git.sur5r.net Git - openldap/blob - libraries/libldap_r/tpool.c

   1 /* $OpenLDAP$ */
   2 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
   3  *
   4  * Copyright 1998-2005 The OpenLDAP Foundation.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted only as authorized by the OpenLDAP
   9  * Public License.
  10  *
  11  * A copy of this license is available in file LICENSE in the
  12  * top-level directory of the distribution or, alternatively, at
  13  * <http://www.OpenLDAP.org/license.html>.
  14  */
  15
  16 #include "portable.h"
  17
  18 #include <stdio.h>
  19
  20 #include <ac/stdarg.h>
  21 #include <ac/stdlib.h>
  22 #include <ac/string.h>
  23 #include <ac/time.h>
  24 #include <ac/errno.h>
  25
  26 #include "ldap-int.h"
  27 #include "ldap_pvt_thread.h"
  28 #include "ldap_queue.h"
  29
  30 #ifndef LDAP_THREAD_HAVE_TPOOL
  31
  32 enum ldap_int_thread_pool_state {
  33         LDAP_INT_THREAD_POOL_RUNNING,
  34         LDAP_INT_THREAD_POOL_FINISHING,
  35         LDAP_INT_THREAD_POOL_STOPPING,
  36         LDAP_INT_THREAD_POOL_PAUSING
  37 };
  38
  39 typedef struct ldap_int_thread_key_s {
  40         void *ltk_key;
  41         void *ltk_data;
  42         ldap_pvt_thread_pool_keyfree_t *ltk_free;
  43 } ldap_int_thread_key_t;
  44
  45 /* Max number of thread-specific keys we store per thread.
  46  * We don't expect to use many...
  47  */
  48 #define MAXKEYS 32
  49 #define LDAP_MAXTHR     1024    /* must be a power of 2 */
  50
  51 static ldap_pvt_thread_t tid_zero;
  52
  53 #ifdef HAVE_PTHREADS
  54 #define TID_EQ(a,b)     pthread_equal((a),(b))
  55 #else
  56 #define TID_EQ(a,b)     ((a) == (b))
  57 #endif
  58 static struct {
  59         ldap_pvt_thread_t id;
  60         ldap_int_thread_key_t *ctx;
  61 } thread_keys[LDAP_MAXTHR];
  62
  63
  64 typedef struct ldap_int_thread_ctx_s {
  65         union {
  66         LDAP_STAILQ_ENTRY(ldap_int_thread_ctx_s) q;
  67         LDAP_SLIST_ENTRY(ldap_int_thread_ctx_s) l;
  68         LDAP_SLIST_ENTRY(ldap_int_thread_ctx_s) al;
  69         } ltc_next;
  70         ldap_pvt_thread_start_t *ltc_start_routine;
  71         void *ltc_arg;
  72 } ldap_int_thread_ctx_t;
  73
  74 struct ldap_int_thread_pool_s {
  75         LDAP_STAILQ_ENTRY(ldap_int_thread_pool_s) ltp_next;
  76         ldap_pvt_thread_mutex_t ltp_mutex;
  77         ldap_pvt_thread_cond_t ltp_cond;
  78         ldap_pvt_thread_cond_t ltp_pcond;
  79         LDAP_STAILQ_HEAD(tcq, ldap_int_thread_ctx_s) ltp_pending_list;
  80         LDAP_SLIST_HEAD(tcl, ldap_int_thread_ctx_s) ltp_free_list;
  81         LDAP_SLIST_HEAD(tclq, ldap_int_thread_ctx_s) ltp_active_list;
  82         long ltp_state;
  83         long ltp_max_count;
  84         long ltp_max_pending;
  85         long ltp_pending_count;
  86         long ltp_active_count;
  87         long ltp_open_count;
  88         long ltp_starting;
  89 };
  90
  91 static LDAP_STAILQ_HEAD(tpq, ldap_int_thread_pool_s)
  92         ldap_int_thread_pool_list =
  93         LDAP_STAILQ_HEAD_INITIALIZER(ldap_int_thread_pool_list);
  94
  95 static ldap_pvt_thread_mutex_t ldap_pvt_thread_pool_mutex;
  96
  97 static void *ldap_int_thread_pool_wrapper( void *pool );
  98
  99 static ldap_pvt_thread_t ldap_int_main_tid;
 100
 101 static ldap_int_thread_key_t ldap_int_main_thrctx[LDAP_MAXTHR];
 102
 103 int
 104 ldap_int_thread_pool_startup ( void )
 105 {
 106         ldap_int_main_tid = ldap_pvt_thread_self();
 107
 108         return ldap_pvt_thread_mutex_init(&ldap_pvt_thread_pool_mutex);
 109 }
 110
 111 int
 112 ldap_int_thread_pool_shutdown ( void )
 113 {
 114         struct ldap_int_thread_pool_s *pool;
 115
 116         while ((pool = LDAP_STAILQ_FIRST(&ldap_int_thread_pool_list)) != NULL) {
 117                 LDAP_STAILQ_REMOVE_HEAD(&ldap_int_thread_pool_list, ltp_next);
 118                 ldap_pvt_thread_pool_destroy( &pool, 0);
 119         }
 120         ldap_pvt_thread_mutex_destroy(&ldap_pvt_thread_pool_mutex);
 121         return(0);
 122 }
 123
 124 int
 125 ldap_pvt_thread_pool_init (
 126         ldap_pvt_thread_pool_t *tpool,
 127         int max_threads,
 128         int max_pending )
 129 {
 130         ldap_pvt_thread_pool_t pool;
