contrib/bind-9.2.4rc7/lib/isc/timer.c

   1 /*
   2  * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 1998-2001  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  15  * PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 /* $Id: timer.c,v 1.64.2.1 2004/03/09 06:11:52 marka Exp $ */
  19
  20 #include <config.h>
  21
  22 #include <isc/condition.h>
  23 #include <isc/heap.h>
  24 #include <isc/magic.h>
  25 #include <isc/mem.h>
  26 #include <isc/msgs.h>
  27 #include <isc/platform.h>
  28 #include <isc/task.h>
  29 #include <isc/thread.h>
  30 #include <isc/time.h>
  31 #include <isc/timer.h>
  32 #include <isc/util.h>
  33
  34 #ifndef ISC_PLATFORM_USETHREADS
  35 #include "timer_p.h"
  36 #endif /* ISC_PLATFORM_USETHREADS */
  37
  38 #ifdef ISC_TIMER_TRACE
  39 #define XTRACE(s)                       printf("%s\n", (s))
  40 #define XTRACEID(s, t)                  printf("%s %p\n", (s), (t))
  41 #define XTRACETIME(s, d)                printf("%s %u.%09u\n", (s), \
  42                                                (d).seconds, (d).nanoseconds)
  43 #define XTRACETIMER(s, t, d)            printf("%s %p %u.%09u\n", (s), (t), \
  44                                                (d).seconds, (d).nanoseconds)
  45 #else
  46 #define XTRACE(s)
  47 #define XTRACEID(s, t)
  48 #define XTRACETIME(s, d)
  49 #define XTRACETIMER(s, t, d)
  50 #endif /* ISC_TIMER_TRACE */
  51
  52 #define TIMER_MAGIC                     ISC_MAGIC('T', 'I', 'M', 'R')
  53 #define VALID_TIMER(t)                  ISC_MAGIC_VALID(t, TIMER_MAGIC)
  54
  55 struct isc_timer {
  56         /* Not locked. */
  57         unsigned int                    magic;
  58         isc_timermgr_t *                manager;
  59         isc_mutex_t                     lock;
  60         /* Locked by timer lock. */
  61         unsigned int                    references;
  62         isc_time_t                      idle;
  63         /* Locked by manager lock. */
  64         isc_timertype_t                 type;
  65         isc_time_t                      expires;
  66         isc_interval_t                  interval;
  67         isc_task_t *                    task;
  68         isc_taskaction_t                action;
  69         void *                          arg;
  70         unsigned int                    index;
  71         isc_time_t                      due;
  72         LINK(isc_timer_t)               link;
  73 };
  74
  75 #define TIMER_MANAGER_MAGIC             ISC_MAGIC('T', 'I', 'M', 'M')
  76 #define VALID_MANAGER(m)                ISC_MAGIC_VALID(m, TIMER_MANAGER_MAGIC)
  77
  78 struct isc_timermgr {
  79         /* Not locked. */
  80         unsigned int                    magic;
  81         isc_mem_t *                     mctx;
  82         isc_mutex_t                     lock;
  83         /* Locked by manager lock. */
  84         isc_boolean_t                   done;
  85         LIST(isc_timer_t)               timers;
  86         unsigned int                    nscheduled;
  87         isc_time_t                      due;
  88 #ifdef ISC_PLATFORM_USETHREADS
  89         isc_condition_t                 wakeup;
  90         isc_thread_t                    thread;
  91 #else /* ISC_PLATFORM_USETHREADS */
  92         unsigned int                    refs;
  93 #endif /* ISC_PLATFORM_USETHREADS */
  94         isc_heap_t *                    heap;
  95 };
  96
  97 #ifndef ISC_PLATFORM_USETHREADS
  98 /*
  99  * If threads are not in use, there can be only one.
 100  */
 101 static isc_timermgr_t *timermgr = NULL;
 102 #endif /* ISC_PLATFORM_USETHREADS */
 103
 104 static inline isc_result_t
 105 schedule(isc_timer_t *timer, isc_time_t *now, isc_boolean_t signal_ok) {
 106         isc_result_t result;
 107         isc_timermgr_t *manager;
 108         isc_time_t due;
 109         int cmp;
 110
 111         /*
 112          * Note: the caller must ensure locking.
