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 1998-2013 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/signal.h>
  21 #include <ac/stdarg.h>
  22 #include <ac/stdlib.h>
  23 #include <ac/string.h>
  24 #include <ac/time.h>
  25 #include <ac/errno.h>
  26
  27 #include "ldap-int.h"
  28 #include "ldap_pvt_thread.h" /* Get the thread interface */
  29 #include "ldap_queue.h"
  30 #define LDAP_THREAD_POOL_IMPLEMENTATION
  31 #include "ldap_thr_debug.h"  /* May rename symbols defined below */
  32
  33 #ifndef LDAP_THREAD_HAVE_TPOOL
  34
  35 /* Thread-specific key with data and optional free function */
  36 typedef struct ldap_int_tpool_key_s {
  37         void *ltk_key;
  38         void *ltk_data;
  39         ldap_pvt_thread_pool_keyfree_t *ltk_free;
  40 } ldap_int_tpool_key_t;
  41
  42 /* Max number of thread-specific keys we store per thread.
  43  * We don't expect to use many...
  44  */
  45 #define MAXKEYS 32
  46
  47 /* Max number of threads */
  48 #define LDAP_MAXTHR     1024    /* must be a power of 2 */
  49
  50 /* (Theoretical) max number of pending requests */
  51 #define MAX_PENDING (INT_MAX/2) /* INT_MAX - (room to avoid overflow) */
  52
  53 /* pool->ltp_pause values */
  54 enum { NOT_PAUSED = 0, WANT_PAUSE = 1, PAUSED = 2 };
  55
  56 /* Context: thread ID and thread-specific key/data pairs */
  57 typedef struct ldap_int_thread_userctx_s {
  58         struct ldap_int_thread_poolq_s *ltu_pq;
  59         ldap_pvt_thread_t ltu_id;
  60         ldap_int_tpool_key_t ltu_key[MAXKEYS];
  61 } ldap_int_thread_userctx_t;
  62
  63
  64 /* Simple {thread ID -> context} hash table; key=ctx->ltu_id.
  65  * Protected by ldap_pvt_thread_pool_mutex except during pauses,
  66  * when it is read-only (used by pool_purgekey and pool_context).
  67  * Protected by ldap_pvt_thread_pool_mutex.
  68  */
  69 static struct {
  70         ldap_int_thread_userctx_t *ctx;
  71         /* ctx is valid when not NULL or DELETED_THREAD_CTX */
  72 #       define DELETED_THREAD_CTX (&ldap_int_main_thrctx + 1) /* dummy addr */
  73 } thread_keys[LDAP_MAXTHR];
  74
  75 #define TID_HASH(tid, hash) do { \
  76         unsigned const char *ptr_ = (unsigned const char *)&(tid); \
  77         unsigned i_; \
  78         for (i_ = 0, (hash) = ptr_[0]; ++i_ < sizeof(tid);) \
  79                 (hash) += ((hash) << 5) ^ ptr_[i_]; \
  80 } while(0)
  81
  82
  83 /* Task for a thread to perform */
  84 typedef struct ldap_int_thread_task_s {
  85         union {
  86                 LDAP_STAILQ_ENTRY(ldap_int_thread_task_s) q;
  87                 LDAP_SLIST_ENTRY(ldap_int_thread_task_s) l;
  88         } ltt_next;
  89         ldap_pvt_thread_start_t *ltt_start_routine;
  90         void *ltt_arg;
  91 } ldap_int_thread_task_t;
  92
  93 typedef LDAP_STAILQ_HEAD(tcq, ldap_int_thread_task_s) ldap_int_tpool_plist_t;
  94
  95 struct ldap_int_thread_poolq_s {
  96         struct ldap_int_thread_pool_s *ltp_pool;
  97
  98         /* protect members below */
  99         ldap_pvt_thread_mutex_t ltp_mutex;
 100
 101         /* not paused and something to do for pool_<wrapper/pause/destroy>()
 102          * Used for normal pool operation, to synch between submitter and
 103          * worker threads. Not used for pauses. In normal operation multiple
 104          * queues can rendezvous without acquiring the main pool lock.
 105          */
 106         ldap_pvt_thread_cond_t ltp_cond;
 107
 108         /* ltp_pause == 0 ? &ltp_pending_list : &empty_pending_list,
 109          * maintaned to reduce work for pool_wrapper()
 110          */
 111         ldap_int_tpool_plist_t *ltp_work_list;
 112
 113         /* pending tasks, and unused task objects */
 114         ldap_int_tpool_plist_t ltp_pending_list;
 115         LDAP_SLIST_HEAD(tcl, ldap_int_thread_task_s) ltp_free_list;
 116
 117         /* Max number of threads in this queue */
 118         int ltp_max_count;
 119
 120         /* Max pending + paused + idle tasks, negated when ltp_finishing */
 121         int ltp_max_pending;
 122
 123         int ltp_pending_count;          /* Pending + paused + idle tasks */
 124         int ltp_active_count;           /* Active, not paused/idle tasks */
 125         int ltp_open_count;                     /* Number of threads, negated when ltp_pause */
 126         int ltp_starting;                       /* Currently starting threads */
 127 };
 128
 129 struct ldap_int_thread_pool_s {
 130         LDAP_STAILQ_ENTRY(ldap_int_thread_pool_s) ltp_next;
 131
 132         struct ldap_int_thread_poolq_s *ltp_wqs;
 133
 134         /* number of poolqs */
 135         int ltp_numqs;
 136
 137         /* protect members below */
 138         ldap_pvt_thread_mutex_t ltp_mutex;
 139
 140         /* paused and waiting for resume
 141          * When a pause is in effect all workers switch to waiting on
 142          * this cond instead of their per-queue cond.
 143          */
 144         ldap_pvt_thread_cond_t ltp_cond;
 145
 146         /* ltp_active_queues < 1 && ltp_pause */
 147         ldap_pvt_thread_cond_t ltp_pcond;
 148
 149         /* number of active queues */
 150         int ltp_active_queues;
 151
 152         /* The pool is finishing, waiting for its threads to close.