 131         int rc;
 132
 133         *tpool = NULL;
 134         pool = (ldap_pvt_thread_pool_t) LDAP_CALLOC(1,
 135                 sizeof(struct ldap_int_thread_pool_s));
 136
 137         if (pool == NULL) return(-1);
 138
 139         rc = ldap_pvt_thread_mutex_init(&pool->ltp_mutex);
 140         if (rc != 0)
 141                 return(rc);
 142         rc = ldap_pvt_thread_cond_init(&pool->ltp_cond);
 143         if (rc != 0)
 144                 return(rc);
 145         rc = ldap_pvt_thread_cond_init(&pool->ltp_pcond);
 146         if (rc != 0)
 147                 return(rc);
 148         pool->ltp_state = LDAP_INT_THREAD_POOL_RUNNING;
 149         pool->ltp_max_count = max_threads;
 150         pool->ltp_max_pending = max_pending;
 151         LDAP_STAILQ_INIT(&pool->ltp_pending_list);
 152         LDAP_SLIST_INIT(&pool->ltp_free_list);
 153         LDAP_SLIST_INIT(&pool->ltp_active_list);
 154         ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
 155         LDAP_STAILQ_INSERT_TAIL(&ldap_int_thread_pool_list, pool, ltp_next);
 156         ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
 157
 158 #if 0
 159         /* THIS WILL NOT WORK on some systems.  If the process
 160          * forks after starting a thread, there is no guarantee
 161          * that the thread will survive the fork.  For example,
 162          * slapd forks in order to daemonize, and does so after
 163          * calling ldap_pvt_thread_pool_init.  On some systems,
 164          * this initial thread does not run in the child process,
 165          * but ltp_open_count == 1, so two things happen:
 166          * 1) the first client connection fails, and 2) when
 167          * slapd is kill'ed, it never terminates since it waits
 168          * for all worker threads to exit. */
 169
 170         /* start up one thread, just so there is one. no need to
 171          * lock the mutex right now, since no threads are running.
 172          */
 173         pool->ltp_open_count++;
 174
 175         ldap_pvt_thread_t thr;
 176         rc = ldap_pvt_thread_create( &thr, 1, ldap_int_thread_pool_wrapper, pool );
 177
 178         if( rc != 0) {
 179                 /* couldn't start one?  then don't start any */
 180                 ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
 181                 LDAP_STAILQ_REMOVE(ldap_int_thread_pool_list, pool,
 182                         ldap_int_thread_pool_s, ltp_next);
 183                 ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
 184                 ldap_pvt_thread_cond_destroy(&pool->ltp_pcond);
 185                 ldap_pvt_thread_cond_destroy(&pool->ltp_cond);
 186                 ldap_pvt_thread_mutex_destroy(&pool->ltp_mutex);
 187                 LDAP_FREE(pool);
 188                 return(-1);
 189         }
 190 #endif
 191
 192         *tpool = pool;
 193         return(0);
 194 }
 195
 196 #define TID_HASH(tid, hash) do { int i; \
 197         unsigned char *ptr = (unsigned char *)&(tid); \
 198         for (i=0, hash=0; i<sizeof(tid); i++) hash += ptr[i]; } while(0)
 199
 200 int
 201 ldap_pvt_thread_pool_submit (
 202         ldap_pvt_thread_pool_t *tpool,
 203         ldap_pvt_thread_start_t *start_routine, void *arg )
 204 {
 205         struct ldap_int_thread_pool_s *pool;
 206         ldap_int_thread_ctx_t *ctx;
 207         int need_thread = 0;
 208         ldap_pvt_thread_t thr;
 209
 210         if (tpool == NULL)
 211                 return(-1);
 212
 213         pool = *tpool;
 214
 215         if (pool == NULL)
 216                 return(-1);
 217
 218         ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
 219         if ((pool->ltp_state != LDAP_INT_THREAD_POOL_RUNNING &&
 220                 pool->ltp_state != LDAP_INT_THREAD_POOL_PAUSING)
 221                 || (pool->ltp_max_pending > 0
 222                         && pool->ltp_pending_count >= pool->ltp_max_pending))
 223         {
 224                 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 225                 return(-1);
 226         }
 227         ctx = LDAP_SLIST_FIRST(&pool->ltp_free_list);
 228         if (ctx) {
 229                 LDAP_SLIST_REMOVE_HEAD(&pool->ltp_free_list, ltc_next.l);
