src/core/timer.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2010 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21
  22 #include "alloc-util.h"
  23 #include "bus-error.h"
  24 #include "bus-util.h"
  25 #include "dbus-timer.h"
  26 #include "fs-util.h"
  27 #include "parse-util.h"
  28 #include "random-util.h"
  29 #include "special.h"
  30 #include "string-table.h"
  31 #include "string-util.h"
  32 #include "timer.h"
  33 #include "unit-name.h"
  34 #include "unit.h"
  35 #include "user-util.h"
  36 #include "virt.h"
  37
  38 static const UnitActiveState state_translation_table[_TIMER_STATE_MAX] = {
  39         [TIMER_DEAD] = UNIT_INACTIVE,
  40         [TIMER_WAITING] = UNIT_ACTIVE,
  41         [TIMER_RUNNING] = UNIT_ACTIVE,
  42         [TIMER_ELAPSED] = UNIT_ACTIVE,
  43         [TIMER_FAILED] = UNIT_FAILED
  44 };
  45
  46 static int timer_dispatch(sd_event_source *s, uint64_t usec, void *userdata);
  47
  48 static void timer_init(Unit *u) {
  49         Timer *t = TIMER(u);
  50
  51         assert(u);
  52         assert(u->load_state == UNIT_STUB);
  53
  54         t->next_elapse_monotonic_or_boottime = USEC_INFINITY;
  55         t->next_elapse_realtime = USEC_INFINITY;
  56         t->accuracy_usec = u->manager->default_timer_accuracy_usec;
  57         t->remain_after_elapse = true;
  58 }
  59
  60 void timer_free_values(Timer *t) {
  61         TimerValue *v;
  62
  63         assert(t);
  64
  65         while ((v = t->values)) {
  66                 LIST_REMOVE(value, t->values, v);
  67                 calendar_spec_free(v->calendar_spec);
  68                 free(v);
  69         }
  70 }
  71
  72 static void timer_done(Unit *u) {
  73         Timer *t = TIMER(u);
  74
  75         assert(t);
  76
  77         timer_free_values(t);
  78
  79         t->monotonic_event_source = sd_event_source_unref(t->monotonic_event_source);
  80         t->realtime_event_source = sd_event_source_unref(t->realtime_event_source);
  81
  82         free(t->stamp_path);
  83 }
  84
  85 static int timer_verify(Timer *t) {
  86         assert(t);
  87
  88         if (UNIT(t)->load_state != UNIT_LOADED)
  89                 return 0;
  90
  91         if (!t->values) {
  92                 log_unit_error(UNIT(t), "Timer unit lacks value setting. Refusing.");
  93                 return -EINVAL;
  94         }
  95
  96         return 0;
  97 }
  98
  99 static int timer_add_default_dependencies(Timer *t) {
 100         int r;
 101         TimerValue *v;
 102
 103         assert(t);
 104
 105         if (!UNIT(t)->default_dependencies)
 106                 return 0;
 107
 108         r = unit_add_dependency_by_name(UNIT(t), UNIT_BEFORE, SPECIAL_TIMERS_TARGET, NULL, true);
 109         if (r < 0)
 110                 return r;
 111
 112         if (UNIT(t)->manager->running_as == MANAGER_SYSTEM) {
 113                 r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true);
 114                 if (r < 0)
 115                         return r;
 116
 117                 LIST_FOREACH(value, v, t->values) {
 118                         if (v->base == TIMER_CALENDAR) {
 119                                 r = unit_add_dependency_by_name(UNIT(t), UNIT_AFTER, SPECIAL_TIME_SYNC_TARGET, NULL, true);
 120                                 if (r < 0)
 121                                         return r;
 122                                 break;
 123                         }
 124                 }
 125         }
 126
 127         return unit_add_two_dependencies_by_name(UNIT(t), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true);
 128 }
 129
 130 static int timer_setup_persistent(Timer *t) {
 131         int r;
 132
 133         assert(t);
 134
 135         if (!t->persistent)
 136                 return 0;
 137
 138         if (UNIT(t)->manager->running_as == MANAGER_SYSTEM) {
 139
 140                 r = unit_require_mounts_for(UNIT(t), "/var/lib/systemd/timers");
 141                 if (r < 0)
 142                         return r;
 143
 144                 t->stamp_path = strappend("/var/lib/systemd/timers/stamp-", UNIT(t)->id);
 145         } else {
 146                 const char *e;
 147
 148                 e = getenv("XDG_DATA_HOME");
 149                 if (e)
 150                         t->stamp_path = strjoin(e, "/systemd/timers/stamp-", UNIT(t)->id, NULL);
 151                 else {
 152
 153                         _cleanup_free_ char *h = NULL;
 154
 155                         r = get_home_dir(&h);
 156                         if (r < 0)
 157                                 return log_unit_error_errno(UNIT(t), r, "Failed to determine home directory: %m");
 158