 153          * They close when ltp_pending_list is done.  pool_submit()
 154          * rejects new tasks.  ltp_max_pending = -(its old value).
 155          */
 156         int ltp_finishing;
 157
 158         /* Some active task needs to be the sole active task.
 159          * Atomic variable so ldap_pvt_thread_pool_pausing() can read it.
 160          */
 161         volatile sig_atomic_t ltp_pause;
 162
 163         /* Max number of threads in pool */
 164         int ltp_max_count;
 165
 166         /* Configured max number of threads in pool, 0 for default (LDAP_MAXTHR) */
 167         int ltp_conf_max_count;
 168
 169         /* Max pending + paused + idle tasks, negated when ltp_finishing */
 170         int ltp_max_pending;
 171 };
 172
 173 static ldap_int_tpool_plist_t empty_pending_list =
 174         LDAP_STAILQ_HEAD_INITIALIZER(empty_pending_list);
 175
 176 static int ldap_int_has_thread_pool = 0;
 177 static LDAP_STAILQ_HEAD(tpq, ldap_int_thread_pool_s)
 178         ldap_int_thread_pool_list =
 179         LDAP_STAILQ_HEAD_INITIALIZER(ldap_int_thread_pool_list);
 180
 181 static ldap_pvt_thread_mutex_t ldap_pvt_thread_pool_mutex;
 182
 183 static void *ldap_int_thread_pool_wrapper( void *pool );
 184
 185 static ldap_pvt_thread_key_t    ldap_tpool_key;
 186
 187 /* Context of the main thread */
 188 static ldap_int_thread_userctx_t ldap_int_main_thrctx;
 189
 190 int
 191 ldap_int_thread_pool_startup ( void )
 192 {
 193         ldap_int_main_thrctx.ltu_id = ldap_pvt_thread_self();
 194         ldap_pvt_thread_key_create( &ldap_tpool_key );
 195         return ldap_pvt_thread_mutex_init(&ldap_pvt_thread_pool_mutex);
 196 }
 197
 198 int
 199 ldap_int_thread_pool_shutdown ( void )
 200 {
 201         struct ldap_int_thread_pool_s *pool;
 202
 203         while ((pool = LDAP_STAILQ_FIRST(&ldap_int_thread_pool_list)) != NULL) {
 204                 (ldap_pvt_thread_pool_destroy)(&pool, 0); /* ignore thr_debug macro */
 205         }
 206         ldap_pvt_thread_mutex_destroy(&ldap_pvt_thread_pool_mutex);
 207         ldap_pvt_thread_key_destroy( ldap_tpool_key );
 208         return(0);
 209 }
 210
 211
 212 /* Create a thread pool */
 213 int
 214 ldap_pvt_thread_pool_init_q (
 215         ldap_pvt_thread_pool_t *tpool,
 216         int max_threads,
 217         int max_pending,
 218         int numqs )
 219 {
 220         ldap_pvt_thread_pool_t pool;
 221         struct ldap_int_thread_poolq_s *pq;
 222         int i, rc, rem_thr, rem_pend;
 223
 224         /* multiple pools are currently not supported (ITS#4943) */
 225         assert(!ldap_int_has_thread_pool);
 226
 227         if (! (0 <= max_threads && max_threads <= LDAP_MAXTHR))
 228                 max_threads = 0;
 229         if (! (1 <= max_pending && max_pending <= MAX_PENDING))
 230                 max_pending = MAX_PENDING;
 231
 232         *tpool = NULL;
 233         pool = (ldap_pvt_thread_pool_t) LDAP_CALLOC(1,
 234                 sizeof(struct ldap_int_thread_pool_s) +
 235                 numqs * sizeof(struct ldap_int_thread_poolq_s));
 236
 237         if (pool == NULL) return(-1);
 238
 239         pool->ltp_wqs = (struct ldap_int_thread_poolq_s *)(pool+1);
 240         pool->ltp_numqs = numqs;
 241         pool->ltp_conf_max_count = max_threads;
 242         if ( !max_threads )
 243                 max_threads = LDAP_MAXTHR;
 244
 245         rc = ldap_pvt_thread_mutex_init(&pool->ltp_mutex);
 246         if (rc != 0)
 247                 return(rc);
 248
 249         rc = ldap_pvt_thread_cond_init(&pool->ltp_cond);
 250         if (rc != 0)
 251                 return(rc);
 252
 253         rc = ldap_pvt_thread_cond_init(&pool->ltp_pcond);
 254         if (rc != 0)
 255                 return(rc);
 256
 257         rem_thr = max_threads % numqs;
 258         rem_pend = max_pending % numqs;
 259         for ( i=0; i<numqs; i++ ) {
 260                 pq = &pool->ltp_wqs[i];
 261                 pq->ltp_pool = pool;
 262                 rc = ldap_pvt_thread_mutex_init(&pq->ltp_mutex);
 263                 if (rc != 0)
 264                         return(rc);
 265                 rc = ldap_pvt_thread_cond_init(&pq->ltp_cond);
 266                 if (rc != 0)
 267                         return(rc);
 268                 LDAP_STAILQ_INIT(&pq->ltp_pending_list);
 269                 pq->ltp_work_list = &pq->ltp_pending_list;
 270                 LDAP_SLIST_INIT(&pq->ltp_free_list);
 271
 272                 pq->ltp_max_count = max_threads / numqs;
 273                 if ( rem_thr ) {
 274                         pq->ltp_max_count++;
 275                         rem_thr--;
 276                 }
 277                 pq->ltp_max_pending = max_pending / numqs;
 278                 if ( rem_pend ) {
 279                         pq->ltp_max_pending++;
 280                         rem_pend--;
 281                 }
 282         }
 283
 284         ldap_int_has_thread_pool = 1;
 285
 286         pool->ltp_max_count = max_threads;
 287         pool->ltp_max_pending = max_pending;
 288
 289         ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
 290         LDAP_STAILQ_INSERT_TAIL(&ldap_int_thread_pool_list, pool, ltp_next);
 291         ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
 292
 293         /* Start no threads just yet.  That can break if the process forks
 294          * later, as slapd does in order to daemonize.  On at least POSIX,
 295          * only the forking thread would survive in the child.  Yet fork()
 296          * can't unlock/clean up other threads' locks and data structures,
 297          * unless pthread_atfork() handlers have been set up to do so.
