1 /* $NetBSD: tpool.c,v 1.2 2021/08/14 16:14:56 christos Exp $ */
2
3 /* $OpenLDAP$ */
4 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
5 *
6 * Copyright 1998-2021 The OpenLDAP Foundation.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted only as authorized by the OpenLDAP
11 * Public License.
12 *
13 * A copy of this license is available in file LICENSE in the
14 * top-level directory of the distribution or, alternatively, at
15 * <http://www.OpenLDAP.org/license.html>.
16 */
17
18 #include <sys/cdefs.h>
19 __RCSID("$NetBSD: tpool.c,v 1.2 2021/08/14 16:14:56 christos Exp $");
20
21 #include "portable.h"
22
23 #include <stdio.h>
24
25 #include <ac/signal.h>
26 #include <ac/stdarg.h>
27 #include <ac/stdlib.h>
28 #include <ac/string.h>
29 #include <ac/time.h>
30 #include <ac/errno.h>
31
32 #include "ldap-int.h"
33
34 #ifdef LDAP_R_COMPILE
35
36 #include "ldap_pvt_thread.h" /* Get the thread interface */
37 #include "ldap_queue.h"
38 #define LDAP_THREAD_POOL_IMPLEMENTATION
39 #include "ldap_thr_debug.h" /* May rename symbols defined below */
40
41 #ifndef LDAP_THREAD_HAVE_TPOOL
42
43 #ifndef CACHELINE
44 #define CACHELINE 64
45 #endif
46
47 /* Thread-specific key with data and optional free function */
48 typedef struct ldap_int_tpool_key_s {
49 void *ltk_key;
50 void *ltk_data;
51 ldap_pvt_thread_pool_keyfree_t *ltk_free;
52 } ldap_int_tpool_key_t;
53
54 /* Max number of thread-specific keys we store per thread.
55 * We don't expect to use many...
56 */
57 #define MAXKEYS 32
58
59 /* Max number of threads */
60 #define LDAP_MAXTHR 1024 /* must be a power of 2 */
61
62 /* (Theoretical) max number of pending requests */
63 #define MAX_PENDING (INT_MAX/2) /* INT_MAX - (room to avoid overflow) */
64
65 /* pool->ltp_pause values */
66 enum { NOT_PAUSED = 0, WANT_PAUSE = 1, PAUSED = 2 };
67
68 /* Context: thread ID and thread-specific key/data pairs */
69 typedef struct ldap_int_thread_userctx_s {
70 struct ldap_int_thread_poolq_s *ltu_pq;
71 ldap_pvt_thread_t ltu_id;
72 ldap_int_tpool_key_t ltu_key[MAXKEYS];
73 } ldap_int_thread_userctx_t;
74
75
76 /* Simple {thread ID -> context} hash table; key=ctx->ltu_id.
77 * Protected by ldap_pvt_thread_pool_mutex.
78 */
79 static struct {
80 ldap_int_thread_userctx_t *ctx;
81 /* ctx is valid when not NULL or DELETED_THREAD_CTX */
82 # define DELETED_THREAD_CTX (&ldap_int_main_thrctx + 1) /* dummy addr */
83 } thread_keys[LDAP_MAXTHR];
84
85 #define TID_HASH(tid, hash) do { \
86 unsigned const char *ptr_ = (unsigned const char *)&(tid); \
87 unsigned i_; \
88 for (i_ = 0, (hash) = ptr_[0]; ++i_ < sizeof(tid);) \
89 (hash) += ((hash) << 5) ^ ptr_[i_]; \
90 } while(0)
91
92
93 /* Task for a thread to perform */
94 typedef struct ldap_int_thread_task_s {
95 union {
96 LDAP_STAILQ_ENTRY(ldap_int_thread_task_s) q;
97 LDAP_SLIST_ENTRY(ldap_int_thread_task_s) l;
98 } ltt_next;
99 ldap_pvt_thread_start_t *ltt_start_routine;
100 void *ltt_arg;
101 struct ldap_int_thread_poolq_s *ltt_queue;
102 } ldap_int_thread_task_t;
103
104 typedef LDAP_STAILQ_HEAD(tcq, ldap_int_thread_task_s) ldap_int_tpool_plist_t;
105
106 struct ldap_int_thread_poolq_s {
107 void *ltp_free;
108
109 struct ldap_int_thread_pool_s *ltp_pool;
110
111 /* protect members below */
112 ldap_pvt_thread_mutex_t ltp_mutex;
113
114 /* not paused and something to do for pool_<wrapper/pause/destroy>()
115 * Used for normal pool operation, to synch between submitter and
116 * worker threads. Not used for pauses. In normal operation multiple
117 * queues can rendezvous without acquiring the main pool lock.
118 */
119 ldap_pvt_thread_cond_t ltp_cond;
120
121 /* ltp_pause == 0 ? <p_pending_list : &empty_pending_list,
122 * maintained to reduce work for pool_wrapper()
123 */
124 ldap_int_tpool_plist_t *ltp_work_list;
125
126 /* pending tasks, and unused task objects */
127 ldap_int_tpool_plist_t ltp_pending_list;
128 LDAP_SLIST_HEAD(tcl, ldap_int_thread_task_s) ltp_free_list;
129
130 /* Max number of threads in this queue */
131 int ltp_max_count;
132
133 /* Max pending + paused + idle tasks, negated when ltp_finishing */
134 int ltp_max_pending;
135
136 int ltp_pending_count; /* Pending + paused + idle tasks */
137 int ltp_active_count; /* Active, not paused/idle tasks */
138 int ltp_open_count; /* Number of threads */
139 int ltp_starting; /* Currently starting threads */
140 };
141
142 struct ldap_int_thread_pool_s {
143 LDAP_STAILQ_ENTRY(ldap_int_thread_pool_s) ltp_next;
144
145 struct ldap_int_thread_poolq_s **ltp_wqs;
146
147 /* number of poolqs */
148 int ltp_numqs;
149
150 /* protect members below */
151 ldap_pvt_thread_mutex_t ltp_mutex;
152
153 /* paused and waiting for resume
154 * When a pause is in effect all workers switch to waiting on
155 * this cond instead of their per-queue cond.
156 */
157 ldap_pvt_thread_cond_t ltp_cond;
158
159 /* ltp_active_queues < 1 && ltp_pause */
160 ldap_pvt_thread_cond_t ltp_pcond;
161
162 /* number of active queues */
163 int ltp_active_queues;
164
165 /* The pool is finishing, waiting for its threads to close.
166 * They close when ltp_pending_list is done. pool_submit()
167 * rejects new tasks. ltp_max_pending = -(its old value).
168 */
169 int ltp_finishing;
170
171 /* Some active task needs to be the sole active task.
172 * Atomic variable so ldap_pvt_thread_pool_pausing() can read it.