 159                         t->stamp_path = strjoin(h, "/.local/share/systemd/timers/stamp-", UNIT(t)->id, NULL);
 160                 }
 161         }
 162
 163         if (!t->stamp_path)
 164                 return log_oom();
 165
 166         return 0;
 167 }
 168
 169 static int timer_load(Unit *u) {
 170         Timer *t = TIMER(u);
 171         int r;
 172
 173         assert(u);
 174         assert(u->load_state == UNIT_STUB);
 175
 176         r = unit_load_fragment_and_dropin(u);
 177         if (r < 0)
 178                 return r;
 179
 180         if (u->load_state == UNIT_LOADED) {
 181
 182                 if (set_isempty(u->dependencies[UNIT_TRIGGERS])) {
 183                         Unit *x;
 184
 185                         r = unit_load_related_unit(u, ".service", &x);
 186                         if (r < 0)
 187                                 return r;
 188
 189                         r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, x, true);
 190                         if (r < 0)
 191                                 return r;
 192                 }
 193
 194                 r = timer_setup_persistent(t);
 195                 if (r < 0)
 196                         return r;
 197
 198                 r = timer_add_default_dependencies(t);
 199                 if (r < 0)
 200                         return r;
 201         }
 202
 203         return timer_verify(t);
 204 }
 205
 206 static void timer_dump(Unit *u, FILE *f, const char *prefix) {
 207         char buf[FORMAT_TIMESPAN_MAX];
 208         Timer *t = TIMER(u);
 209         Unit *trigger;
 210         TimerValue *v;
 211
 212         trigger = UNIT_TRIGGER(u);
 213
 214         fprintf(f,
 215                 "%sTimer State: %s\n"
 216                 "%sResult: %s\n"
 217                 "%sUnit: %s\n"
 218                 "%sPersistent: %s\n"
 219                 "%sWakeSystem: %s\n"
 220                 "%sAccuracy: %s\n"
 221                 "%sRemainAfterElapse: %s\n",
 222                 prefix, timer_state_to_string(t->state),
 223                 prefix, timer_result_to_string(t->result),
 224                 prefix, trigger ? trigger->id : "n/a",
 225                 prefix, yes_no(t->persistent),
 226                 prefix, yes_no(t->wake_system),
 227                 prefix, format_timespan(buf, sizeof(buf), t->accuracy_usec, 1),
 228                 prefix, yes_no(t->remain_after_elapse));
 229
 230         LIST_FOREACH(value, v, t->values) {
 231
 232                 if (v->base == TIMER_CALENDAR) {
 233                         _cleanup_free_ char *p = NULL;
 234
 235                         calendar_spec_to_string(v->calendar_spec, &p);
 236
 237                         fprintf(f,
 238                                 "%s%s: %s\n",
 239                                 prefix,
 240                                 timer_base_to_string(v->base),
 241                                 strna(p));
 242                 } else  {
 243                         char timespan1[FORMAT_TIMESPAN_MAX];
 244
 245                         fprintf(f,
 246                                 "%s%s: %s\n",
 247                                 prefix,
 248                                 timer_base_to_string(v->base),
 249                                 format_timespan(timespan1, sizeof(timespan1), v->value, 0));
 250                 }
 251         }
 252 }
 253
 254 static void timer_set_state(Timer *t, TimerState state) {
 255         TimerState old_state;
 256         assert(t);
 257
 258         old_state = t->state;
 259         t->state = state;
 260
 261         if (state != TIMER_WAITING) {
 262                 t->monotonic_event_source = sd_event_source_unref(t->monotonic_event_source);
 263                 t->realtime_event_source = sd_event_source_unref(t->realtime_event_source);
 264         }
 265
 266         if (state != old_state)
 267                 log_unit_debug(UNIT(t), "Changed %s -> %s", timer_state_to_string(old_state), timer_state_to_string(state));
 268
 269         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], true);
 270 }
 271
 272 static void timer_enter_waiting(Timer *t, bool initial);
 273
 274 static int timer_coldplug(Unit *u) {
 275         Timer *t = TIMER(u);
 276
 277         assert(t);
 278         assert(t->state == TIMER_DEAD);
 279
 280         if (t->deserialized_state == t->state)
 281                 return 0;
 282
 283         if (t->deserialized_state == TIMER_WAITING)
 284                 timer_enter_waiting(t, false);
 285         else
 286                 timer_set_state(t, t->deserialized_state);
 287
 288         return 0;
 289 }
 290
 291 static void timer_enter_dead(Timer *t, TimerResult f) {