 230         } else {
 231                 ctx = (ldap_int_thread_ctx_t *) LDAP_MALLOC(
 232                         sizeof(ldap_int_thread_ctx_t));
 233                 if (ctx == NULL) {
 234                         ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 235                         return(-1);
 236                 }
 237         }
 238
 239         ctx->ltc_start_routine = start_routine;
 240         ctx->ltc_arg = arg;
 241
 242         pool->ltp_pending_count++;
 243         LDAP_STAILQ_INSERT_TAIL(&pool->ltp_pending_list, ctx, ltc_next.q);
 244         if (pool->ltp_state == LDAP_INT_THREAD_POOL_PAUSING) {
 245                 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 246                 return(0);
 247         }
 248         ldap_pvt_thread_cond_signal(&pool->ltp_cond);
 249         if ((pool->ltp_open_count <= 0
 250 #if 0
 251                         || pool->ltp_pending_count > 1
 252 #endif
 253                         || pool->ltp_open_count == pool->ltp_active_count)
 254                 && (pool->ltp_max_count <= 0
 255                         || pool->ltp_open_count < pool->ltp_max_count))
 256         {
 257                 pool->ltp_open_count++;
 258                 pool->ltp_starting++;
 259                 need_thread = 1;
 260         }
 261         ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 262
 263         if (need_thread) {
 264                 int rc;
 265
 266                 ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
 267
 268                 rc = ldap_pvt_thread_create( &thr, 1,
 269                         ldap_int_thread_pool_wrapper, pool );
 270                 if (rc == 0) {
 271                         int hash;
 272                         pool->ltp_starting--;
 273
 274                         /* assign this thread ID to a key slot; start
 275                          * at the thread ID itself (mod LDAP_MAXTHR) and
 276                          * look for an empty slot.
 277                          */
 278                         TID_HASH(thr, hash);
 279                         for (rc = hash & (LDAP_MAXTHR-1);
 280                                 !TID_EQ(thread_keys[rc].id, tid_zero);
 281                                 rc = (rc+1) & (LDAP_MAXTHR-1));
 282                         thread_keys[rc].id = thr;
 283                 } else {
 284                         /* couldn't create thread.  back out of
 285                          * ltp_open_count and check for even worse things.
 286                          */
 287                         pool->ltp_open_count--;
 288                         pool->ltp_starting--;
 289                         if (pool->ltp_open_count == 0) {
 290                                 /* no open threads at all?!?
 291                                  */
 292                                 ldap_int_thread_ctx_t *ptr;
 293                                 LDAP_STAILQ_FOREACH(ptr, &pool->ltp_pending_list, ltc_next.q)
 294                                         if (ptr == ctx) break;
 295                                 if (ptr == ctx) {
 296                                         /* no open threads, context not handled, so
 297                                          * back out of ltp_pending_count, free the context,
 298                                          * report the error.
 299                                          */
 300                                         LDAP_STAILQ_REMOVE(&pool->ltp_pending_list, ctx,
 301                                                 ldap_int_thread_ctx_s, ltc_next.q);
 302                                         pool->ltp_pending_count++;
 303                                         ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 304                                         LDAP_FREE(ctx);
 305                                         return(-1);
 306                                 }
 307                         }
 308                         /* there is another open thread, so this
 309                          * context will be handled eventually.
 310                          * continue on and signal that the context
 311                          * is waiting.