173 */
174 volatile sig_atomic_t ltp_pause;
175
176 /* Max number of threads in pool */
177 int ltp_max_count;
178
179 /* Configured max number of threads in pool, 0 for default (LDAP_MAXTHR) */
180 int ltp_conf_max_count;
181
182 /* Max pending + paused + idle tasks, negated when ltp_finishing */
183 int ltp_max_pending;
184 };
185
186 static ldap_int_tpool_plist_t empty_pending_list =
187 LDAP_STAILQ_HEAD_INITIALIZER(empty_pending_list);
188
189 static int ldap_int_has_thread_pool = 0;
190 static LDAP_STAILQ_HEAD(tpq, ldap_int_thread_pool_s)
191 ldap_int_thread_pool_list =
192 LDAP_STAILQ_HEAD_INITIALIZER(ldap_int_thread_pool_list);
193
194 static ldap_pvt_thread_mutex_t ldap_pvt_thread_pool_mutex;
195
196 static void *ldap_int_thread_pool_wrapper( void *pool );
197
198 static ldap_pvt_thread_key_t ldap_tpool_key;
199
200 /* Context of the main thread */
201 static ldap_int_thread_userctx_t ldap_int_main_thrctx;
202
203 int
ldap_int_thread_pool_startup(void)204 ldap_int_thread_pool_startup ( void )
205 {
206 ldap_int_main_thrctx.ltu_id = ldap_pvt_thread_self();
207 ldap_pvt_thread_key_create( &ldap_tpool_key );
208 return ldap_pvt_thread_mutex_init(&ldap_pvt_thread_pool_mutex);
209 }
210
211 int
ldap_int_thread_pool_shutdown(void)212 ldap_int_thread_pool_shutdown ( void )
213 {
214 struct ldap_int_thread_pool_s *pool;
215
216 while ((pool = LDAP_STAILQ_FIRST(&ldap_int_thread_pool_list)) != NULL) {
217 (ldap_pvt_thread_pool_destroy)(&pool, 0); /* ignore thr_debug macro */
218 }
219 ldap_pvt_thread_mutex_destroy(&ldap_pvt_thread_pool_mutex);
220 ldap_pvt_thread_key_destroy( ldap_tpool_key );
221 return(0);
222 }
223
224
225 /* Create a thread pool */
226 int
ldap_pvt_thread_pool_init_q(ldap_pvt_thread_pool_t * tpool,int max_threads,int max_pending,int numqs)227 ldap_pvt_thread_pool_init_q (
228 ldap_pvt_thread_pool_t *tpool,
229 int max_threads,
230 int max_pending,
231 int numqs )
232 {
233 ldap_pvt_thread_pool_t pool;
234 struct ldap_int_thread_poolq_s *pq;
235 int i, rc, rem_thr, rem_pend;
236
237 /* multiple pools are currently not supported (ITS#4943) */
238 assert(!ldap_int_has_thread_pool);
239
240 if (! (0 <= max_threads && max_threads <= LDAP_MAXTHR))
241 max_threads = 0;
242 if (! (1 <= max_pending && max_pending <= MAX_PENDING))
243 max_pending = MAX_PENDING;
244
245 *tpool = NULL;
246 pool = (ldap_pvt_thread_pool_t) LDAP_CALLOC(1,
247 sizeof(struct ldap_int_thread_pool_s));
248
249 if (pool == NULL) return(-1);
250
251 pool->ltp_wqs = LDAP_MALLOC(numqs * sizeof(struct ldap_int_thread_poolq_s *));
252 if (pool->ltp_wqs == NULL) {
253 LDAP_FREE(pool);
254 return(-1);
255 }
256
257 for (i=0; i<numqs; i++) {
258 char *ptr = LDAP_CALLOC(1, sizeof(struct ldap_int_thread_poolq_s) + CACHELINE-1);
259 if (ptr == NULL) {
260 for (--i; i>=0; i--)
261 LDAP_FREE(pool->ltp_wqs[i]->ltp_free);
262 LDAP_FREE(pool->ltp_wqs);
263 LDAP_FREE(pool);
264 return(-1);
265 }
266 pool->ltp_wqs[i] = (struct ldap_int_thread_poolq_s *)(((size_t)ptr + CACHELINE-1) & ~(CACHELINE-1));
267 pool->ltp_wqs[i]->ltp_free = ptr;
268 }
269
270 pool->ltp_numqs = numqs;
271 pool->ltp_conf_max_count = max_threads;
272 if ( !max_threads )
273 max_threads = LDAP_MAXTHR;
274
275 rc = ldap_pvt_thread_mutex_init(&pool->ltp_mutex);
276 if (rc != 0) {
277 fail:
278 for (i=0; i<numqs; i++)
279 LDAP_FREE(pool->ltp_wqs[i]->ltp_free);
280 LDAP_FREE(pool->ltp_wqs);
281 LDAP_FREE(pool);
282 return(rc);
283 }
284
285 rc = ldap_pvt_thread_cond_init(&pool->ltp_cond);
286 if (rc != 0)
287 goto fail;
288
289 rc = ldap_pvt_thread_cond_init(&pool->ltp_pcond);
290 if (rc != 0)
291 goto fail;
292
293 rem_thr = max_threads % numqs;
294 rem_pend = max_pending % numqs;
295 for ( i=0; i<numqs; i++ ) {
296 pq = pool->ltp_wqs[i];
297 pq->ltp_pool = pool;
298 rc = ldap_pvt_thread_mutex_init(&pq->ltp_mutex);
299 if (rc != 0)
300 return(rc);
301 rc = ldap_pvt_thread_cond_init(&pq->ltp_cond);
302 if (rc != 0)
303 return(rc);
304 LDAP_STAILQ_INIT(&pq->ltp_pending_list);
305 pq->ltp_work_list = &pq->ltp_pending_list;
306 LDAP_SLIST_INIT(&pq->ltp_free_list);
307
308 pq->ltp_max_count = max_threads / numqs;
309 if ( rem_thr ) {
310 pq->ltp_max_count++;
311 rem_thr--;
312 }
313 pq->ltp_max_pending = max_pending / numqs;
314 if ( rem_pend ) {
315 pq->ltp_max_pending++;
316 rem_pend--;
317 }
318 }
319
320 ldap_int_has_thread_pool = 1;
321
322 pool->ltp_max_count = max_threads;
323 pool->ltp_max_pending = max_pending;
324
325 ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
326 LDAP_STAILQ_INSERT_TAIL(&ldap_int_thread_pool_list, pool, ltp_next);
327 ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
328
329 /* Start no threads just yet. That can break if the process forks
330 * later, as slapd does in order to daemonize. On at least POSIX,
331 * only the forking thread would survive in the child. Yet fork()
332 * can't unlock/clean up other threads' locks and data structures,
333 * unless pthread_atfork() handlers have been set up to do so.