 113          */
 114
 115         REQUIRE(timer->type != isc_timertype_inactive);
 116
 117 #ifndef ISC_PLATFORM_USETHREADS
 118         UNUSED(signal_ok);
 119 #endif /* ISC_PLATFORM_USETHREADS */
 120
 121         /*
 122          * Compute the new due time.
 123          */
 124         if (timer->type == isc_timertype_ticker) {
 125                 result = isc_time_add(now, &timer->interval, &due);
 126                 if (result != ISC_R_SUCCESS)
 127                         return (result);
 128         } else {
 129                 if (isc_time_isepoch(&timer->idle))
 130                         due = timer->expires;
 131                 else if (isc_time_isepoch(&timer->expires))
 132                         due = timer->idle;
 133                 else if (isc_time_compare(&timer->idle, &timer->expires) < 0)
 134                         due = timer->idle;
 135                 else
 136                         due = timer->expires;
 137         }
 138
 139         /*
 140          * Schedule the timer.
 141          */
 142         manager = timer->manager;
 143         if (timer->index > 0) {
 144                 /*
 145                  * Already scheduled.
 146                  */
 147                 cmp = isc_time_compare(&due, &timer->due);
 148                 timer->due = due;
 149                 switch (cmp) {
 150                 case -1:
 151                         isc_heap_increased(manager->heap, timer->index);
 152                         break;
 153                 case 1:
 154                         isc_heap_decreased(manager->heap, timer->index);
 155                         break;
 156                 case 0:
 157                         /* Nothing to do. */
 158                         break;
 159                 }
 160         } else {
 161                 timer->due = due;
 162                 result = isc_heap_insert(manager->heap, timer);
 163                 if (result != ISC_R_SUCCESS) {
 164                         INSIST(result == ISC_R_NOMEMORY);
 165                         return (ISC_R_NOMEMORY);
 166                 }
 167                 manager->nscheduled++;
 168         }
 169
 170         XTRACETIMER(isc_msgcat_get(isc_msgcat, ISC_MSGSET_TIMER,
 171                                    ISC_MSG_SCHEDULE, "schedule"), timer, due);
 172
 173         /*
 174          * If this timer is at the head of the queue, we need to ensure
 175          * that we won't miss it if it has a more recent due time than
 176          * the current "next" timer.  We do this either by waking up the
 177          * run thread, or explicitly setting the value in the manager.
 178          */
 179 #ifdef ISC_PLATFORM_USETHREADS
 180         if (timer->index == 1 && signal_ok) {
 181                 XTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_TIMER,
 182                                       ISC_MSG_SIGNALSCHED,
 183                                       "signal (schedule)"));
 184                 SIGNAL(&manager->wakeup);
 185         }
 186 #else /* ISC_PLATFORM_USETHREADS */
 187         if (timer->index == 1 &&
 188             isc_time_compare(&timer->due, &manager->due) < 0)
 189                 manager->due = timer->due;
 190 #endif /* ISC_PLATFORM_USETHREADS */
 191
 192         return (ISC_R_SUCCESS);
 193 }
 194
 195 static inline void
 196 deschedule(isc_timer_t *timer) {
 197         isc_boolean_t need_wakeup = ISC_FALSE;
 198         isc_timermgr_t *manager;
 199
 200         /*
 201          * The caller must ensure locking.
 202          */
 203
 204         manager = timer->manager;
 205         if (timer->index > 0) {
 206                 if (timer->index == 1)
 207                         need_wakeup = ISC_TRUE;
 208                 isc_heap_delete(manager->heap, timer->index);
 209                 timer->index = 0;
 210                 INSIST(manager->nscheduled > 0);
 211                 manager->nscheduled--;
 212 #ifdef ISC_PLATFORM_USETHREADS
 213                 if (need_wakeup) {
 214                         XTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_TIMER,
 215                                               ISC_MSG_SIGNALDESCHED,
 216                                               "signal (deschedule)"));
 217                         SIGNAL(&manager->wakeup);
 218                 }
 219 #endif /* ISC_PLATFORM_USETHREADS */
 220         }
 221 }
 222
 223 static void
 224 destroy(isc_timer_t *timer) {
 225         isc_timermgr_t *manager = timer->manager;
 226
 227         /*
 228          * The caller must ensure it is safe to destroy the timer.