 298          */
 299
 300         *tpool = pool;
 301         return(0);
 302 }
 303
 304 int
 305 ldap_pvt_thread_pool_init (
 306         ldap_pvt_thread_pool_t *tpool,
 307         int max_threads,
 308         int max_pending )
 309 {
 310         return ldap_pvt_thread_pool_init_q( tpool, max_threads, max_pending, 1 );
 311 }
 312
 313 static int
 314 ldap_int_poolq_hash(
 315         struct ldap_int_thread_pool_s *pool,
 316         void *arg )
 317 {
 318         int i = 0, j;
 319         unsigned char *ptr = (unsigned char *)&arg;
 320         /* dumb hash of arg to choose a queue */
 321         for (j=0; j<sizeof(arg); j++)
 322                 i += *ptr++;
 323         i %= pool->ltp_numqs;
 324         return i;
 325 }
 326
 327 /* Submit a task to be performed by the thread pool */
 328 int
 329 ldap_pvt_thread_pool_submit (
 330         ldap_pvt_thread_pool_t *tpool,
 331         ldap_pvt_thread_start_t *start_routine, void *arg )
 332 {
 333         struct ldap_int_thread_pool_s *pool;
 334         struct ldap_int_thread_poolq_s *pq;
 335         ldap_int_thread_task_t *task;
 336         ldap_pvt_thread_t thr;
 337         int i, j;
 338
 339         if (tpool == NULL)
 340                 return(-1);
 341
 342         pool = *tpool;
 343
 344         if (pool == NULL)
 345                 return(-1);
 346
 347         if ( pool->ltp_numqs > 1 )
 348                 i = ldap_int_poolq_hash( pool, arg );
 349         else
 350                 i = 0;
 351
 352         j = i;
 353         while(1) {
 354                 ldap_pvt_thread_mutex_lock(&pool->ltp_wqs[i].ltp_mutex);
 355                 if (pool->ltp_wqs[i].ltp_pending_count < pool->ltp_wqs[i].ltp_max_pending) {
 356                         break;
 357                 }
 358                 ldap_pvt_thread_mutex_unlock(&pool->ltp_wqs[i].ltp_mutex);
 359                 i++;
 360                 i %= pool->ltp_numqs;
 361                 if ( i == j )
 362                         return -1;
 363         }
 364
 365         pq = &pool->ltp_wqs[i];
 366         task = LDAP_SLIST_FIRST(&pq->ltp_free_list);
 367         if (task) {
 368                 LDAP_SLIST_REMOVE_HEAD(&pq->ltp_free_list, ltt_next.l);
 369         } else {
 370                 task = (ldap_int_thread_task_t *) LDAP_MALLOC(sizeof(*task));
 371                 if (task == NULL)
 372                         goto failed;
 373         }
 374
 375         task->ltt_start_routine = start_routine;
 376         task->ltt_arg = arg;
 377
 378         pq->ltp_pending_count++;
 379         LDAP_STAILQ_INSERT_TAIL(&pq->ltp_pending_list, task, ltt_next.q);
 380
 381         if (pool->ltp_pause)
 382                 goto done;
 383
 384         /* should we open (create) a thread? */
 385         if (pq->ltp_open_count < pq->ltp_active_count+pq->ltp_pending_count &&
 386                 pq->ltp_open_count < pq->ltp_max_count)
 387         {
 388                 pq->ltp_starting++;
 389                 pq->ltp_open_count++;
 390
 391                 if (0 != ldap_pvt_thread_create(
 392                         &thr, 1, ldap_int_thread_pool_wrapper, pq))
 393                 {
 394                         /* couldn't create thread.  back out of
 395                          * ltp_open_count and check for even worse things.
 396                          */
 397                         pq->ltp_starting--;
 398                         pq->ltp_open_count--;
 399
 400                         if (pq->ltp_open_count == 0) {
 401                                 /* no open threads at all?!?
 402                                  */
 403                                 ldap_int_thread_task_t *ptr;
 404
 405                                 /* let pool_destroy know there are no more threads */
 406                                 ldap_pvt_thread_cond_signal(&pq->ltp_cond);
 407
 408                                 LDAP_STAILQ_FOREACH(ptr, &pq->ltp_pending_list, ltt_next.q)
 409                                         if (ptr == task) break;
 410                                 if (ptr == task) {
 411                                         /* no open threads, task not handled, so
 412                                          * back out of ltp_pending_count, free the task,
 413                                          * report the error.
 414                                          */
 415                                         pq->ltp_pending_count--;
 416                                         LDAP_STAILQ_REMOVE(&pq->ltp_pending_list, task,
 417                                                 ldap_int_thread_task_s, ltt_next.q);
 418                                         LDAP_SLIST_INSERT_HEAD(&pq->ltp_free_list, task,
 419                                                 ltt_next.l);
 420                                         goto failed;
 421                                 }
 422                         }
 423                         /* there is another open thread, so this
 424                          * task will be handled eventually.
 425                          */
 426                 }
 427         }
 428         ldap_pvt_thread_cond_signal(&pq->ltp_cond);
 429
 430  done:
 431         ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
 432         return(0);
 433
 434  failed:
 435         ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
 436         return(-1);
 437 }
 438
 439 static void *
 440 no_task( void *ctx, void *arg )
 441 {
 442         return NULL;
 443 }
 444
 445 /* Cancel a pending task that was previously submitted.