334 */
335
336 *tpool = pool;
337 return(0);
338 }
339
340 int
ldap_pvt_thread_pool_init(ldap_pvt_thread_pool_t * tpool,int max_threads,int max_pending)341 ldap_pvt_thread_pool_init (
342 ldap_pvt_thread_pool_t *tpool,
343 int max_threads,
344 int max_pending )
345 {
346 return ldap_pvt_thread_pool_init_q( tpool, max_threads, max_pending, 1 );
347 }
348
349 /* Submit a task to be performed by the thread pool */
350 int
ldap_pvt_thread_pool_submit(ldap_pvt_thread_pool_t * tpool,ldap_pvt_thread_start_t * start_routine,void * arg)351 ldap_pvt_thread_pool_submit (
352 ldap_pvt_thread_pool_t *tpool,
353 ldap_pvt_thread_start_t *start_routine, void *arg )
354 {
355 return ldap_pvt_thread_pool_submit2( tpool, start_routine, arg, NULL );
356 }
357
358 /* Submit a task to be performed by the thread pool */
359 int
ldap_pvt_thread_pool_submit2(ldap_pvt_thread_pool_t * tpool,ldap_pvt_thread_start_t * start_routine,void * arg,void ** cookie)360 ldap_pvt_thread_pool_submit2 (
361 ldap_pvt_thread_pool_t *tpool,
362 ldap_pvt_thread_start_t *start_routine, void *arg,
363 void **cookie )
364 {
365 struct ldap_int_thread_pool_s *pool;
366 struct ldap_int_thread_poolq_s *pq;
367 ldap_int_thread_task_t *task;
368 ldap_pvt_thread_t thr;
369 int i, j;
370
371 if (tpool == NULL)
372 return(-1);
373
374 pool = *tpool;
375
376 if (pool == NULL)
377 return(-1);
378
379 if ( pool->ltp_numqs > 1 ) {
380 int min = pool->ltp_wqs[0]->ltp_max_pending + pool->ltp_wqs[0]->ltp_max_count;
381 int min_x = 0, cnt;
382 for ( i = 0; i < pool->ltp_numqs; i++ ) {
383 /* take first queue that has nothing active */
384 if ( !pool->ltp_wqs[i]->ltp_active_count ) {
385 min_x = i;
386 break;
387 }
388 cnt = pool->ltp_wqs[i]->ltp_active_count + pool->ltp_wqs[i]->ltp_pending_count;
389 if ( cnt < min ) {
390 min = cnt;
391 min_x = i;
392 }
393 }
394 i = min_x;
395 } else
396 i = 0;
397
398 j = i;
399 while(1) {
400 ldap_pvt_thread_mutex_lock(&pool->ltp_wqs[i]->ltp_mutex);
401 if (pool->ltp_wqs[i]->ltp_pending_count < pool->ltp_wqs[i]->ltp_max_pending) {
402 break;
403 }
404 ldap_pvt_thread_mutex_unlock(&pool->ltp_wqs[i]->ltp_mutex);
405 i++;
406 i %= pool->ltp_numqs;
407 if ( i == j )
408 return -1;
409 }
410
411 pq = pool->ltp_wqs[i];
412 task = LDAP_SLIST_FIRST(&pq->ltp_free_list);
413 if (task) {
414 LDAP_SLIST_REMOVE_HEAD(&pq->ltp_free_list, ltt_next.l);
415 } else {
416 task = (ldap_int_thread_task_t *) LDAP_MALLOC(sizeof(*task));
417 if (task == NULL)
418 goto failed;
419 }
420
421 task->ltt_start_routine = start_routine;
422 task->ltt_arg = arg;
423 task->ltt_queue = pq;
424 if ( cookie )
425 *cookie = task;
426
427 pq->ltp_pending_count++;
428 LDAP_STAILQ_INSERT_TAIL(&pq->ltp_pending_list, task, ltt_next.q);
429
430 if (pool->ltp_pause)
431 goto done;
432
433 /* should we open (create) a thread? */
434 if (pq->ltp_open_count < pq->ltp_active_count+pq->ltp_pending_count &&
435 pq->ltp_open_count < pq->ltp_max_count)
436 {
437 pq->ltp_starting++;
438 pq->ltp_open_count++;
439
440 if (0 != ldap_pvt_thread_create(
441 &thr, 1, ldap_int_thread_pool_wrapper, pq))
442 {
443 /* couldn't create thread. back out of
444 * ltp_open_count and check for even worse things.
445 */
446 pq->ltp_starting--;
447 pq->ltp_open_count--;
448
449 if (pq->ltp_open_count == 0) {
450 /* no open threads at all?!?
451 */
452 ldap_int_thread_task_t *ptr;
453
454 /* let pool_close know there are no more threads */
455 ldap_pvt_thread_cond_signal(&pq->ltp_cond);
456
457 LDAP_STAILQ_FOREACH(ptr, &pq->ltp_pending_list, ltt_next.q)
458 if (ptr == task) break;
459 if (ptr == task) {
460 /* no open threads, task not handled, so
461 * back out of ltp_pending_count, free the task,
462 * report the error.
463 */
464 pq->ltp_pending_count--;
465 LDAP_STAILQ_REMOVE(&pq->ltp_pending_list, task,
466 ldap_int_thread_task_s, ltt_next.q);
467 LDAP_SLIST_INSERT_HEAD(&pq->ltp_free_list, task,
468 ltt_next.l);
469 goto failed;
470 }
471 }
472 /* there is another open thread, so this
473 * task will be handled eventually.
474 */
475 }
476 }
477 ldap_pvt_thread_cond_signal(&pq->ltp_cond);
478
479 done:
480 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
481 return(0);
482
483 failed:
484 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
485 return(-1);
486 }
487
488 static void *
no_task(void * ctx,void * arg)489 no_task( void *ctx, void *arg )
490 {
491 return NULL;
492 }
493
494 /* Cancel a pending task that was previously submitted.
495 * Return 1 if the task was successfully cancelled, 0 if
496 * not found, -1 for invalid parameters
497 */
498 int
ldap_pvt_thread_pool_retract(void * cookie)499 ldap_pvt_thread_pool_retract (
500 void *cookie )
501 {
502 ldap_int_thread_task_t *task, *ttmp;
503 struct ldap_int_thread_poolq_s *pq;
504
505 if (cookie == NULL)
506 return(-1);
507
508 ttmp = cookie;
509 pq = ttmp->ltt_queue;
510 if (pq == NULL)
511 return(-1);
512
513 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
514 LDAP_STAILQ_FOREACH(task, &pq->ltp_pending_list, ltt_next.q)
515 if (task == ttmp) {
516 /* Could LDAP_STAILQ_REMOVE the task, but that
517 * walks ltp_pending_list again to find it.