 229          */
 230
 231         LOCK(&manager->lock);
 232
 233         isc_task_purgerange(timer->task,
 234                             timer,
 235                             ISC_TIMEREVENT_FIRSTEVENT,
 236                             ISC_TIMEREVENT_LASTEVENT,
 237                             NULL);
 238         deschedule(timer);
 239         UNLINK(manager->timers, timer, link);
 240
 241         UNLOCK(&manager->lock);
 242
 243         isc_task_detach(&timer->task);
 244         DESTROYLOCK(&timer->lock);
 245         timer->magic = 0;
 246         isc_mem_put(manager->mctx, timer, sizeof *timer);
 247 }
 248
 249 isc_result_t
 250 isc_timer_create(isc_timermgr_t *manager, isc_timertype_t type,
 251                  isc_time_t *expires, isc_interval_t *interval,
 252                  isc_task_t *task, isc_taskaction_t action, const void *arg,
 253                  isc_timer_t **timerp)
 254 {
 255         isc_timer_t *timer;
 256         isc_result_t result;
 257         isc_time_t now;
 258
 259         /*
 260          * Create a new 'type' timer managed by 'manager'.  The timers
 261          * parameters are specified by 'expires' and 'interval'.  Events
 262          * will be posted to 'task' and when dispatched 'action' will be
 263          * called with 'arg' as the arg value.  The new timer is returned
 264          * in 'timerp'.
 265          */
 266
 267         REQUIRE(VALID_MANAGER(manager));
 268         REQUIRE(task != NULL);
 269         REQUIRE(action != NULL);
 270         if (expires == NULL)
 271                 expires = isc_time_epoch;
 272         if (interval == NULL)
 273                 interval = isc_interval_zero;
 274         REQUIRE(type == isc_timertype_inactive ||
 275                 !(isc_time_isepoch(expires) && isc_interval_iszero(interval)));
 276         REQUIRE(timerp != NULL && *timerp == NULL);
 277
 278         /*
 279          * Get current time.
 280          */
 281         if (type != isc_timertype_inactive) {
 282                 result = isc_time_now(&now);
 283                 if (result != ISC_R_SUCCESS) {
 284                         UNEXPECTED_ERROR(__FILE__, __LINE__,
 285                                          "isc_time_now() %s: %s",
 286                                          isc_msgcat_get(isc_msgcat,
 287                                                         ISC_MSGSET_GENERAL,
 288                                                         ISC_MSG_FAILED,
 289                                                         "failed"),
 290                                          isc_result_totext(result));
 291                         return (ISC_R_UNEXPECTED);
 292                 }
 293         } else {
 294                 /*
 295                  * We don't have to do this, but it keeps the compiler from
 296                  * complaining about "now" possibly being used without being
 297                  * set, even though it will never actually happen.
 298                  */
 299                 isc_time_settoepoch(&now);
 300         }
 301
 302
 303         timer = isc_mem_get(manager->mctx, sizeof *timer);
 304         if (timer == NULL)
 305                 return (ISC_R_NOMEMORY);
 306
 307         timer->manager = manager;
 308         timer->references = 1;
 309
 310         if (type == isc_timertype_once && !isc_interval_iszero(interval)) {
 311                 result = isc_time_add(&now, interval, &timer->idle);
 312                 if (result != ISC_R_SUCCESS)
 313                         return (result);
 314         } else
 315                 isc_time_settoepoch(&timer->idle);
 316
 317         timer->type = type;
 318         timer->expires = *expires;
 319         timer->interval = *interval;
 320         timer->task = NULL;
 321         isc_task_attach(task, &timer->task);
 322         timer->action = action;
 323         /*
 324          * Removing the const attribute from "arg" is the best of two
 325          * evils here.  If the timer->arg member is made const, then
 326          * it affects a great many recipients of the timer event
 327          * which did not pass in an "arg" that was truly const.