 446  * Return 1 if the task was successfully cancelled, 0 if
 447  * not found, -1 for invalid parameters
 448  */
 449 int
 450 ldap_pvt_thread_pool_retract (
 451         ldap_pvt_thread_pool_t *tpool,
 452         ldap_pvt_thread_start_t *start_routine, void *arg )
 453 {
 454         struct ldap_int_thread_pool_s *pool;
 455         struct ldap_int_thread_poolq_s *pq;
 456         ldap_int_thread_task_t *task;
 457         int i;
 458
 459         if (tpool == NULL)
 460                 return(-1);
 461
 462         pool = *tpool;
 463
 464         if (pool == NULL)
 465                 return(-1);
 466
 467         i = ldap_int_poolq_hash( pool, arg );
 468         pq = &pool->ltp_wqs[i];
 469
 470         ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
 471         LDAP_STAILQ_FOREACH(task, &pq->ltp_pending_list, ltt_next.q)
 472                 if (task->ltt_start_routine == start_routine &&
 473                         task->ltt_arg == arg) {
 474                         /* Could LDAP_STAILQ_REMOVE the task, but that
 475                          * walks ltp_pending_list again to find it.
 476                          */
 477                         task->ltt_start_routine = no_task;
 478                         task->ltt_arg = NULL;
 479                         break;
 480                 }
 481         ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
 482         return task != NULL;
 483 }
 484
 485 /* Set max #threads.  value <= 0 means max supported #threads (LDAP_MAXTHR) */
 486 int
 487 ldap_pvt_thread_pool_maxthreads(
 488         ldap_pvt_thread_pool_t *tpool,
 489         int max_threads )
 490 {
 491         struct ldap_int_thread_pool_s *pool;
 492         struct ldap_int_thread_poolq_s *pq;
 493         int remthr, i;
 494
 495         if (! (0 <= max_threads && max_threads <= LDAP_MAXTHR))
 496                 max_threads = 0;
 497
 498         if (tpool == NULL)
 499                 return(-1);
 500
 501         pool = *tpool;
 502
 503         if (pool == NULL)
 504                 return(-1);
 505
 506         pool->ltp_conf_max_count = max_threads;
 507         if ( !max_threads )
 508                 max_threads = LDAP_MAXTHR;
 509         pool->ltp_max_count = max_threads;
 510
 511         remthr = max_threads % pool->ltp_numqs;
 512         max_threads /= pool->ltp_numqs;
 513
 514         for (i=0; i<pool->ltp_numqs; i++) {
 515                 pq = &pool->ltp_wqs[i];
 516                 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
 517                 pq->ltp_max_count = max_threads;
 518                 if (remthr) {
 519                         pq->ltp_max_count++;
 520                         remthr--;
 521                 }
 522                 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
 523         }
 524         return(0);
 525 }
 526
 527 /* Inspect the pool */
 528 int
 529 ldap_pvt_thread_pool_query(
 530         ldap_pvt_thread_pool_t *tpool,
 531         ldap_pvt_thread_pool_param_t param,
 532         void *value )
 533 {
 534         struct ldap_int_thread_pool_s   *pool;
 535         int                             count = -1;
 536
 537         if ( tpool == NULL || value == NULL ) {
 538                 return -1;
 539         }
 540
 541         pool = *tpool;
 542
 543         if ( pool == NULL ) {
 544                 return 0;
 545         }
 546
 547         switch ( param ) {
 548         case LDAP_PVT_THREAD_POOL_PARAM_MAX:
 549                 count = pool->ltp_conf_max_count;
 550                 break;
 551
 552         case LDAP_PVT_THREAD_POOL_PARAM_MAX_PENDING:
 553                 count = pool->ltp_max_pending;
 554                 if (count < 0)
 555                         count = -count;
 556                 if (count == MAX_PENDING)
 557                         count = 0;
 558                 break;
 559
 560         case LDAP_PVT_THREAD_POOL_PARAM_PAUSING:
 561                 ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
 562                 count = (pool->ltp_pause != 0);
 563                 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 564                 break;
 565
 566         case LDAP_PVT_THREAD_POOL_PARAM_OPEN:
 567         case LDAP_PVT_THREAD_POOL_PARAM_STARTING:
 568         case LDAP_PVT_THREAD_POOL_PARAM_ACTIVE:
 569         case LDAP_PVT_THREAD_POOL_PARAM_PENDING:
 570         case LDAP_PVT_THREAD_POOL_PARAM_BACKLOAD:
 571                 {
 572                         int i;
 573                         count = 0;
 574                         for (i=0; i<pool->ltp_numqs; i++) {
 575                                 struct ldap_int_thread_poolq_s *pq = &pool->ltp_wqs[i];
 576                                 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
 577                                 switch(param) {
 578                                         case LDAP_PVT_THREAD_POOL_PARAM_OPEN:
 579                                                 count += pq->ltp_open_count;
 580                                                 break;
 581                                         case LDAP_PVT_THREAD_POOL_PARAM_STARTING:
 582                                                 count += pq->ltp_starting;
 583                                                 break;
 584                                         case LDAP_PVT_THREAD_POOL_PARAM_ACTIVE:
 585                                                 count += pq->ltp_active_count;
 586                                                 break;
 587                                         case LDAP_PVT_THREAD_POOL_PARAM_PENDING:
 588                                                 count += pq->ltp_pending_count;
 589                                                 break;
 590                                         case LDAP_PVT_THREAD_POOL_PARAM_BACKLOAD:
 591                                                 count += pq->ltp_pending_count + pq->ltp_active_count;
 592                                                 break;
 593                                 }
 594                                 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
 595                         }
 596                         if (count < 0)
 597                                 count = -count;
 598                 }
 599                 break;
 600
 601         case LDAP_PVT_THREAD_POOL_PARAM_ACTIVE_MAX:
 602                 break;
 603
 604         case LDAP_PVT_THREAD_POOL_PARAM_PENDING_MAX:
 605                 break;
 606
 607         case LDAP_PVT_THREAD_POOL_PARAM_BACKLOAD_MAX:
 608                 break;
 609
 610         case LDAP_PVT_THREAD_POOL_PARAM_STATE:
 611                 if (pool->ltp_pause)
 612                         *((char **)value) = "pausing";
 613                 else if (!pool->ltp_finishing)
 614                         *((char **)value) = "running";
 615                 else {
 616                         int i;
 617                         for (i=0; i<pool->ltp_numqs; i++)
 618                                 if (pool->ltp_wqs[i].ltp_pending_count) break;
 619                         if (i<pool->ltp_numqs)
 620                                 *((char **)value) = "finishing";
 621                         else
 622                                 *((char **)value) = "stopping";
 623                 }
 624                 break;
 625
 626         case LDAP_PVT_THREAD_POOL_PARAM_UNKNOWN:
 627                 break;
 628         }
 629
 630         if ( count > -1 ) {
 631                 *((int *)value) = count;
 632         }
 633
 634         return ( count == -1 ? -1 : 0 );
 635 }
 636
 637 /*
 638  * true if pool is pausing; does not lock any mutex to check.