518 */
519 task->ltt_start_routine = no_task;
520 task->ltt_arg = NULL;
521 break;
522 }
523 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
524 return task != NULL;
525 }
526
527 /* Walk the pool and allow tasks to be retracted, only to be called while the
528 * pool is paused */
529 int
ldap_pvt_thread_pool_walk(ldap_pvt_thread_pool_t * tpool,ldap_pvt_thread_start_t * start,ldap_pvt_thread_walk_t * cb,void * arg)530 ldap_pvt_thread_pool_walk(
531 ldap_pvt_thread_pool_t *tpool,
532 ldap_pvt_thread_start_t *start,
533 ldap_pvt_thread_walk_t *cb, void *arg )
534 {
535 struct ldap_int_thread_pool_s *pool;
536 struct ldap_int_thread_poolq_s *pq;
537 ldap_int_thread_task_t *task;
538 int i;
539
540 if (tpool == NULL)
541 return(-1);
542
543 pool = *tpool;
544
545 if (pool == NULL)
546 return(-1);
547
548 ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
549 assert(pool->ltp_pause == PAUSED);
550 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
551
552 for (i=0; i<pool->ltp_numqs; i++) {
553 pq = pool->ltp_wqs[i];
554 LDAP_STAILQ_FOREACH(task, &pq->ltp_pending_list, ltt_next.q) {
555 if ( task->ltt_start_routine == start ) {
556 if ( cb( task->ltt_start_routine, task->ltt_arg, arg ) ) {
557 /* retract */
558 task->ltt_start_routine = no_task;
559 task->ltt_arg = NULL;
560 }
561 }
562 }
563 }
564 return 0;
565 }
566
567 /* Set number of work queues in this pool. Should not be
568 * more than the number of CPUs. */
569 int
ldap_pvt_thread_pool_queues(ldap_pvt_thread_pool_t * tpool,int numqs)570 ldap_pvt_thread_pool_queues(
571 ldap_pvt_thread_pool_t *tpool,
572 int numqs )
573 {
574 struct ldap_int_thread_pool_s *pool;
575 struct ldap_int_thread_poolq_s *pq;
576 int i, rc, rem_thr, rem_pend;
577
578 if (numqs < 1 || tpool == NULL)
579 return(-1);
580
581 pool = *tpool;
582
583 if (pool == NULL)
584 return(-1);
585
586 if (numqs < pool->ltp_numqs) {
587 for (i=numqs; i<pool->ltp_numqs; i++)
588 pool->ltp_wqs[i]->ltp_max_count = 0;
589 } else if (numqs > pool->ltp_numqs) {
590 struct ldap_int_thread_poolq_s **wqs;
591 wqs = LDAP_REALLOC(pool->ltp_wqs, numqs * sizeof(struct ldap_int_thread_poolq_s *));
592 if (wqs == NULL)
593 return(-1);
594 pool->ltp_wqs = wqs;
595 for (i=pool->ltp_numqs; i<numqs; i++) {
596 char *ptr = LDAP_CALLOC(1, sizeof(struct ldap_int_thread_poolq_s) + CACHELINE-1);
597 if (ptr == NULL) {
598 for (; i<numqs; i++)
599 pool->ltp_wqs[i] = NULL;
600 return(-1);
601 }
602 pq = (struct ldap_int_thread_poolq_s *)(((size_t)ptr + CACHELINE-1) & ~(CACHELINE-1));
603 pq->ltp_free = ptr;
604 pool->ltp_wqs[i] = pq;
605 pq->ltp_pool = pool;
606 rc = ldap_pvt_thread_mutex_init(&pq->ltp_mutex);
607 if (rc != 0)
608 return(rc);
609 rc = ldap_pvt_thread_cond_init(&pq->ltp_cond);
610 if (rc != 0)
611 return(rc);
612 LDAP_STAILQ_INIT(&pq->ltp_pending_list);
613 pq->ltp_work_list = &pq->ltp_pending_list;
614 LDAP_SLIST_INIT(&pq->ltp_free_list);
615 }
616 }
617 rem_thr = pool->ltp_max_count % numqs;
618 rem_pend = pool->ltp_max_pending % numqs;
619 for ( i=0; i<numqs; i++ ) {
620 pq = pool->ltp_wqs[i];
621 pq->ltp_max_count = pool->ltp_max_count / numqs;
622 if ( rem_thr ) {
623 pq->ltp_max_count++;
624 rem_thr--;
625 }
626 pq->ltp_max_pending = pool->ltp_max_pending / numqs;
627 if ( rem_pend ) {
628 pq->ltp_max_pending++;
629 rem_pend--;
630 }
631 }
632 pool->ltp_numqs = numqs;
633 return 0;
634 }
635
636 /* Set max #threads. value <= 0 means max supported #threads (LDAP_MAXTHR) */
637 int
ldap_pvt_thread_pool_maxthreads(ldap_pvt_thread_pool_t * tpool,int max_threads)638 ldap_pvt_thread_pool_maxthreads(
639 ldap_pvt_thread_pool_t *tpool,
640 int max_threads )
641 {
642 struct ldap_int_thread_pool_s *pool;
643 struct ldap_int_thread_poolq_s *pq;
644 int remthr, i;
645
646 if (! (0 <= max_threads && max_threads <= LDAP_MAXTHR))
647 max_threads = 0;
648
649 if (tpool == NULL)
650 return(-1);
651
652 pool = *tpool;
653
654 if (pool == NULL)
655 return(-1);
656
657 pool->ltp_conf_max_count = max_threads;
658 if ( !max_threads )
659 max_threads = LDAP_MAXTHR;
660 pool->ltp_max_count = max_threads;
661
662 remthr = max_threads % pool->ltp_numqs;
663 max_threads /= pool->ltp_numqs;
664
665 for (i=0; i<pool->ltp_numqs; i++) {
666 pq = pool->ltp_wqs[i];
667 pq->ltp_max_count = max_threads;
668 if (remthr) {
669 pq->ltp_max_count++;
670 remthr--;
671 }
672 }
673 return(0);
674 }
675
676 /* Inspect the pool */
677 int
ldap_pvt_thread_pool_query(ldap_pvt_thread_pool_t * tpool,ldap_pvt_thread_pool_param_t param,void * value)678 ldap_pvt_thread_pool_query(
679 ldap_pvt_thread_pool_t *tpool,
680 ldap_pvt_thread_pool_param_t param,
681 void *value )
682 {
683 struct ldap_int_thread_pool_s *pool;
684 int count = -1;
685
686 if ( tpool == NULL || value == NULL ) {
687 return -1;
688 }
689
690 pool = *tpool;
691
692 if ( pool == NULL ) {
693 return 0;
694 }
695
696 switch ( param ) {
697 case LDAP_PVT_THREAD_POOL_PARAM_MAX:
698 count = pool->ltp_conf_max_count;
699 break;
700
701 case LDAP_PVT_THREAD_POOL_PARAM_MAX_PENDING:
702 count = pool->ltp_max_pending;
703 if (count < 0)
704 count = -count;
705 if (count == MAX_PENDING)
706 count = 0;
707 break;
708
709 case LDAP_PVT_THREAD_POOL_PARAM_PAUSING:
710 ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
711 count = (pool->ltp_pause != 0);
712 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
713 break;
714
715 case LDAP_PVT_THREAD_POOL_PARAM_OPEN:
716 case LDAP_PVT_THREAD_POOL_PARAM_STARTING:
717 case LDAP_PVT_THREAD_POOL_PARAM_ACTIVE:
718 case LDAP_PVT_THREAD_POOL_PARAM_PENDING:
719 case LDAP_PVT_THREAD_POOL_PARAM_BACKLOAD:
720 {
721 int i;
722 count = 0;
723 for (i=0; i<pool->ltp_numqs; i++) {
724 struct ldap_int_thread_poolq_s *pq = pool->ltp_wqs[i];
725 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
726 switch(param) {
727 case LDAP_PVT_THREAD_POOL_PARAM_OPEN:
728 count += pq->ltp_open_count;
729 break;
730 case LDAP_PVT_THREAD_POOL_PARAM_STARTING:
731 count += pq->ltp_starting;
732 break;
733 case LDAP_PVT_THREAD_POOL_PARAM_ACTIVE:
734 count += pq->ltp_active_count;
735 break;
736 case LDAP_PVT_THREAD_POOL_PARAM_PENDING:
737 count += pq->ltp_pending_count;
738 break;
739 case LDAP_PVT_THREAD_POOL_PARAM_BACKLOAD:
740 count += pq->ltp_pending_count + pq->ltp_active_count;
741 break;
742 default:
743 break;
744 }
745 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
746 }
747 if (count < 0)
748 count = -count;
749 }
750 break;
751
752 case LDAP_PVT_THREAD_POOL_PARAM_ACTIVE_MAX:
753 break;
754
755 case LDAP_PVT_THREAD_POOL_PARAM_PENDING_MAX:
756 break;
757
758 case LDAP_PVT_THREAD_POOL_PARAM_BACKLOAD_MAX:
759 break;
760
761 case LDAP_PVT_THREAD_POOL_PARAM_STATE:
762 if (pool->ltp_pause)
763 *((char **)value) = "pausing";
764 else if (!pool->ltp_finishing)
765 *((char **)value) = "running";
766 else {
767 int i;
768 for (i=0; i<pool->ltp_numqs; i++)
769 if (pool->ltp_wqs[i]->ltp_pending_count) break;
770 if (i<pool->ltp_numqs)
771 *((char **)value) = "finishing";
772 else
773 *((char **)value) = "stopping";
774 }
775 break;
776
777 case LDAP_PVT_THREAD_POOL_PARAM_UNKNOWN:
778 break;
779 }
780
781 if ( count > -1 ) {
782 *((int *)value) = count;
783 }
784
785 return ( count == -1 ? -1 : 0 );
786 }
787
788 /*
789 * true if pool is pausing; does not lock any mutex to check.