 312                          */
 313                 }
 314                 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 315         }
 316
 317         return(0);
 318 }
 319
 320 int
 321 ldap_pvt_thread_pool_maxthreads ( ldap_pvt_thread_pool_t *tpool, int max_threads )
 322 {
 323         struct ldap_int_thread_pool_s *pool;
 324
 325         if (tpool == NULL)
 326                 return(-1);
 327
 328         pool = *tpool;
 329
 330         if (pool == NULL)
 331                 return(-1);
 332
 333         ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
 334         pool->ltp_max_count = max_threads;
 335         ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 336         return(0);
 337 }
 338
 339 int
 340 ldap_pvt_thread_pool_backload ( ldap_pvt_thread_pool_t *tpool )
 341 {
 342         struct ldap_int_thread_pool_s *pool;
 343         int count;
 344
 345         if (tpool == NULL)
 346                 return(-1);
 347
 348         pool = *tpool;
 349
 350         if (pool == NULL)
 351                 return(0);
 352
 353         ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
 354         count = pool->ltp_pending_count + pool->ltp_active_count;
 355         ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 356         return(count);
 357 }
 358
 359 int
 360 ldap_pvt_thread_pool_destroy ( ldap_pvt_thread_pool_t *tpool, int run_pending )
 361 {
 362         struct ldap_int_thread_pool_s *pool, *pptr;
 363         long waiting;
 364         ldap_int_thread_ctx_t *ctx;
 365
 366         if (tpool == NULL)
 367                 return(-1);
 368
 369         pool = *tpool;
 370
 371         if (pool == NULL) return(-1);
 372
 373         ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
 374         LDAP_STAILQ_FOREACH(pptr, &ldap_int_thread_pool_list, ltp_next)
 375                 if (pptr == pool) break;
 376         if (pptr == pool)
 377                 LDAP_STAILQ_REMOVE(&ldap_int_thread_pool_list, pool,
 378                         ldap_int_thread_pool_s, ltp_next);
 379         ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
 380
 381         if (pool != pptr) return(-1);
 382
 383         ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
 384         pool->ltp_state = run_pending
 385                 ? LDAP_INT_THREAD_POOL_FINISHING
 386                 : LDAP_INT_THREAD_POOL_STOPPING;
 387
 388         ldap_pvt_thread_cond_broadcast(&pool->ltp_cond);
 389         ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 390
 391         do {
 392                 ldap_pvt_thread_yield();
 393                 ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
 394                 waiting = pool->ltp_open_count;
 395                 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 396         } while (waiting > 0);
 397
 398         while ((ctx = LDAP_STAILQ_FIRST(&pool->ltp_pending_list)) != NULL)
 399         {
 400                 LDAP_STAILQ_REMOVE_HEAD(&pool->ltp_pending_list, ltc_next.q);
 401                 LDAP_FREE(ctx);
 402         }
 403
 404         while ((ctx = LDAP_SLIST_FIRST(&pool->ltp_free_list)) != NULL)
 405         {
 406                 LDAP_SLIST_REMOVE_HEAD(&pool->ltp_free_list, ltc_next.l);
 407                 LDAP_FREE(ctx);
 408         }
 409
 410         ldap_pvt_thread_cond_destroy(&pool->ltp_pcond);
 411         ldap_pvt_thread_cond_destroy(&pool->ltp_cond);
 412         ldap_pvt_thread_mutex_destroy(&pool->ltp_mutex);
 413         LDAP_FREE(pool);
 414         return(0);
 415 }
 416
 417 static void *
 418 ldap_int_thread_pool_wrapper (
 419         void *xpool )
 420 {
 421         struct ldap_int_thread_pool_s *pool = xpool;
 422         ldap_int_thread_ctx_t *ctx;
 423         ldap_int_thread_key_t ltc_key[MAXKEYS];
 424         ldap_pvt_thread_t tid;
 425         int i, keyslot, hash;
 426
 427         if (pool == NULL)
 428                 return NULL;
 429
 430         for ( i=0; i<MAXKEYS; i++ ) {
 431                 ltc_key[i].ltk_key = NULL;
 432         }
 433
 434         tid = ldap_pvt_thread_self();
 435
 436         ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
 437
 438         /* store pointer to our keys */
 439         TID_HASH(tid, hash);
 440         for (i = hash & (LDAP_MAXTHR-1); !TID_EQ(thread_keys[i].id, tid);
 441                                 i = (i+1) & (LDAP_MAXTHR-1));
 442         thread_keys[i].ctx = ltc_key;
 443         keyslot = i;
 444
 445         while (pool->ltp_state != LDAP_INT_THREAD_POOL_STOPPING) {
 446                 ctx = LDAP_STAILQ_FIRST(&pool->ltp_pending_list);
 447                 if (ctx) {
 448                         LDAP_STAILQ_REMOVE_HEAD(&pool->ltp_pending_list, ltc_next.q);
 449                 } else {
 450                         if (pool->ltp_state == LDAP_INT_THREAD_POOL_FINISHING)
 451                                 break;
 452                         if (pool->ltp_max_count > 0
 453                                 && pool->ltp_open_count > pool->ltp_max_count)
 454                         {
 455                                 /* too many threads running (can happen if the
 456                                  * maximum threads value is set during ongoing
 457                                  * operation using ldap_pvt_thread_pool_maxthreads)
 458                                  * so let this thread die.