 639  * 0 if not pause, 1 if pause, -1 if error or no pool.
 640  */
 641 int
 642 ldap_pvt_thread_pool_pausing( ldap_pvt_thread_pool_t *tpool )
 643 {
 644         int rc = -1;
 645         struct ldap_int_thread_pool_s *pool;
 646
 647         if ( tpool != NULL && (pool = *tpool) != NULL ) {
 648                 rc = (pool->ltp_pause != 0);
 649         }
 650
 651         return rc;
 652 }
 653
 654 /*
 655  * wrapper for ldap_pvt_thread_pool_query(), left around
 656  * for backwards compatibility
 657  */
 658 int
 659 ldap_pvt_thread_pool_backload ( ldap_pvt_thread_pool_t *tpool )
 660 {
 661         int     rc, count;
 662
 663         rc = ldap_pvt_thread_pool_query( tpool,
 664                 LDAP_PVT_THREAD_POOL_PARAM_BACKLOAD, (void *)&count );
 665
 666         if ( rc == 0 ) {
 667                 return count;
 668         }
 669
 670         return rc;
 671 }
 672
 673 /* Destroy the pool after making its threads finish */
 674 int
 675 ldap_pvt_thread_pool_destroy ( ldap_pvt_thread_pool_t *tpool, int run_pending )
 676 {
 677         struct ldap_int_thread_pool_s *pool, *pptr;
 678         struct ldap_int_thread_poolq_s *pq;
 679         ldap_int_thread_task_t *task;
 680         int i;
 681
 682         if (tpool == NULL)
 683                 return(-1);
 684
 685         pool = *tpool;
 686
 687         if (pool == NULL) return(-1);
 688
 689         ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
 690         LDAP_STAILQ_FOREACH(pptr, &ldap_int_thread_pool_list, ltp_next)
 691                 if (pptr == pool) break;
 692         if (pptr == pool)
 693                 LDAP_STAILQ_REMOVE(&ldap_int_thread_pool_list, pool,
 694                         ldap_int_thread_pool_s, ltp_next);
 695         ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
 696
 697         if (pool != pptr) return(-1);
 698
 699         ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
 700
 701         pool->ltp_finishing = 1;
 702         if (pool->ltp_max_pending > 0)
 703                 pool->ltp_max_pending = -pool->ltp_max_pending;
 704
 705         ldap_pvt_thread_cond_broadcast(&pool->ltp_cond);
 706         ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 707
 708         for (i=0; i<pool->ltp_numqs; i++) {
 709                 pq = &pool->ltp_wqs[i];
 710                 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
 711                 if (pq->ltp_max_pending > 0)
 712                         pq->ltp_max_pending = -pq->ltp_max_pending;
 713                 if (!run_pending) {
 714                         while ((task = LDAP_STAILQ_FIRST(&pq->ltp_pending_list)) != NULL) {
 715                                 LDAP_STAILQ_REMOVE_HEAD(&pq->ltp_pending_list, ltt_next.q);
 716                                 LDAP_FREE(task);
 717                         }
 718                         pq->ltp_pending_count = 0;
 719                 }
 720
 721                 while (pq->ltp_open_count) {
 722                         ldap_pvt_thread_cond_broadcast(&pq->ltp_cond);
 723                         ldap_pvt_thread_cond_wait(&pq->ltp_cond, &pq->ltp_mutex);
 724                 }
 725
 726                 while ((task = LDAP_SLIST_FIRST(&pq->ltp_free_list)) != NULL)
 727                 {
 728                         LDAP_SLIST_REMOVE_HEAD(&pq->ltp_free_list, ltt_next.l);
 729                         LDAP_FREE(task);
 730                 }
 731                 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
 732                 ldap_pvt_thread_cond_destroy(&pq->ltp_cond);
 733                 ldap_pvt_thread_mutex_destroy(&pq->ltp_mutex);
 734         }
 735
 736         ldap_pvt_thread_cond_destroy(&pool->ltp_pcond);
 737         ldap_pvt_thread_cond_destroy(&pool->ltp_cond);
 738         ldap_pvt_thread_mutex_destroy(&pool->ltp_mutex);
 739         LDAP_FREE(pool);
 740         *tpool = NULL;
 741         ldap_int_has_thread_pool = 0;
 742         return(0);
 743 }
 744
 745 /* Thread loop.  Accept and handle submitted tasks. */
 746 static void *
 747 ldap_int_thread_pool_wrapper (
 748         void *xpool )
 749 {
 750         struct ldap_int_thread_poolq_s *pq = xpool;
 751         struct ldap_int_thread_pool_s *pool = pq->ltp_pool;
 752         ldap_int_thread_task_t *task;
 753         ldap_int_tpool_plist_t *work_list;
 754         ldap_int_thread_userctx_t ctx, *kctx;
 755         unsigned i, keyslot, hash;
 756         int pool_lock = 0;
 757
 758         assert(pool != NULL);
 759
 760         for ( i=0; i<MAXKEYS; i++ ) {
 761                 ctx.ltu_key[i].ltk_key = NULL;
 762         }
 763
 764         ctx.ltu_pq = pq;
 765         ctx.ltu_id = ldap_pvt_thread_self();
 766         TID_HASH(ctx.ltu_id, hash);
 767
 768         ldap_pvt_thread_key_setdata( ldap_tpool_key, &ctx );
 769
 770         if (pool->ltp_pause) {
 771                 ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
 772                 /* thread_keys[] is read-only when paused */
 773                 while (pool->ltp_pause)
 774                         ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
 775                 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 776         }
 777
 778         /* find a key slot to give this thread ID and store a
 779          * pointer to our keys there; start at the thread ID
 780          * itself (mod LDAP_MAXTHR) and look for an empty slot.