790 * 0 if not pause, 1 if pause, -1 if error or no pool.
791 */
792 int
ldap_pvt_thread_pool_pausing(ldap_pvt_thread_pool_t * tpool)793 ldap_pvt_thread_pool_pausing( ldap_pvt_thread_pool_t *tpool )
794 {
795 int rc = -1;
796 struct ldap_int_thread_pool_s *pool;
797
798 if ( tpool != NULL && (pool = *tpool) != NULL ) {
799 rc = (pool->ltp_pause != 0);
800 }
801
802 return rc;
803 }
804
805 /*
806 * wrapper for ldap_pvt_thread_pool_query(), left around
807 * for backwards compatibility
808 */
809 int
ldap_pvt_thread_pool_backload(ldap_pvt_thread_pool_t * tpool)810 ldap_pvt_thread_pool_backload ( ldap_pvt_thread_pool_t *tpool )
811 {
812 int rc, count;
813
814 rc = ldap_pvt_thread_pool_query( tpool,
815 LDAP_PVT_THREAD_POOL_PARAM_BACKLOAD, (void *)&count );
816
817 if ( rc == 0 ) {
818 return count;
819 }
820
821 return rc;
822 }
823
824
825 /*
826 * wrapper for ldap_pvt_thread_pool_close+free(), left around
827 * for backwards compatibility
828 */
829 int
ldap_pvt_thread_pool_destroy(ldap_pvt_thread_pool_t * tpool,int run_pending)830 ldap_pvt_thread_pool_destroy ( ldap_pvt_thread_pool_t *tpool, int run_pending )
831 {
832 int rc;
833
834 if ( (rc = ldap_pvt_thread_pool_close( tpool, run_pending )) ) {
835 return rc;
836 }
837
838 return ldap_pvt_thread_pool_free( tpool );
839 }
840
841 /* Shut down the pool making its threads finish */
842 int
ldap_pvt_thread_pool_close(ldap_pvt_thread_pool_t * tpool,int run_pending)843 ldap_pvt_thread_pool_close ( ldap_pvt_thread_pool_t *tpool, int run_pending )
844 {
845 struct ldap_int_thread_pool_s *pool, *pptr;
846 struct ldap_int_thread_poolq_s *pq;
847 ldap_int_thread_task_t *task;
848 int i;
849
850 if (tpool == NULL)
851 return(-1);
852
853 pool = *tpool;
854
855 if (pool == NULL) return(-1);
856
857 ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
858 LDAP_STAILQ_FOREACH(pptr, &ldap_int_thread_pool_list, ltp_next)
859 if (pptr == pool) break;
860 ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
861
862 if (pool != pptr) return(-1);
863
864 ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
865
866 pool->ltp_finishing = 1;
867 if (pool->ltp_max_pending > 0)
868 pool->ltp_max_pending = -pool->ltp_max_pending;
869
870 ldap_pvt_thread_cond_broadcast(&pool->ltp_cond);
871 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
872
873 for (i=0; i<pool->ltp_numqs; i++) {
874 pq = pool->ltp_wqs[i];
875 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
876 if (pq->ltp_max_pending > 0)
877 pq->ltp_max_pending = -pq->ltp_max_pending;
878 if (!run_pending) {
879 while ((task = LDAP_STAILQ_FIRST(&pq->ltp_pending_list)) != NULL) {
880 LDAP_STAILQ_REMOVE_HEAD(&pq->ltp_pending_list, ltt_next.q);
881 LDAP_FREE(task);
882 }
883 pq->ltp_pending_count = 0;
884 }
885
886 while (pq->ltp_open_count) {
887 ldap_pvt_thread_cond_broadcast(&pq->ltp_cond);
888 ldap_pvt_thread_cond_wait(&pq->ltp_cond, &pq->ltp_mutex);
889 }
890
891 while ((task = LDAP_SLIST_FIRST(&pq->ltp_free_list)) != NULL)
892 {
893 LDAP_SLIST_REMOVE_HEAD(&pq->ltp_free_list, ltt_next.l);
894 LDAP_FREE(task);
895 }
896 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
897 }
898
899 return(0);
900 }
901
902 /* Destroy the pool, everything must have already shut down */
903 int
ldap_pvt_thread_pool_free(ldap_pvt_thread_pool_t * tpool)904 ldap_pvt_thread_pool_free ( ldap_pvt_thread_pool_t *tpool )
905 {
906 struct ldap_int_thread_pool_s *pool, *pptr;
907 struct ldap_int_thread_poolq_s *pq;
908 int i;
909
910 if (tpool == NULL)
911 return(-1);
912
913 pool = *tpool;
914
915 if (pool == NULL) return(-1);
916
917 ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
918 LDAP_STAILQ_FOREACH(pptr, &ldap_int_thread_pool_list, ltp_next)
919 if (pptr == pool) break;
920 if (pptr == pool)
921 LDAP_STAILQ_REMOVE(&ldap_int_thread_pool_list, pool,
922 ldap_int_thread_pool_s, ltp_next);
923 ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
924
925 if (pool != pptr) return(-1);
926
927 ldap_pvt_thread_cond_destroy(&pool->ltp_pcond);
928 ldap_pvt_thread_cond_destroy(&pool->ltp_cond);
929 ldap_pvt_thread_mutex_destroy(&pool->ltp_mutex);
930 for (i=0; i<pool->ltp_numqs; i++) {
931 pq = pool->ltp_wqs[i];
932
933 assert( !pq->ltp_open_count );
934 assert( LDAP_SLIST_EMPTY(&pq->ltp_free_list) );
935 ldap_pvt_thread_cond_destroy(&pq->ltp_cond);
936 ldap_pvt_thread_mutex_destroy(&pq->ltp_mutex);
937 if (pq->ltp_free) {
938 LDAP_FREE(pq->ltp_free);
939 }
940 }
941 LDAP_FREE(pool->ltp_wqs);
942 LDAP_FREE(pool);
943 *tpool = NULL;
944 ldap_int_has_thread_pool = 0;
945 return(0);
946 }
947
948 /* Thread loop. Accept and handle submitted tasks. */
949 static void *
ldap_int_thread_pool_wrapper(void * xpool)950 ldap_int_thread_pool_wrapper (
951 void *xpool )
952 {
953 struct ldap_int_thread_poolq_s *pq = xpool;
954 struct ldap_int_thread_pool_s *pool = pq->ltp_pool;
955 ldap_int_thread_task_t *task;
956 ldap_int_tpool_plist_t *work_list;
957 ldap_int_thread_userctx_t ctx, *kctx;
958 unsigned i, keyslot, hash;
959 int pool_lock = 0, freeme = 0;
960
961 assert(pool != NULL);
962
963 for ( i=0; i<MAXKEYS; i++ ) {
964 ctx.ltu_key[i].ltk_key = NULL;
965 }
966
967 ctx.ltu_pq = pq;
968 ctx.ltu_id = ldap_pvt_thread_self();
969 TID_HASH(ctx.ltu_id, hash);
970
971 ldap_pvt_thread_key_setdata( ldap_tpool_key, &ctx );
972
973 if (pool->ltp_pause) {
974 ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
975 /* thread_keys[] is read-only when paused */
976 while (pool->ltp_pause)
977 ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
978 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
979 }
980
981 /* find a key slot to give this thread ID and store a
982 * pointer to our keys there; start at the thread ID
983 * itself (mod LDAP_MAXTHR) and look for an empty slot.