 292         assert(t);
 293
 294         if (f != TIMER_SUCCESS)
 295                 t->result = f;
 296
 297         timer_set_state(t, t->result != TIMER_SUCCESS ? TIMER_FAILED : TIMER_DEAD);
 298 }
 299
 300 static void timer_enter_elapsed(Timer *t, bool leave_around) {
 301         assert(t);
 302
 303         /* If a unit is marked with RemainAfterElapse=yes we leave it
 304          * around even after it elapsed once, so that starting it
 305          * later again does not necessarily mean immediate
 306          * retriggering. We unconditionally leave units with
 307          * TIMER_UNIT_ACTIVE or TIMER_UNIT_INACTIVE triggers around,
 308          * since they might be restarted automatically at any time
 309          * later on. */
 310
 311         if (t->remain_after_elapse || leave_around)
 312                 timer_set_state(t, TIMER_ELAPSED);
 313         else
 314                 timer_enter_dead(t, TIMER_SUCCESS);
 315 }
 316
 317 static usec_t monotonic_to_boottime(usec_t t) {
 318         usec_t a, b;
 319
 320         if (t <= 0)
 321                 return 0;
 322
 323         a = now(CLOCK_BOOTTIME);
 324         b = now(CLOCK_MONOTONIC);
 325
 326         if (t + a > b)
 327                 return t + a - b;
 328         else
 329                 return 0;
 330 }
 331
 332 static void add_random(Timer *t, usec_t *v) {
 333         char s[FORMAT_TIMESPAN_MAX];
 334         usec_t add;
 335
 336         assert(t);
 337         assert(v);
 338
 339         if (t->random_usec == 0)
 340                 return;
 341         if (*v == USEC_INFINITY)
 342                 return;
 343
 344         add = random_u64() % t->random_usec;
 345
 346         if (*v + add < *v) /* overflow */
 347                 *v = (usec_t) -2; /* Highest possible value, that is not USEC_INFINITY */
 348         else
 349                 *v += add;
 350
 351         log_unit_info(UNIT(t), "Adding %s random time.", format_timespan(s, sizeof(s), add, 0));
 352 }
 353
 354 static void timer_enter_waiting(Timer *t, bool initial) {
 355         bool found_monotonic = false, found_realtime = false;
 356         usec_t ts_realtime, ts_monotonic;
 357         usec_t base = 0;
 358         bool leave_around = false;
 359         TimerValue *v;
 360         Unit *trigger;
 361         int r;
 362
 363         assert(t);
 364
 365         trigger = UNIT_TRIGGER(UNIT(t));
 366         if (!trigger) {
 367                 log_unit_error(UNIT(t), "Unit to trigger vanished.");
 368                 timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 369                 return;
 370         }
 371
 372         /* If we shall wake the system we use the boottime clock
 373          * rather than the monotonic clock. */
 374
 375         ts_realtime = now(CLOCK_REALTIME);
 376         ts_monotonic = now(t->wake_system ? CLOCK_BOOTTIME : CLOCK_MONOTONIC);
 377         t->next_elapse_monotonic_or_boottime = t->next_elapse_realtime = 0;
 378
 379         LIST_FOREACH(value, v, t->values) {
 380
 381                 if (v->disabled)
 382                         continue;
 383
 384                 if (v->base == TIMER_CALENDAR) {
 385                         usec_t b;
 386
 387                         /* If we know the last time this was
 388                          * triggered, schedule the job based relative
 389                          * to that. If we don't just start from
 390                          * now. */
 391
 392                         b = t->last_trigger.realtime > 0 ? t->last_trigger.realtime : ts_realtime;
 393
 394                         r = calendar_spec_next_usec(v->calendar_spec, b, &v->next_elapse);
 395                         if (r < 0)
 396                                 continue;
 397
 398                         if (!found_realtime)
 399                                 t->next_elapse_realtime = v->next_elapse;
 400                         else
 401                                 t->next_elapse_realtime = MIN(t->next_elapse_realtime, v->next_elapse);
 402
 403                         found_realtime = true;
 404
 405                 } else  {
 406                         switch (v->base) {
 407
 408                         case TIMER_ACTIVE:
 409                                 if (state_translation_table[t->state] == UNIT_ACTIVE)
 410                                         base = UNIT(t)->inactive_exit_timestamp.monotonic;
 411                                 else
 412                                         base = ts_monotonic;
 413                                 break;
 414
 415                         case TIMER_BOOT:
 416                                 if (detect_container() <= 0) {