 781          */
 782         ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
 783         for (keyslot = hash & (LDAP_MAXTHR-1);
 784                 (kctx = thread_keys[keyslot].ctx) && kctx != DELETED_THREAD_CTX;
 785                 keyslot = (keyslot+1) & (LDAP_MAXTHR-1));
 786         thread_keys[keyslot].ctx = &ctx;
 787         ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
 788
 789         ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
 790         pq->ltp_starting--;
 791         pq->ltp_active_count++;
 792
 793         for (;;) {
 794                 work_list = pq->ltp_work_list; /* help the compiler a bit */
 795                 task = LDAP_STAILQ_FIRST(work_list);
 796                 if (task == NULL) {     /* paused or no pending tasks */
 797                         if (--(pq->ltp_active_count) < 1) {
 798                                 if (pool->ltp_pause) {
 799                                         ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
 800                                         ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
 801                                         pool_lock = 1;
 802                                         if (--(pool->ltp_active_queues) < 1) {
 803                                                 /* Notify pool_pause it is the sole active thread. */
 804                                                 ldap_pvt_thread_cond_signal(&pool->ltp_pcond);
 805                                         }
 806                                 }
 807                         }
 808
 809                         do {
 810                                 if (pool->ltp_finishing || pq->ltp_open_count > pq->ltp_max_count) {
 811                                         /* Not paused, and either finishing or too many
 812                                          * threads running (can happen if ltp_max_count
 813                                          * was reduced).  Let this thread die.
 814                                          */
 815                                         goto done;
 816                                 }
 817
 818                                 /* We could check an idle timer here, and let the
 819                                  * thread die if it has been inactive for a while.
 820                                  * Only die if there are other open threads (i.e.,
 821                                  * always have at least one thread open).
 822                                  * The check should be like this:
 823                                  *   if (pool->ltp_open_count>1 && pool->ltp_starting==0)
 824                                  *       check timer, wait if ltp_pause, leave thread;
 825                                  *
 826                                  * Just use pthread_cond_timedwait() if we want to
 827                                  * check idle time.
 828                                  */
 829                                 if (pool_lock) {
 830                                         ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
 831                                         if (!pool->ltp_pause) {
 832                                                 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 833                                                 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
 834                                                 pool_lock = 0;
 835                                         }
 836                                 } else
 837                                         ldap_pvt_thread_cond_wait(&pq->ltp_cond, &pq->ltp_mutex);
 838
 839                                 work_list = pq->ltp_work_list;
 840                                 task = LDAP_STAILQ_FIRST(work_list);
 841                         } while (task == NULL);
 842
 843                         if (pool_lock) {
 844                                 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 845                                 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
 846                                 pool_lock = 0;
 847                         }
 848                         pq->ltp_active_count++;
 849                 }
 850
 851                 LDAP_STAILQ_REMOVE_HEAD(work_list, ltt_next.q);
 852                 pq->ltp_pending_count--;
 853                 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
 854
 855                 task->ltt_start_routine(&ctx, task->ltt_arg);
 856
 857                 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
 858                 LDAP_SLIST_INSERT_HEAD(&pq->ltp_free_list, task, ltt_next.l);
 859         }
 860  done:
 861
 862         ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
 863
 864         /* The pool_mutex lock protects ctx->ltu_key from pool_purgekey()
 865          * during this call, since it prevents new pauses. */
 866         ldap_pvt_thread_pool_context_reset(&ctx);
 867
 868         thread_keys[keyslot].ctx = DELETED_THREAD_CTX;
 869         ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
 870
 871         pq->ltp_open_count--;
 872         /* let pool_destroy know we're all done */
 873         if (pq->ltp_open_count == 0)
 874                 ldap_pvt_thread_cond_signal(&pq->ltp_cond);
 875
 876         if (pool_lock)
 877                 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
 878         else
 879                 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
 880
 881         ldap_pvt_thread_exit(NULL);
 882         return(NULL);
 883 }
 884
 885 /* Arguments > ltp_pause to handle_pause(,PAUSE_ARG()).  arg=PAUSE_ARG
 886  * ensures (arg-ltp_pause) sets GO_* at need and keeps DO_PAUSE/GO_*.