 328          * Changing isc_timer_create() to not have "arg" prototyped as const,
 329          * though, can cause compilers warnings for calls that *do*
 330          * have a truly const arg.  The caller will have to carefully
 331          * keep track of whether arg started as a true const.
 332          */
 333         DE_CONST(arg, timer->arg);
 334         timer->index = 0;
 335         if (isc_mutex_init(&timer->lock) != ISC_R_SUCCESS) {
 336                 isc_task_detach(&timer->task);
 337                 isc_mem_put(manager->mctx, timer, sizeof *timer);
 338                 UNEXPECTED_ERROR(__FILE__, __LINE__,
 339                                  "isc_mutex_init() %s",
 340                                  isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
 341                                                 ISC_MSG_FAILED, "failed"));
 342                 return (ISC_R_UNEXPECTED);
 343         }
 344         ISC_LINK_INIT(timer, link);
 345         timer->magic = TIMER_MAGIC;
 346
 347         LOCK(&manager->lock);
 348
 349         /*
 350          * Note we don't have to lock the timer like we normally would because
 351          * there are no external references to it yet.
 352          */
 353
 354         if (type != isc_timertype_inactive)
 355                 result = schedule(timer, &now, ISC_TRUE);
 356         else
 357                 result = ISC_R_SUCCESS;
 358         if (result == ISC_R_SUCCESS)
 359                 APPEND(manager->timers, timer, link);
 360
 361         UNLOCK(&manager->lock);
 362
 363         if (result != ISC_R_SUCCESS) {
 364                 timer->magic = 0;
 365                 DESTROYLOCK(&timer->lock);
 366                 isc_task_detach(&timer->task);
 367                 isc_mem_put(manager->mctx, timer, sizeof *timer);
 368                 return (result);
 369         }
 370
 371         *timerp = timer;
 372
 373         return (ISC_R_SUCCESS);
 374 }
 375
 376 isc_result_t
 377 isc_timer_reset(isc_timer_t *timer, isc_timertype_t type,
 378                 isc_time_t *expires, isc_interval_t *interval,
 379                 isc_boolean_t purge)
 380 {
 381         isc_time_t now;
 382         isc_timermgr_t *manager;
 383         isc_result_t result;
 384
 385         /*
 386          * Change the timer's type, expires, and interval values to the given
 387          * values.  If 'purge' is ISC_TRUE, any pending events from this timer
 388          * are purged from its task's event queue.
 389          */
 390
 391         REQUIRE(VALID_TIMER(timer));
 392         manager = timer->manager;
 393         REQUIRE(VALID_MANAGER(manager));
 394         if (expires == NULL)
 395                 expires = isc_time_epoch;
 396         if (interval == NULL)
 397                 interval = isc_interval_zero;
 398         REQUIRE(type == isc_timertype_inactive ||
 399                 !(isc_time_isepoch(expires) && isc_interval_iszero(interval)));
 400
 401         /*
 402          * Get current time.
 403          */
 404         if (type != isc_timertype_inactive) {
 405                 result = isc_time_now(&now);
 406                 if (result != ISC_R_SUCCESS) {
 407                         UNEXPECTED_ERROR(__FILE__, __LINE__,
 408                                          "isc_time_now() %s: %s",
 409                                          isc_msgcat_get(isc_msgcat,
 410                                                         ISC_MSGSET_GENERAL,
 411                                                         ISC_MSG_FAILED,
 412                                                         "failed"),
 413                                          isc_result_totext(result));
 414                         return (ISC_R_UNEXPECTED);
 415                 }
 416         } else {
 417                 /*
 418                  * We don't have to do this, but it keeps the compiler from
 419                  * complaining about "now" possibly being used without being
 420                  * set, even though it will never actually happen.