 459                                  */
 460                                 break;
 461                         }
 462
 463                         /* we could check an idle timer here, and let the
 464                          * thread die if it has been inactive for a while.
 465                          * only die if there are other open threads (i.e.,
 466                          * always have at least one thread open).  the check
 467                          * should be like this:
 468                          *   if (pool->ltp_open_count > 1 && pool->ltp_starting == 0)
 469                          *       check timer, leave thread (break;)
 470                          */
 471
 472                         if (pool->ltp_state == LDAP_INT_THREAD_POOL_RUNNING)
 473                                 ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
 474
 475                         continue;
 476                 }
 477
 478                 pool->ltp_pending_count--;
 479
 480                 LDAP_SLIST_INSERT_HEAD(&pool->ltp_active_list, ctx, ltc_next.al);
 481                 pool->ltp_active_count++;
 482                 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 483
 484                 ctx->ltc_start_routine(ltc_key, ctx->ltc_arg);
 485
 486                 ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
 487                 LDAP_SLIST_REMOVE(&pool->ltp_active_list, ctx,
 488                         ldap_int_thread_ctx_s, ltc_next.al);
 489                 LDAP_SLIST_INSERT_HEAD(&pool->ltp_free_list, ctx, ltc_next.l);
 490                 pool->ltp_active_count--;
 491
 492                 if (pool->ltp_state == LDAP_INT_THREAD_POOL_PAUSING) {
 493                         if (pool->ltp_active_count < 2) {
 494                                 ldap_pvt_thread_cond_signal(&pool->ltp_pcond);
 495                         }
 496                         ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
 497                 }
 498                 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 499
 500                 ldap_pvt_thread_yield();
 501
 502                 /* if we use an idle timer, here's
 503                  * a good place to update it
 504                  */
 505
 506                 ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
 507         }
 508
 509         for ( i=0; i<MAXKEYS && ltc_key[i].ltk_key; i++ ) {
 510                 if (ltc_key[i].ltk_free)
 511                         ltc_key[i].ltk_free(
 512                                 ltc_key[i].ltk_key,
 513                                 ltc_key[i].ltk_data );
 514         }
 515
 516         thread_keys[keyslot].ctx = NULL;
 517         thread_keys[keyslot].id = tid_zero;
 518
 519         pool->ltp_open_count--;
 520         ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 521
 522         ldap_pvt_thread_exit(NULL);
 523         return(NULL);
 524 }
 525
 526 int
 527 ldap_pvt_thread_pool_pause (
 528         ldap_pvt_thread_pool_t *tpool )
 529 {
 530         struct ldap_int_thread_pool_s *pool;
 531
 532         if (tpool == NULL)
 533                 return(-1);
 534
 535         pool = *tpool;
 536
 537         if (pool == NULL)
 538                 return(0);
 539
 540         ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
 541
 542         /* If someone else has already requested a pause, we have to wait */
 543         if (pool->ltp_state == LDAP_INT_THREAD_POOL_PAUSING) {
 544                 pool->ltp_pending_count++;
 545                 pool->ltp_active_count--;
 546                 ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
 547                 pool->ltp_pending_count--;
 548                 pool->ltp_active_count++;
 549         }
 550         /* Wait for everyone else to finish */
 551         pool->ltp_state = LDAP_INT_THREAD_POOL_PAUSING;
 552         while (pool->ltp_active_count > 1) {
 553                 ldap_pvt_thread_cond_wait(&pool->ltp_pcond, &pool->ltp_mutex);
 554         }
 555         ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 556         return(0);
 557 }
 558
 559 int
 560 ldap_pvt_thread_pool_resume (