 417                                         /* CLOCK_MONOTONIC equals the uptime on Linux */
 418                                         base = 0;
 419                                         break;
 420                                 }
 421                                 /* In a container we don't want to include the time the host
 422                                  * was already up when the container started, so count from
 423                                  * our own startup. Fall through. */
 424                         case TIMER_STARTUP:
 425                                 base = UNIT(t)->manager->userspace_timestamp.monotonic;
 426                                 break;
 427
 428                         case TIMER_UNIT_ACTIVE:
 429                                 leave_around = true;
 430                                 base = trigger->inactive_exit_timestamp.monotonic;
 431
 432                                 if (base <= 0)
 433                                         base = t->last_trigger.monotonic;
 434
 435                                 if (base <= 0)
 436                                         continue;
 437
 438                                 break;
 439
 440                         case TIMER_UNIT_INACTIVE:
 441                                 leave_around = true;
 442                                 base = trigger->inactive_enter_timestamp.monotonic;
 443
 444                                 if (base <= 0)
 445                                         base = t->last_trigger.monotonic;
 446
 447                                 if (base <= 0)
 448                                         continue;
 449
 450                                 break;
 451
 452                         default:
 453                                 assert_not_reached("Unknown timer base");
 454                         }
 455
 456                         if (t->wake_system)
 457                                 base = monotonic_to_boottime(base);
 458
 459                         v->next_elapse = base + v->value;
 460
 461                         if (!initial && v->next_elapse < ts_monotonic && IN_SET(v->base, TIMER_ACTIVE, TIMER_BOOT, TIMER_STARTUP)) {
 462                                 /* This is a one time trigger, disable it now */
 463                                 v->disabled = true;
 464                                 continue;
 465                         }
 466
 467                         if (!found_monotonic)
 468                                 t->next_elapse_monotonic_or_boottime = v->next_elapse;
 469                         else
 470                                 t->next_elapse_monotonic_or_boottime = MIN(t->next_elapse_monotonic_or_boottime, v->next_elapse);
 471
 472                         found_monotonic = true;
 473                 }
 474         }
 475
 476         if (!found_monotonic && !found_realtime) {
 477                 log_unit_debug(UNIT(t), "Timer is elapsed.");
 478                 timer_enter_elapsed(t, leave_around);
 479                 return;
 480         }
 481
 482         if (found_monotonic) {
 483                 char buf[FORMAT_TIMESPAN_MAX];
 484                 usec_t left;
 485
 486                 add_random(t, &t->next_elapse_monotonic_or_boottime);
 487
 488                 left = t->next_elapse_monotonic_or_boottime > ts_monotonic ? t->next_elapse_monotonic_or_boottime - ts_monotonic : 0;
 489                 log_unit_debug(UNIT(t), "Monotonic timer elapses in %s.", format_timespan(buf, sizeof(buf), left, 0));
 490
 491                 if (t->monotonic_event_source) {
 492                         r = sd_event_source_set_time(t->monotonic_event_source, t->next_elapse_monotonic_or_boottime);
 493                         if (r < 0)
 494                                 goto fail;
 495
 496                         r = sd_event_source_set_enabled(t->monotonic_event_source, SD_EVENT_ONESHOT);
 497                         if (r < 0)
 498                                 goto fail;
 499                 } else {
 500
 501                         r = sd_event_add_time(
 502                                         UNIT(t)->manager->event,
 503                                         &t->monotonic_event_source,
 504                                         t->wake_system ? CLOCK_BOOTTIME_ALARM : CLOCK_MONOTONIC,
 505                                         t->next_elapse_monotonic_or_boottime, t->accuracy_usec,
 506                                         timer_dispatch, t);
 507                         if (r < 0)
 508                                 goto fail;
 509
 510                         (void) sd_event_source_set_description(t->monotonic_event_source, "timer-monotonic");