 421                  */
 422                 isc_time_settoepoch(&now);
 423         }
 424
 425         manager = timer->manager;
 426
 427         LOCK(&manager->lock);
 428         LOCK(&timer->lock);
 429
 430         if (purge)
 431                 isc_task_purgerange(timer->task,
 432                                     timer,
 433                                     ISC_TIMEREVENT_FIRSTEVENT,
 434                                     ISC_TIMEREVENT_LASTEVENT,
 435                                     NULL);
 436         timer->type = type;
 437         timer->expires = *expires;
 438         timer->interval = *interval;
 439         if (type == isc_timertype_once && !isc_interval_iszero(interval)) {
 440                 result = isc_time_add(&now, interval, &timer->idle);
 441         } else {
 442                 isc_time_settoepoch(&timer->idle);
 443                 result = ISC_R_SUCCESS;
 444         }
 445
 446         if (result == ISC_R_SUCCESS) {
 447                 if (type == isc_timertype_inactive) {
 448                         deschedule(timer);
 449                         result = ISC_R_SUCCESS;
 450                 } else
 451                         result = schedule(timer, &now, ISC_TRUE);
 452         }
 453
 454         UNLOCK(&timer->lock);
 455         UNLOCK(&manager->lock);
 456
 457         return (result);
 458 }
 459
 460 isc_result_t
 461 isc_timer_touch(isc_timer_t *timer) {
 462         isc_result_t result;
 463         isc_time_t now;
 464
 465         /*
 466          * Set the last-touched time of 'timer' to the current time.
 467          */
 468
 469         REQUIRE(VALID_TIMER(timer));
 470
 471         LOCK(&timer->lock);
 472
 473         /*
 474          * We'd like to
 475          *
 476          *      REQUIRE(timer->type == isc_timertype_once);
 477          *
 478          * but we cannot without locking the manager lock too, which we
 479          * don't want to do.
 480          */
 481
 482         result = isc_time_now(&now);
 483         if (result != ISC_R_SUCCESS) {
 484                 UNEXPECTED_ERROR(__FILE__, __LINE__,
 485                                  "isc_time_now() %s: %s",
 486                                  isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
 487                                                 ISC_MSG_FAILED, "failed"),
 488                                  isc_result_totext(result));
 489                 result = ISC_R_UNEXPECTED;
 490         } else
 491                 result = isc_time_add(&now, &timer->interval, &timer->idle);
 492
 493         UNLOCK(&timer->lock);
 494
 495         return (result);
 496 }
 497
 498 void
 499 isc_timer_attach(isc_timer_t *timer, isc_timer_t **timerp) {
 500         /*
 501          * Attach *timerp to timer.
 502          */
 503
 504         REQUIRE(VALID_TIMER(timer));
 505         REQUIRE(timerp != NULL && *timerp == NULL);
 506
 507         LOCK(&timer->lock);
 508         timer->references++;
 509         UNLOCK(&timer->lock);
 510
 511         *timerp = timer;
 512 }
 513
 514 void
 515 isc_timer_detach(isc_timer_t **timerp) {
 516         isc_timer_t *timer;
 517         isc_boolean_t free_timer = ISC_FALSE;
 518
 519         /*
 520          * Detach *timerp from its timer.
 521          */
 522
 523         REQUIRE(timerp != NULL);
 524         timer = *timerp;
 525         REQUIRE(VALID_TIMER(timer));
 526
 527         LOCK(&timer->lock);
 528         REQUIRE(timer->references > 0);
 529         timer->references--;
 530         if (timer->references == 0)
 531                 free_timer = ISC_TRUE;
 532         UNLOCK(&timer->lock);
 533
 534         if (free_timer)
 535                 destroy(timer);
 536
 537         *timerp = NULL;
 538 }
 539
 540 static void
 541 dispatch(isc_timermgr_t *manager, isc_time_t *now) {
 542         isc_boolean_t done = ISC_FALSE, post_event, need_schedule;
 543         isc_event_t *event;
 544         isc_eventtype_t type = 0;
 545         isc_timer_t *timer;
 546         isc_result_t result;
 547
 548         /*
 549          * The caller must be holding the manager lock.