 887  */
 888 #define GO_IDLE         8
 889 #define GO_UNIDLE       16
 890 #define CHECK_PAUSE     32      /* if ltp_pause: GO_IDLE; wait; GO_UNIDLE */
 891 #define DO_PAUSE        64      /* CHECK_PAUSE; pause the pool */
 892 #define PAUSE_ARG(a) \
 893                 ((a) | ((a) & (GO_IDLE|GO_UNIDLE) ? GO_IDLE-1 : CHECK_PAUSE))
 894
 895 static int
 896 handle_pause( ldap_pvt_thread_pool_t *tpool, int pause_type )
 897 {
 898         struct ldap_int_thread_pool_s *pool;
 899         struct ldap_int_thread_poolq_s *pq;
 900         int ret = 0, pause, max_ltp_pause;
 901
 902         if (tpool == NULL)
 903                 return(-1);
 904
 905         pool = *tpool;
 906
 907         if (pool == NULL)
 908                 return(0);
 909
 910         if (pause_type == CHECK_PAUSE && !pool->ltp_pause)
 911                 return(0);
 912
 913         {
 914                 ldap_int_thread_userctx_t *ctx = ldap_pvt_thread_pool_context();
 915                 pq = ctx->ltu_pq;
 916         }
 917
 918         /* Let pool_unidle() ignore requests for new pauses */
 919         max_ltp_pause = pause_type==PAUSE_ARG(GO_UNIDLE) ? WANT_PAUSE : NOT_PAUSED;
 920
 921         ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
 922
 923         pause = pool->ltp_pause;        /* NOT_PAUSED, WANT_PAUSE or PAUSED */
 924
 925         /* If ltp_pause and not GO_IDLE|GO_UNIDLE: Set GO_IDLE,GO_UNIDLE */
 926         pause_type -= pause;
 927
 928         if (pause_type & GO_IDLE) {
 929                 int do_pool = 0;
 930                 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
 931                 pq->ltp_pending_count++;
 932                 pq->ltp_active_count--;
 933                 if (pause && pq->ltp_active_count < 1) {
 934                         do_pool = 1;
 935                 }
 936                 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
 937                 if (do_pool) {
 938                         pool->ltp_active_queues--;
 939                         if (pool->ltp_active_queues < 1)
 940                         /* Tell the task waiting to DO_PAUSE it can proceed */
 941                                 ldap_pvt_thread_cond_signal(&pool->ltp_pcond);
 942                 }
 943         }
 944
 945         if (pause_type & GO_UNIDLE) {
 946                 /* Wait out pause if any, then cancel GO_IDLE */
 947                 if (pause > max_ltp_pause) {
 948                         ret = 1;
 949                         do {
 950                                 ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
 951                         } while (pool->ltp_pause > max_ltp_pause);
 952                 }
 953                 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
 954                 pq->ltp_pending_count--;
 955                 pq->ltp_active_count++;
 956                 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
 957         }
 958
 959         if (pause_type & DO_PAUSE) {
 960                 int i, j;
 961                 /* Tell everyone else to pause or finish, then await that */
 962                 ret = 0;
 963                 assert(!pool->ltp_pause);
 964                 pool->ltp_pause = WANT_PAUSE;
 965                 pool->ltp_active_queues = 0;
 966
 967                 for (i=0; i<pool->ltp_numqs; i++)
 968                         if (&pool->ltp_wqs[i] == pq) break;
 969
 970                 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
 971                 /* temporarily remove ourself from active count */
 972                 pq->ltp_active_count--;
 973
 974                 j=i;
 975                 do {
 976                         pq = &pool->ltp_wqs[j];
 977                         if (j != i)
 978                                 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
 979
 980                         /* Let ldap_pvt_thread_pool_submit() through to its ltp_pause test,
 981                          * and do not finish threads in ldap_pvt_thread_pool_wrapper() */
 982                         pq->ltp_open_count = -pq->ltp_open_count;
 983                         /* Hide pending tasks from ldap_pvt_thread_pool_wrapper() */
 984                         pq->ltp_work_list = &empty_pending_list;
 985
 986                         if (pq->ltp_active_count > 0)
 987                                 pool->ltp_active_queues++;
 988
 989                         ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
 990                         if (pool->ltp_numqs > 1) {
 991                                 j++;
 992                                 j %= pool->ltp_numqs;
 993                         }
 994                 } while (j != i);
 995
 996                 /* Wait for this task to become the sole active task */
 997                 while (pool->ltp_active_queues > 0)
 998                         ldap_pvt_thread_cond_wait(&pool->ltp_pcond, &pool->ltp_mutex);
 999
1000                 /* restore us to active count */
1001                 pool->ltp_wqs[i].ltp_active_count++;
1002
1003                 assert(pool->ltp_pause == WANT_PAUSE);
1004                 pool->ltp_pause = PAUSED;
1005         }
1006         ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
1007
1008         return(ret);
1009 }
1010
1011 /* Consider this task idle: It will not block pool_pause() in other tasks. */
1012 void
1013 ldap_pvt_thread_pool_idle( ldap_pvt_thread_pool_t *tpool )
1014 {
1015         handle_pause(tpool, PAUSE_ARG(GO_IDLE));
1016 }
1017
1018 /* Cancel pool_idle(). If the pool is paused, wait it out first. */
1019 void
1020 ldap_pvt_thread_pool_unidle( ldap_pvt_thread_pool_t *tpool )
1021 {
1022         handle_pause(tpool, PAUSE_ARG(GO_UNIDLE));
1023 }
1024
1025 /*
1026  * If a pause was requested, wait for it.  If several threads
1027  * are waiting to pause, let through one or more pauses.
1028  * The calling task must be active, not idle.
1029  * Return 1 if we waited, 0 if not, -1 at parameter error.
1030  */
1031 int
1032 ldap_pvt_thread_pool_pausecheck( ldap_pvt_thread_pool_t *tpool )
1033 {
1034         return handle_pause(tpool, PAUSE_ARG(CHECK_PAUSE));
1035 }
1036
1037 /*
1038  * Pause the pool.  The calling task must be active, not idle.
1039  * Return when all other tasks are paused or idle.
1040  */
1041 int
1042 ldap_pvt_thread_pool_pause( ldap_pvt_thread_pool_t *tpool )
1043 {
1044         return handle_pause(tpool, PAUSE_ARG(DO_PAUSE));
1045 }
1046
1047 /* End a pause */
1048 int
1049 ldap_pvt_thread_pool_resume (
1050         ldap_pvt_thread_pool_t *tpool )
1051 {
1052         struct ldap_int_thread_pool_s *pool;
1053         struct ldap_int_thread_poolq_s *pq;
1054         int i;
1055
1056         if (tpool == NULL)
1057                 return(-1);
1058
1059         pool = *tpool;
1060
1061         if (pool == NULL)
1062                 return(0);
1063
1064         ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
1065         assert(pool->ltp_pause == PAUSED);
1066         pool->ltp_pause = 0;
1067         for (i=0; i<pool->ltp_numqs; i++) {
1068                 pq = &pool->ltp_wqs[i];
1069                 if (pq->ltp_open_count <= 0) /* true when paused, but be paranoid */
1070                         pq->ltp_open_count = -pq->ltp_open_count;
1071                 pq->ltp_work_list = &pq->ltp_pending_list;
1072                 ldap_pvt_thread_cond_broadcast(&pq->ltp_cond);
1073         }
1074         ldap_pvt_thread_cond_broadcast(&pool->ltp_cond);
1075         ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
1076         return(0);
1077 }
1078
1079 /*
1080  * Get the key's data and optionally free function in the given context.