 511                 }
 512
 513         } else if (t->monotonic_event_source) {
 514
 515                 r = sd_event_source_set_enabled(t->monotonic_event_source, SD_EVENT_OFF);
 516                 if (r < 0)
 517                         goto fail;
 518         }
 519
 520         if (found_realtime) {
 521                 char buf[FORMAT_TIMESTAMP_MAX];
 522
 523                 add_random(t, &t->next_elapse_realtime);
 524
 525                 log_unit_debug(UNIT(t), "Realtime timer elapses at %s.", format_timestamp(buf, sizeof(buf), t->next_elapse_realtime));
 526
 527                 if (t->realtime_event_source) {
 528                         r = sd_event_source_set_time(t->realtime_event_source, t->next_elapse_realtime);
 529                         if (r < 0)
 530                                 goto fail;
 531
 532                         r = sd_event_source_set_enabled(t->realtime_event_source, SD_EVENT_ONESHOT);
 533                         if (r < 0)
 534                                 goto fail;
 535                 } else {
 536                         r = sd_event_add_time(
 537                                         UNIT(t)->manager->event,
 538                                         &t->realtime_event_source,
 539                                         t->wake_system ? CLOCK_REALTIME_ALARM : CLOCK_REALTIME,
 540                                         t->next_elapse_realtime, t->accuracy_usec,
 541                                         timer_dispatch, t);
 542                         if (r < 0)
 543                                 goto fail;
 544
 545                         (void) sd_event_source_set_description(t->realtime_event_source, "timer-realtime");
 546                 }
 547
 548         } else if (t->realtime_event_source) {
 549
 550                 r = sd_event_source_set_enabled(t->realtime_event_source, SD_EVENT_OFF);
 551                 if (r < 0)
 552                         goto fail;
 553         }
 554
 555         timer_set_state(t, TIMER_WAITING);
 556         return;
 557
 558 fail:
 559         log_unit_warning_errno(UNIT(t), r, "Failed to enter waiting state: %m");
 560         timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 561 }
 562
 563 static void timer_enter_running(Timer *t) {
 564         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 565         Unit *trigger;
 566         int r;
 567
 568         assert(t);
 569
 570         /* Don't start job if we are supposed to go down */
 571         if (unit_stop_pending(UNIT(t)))
 572                 return;
 573
 574         trigger = UNIT_TRIGGER(UNIT(t));
 575         if (!trigger) {
 576                 log_unit_error(UNIT(t), "Unit to trigger vanished.");
 577                 timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 578                 return;
 579         }
 580
 581         r = manager_add_job(UNIT(t)->manager, JOB_START, trigger, JOB_REPLACE, &error, NULL);
 582         if (r < 0)
 583                 goto fail;
 584
 585         dual_timestamp_get(&t->last_trigger);
 586
 587         if (t->stamp_path)
 588                 touch_file(t->stamp_path, true, t->last_trigger.realtime, UID_INVALID, GID_INVALID, MODE_INVALID);
 589
 590         timer_set_state(t, TIMER_RUNNING);
 591         return;
 592
 593 fail:
 594         log_unit_warning(UNIT(t), "Failed to queue unit startup job: %s", bus_error_message(&error, r));
 595         timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 596 }
 597
 598 static int timer_start(Unit *u) {
 599         Timer *t = TIMER(u);
 600         TimerValue *v;
 601         Unit *trigger;
 602
 603         assert(t);
 604         assert(t->state == TIMER_DEAD || t->state == TIMER_FAILED);
 605
 606         trigger = UNIT_TRIGGER(u);
 607         if (!trigger || trigger->load_state != UNIT_LOADED) {
 608                 log_unit_error(u, "Refusing to start, unit to trigger not loaded.");
 609                 return -ENOENT;
 610         }
 611
 612         t->last_trigger = DUAL_TIMESTAMP_NULL;
 613
 614         /* Reenable all timers that depend on unit activation time */
 615         LIST_FOREACH(value, v, t->values)
 616                 if (v->base == TIMER_ACTIVE)
 617                         v->disabled = false;
 618
 619         if (t->stamp_path) {
 620                 struct stat st;
 621
 622                 if (stat(t->stamp_path, &st) >= 0)
 623                         t->last_trigger.realtime = timespec_load(&st.st_atim);
 624                 else if (errno == ENOENT)
 625                         /* The timer has never run before,
 626                          * make sure a stamp file exists.