 550          */
 551
 552         while (manager->nscheduled > 0 && !done) {
 553                 timer = isc_heap_element(manager->heap, 1);
 554                 INSIST(timer->type != isc_timertype_inactive);
 555                 if (isc_time_compare(now, &timer->due) >= 0) {
 556                         if (timer->type == isc_timertype_ticker) {
 557                                 type = ISC_TIMEREVENT_TICK;
 558                                 post_event = ISC_TRUE;
 559                                 need_schedule = ISC_TRUE;
 560                         } else if (!isc_time_isepoch(&timer->expires) &&
 561                                    isc_time_compare(now,
 562                                                     &timer->expires) >= 0) {
 563                                 type = ISC_TIMEREVENT_LIFE;
 564                                 post_event = ISC_TRUE;
 565                                 need_schedule = ISC_FALSE;
 566                         } else if (!isc_time_isepoch(&timer->idle) &&
 567                                    isc_time_compare(now,
 568                                                     &timer->idle) >= 0) {
 569                                 type = ISC_TIMEREVENT_IDLE;
 570                                 post_event = ISC_TRUE;
 571                                 need_schedule = ISC_FALSE;
 572                         } else {
 573                                 /*
 574                                  * Idle timer has been touched; reschedule.
 575                                  */
 576                                 XTRACEID(isc_msgcat_get(isc_msgcat,
 577                                                         ISC_MSGSET_TIMER,
 578                                                         ISC_MSG_IDLERESCHED,
 579                                                         "idle reschedule"),
 580                                          timer);
 581                                 post_event = ISC_FALSE;
 582                                 need_schedule = ISC_TRUE;
 583                         }
 584
 585                         if (post_event) {
 586                                 XTRACEID(isc_msgcat_get(isc_msgcat,
 587                                                         ISC_MSGSET_TIMER,
 588                                                         ISC_MSG_POSTING,
 589                                                         "posting"), timer);
 590                                 /*
 591                                  * XXX We could preallocate this event.
 592                                  */
 593                                 event = isc_event_allocate(manager->mctx,
 594                                                            timer,
 595                                                            type,
 596                                                            timer->action,
 597                                                            timer->arg,
 598                                                            sizeof *event);
 599
 600                                 if (event != NULL)
 601                                         isc_task_send(timer->task, &event);
 602                                 else
 603                                         UNEXPECTED_ERROR(__FILE__, __LINE__,
 604                                                  isc_msgcat_get(isc_msgcat,
 605                                                          ISC_MSGSET_TIMER,
 606                                                          ISC_MSG_EVENTNOTALLOC,
 607                                                          "couldn't "
 608                                                          "allocate event"));
 609                         }
 610
 611                         timer->index = 0;
 612                         isc_heap_delete(manager->heap, 1);
 613                         manager->nscheduled--;
 614
 615                         if (need_schedule) {
 616                                 result = schedule(timer, now, ISC_FALSE);
 617                                 if (result != ISC_R_SUCCESS)
 618                                         UNEXPECTED_ERROR(__FILE__, __LINE__,
 619                                                 isc_msgcat_get(isc_msgcat,
 620                                                         ISC_MSGSET_TIMER,
 621                                                         ISC_MSG_SCHEDFAIL,
 622                                                         "couldn't "
 623                                                         "schedule timer: %u"),
 624                                                          result);
 625                         }
 626                 } else {
 627                         manager->due = timer->due;
 628                         done = ISC_TRUE;
 629                 }
 630         }
 631 }
 632
 633 #ifdef ISC_PLATFORM_USETHREADS
 634 static isc_threadresult_t
 635 #ifdef _WIN32                   /* XXXDCL */
 636 WINAPI
 637 #endif
 638 run(void *uap) {
 639         isc_timermgr_t *manager = uap;
 640         isc_time_t now;
 641         isc_result_t result;
 642
 643         LOCK(&manager->lock);
 644         while (!manager->done) {
 645                 RUNTIME_CHECK(isc_time_now(&now) == ISC_R_SUCCESS);
 646
 647                 XTRACETIME(isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
 648                                           ISC_MSG_RUNNING,
 649                                           "running"), now);
 650
 651                 dispatch(manager, &now);
 652
 653                 if (manager->nscheduled > 0) {