 561         ldap_pvt_thread_pool_t *tpool )
 562 {
 563         struct ldap_int_thread_pool_s *pool;
 564
 565         if (tpool == NULL)
 566                 return(-1);
 567
 568         pool = *tpool;
 569
 570         if (pool == NULL)
 571                 return(0);
 572
 573         ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
 574
 575         pool->ltp_state = LDAP_INT_THREAD_POOL_RUNNING;
 576         ldap_pvt_thread_cond_broadcast(&pool->ltp_cond);
 577         ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 578         return(0);
 579 }
 580
 581 int ldap_pvt_thread_pool_getkey(
 582         void *xctx,
 583         void *key,
 584         void **data,
 585         ldap_pvt_thread_pool_keyfree_t **kfree )
 586 {
 587         ldap_int_thread_key_t *ctx = xctx;
 588         int i;
 589
 590         if ( !ctx || !data ) return EINVAL;
 591
 592         for ( i=0; i<MAXKEYS && ctx[i].ltk_key; i++ ) {
 593                 if ( ctx[i].ltk_key == key ) {
 594                         *data = ctx[i].ltk_data;
 595                         if ( kfree ) *kfree = ctx[i].ltk_free;
 596                         return 0;
 597                 }
 598         }
 599         return ENOENT;
 600 }
 601
 602 int ldap_pvt_thread_pool_setkey(
 603         void *xctx,
 604         void *key,
 605         void *data,
 606         ldap_pvt_thread_pool_keyfree_t *kfree )
 607 {
 608         ldap_int_thread_key_t *ctx = xctx;
 609         int i;
 610
 611         if ( !ctx || !key ) return EINVAL;
 612
 613         for ( i=0; i<MAXKEYS; i++ ) {
 614                 if ( !ctx[i].ltk_key || ctx[i].ltk_key == key ) {
 615                         ctx[i].ltk_key = key;
 616                         ctx[i].ltk_data = data;
 617                         ctx[i].ltk_free = kfree;
 618                         return 0;
 619                 }
 620         }
 621         return ENOMEM;
 622 }
 623
 624 /* Free all elements with this key, no matter which thread they're in.
 625  * May only be called while the pool is paused.
 626  */
 627 void ldap_pvt_thread_pool_purgekey( void *key )
 628 {
 629         int i, j;
 630         ldap_int_thread_key_t *ctx;
 631
 632         for ( i=0; i<LDAP_MAXTHR; i++ ) {
 633                 if ( thread_keys[i].ctx ) {
 634                         ctx = thread_keys[i].ctx;
 635                         for ( j=0; j<MAXKEYS; j++ ) {
 636                                 if ( ctx[j].ltk_key == key ) {
 637                                         if (ctx[j].ltk_free)
 638                                                 ctx[j].ltk_free( ctx[j].ltk_key, ctx[j].ltk_data );
 639                                         ctx[j].ltk_key = NULL;
 640                                         ctx[j].ltk_free = NULL;
 641                                         break;
 642                                 }
 643                         }
 644                 }
 645         }
 646 }
 647
 648 /*
 649  * This is necessary if the caller does not have access to the
 650  * thread context handle (for example, a slapd plugin calling
 651  * slapi_search_internal()). No doubt it is more efficient to
 652  * for the application to keep track of the thread context
 653  * handles itself.
 654  */
 655 void *ldap_pvt_thread_pool_context( )
 656 {
 657         ldap_pvt_thread_t tid;
 658         int i, hash;
 659
 660         tid = ldap_pvt_thread_self();
 661         if ( TID_EQ( tid, ldap_int_main_tid ))
 662                 return ldap_int_main_thrctx;
 663
 664         TID_HASH( tid, hash );
 665         for (i = hash & (LDAP_MAXTHR-1); !TID_EQ(thread_keys[i].id, tid_zero) &&
 666                 !TID_EQ(thread_keys[i].id, tid); i = (i+1) & (LDAP_MAXTHR-1));
 667
 668         return thread_keys[i].ctx;
 669 }
 670
 671 void ldap_pvt_thread_pool_context_reset( void *vctx )
 672 {
 673         ldap_int_thread_key_t *ctx = vctx;
 674         int i;
 675
 676         for ( i=0; i<MAXKEYS && ctx[i].ltk_key; i++) {
 677                 if ( ctx[i].ltk_free )
 678                         ctx[i].ltk_free( ctx[i].ltk_key, ctx[i].ltk_data );
 679                 ctx[i].ltk_key = NULL;
 680         }
 681 }
 682 #endif /* LDAP_THREAD_HAVE_TPOOL */