 627                          */
 628                         touch_file(t->stamp_path, true, USEC_INFINITY, UID_INVALID, GID_INVALID, MODE_INVALID);
 629         }
 630
 631         t->result = TIMER_SUCCESS;
 632         timer_enter_waiting(t, true);
 633         return 1;
 634 }
 635
 636 static int timer_stop(Unit *u) {
 637         Timer *t = TIMER(u);
 638
 639         assert(t);
 640         assert(t->state == TIMER_WAITING || t->state == TIMER_RUNNING || t->state == TIMER_ELAPSED);
 641
 642         timer_enter_dead(t, TIMER_SUCCESS);
 643         return 1;
 644 }
 645
 646 static int timer_serialize(Unit *u, FILE *f, FDSet *fds) {
 647         Timer *t = TIMER(u);
 648
 649         assert(u);
 650         assert(f);
 651         assert(fds);
 652
 653         unit_serialize_item(u, f, "state", timer_state_to_string(t->state));
 654         unit_serialize_item(u, f, "result", timer_result_to_string(t->result));
 655
 656         if (t->last_trigger.realtime > 0)
 657                 unit_serialize_item_format(u, f, "last-trigger-realtime", "%" PRIu64, t->last_trigger.realtime);
 658
 659         if (t->last_trigger.monotonic > 0)
 660                 unit_serialize_item_format(u, f, "last-trigger-monotonic", "%" PRIu64, t->last_trigger.monotonic);
 661
 662         return 0;
 663 }
 664
 665 static int timer_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 666         Timer *t = TIMER(u);
 667         int r;
 668
 669         assert(u);
 670         assert(key);
 671         assert(value);
 672         assert(fds);
 673
 674         if (streq(key, "state")) {
 675                 TimerState state;
 676
 677                 state = timer_state_from_string(value);
 678                 if (state < 0)
 679                         log_unit_debug(u, "Failed to parse state value: %s", value);
 680                 else
 681                         t->deserialized_state = state;
 682         } else if (streq(key, "result")) {
 683                 TimerResult f;
 684
 685                 f = timer_result_from_string(value);
 686                 if (f < 0)
 687                         log_unit_debug(u, "Failed to parse result value: %s", value);
 688                 else if (f != TIMER_SUCCESS)
 689                         t->result = f;
 690         } else if (streq(key, "last-trigger-realtime")) {
 691
 692                 r = safe_atou64(value, &t->last_trigger.realtime);
 693                 if (r < 0)
 694                         log_unit_debug(u, "Failed to parse last-trigger-realtime value: %s", value);
 695
 696         } else if (streq(key, "last-trigger-monotonic")) {
 697
 698                 r = safe_atou64(value, &t->last_trigger.monotonic);
 699                 if (r < 0)
 700                         log_unit_debug(u, "Failed to parse last-trigger-monotonic value: %s", value);
 701
 702         } else
 703                 log_unit_debug(u, "Unknown serialization key: %s", key);
 704
 705         return 0;
 706 }
 707
 708 _pure_ static UnitActiveState timer_active_state(Unit *u) {
 709         assert(u);
 710
 711         return state_translation_table[TIMER(u)->state];
 712 }
 713
 714 _pure_ static const char *timer_sub_state_to_string(Unit *u) {
 715         assert(u);
 716
 717         return timer_state_to_string(TIMER(u)->state);
 718 }
 719
 720 static int timer_dispatch(sd_event_source *s, uint64_t usec, void *userdata) {
 721         Timer *t = TIMER(userdata);
 722
 723         assert(t);
 724
 725         if (t->state != TIMER_WAITING)
 726                 return 0;
 727
 728         log_unit_debug(UNIT(t), "Timer elapsed.");
 729         timer_enter_running(t);
 730         return 0;