 654                         XTRACETIME(isc_msgcat_get(isc_msgcat,
 655                                                   ISC_MSGSET_GENERAL,
 656                                                   ISC_MSG_WAITUNTIL,
 657                                                   "waituntil"),
 658                                    manager->due);
 659                         result = WAITUNTIL(&manager->wakeup, &manager->lock,
 660                                            &manager->due);
 661                         INSIST(result == ISC_R_SUCCESS ||
 662                                result == ISC_R_TIMEDOUT);
 663                 } else {
 664                         XTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
 665                                               ISC_MSG_WAIT, "wait"));
 666                         WAIT(&manager->wakeup, &manager->lock);
 667                 }
 668                 XTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_TIMER,
 669                                       ISC_MSG_WAKEUP, "wakeup"));
 670         }
 671         UNLOCK(&manager->lock);
 672
 673         return ((isc_threadresult_t)0);
 674 }
 675 #endif /* ISC_PLATFORM_USETHREADS */
 676
 677 static isc_boolean_t
 678 sooner(void *v1, void *v2) {
 679         isc_timer_t *t1, *t2;
 680
 681         t1 = v1;
 682         t2 = v2;
 683         REQUIRE(VALID_TIMER(t1));
 684         REQUIRE(VALID_TIMER(t2));
 685
 686         if (isc_time_compare(&t1->due, &t2->due) < 0)
 687                 return (ISC_TRUE);
 688         return (ISC_FALSE);
 689 }
 690
 691 static void
 692 set_index(void *what, unsigned int index) {
 693         isc_timer_t *timer;
 694
 695         timer = what;
 696         REQUIRE(VALID_TIMER(timer));
 697
 698         timer->index = index;
 699 }
 700
 701 isc_result_t
 702 isc_timermgr_create(isc_mem_t *mctx, isc_timermgr_t **managerp) {
 703         isc_timermgr_t *manager;
 704         isc_result_t result;
 705
 706         /*
 707          * Create a timer manager.
 708          */
 709
 710         REQUIRE(managerp != NULL && *managerp == NULL);
 711
 712 #ifndef ISC_PLATFORM_USETHREADS
 713         if (timermgr != NULL) {
 714                 timermgr->refs++;
 715                 *managerp = timermgr;
 716                 return (ISC_R_SUCCESS);
 717         }
 718 #endif /* ISC_PLATFORM_USETHREADS */
 719
 720         manager = isc_mem_get(mctx, sizeof *manager);
 721         if (manager == NULL)
 722                 return (ISC_R_NOMEMORY);
 723
 724         manager->magic = TIMER_MANAGER_MAGIC;
 725         manager->mctx = NULL;
 726         manager->done = ISC_FALSE;
 727         INIT_LIST(manager->timers);
 728         manager->nscheduled = 0;
 729         isc_time_settoepoch(&manager->due);
 730         manager->heap = NULL;
 731         result = isc_heap_create(mctx, sooner, set_index, 0, &manager->heap);
 732         if (result != ISC_R_SUCCESS) {
 733                 INSIST(result == ISC_R_NOMEMORY);
 734                 isc_mem_put(mctx, manager, sizeof *manager);
 735                 return (ISC_R_NOMEMORY);
 736         }
 737         if (isc_mutex_init(&manager->lock) != ISC_R_SUCCESS) {
 738                 isc_heap_destroy(&manager->heap);
 739                 isc_mem_put(mctx, manager, sizeof *manager);
 740                 UNEXPECTED_ERROR(__FILE__, __LINE__,
 741                                  "isc_mutex_init() %s",
 742                                  isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
 743                                                 ISC_MSG_FAILED, "failed"));
 744                 return (ISC_R_UNEXPECTED);
 745         }
 746         isc_mem_attach(mctx, &manager->mctx);
 747 #ifdef ISC_PLATFORM_USETHREADS
 748         if (isc_condition_init(&manager->wakeup) != ISC_R_SUCCESS) {
 749                 isc_mem_detach(&manager->mctx);
 750                 DESTROYLOCK(&manager->lock);
 751                 isc_heap_destroy(&manager->heap);
 752                 isc_mem_put(mctx, manager, sizeof *manager);
 753                 UNEXPECTED_ERROR(__FILE__, __LINE__,
 754                                  "isc_condition_init() %s",
 755                                  isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
 756                                                 ISC_MSG_FAILED, "failed"));
 757                 return (ISC_R_UNEXPECTED);
 758         }
 759         if (isc_thread_create(run, manager, &manager->thread) !=
 760             ISC_R_SUCCESS) {
 761                 isc_mem_detach(&manager->mctx);
 762                 (void)isc_condition_destroy(&manager->wakeup);
 763                 DESTROYLOCK(&manager->lock);
 764                 isc_heap_destroy(&manager->heap);
 765                 isc_mem_put(mctx, manager, sizeof *manager);
 766                 UNEXPECTED_ERROR(__FILE__, __LINE__,
 767                                  "isc_thread_create() %s",
 768                                  isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
 769                                                 ISC_MSG_FAILED, "failed"));
 770                 return (ISC_R_UNEXPECTED);
 771         }
 772 #else /* ISC_PLATFORM_USETHREADS */
 773         manager->refs = 1;
 774         timermgr = manager;
 775 #endif /* ISC_PLATFORM_USETHREADS */
 776
 777         *managerp = manager;
 778
 779         return (ISC_R_SUCCESS);
 780 }
 781
 782 void
 783 isc_timermgr_destroy(isc_timermgr_t **managerp) {
 784         isc_timermgr_t *manager;
 785         isc_mem_t *mctx;
 786
 787         /*
 788          * Destroy a timer manager.