984 */
985 ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
986 for (keyslot = hash & (LDAP_MAXTHR-1);
987 (kctx = thread_keys[keyslot].ctx) && kctx != DELETED_THREAD_CTX;
988 keyslot = (keyslot+1) & (LDAP_MAXTHR-1));
989 thread_keys[keyslot].ctx = &ctx;
990 ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
991
992 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
993 pq->ltp_starting--;
994 pq->ltp_active_count++;
995
996 for (;;) {
997 work_list = pq->ltp_work_list; /* help the compiler a bit */
998 task = LDAP_STAILQ_FIRST(work_list);
999 if (task == NULL) { /* paused or no pending tasks */
1000 if (--(pq->ltp_active_count) < 1) {
1001 if (pool->ltp_pause) {
1002 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
1003 ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
1004 pool_lock = 1;
1005 if (--(pool->ltp_active_queues) < 1) {
1006 /* Notify pool_pause it is the sole active thread. */
1007 ldap_pvt_thread_cond_signal(&pool->ltp_pcond);
1008 }
1009 }
1010 }
1011
1012 do {
1013 if (pool->ltp_finishing || pq->ltp_open_count > pq->ltp_max_count) {
1014 /* Not paused, and either finishing or too many
1015 * threads running (can happen if ltp_max_count
1016 * was reduced). Let this thread die.
1017 */
1018 goto done;
1019 }
1020
1021 /* We could check an idle timer here, and let the
1022 * thread die if it has been inactive for a while.
1023 * Only die if there are other open threads (i.e.,
1024 * always have at least one thread open).
1025 * The check should be like this:
1026 * if (pool->ltp_open_count>1 && pool->ltp_starting==0)
1027 * check timer, wait if ltp_pause, leave thread;
1028 *
1029 * Just use pthread_cond_timedwait() if we want to
1030 * check idle time.
1031 */
1032 if (pool_lock) {
1033 ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
1034 if (!pool->ltp_pause) {
1035 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
1036 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
1037 pool_lock = 0;
1038 }
1039 } else
1040 ldap_pvt_thread_cond_wait(&pq->ltp_cond, &pq->ltp_mutex);
1041
1042 work_list = pq->ltp_work_list;
1043 task = LDAP_STAILQ_FIRST(work_list);
1044 } while (task == NULL);
1045
1046 if (pool_lock) {
1047 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
1048 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
1049 pool_lock = 0;
1050 }
1051 pq->ltp_active_count++;
1052 }
1053
1054 LDAP_STAILQ_REMOVE_HEAD(work_list, ltt_next.q);
1055 pq->ltp_pending_count--;
1056 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
1057
1058 task->ltt_start_routine(&ctx, task->ltt_arg);
1059
1060 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
1061 LDAP_SLIST_INSERT_HEAD(&pq->ltp_free_list, task, ltt_next.l);
1062 }
1063 done:
1064
1065 ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
1066
1067 /* The pool_mutex lock protects ctx->ltu_key from pool_purgekey()
1068 * during this call, since it prevents new pauses. */
1069 ldap_pvt_thread_pool_context_reset(&ctx);
1070
1071 thread_keys[keyslot].ctx = DELETED_THREAD_CTX;
1072 ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
1073
1074 pq->ltp_open_count--;
1075 if (pq->ltp_open_count == 0) {
1076 if (pool->ltp_finishing)
1077 /* let pool_destroy know we're all done */
1078 ldap_pvt_thread_cond_signal(&pq->ltp_cond);
1079 else
1080 freeme = 1;
1081 }
1082
1083 if (pool_lock)
1084 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
1085 else
1086 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
1087
1088 if (freeme) {
1089 ldap_pvt_thread_cond_destroy(&pq->ltp_cond);
1090 ldap_pvt_thread_mutex_destroy(&pq->ltp_mutex);
1091 LDAP_FREE(pq->ltp_free);
1092 pq->ltp_free = NULL;
1093 }
1094 ldap_pvt_thread_exit(NULL);
1095 return(NULL);
1096 }
1097
1098 /* Arguments > ltp_pause to handle_pause(,PAUSE_ARG()). arg=PAUSE_ARG
1099 * ensures (arg-ltp_pause) sets GO_* at need and keeps DO_PAUSE/GO_*.