 731 }
 732
 733 static void timer_trigger_notify(Unit *u, Unit *other) {
 734         Timer *t = TIMER(u);
 735         TimerValue *v;
 736
 737         assert(u);
 738         assert(other);
 739
 740         if (other->load_state != UNIT_LOADED)
 741                 return;
 742
 743         /* Reenable all timers that depend on unit state */
 744         LIST_FOREACH(value, v, t->values)
 745                 if (v->base == TIMER_UNIT_ACTIVE ||
 746                     v->base == TIMER_UNIT_INACTIVE)
 747                         v->disabled = false;
 748
 749         switch (t->state) {
 750
 751         case TIMER_WAITING:
 752         case TIMER_ELAPSED:
 753
 754                 /* Recalculate sleep time */
 755                 timer_enter_waiting(t, false);
 756                 break;
 757
 758         case TIMER_RUNNING:
 759
 760                 if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other))) {
 761                         log_unit_debug(UNIT(t), "Got notified about unit deactivation.");
 762                         timer_enter_waiting(t, false);
 763                 }
 764                 break;
 765
 766         case TIMER_DEAD:
 767         case TIMER_FAILED:
 768                 break;
 769
 770         default:
 771                 assert_not_reached("Unknown timer state");
 772         }
 773 }
 774
 775 static void timer_reset_failed(Unit *u) {
 776         Timer *t = TIMER(u);
 777
 778         assert(t);
 779
 780         if (t->state == TIMER_FAILED)
 781                 timer_set_state(t, TIMER_DEAD);
 782
 783         t->result = TIMER_SUCCESS;
 784 }
 785
 786 static void timer_time_change(Unit *u) {
 787         Timer *t = TIMER(u);
 788
 789         assert(u);
 790
 791         if (t->state != TIMER_WAITING)
 792                 return;
 793
 794         log_unit_debug(u, "Time change, recalculating next elapse.");
 795         timer_enter_waiting(t, false);
 796 }
 797
 798 static const char* const timer_base_table[_TIMER_BASE_MAX] = {
 799         [TIMER_ACTIVE] = "OnActiveSec",
 800         [TIMER_BOOT] = "OnBootSec",
 801         [TIMER_STARTUP] = "OnStartupSec",
 802         [TIMER_UNIT_ACTIVE] = "OnUnitActiveSec",
 803         [TIMER_UNIT_INACTIVE] = "OnUnitInactiveSec",
 804         [TIMER_CALENDAR] = "OnCalendar"
 805 };
 806
 807 DEFINE_STRING_TABLE_LOOKUP(timer_base, TimerBase);
 808
 809 static const char* const timer_result_table[_TIMER_RESULT_MAX] = {
 810         [TIMER_SUCCESS] = "success",
 811         [TIMER_FAILURE_RESOURCES] = "resources"
 812 };
 813
 814 DEFINE_STRING_TABLE_LOOKUP(timer_result, TimerResult);
 815
 816 const UnitVTable timer_vtable = {
 817         .object_size = sizeof(Timer),
 818
 819         .sections =
 820                 "Unit\0"
 821                 "Timer\0"
 822                 "Install\0",
 823         .private_section = "Timer",
 824
 825         .init = timer_init,
 826         .done = timer_done,
 827         .load = timer_load,
 828
 829         .coldplug = timer_coldplug,
 830
 831         .dump = timer_dump,
 832
 833         .start = timer_start,
 834         .stop = timer_stop,
 835
 836         .serialize = timer_serialize,
 837         .deserialize_item = timer_deserialize_item,
 838
 839         .active_state = timer_active_state,
 840         .sub_state_to_string = timer_sub_state_to_string,
 841
 842         .trigger_notify = timer_trigger_notify,
 843
 844         .reset_failed = timer_reset_failed,
 845         .time_change = timer_time_change,
 846
 847         .bus_vtable = bus_timer_vtable,
 848         .bus_set_property = bus_timer_set_property,
 849
 850         .can_transient = true,
 851 };