1081  */
1082 int ldap_pvt_thread_pool_getkey(
1083         void *xctx,
1084         void *key,
1085         void **data,
1086         ldap_pvt_thread_pool_keyfree_t **kfree )
1087 {
1088         ldap_int_thread_userctx_t *ctx = xctx;
1089         int i;
1090
1091         if ( !ctx || !key || !data ) return EINVAL;
1092
1093         for ( i=0; i<MAXKEYS && ctx->ltu_key[i].ltk_key; i++ ) {
1094                 if ( ctx->ltu_key[i].ltk_key == key ) {
1095                         *data = ctx->ltu_key[i].ltk_data;
1096                         if ( kfree ) *kfree = ctx->ltu_key[i].ltk_free;
1097                         return 0;
1098                 }
1099         }
1100         return ENOENT;
1101 }
1102
1103 static void
1104 clear_key_idx( ldap_int_thread_userctx_t *ctx, int i )
1105 {
1106         for ( ; i < MAXKEYS-1 && ctx->ltu_key[i+1].ltk_key; i++ )
1107                 ctx->ltu_key[i] = ctx->ltu_key[i+1];
1108         ctx->ltu_key[i].ltk_key = NULL;
1109 }
1110
1111 /*
1112  * Set or remove data for the key in the given context.
1113  * key can be any unique pointer.
1114  * kfree() is an optional function to free the data (but not the key):
1115  *   pool_context_reset() and pool_purgekey() call kfree(key, data),
1116  *   but pool_setkey() does not.  For pool_setkey() it is the caller's
1117  *   responsibility to free any existing data with the same key.
1118  *   kfree() must not call functions taking a tpool argument.
1119  */
1120 int ldap_pvt_thread_pool_setkey(
1121         void *xctx,
1122         void *key,
1123         void *data,
1124         ldap_pvt_thread_pool_keyfree_t *kfree,
1125         void **olddatap,
1126         ldap_pvt_thread_pool_keyfree_t **oldkfreep )
1127 {
1128         ldap_int_thread_userctx_t *ctx = xctx;
1129         int i, found;
1130
1131         if ( !ctx || !key ) return EINVAL;
1132
1133         for ( i=found=0; i<MAXKEYS; i++ ) {
1134                 if ( ctx->ltu_key[i].ltk_key == key ) {
1135                         found = 1;
1136                         break;
1137                 } else if ( !ctx->ltu_key[i].ltk_key ) {
1138                         break;
1139                 }
1140         }
1141
1142         if ( olddatap ) {
1143                 if ( found ) {
1144                         *olddatap = ctx->ltu_key[i].ltk_data;
1145                 } else {
1146                         *olddatap = NULL;
1147                 }
1148         }
1149
1150         if ( oldkfreep ) {
1151                 if ( found ) {
1152                         *oldkfreep = ctx->ltu_key[i].ltk_free;
1153                 } else {
1154                         *oldkfreep = 0;
1155                 }
1156         }
1157
1158         if ( data || kfree ) {
1159                 if ( i>=MAXKEYS )
1160                         return ENOMEM;
1161                 ctx->ltu_key[i].ltk_key = key;
1162                 ctx->ltu_key[i].ltk_data = data;
1163                 ctx->ltu_key[i].ltk_free = kfree;
1164         } else if ( found ) {
1165                 clear_key_idx( ctx, i );
1166         }
1167
1168         return 0;
1169 }
1170
1171 /* Free all elements with this key, no matter which thread they're in.
1172  * May only be called while the pool is paused.
1173  */
1174 void ldap_pvt_thread_pool_purgekey( void *key )
1175 {
1176         int i, j;
1177         ldap_int_thread_userctx_t *ctx;
1178
1179         assert ( key != NULL );
1180
1181         ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
1182         for ( i=0; i<LDAP_MAXTHR; i++ ) {
1183                 ctx = thread_keys[i].ctx;
1184                 if ( ctx && ctx != DELETED_THREAD_CTX ) {
1185                         for ( j=0; j<MAXKEYS && ctx->ltu_key[j].ltk_key; j++ ) {
1186                                 if ( ctx->ltu_key[j].ltk_key == key ) {
1187                                         if (ctx->ltu_key[j].ltk_free)
1188                                                 ctx->ltu_key[j].ltk_free( ctx->ltu_key[j].ltk_key,
1189                                                 ctx->ltu_key[j].ltk_data );
1190                                         clear_key_idx( ctx, j );
1191                                         break;
1192                                 }
1193                         }
1194                 }
1195         }
1196         ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
1197 }
1198
1199 /*
1200  * Find the context of the current thread.
1201  * This is necessary if the caller does not have access to the
1202  * thread context handle (for example, a slapd plugin calling
1203  * slapi_search_internal()). No doubt it is more efficient
1204  * for the application to keep track of the thread context
1205  * handles itself.
1206  */
1207 void *ldap_pvt_thread_pool_context( )
1208 {
1209         void *ctx = NULL;
1210
1211         ldap_pvt_thread_key_getdata( ldap_tpool_key, &ctx );
1212         return ctx ? ctx : (void *) &ldap_int_main_thrctx;
1213 }
1214
1215 /*
1216  * Free the context's keys.
1217  * Must not call functions taking a tpool argument (because this
1218  * thread already holds ltp_mutex when called from pool_wrapper()).
1219  */
1220 void ldap_pvt_thread_pool_context_reset( void *vctx )
1221 {
1222         ldap_int_thread_userctx_t *ctx = vctx;
1223         int i;
1224
1225         for ( i=MAXKEYS-1; i>=0; i--) {
1226                 if ( !ctx->ltu_key[i].ltk_key )
1227                         continue;
1228                 if ( ctx->ltu_key[i].ltk_free )
1229                         ctx->ltu_key[i].ltk_free( ctx->ltu_key[i].ltk_key,
1230                         ctx->ltu_key[i].ltk_data );
1231                 ctx->ltu_key[i].ltk_key = NULL;
1232         }
1233 }
1234
1235 ldap_pvt_thread_t ldap_pvt_thread_pool_tid( void *vctx )
1236 {
1237         ldap_int_thread_userctx_t *ctx = vctx;
1238
1239         return ctx->ltu_id;
1240 }
1241 #endif /* LDAP_THREAD_HAVE_TPOOL */