1100 */
1101 #define GO_IDLE 8
1102 #define GO_UNIDLE 16
1103 #define CHECK_PAUSE 32 /* if ltp_pause: GO_IDLE; wait; GO_UNIDLE */
1104 #define DO_PAUSE 64 /* CHECK_PAUSE; pause the pool */
1105 #define PAUSE_ARG(a) \
1106 ((a) | ((a) & (GO_IDLE|GO_UNIDLE) ? GO_IDLE-1 : CHECK_PAUSE))
1107
1108 static int
handle_pause(ldap_pvt_thread_pool_t * tpool,int pause_type)1109 handle_pause( ldap_pvt_thread_pool_t *tpool, int pause_type )
1110 {
1111 struct ldap_int_thread_pool_s *pool;
1112 struct ldap_int_thread_poolq_s *pq;
1113 int ret = 0, pause, max_ltp_pause;
1114
1115 if (tpool == NULL)
1116 return(-1);
1117
1118 pool = *tpool;
1119
1120 if (pool == NULL)
1121 return(0);
1122
1123 if (pause_type == CHECK_PAUSE && !pool->ltp_pause)
1124 return(0);
1125
1126 {
1127 ldap_int_thread_userctx_t *ctx = ldap_pvt_thread_pool_context();
1128 pq = ctx->ltu_pq;
1129 if ( !pq )
1130 return(-1);
1131 }
1132
1133 /* Let pool_unidle() ignore requests for new pauses */
1134 max_ltp_pause = pause_type==PAUSE_ARG(GO_UNIDLE) ? WANT_PAUSE : NOT_PAUSED;
1135
1136 ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
1137
1138 pause = pool->ltp_pause; /* NOT_PAUSED, WANT_PAUSE or PAUSED */
1139
1140 /* If ltp_pause and not GO_IDLE|GO_UNIDLE: Set GO_IDLE,GO_UNIDLE */
1141 pause_type -= pause;
1142
1143 if (pause_type & GO_IDLE) {
1144 int do_pool = 0;
1145 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
1146 pq->ltp_pending_count++;
1147 pq->ltp_active_count--;
1148 if (pause && pq->ltp_active_count < 1) {
1149 do_pool = 1;
1150 }
1151 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
1152 if (do_pool) {
1153 pool->ltp_active_queues--;
1154 if (pool->ltp_active_queues < 1)
1155 /* Tell the task waiting to DO_PAUSE it can proceed */
1156 ldap_pvt_thread_cond_signal(&pool->ltp_pcond);
1157 }
1158 }
1159
1160 if (pause_type & GO_UNIDLE) {
1161 /* Wait out pause if any, then cancel GO_IDLE */
1162 if (pause > max_ltp_pause) {
1163 ret = 1;
1164 do {
1165 ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
1166 } while (pool->ltp_pause > max_ltp_pause);
1167 }
1168 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
1169 pq->ltp_pending_count--;
1170 pq->ltp_active_count++;
1171 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
1172 }
1173
1174 if (pause_type & DO_PAUSE) {
1175 int i, j;
1176 /* Tell everyone else to pause or finish, then await that */
1177 ret = 0;
1178 assert(!pool->ltp_pause);
1179 pool->ltp_pause = WANT_PAUSE;
1180 pool->ltp_active_queues = 0;
1181
1182 for (i=0; i<pool->ltp_numqs; i++)
1183 if (pool->ltp_wqs[i] == pq) break;
1184
1185 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
1186 /* temporarily remove ourself from active count */
1187 pq->ltp_active_count--;
1188
1189 j=i;
1190 do {
1191 pq = pool->ltp_wqs[j];
1192 if (j != i)
1193 ldap_pvt_thread_mutex_lock(&pq->ltp_mutex);
1194
1195 /* Hide pending tasks from ldap_pvt_thread_pool_wrapper() */
1196 pq->ltp_work_list = &empty_pending_list;
1197
1198 if (pq->ltp_active_count > 0)
1199 pool->ltp_active_queues++;
1200
1201 ldap_pvt_thread_mutex_unlock(&pq->ltp_mutex);
1202 if (pool->ltp_numqs > 1) {
1203 j++;
1204 j %= pool->ltp_numqs;
1205 }
1206 } while (j != i);
1207
1208 /* Wait for this task to become the sole active task */
1209 while (pool->ltp_active_queues > 0)
1210 ldap_pvt_thread_cond_wait(&pool->ltp_pcond, &pool->ltp_mutex);
1211
1212 /* restore us to active count */
1213 pool->ltp_wqs[i]->ltp_active_count++;
1214
1215 assert(pool->ltp_pause == WANT_PAUSE);
1216 pool->ltp_pause = PAUSED;
1217 }
1218 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
1219
1220 return(ret);
1221 }
1222
1223 /* Consider this task idle: It will not block pool_pause() in other tasks. */
1224 void
ldap_pvt_thread_pool_idle(ldap_pvt_thread_pool_t * tpool)1225 ldap_pvt_thread_pool_idle( ldap_pvt_thread_pool_t *tpool )
1226 {
1227 handle_pause(tpool, PAUSE_ARG(GO_IDLE));
1228 }
1229
1230 /* Cancel pool_idle(). If the pool is paused, wait it out first. */
1231 void
ldap_pvt_thread_pool_unidle(ldap_pvt_thread_pool_t * tpool)1232 ldap_pvt_thread_pool_unidle( ldap_pvt_thread_pool_t *tpool )
1233 {
1234 handle_pause(tpool, PAUSE_ARG(GO_UNIDLE));
1235 }
1236
1237 /*
1238 * If a pause was requested, wait for it. If several threads
1239 * are waiting to pause, let through one or more pauses.
1240 * The calling task must be active, not idle.
1241 * Return 1 if we waited, 0 if not, -1 at parameter error.
1242 */
1243 int
ldap_pvt_thread_pool_pausecheck(ldap_pvt_thread_pool_t * tpool)1244 ldap_pvt_thread_pool_pausecheck( ldap_pvt_thread_pool_t *tpool )
1245 {
1246 return handle_pause(tpool, PAUSE_ARG(CHECK_PAUSE));
1247 }
1248
1249 /*
1250 * Wait for a pause, from a non-pooled thread.
1251 */
1252 int
ldap_pvt_thread_pool_pausecheck_native(ldap_pvt_thread_pool_t * tpool)1253 ldap_pvt_thread_pool_pausecheck_native( ldap_pvt_thread_pool_t *tpool )
1254 {
1255 struct ldap_int_thread_pool_s *pool;
1256
1257 if (tpool == NULL)
1258 return(-1);
1259
1260 pool = *tpool;
1261
1262 if (pool == NULL)
1263 return(0);
1264
1265 if (!pool->ltp_pause)
1266 return(0);
1267
1268 ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
1269 while (pool->ltp_pause)
1270 ldap_pvt_thread_cond_wait(&pool->ltp_cond, &pool->ltp_mutex);
1271 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
1272 return 1;
1273 }
1274
1275 /*
1276 * Pause the pool. The calling task must be active, not idle.
1277 * Return when all other tasks are paused or idle.
1278 */
1279 int
ldap_pvt_thread_pool_pause(ldap_pvt_thread_pool_t * tpool)1280 ldap_pvt_thread_pool_pause( ldap_pvt_thread_pool_t *tpool )
1281 {
1282 return handle_pause(tpool, PAUSE_ARG(DO_PAUSE));
1283 }
1284
1285 /* End a pause */
1286 int
ldap_pvt_thread_pool_resume(ldap_pvt_thread_pool_t * tpool)1287 ldap_pvt_thread_pool_resume (
1288 ldap_pvt_thread_pool_t *tpool )
1289 {
1290 struct ldap_int_thread_pool_s *pool;
1291 struct ldap_int_thread_poolq_s *pq;
1292 int i;
1293
1294 if (tpool == NULL)
1295 return(-1);
1296
1297 pool = *tpool;
1298
1299 if (pool == NULL)
1300 return(0);
1301
1302 ldap_pvt_thread_mutex_lock(&pool->ltp_mutex);
1303 assert(pool->ltp_pause == PAUSED);
1304 pool->ltp_pause = 0;
1305 for (i=0; i<pool->ltp_numqs; i++) {
1306 pq = pool->ltp_wqs[i];
1307 pq->ltp_work_list = &pq->ltp_pending_list;
1308 ldap_pvt_thread_cond_broadcast(&pq->ltp_cond);
1309 }
1310 ldap_pvt_thread_cond_broadcast(&pool->ltp_cond);
1311 ldap_pvt_thread_mutex_unlock(&pool->ltp_mutex);
1312 return(0);
1313 }
1314
1315 /*
1316 * Get the key's data and optionally free function in the given context.
