 0 );
 794 #endif
 795
 796         ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
 797         rc = bdb_cache_delete_entry_internal( cache, e );
 798         ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
 799
 800         /* free cache mutex */
 801         ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 802         return( rc );
 803 }
 804
 805 static int
 806 bdb_cache_delete_entry_internal(
 807     Cache       *cache,
 808     Entry               *e
 809 )
 810 {
 811         int rc = 0;     /* return code */
 812
 813         /* dn tree */
 814         if ( avl_delete( &cache->c_dntree, (caddr_t) e, (AVL_CMP) entry_dn_cmp )
 815                 == NULL )
 816         {
 817                 rc = -1;
 818         }
 819
 820         /* id tree */
 821         if ( avl_delete( &cache->c_idtree, (caddr_t) e, (AVL_CMP) entry_id_cmp )
 822                 == NULL )
 823         {
 824                 rc = -1;
 825         }
 826
 827         if (rc != 0) {
 828                 return rc;
 829         }
 830
 831         /* lru */
 832         LRU_DELETE( cache, e );
 833         cache->c_cursize--;
 834
 835         /*
 836          * flag entry to be freed later by a call to cache_return_entry()
 837          */
 838         BEI(e)->bei_state = CACHE_ENTRY_DELETED;
 839
 840         return( 0 );
 841 }
 842
 843 void
 844 bdb_cache_release_all( Cache *cache )
 845 {
 846         Entry *e;
 847         int rc;
 848
 849         /* set cache mutex */
 850         ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
 851         ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
 852
 853 #ifdef NEW_LOGGING
 854         LDAP_LOG(( "cache", LDAP_LEVEL_ENTRY,
 855                    "bdb_cache_release_all: enter\n" ));
 856 #else
 857         Debug( LDAP_DEBUG_TRACE, "====> bdb_cache_release_all\n", 0, 0, 0 );
 858 #endif
 859
 860         while ( (e = cache->c_lrutail) != NULL && BEI(e)->bei_refcnt == 0 ) {
 861 #ifdef LDAP_RDWR_DEBUG
 862                 assert(!ldap_pvt_thread_rdwr_active(&BEI(e)->bei_rdwr));
 863 #endif
 864
 865                 /* delete from cache and lru q */
 866                 /* XXX do we need rc ? */
 867                 rc = bdb_cache_delete_entry_internal( cache, e );
 868                 bdb_cache_entry_private_destroy( e );
 869                 bdb_entry_return( e );
 870         }
 871
 872         if ( cache->c_cursize ) {
 873 #ifdef NEW_LOGGING
 874                 LDAP_LOG(( "cache", LDAP_LEVEL_INFO,
 875                            "bdb_cache_release_all: Entry cache could not be emptied.\n" ));
 876 #else
 877                 Debug( LDAP_DEBUG_TRACE, "Entry-cache could not be emptied\n", 0, 0, 0 );
 878 #endif
 879
 880         }
 881
 882         /* free cache mutex */
 883         ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
 884         ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 885 }
 886
 887 #ifdef LDAP_DEBUG
 888 static void
 889 bdb_lru_print( Cache *cache )
 890 {
 891         Entry   *e;
 892
 893         fprintf( stderr, "LRU queue (head to tail):\n" );
 894         for ( e = cache->c_lruhead; e != NULL; e = BEI(e)->bei_lrunext ) {
 895                 fprintf( stderr, "\tdn \"%20s\" id %ld refcnt %d\n",
 896                         e->e_dn, e->e_id, BEI(e)->bei_refcnt );
 897         }
 898         fprintf( stderr, "LRU queue (tail to head):\n" );
 899         for ( e = cache->c_lrutail; e != NULL; e = BEI(e)->bei_lruprev ) {
 900                 fprintf( stderr, "\tdn \"%20s\" id %ld refcnt %d\n",
 901                         e->e_dn, e->e_id, BEI(e)->bei_refcnt );
 902         }
 903 }
 904 #endif