 789          */
 790
 791         REQUIRE(managerp != NULL);
 792         manager = *managerp;
 793         REQUIRE(VALID_MANAGER(manager));
 794
 795         LOCK(&manager->lock);
 796
 797 #ifndef ISC_PLATFORM_USETHREADS
 798         if (manager->refs > 1) {
 799                 manager->refs--;
 800                 UNLOCK(&manager->lock);
 801                 *managerp = NULL;
 802                 return;
 803         }
 804
 805         isc__timermgr_dispatch();
 806 #endif /* ISC_PLATFORM_USETHREADS */
 807
 808         REQUIRE(EMPTY(manager->timers));
 809         manager->done = ISC_TRUE;
 810
 811 #ifdef ISC_PLATFORM_USETHREADS
 812         XTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_TIMER,
 813                               ISC_MSG_SIGNALDESTROY, "signal (destroy)"));
 814         SIGNAL(&manager->wakeup);
 815 #endif /* ISC_PLATFORM_USETHREADS */
 816
 817         UNLOCK(&manager->lock);
 818
 819 #ifdef ISC_PLATFORM_USETHREADS
 820         /*
 821          * Wait for thread to exit.
 822          */
 823         if (isc_thread_join(manager->thread, NULL) != ISC_R_SUCCESS)
 824                 UNEXPECTED_ERROR(__FILE__, __LINE__,
 825                                  "isc_thread_join() %s",
 826                                  isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
 827                                                 ISC_MSG_FAILED, "failed"));
 828 #endif /* ISC_PLATFORM_USETHREADS */
 829
 830         /*
 831          * Clean up.
 832          */
 833 #ifdef ISC_PLATFORM_USETHREADS
 834         (void)isc_condition_destroy(&manager->wakeup);
 835 #endif /* ISC_PLATFORM_USETHREADS */
 836         DESTROYLOCK(&manager->lock);
 837         isc_heap_destroy(&manager->heap);
 838         manager->magic = 0;
 839         mctx = manager->mctx;
 840         isc_mem_put(mctx, manager, sizeof *manager);
 841         isc_mem_detach(&mctx);
 842
 843         *managerp = NULL;
 844 }
 845
 846 #ifndef ISC_PLATFORM_USETHREADS
 847 isc_result_t
 848 isc__timermgr_nextevent(isc_time_t *when) {
 849         if (timermgr == NULL || timermgr->nscheduled == 0)
 850                 return (ISC_R_NOTFOUND);
 851         *when = timermgr->due;
 852         return (ISC_R_SUCCESS);
 853 }
 854
 855 isc_result_t
 856 isc__timermgr_dispatch(void) {
 857         isc_time_t now;
 858         if (timermgr == NULL)
 859                 return (ISC_R_NOTFOUND);
 860         isc_time_now(&now);
 861         dispatch(timermgr, &now);
 862         return (ISC_R_SUCCESS);
 863 }
 864 #endif /* ISC_PLATFORM_USETHREADS */