1317 */
ldap_pvt_thread_pool_getkey(void * xctx,void * key,void ** data,ldap_pvt_thread_pool_keyfree_t ** kfree)1318 int ldap_pvt_thread_pool_getkey(
1319 void *xctx,
1320 void *key,
1321 void **data,
1322 ldap_pvt_thread_pool_keyfree_t **kfree )
1323 {
1324 ldap_int_thread_userctx_t *ctx = xctx;
1325 int i;
1326
1327 if ( !ctx || !key || !data ) return EINVAL;
1328
1329 for ( i=0; i<MAXKEYS && ctx->ltu_key[i].ltk_key; i++ ) {
1330 if ( ctx->ltu_key[i].ltk_key == key ) {
1331 *data = ctx->ltu_key[i].ltk_data;
1332 if ( kfree ) *kfree = ctx->ltu_key[i].ltk_free;
1333 return 0;
1334 }
1335 }
1336 return ENOENT;
1337 }
1338
1339 static void
clear_key_idx(ldap_int_thread_userctx_t * ctx,int i)1340 clear_key_idx( ldap_int_thread_userctx_t *ctx, int i )
1341 {
1342 for ( ; i < MAXKEYS-1 && ctx->ltu_key[i+1].ltk_key; i++ )
1343 ctx->ltu_key[i] = ctx->ltu_key[i+1];
1344 ctx->ltu_key[i].ltk_key = NULL;
1345 }
1346
1347 /*
1348 * Set or remove data for the key in the given context.
1349 * key can be any unique pointer.
1350 * kfree() is an optional function to free the data (but not the key):
1351 * pool_context_reset() and pool_purgekey() call kfree(key, data),
1352 * but pool_setkey() does not. For pool_setkey() it is the caller's
1353 * responsibility to free any existing data with the same key.
1354 * kfree() must not call functions taking a tpool argument.
1355 */
ldap_pvt_thread_pool_setkey(void * xctx,void * key,void * data,ldap_pvt_thread_pool_keyfree_t * kfree,void ** olddatap,ldap_pvt_thread_pool_keyfree_t ** oldkfreep)1356 int ldap_pvt_thread_pool_setkey(
1357 void *xctx,
1358 void *key,
1359 void *data,
1360 ldap_pvt_thread_pool_keyfree_t *kfree,
1361 void **olddatap,
1362 ldap_pvt_thread_pool_keyfree_t **oldkfreep )
1363 {
1364 ldap_int_thread_userctx_t *ctx = xctx;
1365 int i, found;
1366
1367 if ( !ctx || !key ) return EINVAL;
1368
1369 for ( i=found=0; i<MAXKEYS; i++ ) {
1370 if ( ctx->ltu_key[i].ltk_key == key ) {
1371 found = 1;
1372 break;
1373 } else if ( !ctx->ltu_key[i].ltk_key ) {
1374 break;
1375 }
1376 }
1377
1378 if ( olddatap ) {
1379 if ( found ) {
1380 *olddatap = ctx->ltu_key[i].ltk_data;
1381 } else {
1382 *olddatap = NULL;
1383 }
1384 }
1385
1386 if ( oldkfreep ) {
1387 if ( found ) {
1388 *oldkfreep = ctx->ltu_key[i].ltk_free;
1389 } else {
1390 *oldkfreep = 0;
1391 }
1392 }
1393
1394 if ( data || kfree ) {
1395 if ( i>=MAXKEYS )
1396 return ENOMEM;
1397 ctx->ltu_key[i].ltk_key = key;
1398 ctx->ltu_key[i].ltk_data = data;
1399 ctx->ltu_key[i].ltk_free = kfree;
1400 } else if ( found ) {
1401 clear_key_idx( ctx, i );
1402 }
1403
1404 return 0;
1405 }
1406
1407 /* Free all elements with this key, no matter which thread they're in.
1408 * May only be called while the pool is paused.
1409 */
ldap_pvt_thread_pool_purgekey(void * key)1410 void ldap_pvt_thread_pool_purgekey( void *key )
1411 {
1412 int i, j;
1413 ldap_int_thread_userctx_t *ctx;
1414
1415 assert ( key != NULL );
1416
1417 ldap_pvt_thread_mutex_lock(&ldap_pvt_thread_pool_mutex);
1418 for ( i=0; i<LDAP_MAXTHR; i++ ) {
1419 ctx = thread_keys[i].ctx;
1420 if ( ctx && ctx != DELETED_THREAD_CTX ) {
1421 for ( j=0; j<MAXKEYS && ctx->ltu_key[j].ltk_key; j++ ) {
1422 if ( ctx->ltu_key[j].ltk_key == key ) {
1423 if (ctx->ltu_key[j].ltk_free)
1424 ctx->ltu_key[j].ltk_free( ctx->ltu_key[j].ltk_key,
1425 ctx->ltu_key[j].ltk_data );
1426 clear_key_idx( ctx, j );
1427 break;
1428 }
1429 }
1430 }
1431 }
1432 ldap_pvt_thread_mutex_unlock(&ldap_pvt_thread_pool_mutex);
1433 }
1434
1435 /*
1436 * Find the context of the current thread.
1437 * This is necessary if the caller does not have access to the
1438 * thread context handle (for example, a slapd plugin calling
1439 * slapi_search_internal()). No doubt it is more efficient
1440 * for the application to keep track of the thread context
1441 * handles itself.
1442 */
ldap_pvt_thread_pool_context()1443 void *ldap_pvt_thread_pool_context( )
1444 {
1445 void *ctx = NULL;
1446
1447 ldap_pvt_thread_key_getdata( ldap_tpool_key, &ctx );
1448 return ctx ? ctx : (void *) &ldap_int_main_thrctx;
1449 }
1450
1451 /*
1452 * Free the context's keys.
1453 * Must not call functions taking a tpool argument (because this
1454 * thread already holds ltp_mutex when called from pool_wrapper()).
1455 */
ldap_pvt_thread_pool_context_reset(void * vctx)1456 void ldap_pvt_thread_pool_context_reset( void *vctx )
1457 {
1458 ldap_int_thread_userctx_t *ctx = vctx;
1459 int i;
1460
1461 for ( i=MAXKEYS-1; i>=0; i--) {
1462 if ( !ctx->ltu_key[i].ltk_key )
1463 continue;
1464 if ( ctx->ltu_key[i].ltk_free )
1465 ctx->ltu_key[i].ltk_free( ctx->ltu_key[i].ltk_key,
1466 ctx->ltu_key[i].ltk_data );
1467 ctx->ltu_key[i].ltk_key = NULL;
1468 }
1469 }
1470
ldap_pvt_thread_pool_tid(void * vctx)1471 ldap_pvt_thread_t ldap_pvt_thread_pool_tid( void *vctx )
1472 {
1473 ldap_int_thread_userctx_t *ctx = vctx;
1474
1475 return ctx->ltu_id;
1476 }
1477 #endif /* LDAP_THREAD_HAVE_TPOOL */
1478
1479 #endif /* LDAP_R_COMPILE */
1480