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 (MANAGER_IS_SYSTEM(UNIT(t)->manager)) {
 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 (MANAGER_IS_SYSTEM(UNIT(t)->manager)) {
 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);
 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);
 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                         (void) 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                 t->next_elapse_monotonic_or_boottime = USEC_INFINITY;
 265                 t->next_elapse_realtime = USEC_INFINITY;
 266         }
 267
 268         if (state != old_state)
 269                 log_unit_debug(UNIT(t), "Changed %s -> %s", timer_state_to_string(old_state), timer_state_to_string(state));
 270
 271         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], true);
 272 }
 273
 274 static void timer_enter_waiting(Timer *t, bool initial);
 275
 276 static int timer_coldplug(Unit *u) {
 277         Timer *t = TIMER(u);
 278
 279         assert(t);
 280         assert(t->state == TIMER_DEAD);
 281
 282         if (t->deserialized_state == t->state)
 283                 return 0;
 284
 285         if (t->deserialized_state == TIMER_WAITING)
 286                 timer_enter_waiting(t, false);
 287         else
 288                 timer_set_state(t, t->deserialized_state);
 289
 290         return 0;
 291 }
 292
 293 static void timer_enter_dead(Timer *t, TimerResult f) {
 294         assert(t);
 295
 296         if (t->result == TIMER_SUCCESS)
 297                 t->result = f;
 298
 299         timer_set_state(t, t->result != TIMER_SUCCESS ? TIMER_FAILED : TIMER_DEAD);
 300 }
 301
 302 static void timer_enter_elapsed(Timer *t, bool leave_around) {
 303         assert(t);
 304
 305         /* If a unit is marked with RemainAfterElapse=yes we leave it
 306          * around even after it elapsed once, so that starting it
 307          * later again does not necessarily mean immediate
 308          * retriggering. We unconditionally leave units with
 309          * TIMER_UNIT_ACTIVE or TIMER_UNIT_INACTIVE triggers around,
 310          * since they might be restarted automatically at any time
 311          * later on. */
 312
 313         if (t->remain_after_elapse || leave_around)
 314                 timer_set_state(t, TIMER_ELAPSED);
 315         else
 316                 timer_enter_dead(t, TIMER_SUCCESS);
 317 }
 318
 319 static void add_random(Timer *t, usec_t *v) {
 320         char s[FORMAT_TIMESPAN_MAX];
 321         usec_t add;
 322
 323         assert(t);
 324         assert(v);
 325
 326         if (t->random_usec == 0)
 327                 return;
 328         if (*v == USEC_INFINITY)
 329                 return;
 330
 331         add = random_u64() % t->random_usec;
 332
 333         if (*v + add < *v) /* overflow */
 334                 *v = (usec_t) -2; /* Highest possible value, that is not USEC_INFINITY */
 335         else
 336                 *v += add;
 337
 338         log_unit_debug(UNIT(t), "Adding %s random time.", format_timespan(s, sizeof(s), add, 0));
 339 }
 340
 341 static void timer_enter_waiting(Timer *t, bool initial) {
 342         bool found_monotonic = false, found_realtime = false;
 343         bool leave_around = false;
 344         triple_timestamp ts;
 345         usec_t base = 0;
 346         TimerValue *v;
 347         Unit *trigger;
 348         int r;
 349
 350         assert(t);
 351
 352         trigger = UNIT_TRIGGER(UNIT(t));
 353         if (!trigger) {
 354                 log_unit_error(UNIT(t), "Unit to trigger vanished.");
 355                 timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 356                 return;
 357         }
 358
 359         triple_timestamp_get(&ts);
 360         t->next_elapse_monotonic_or_boottime = t->next_elapse_realtime = 0;
 361
 362         LIST_FOREACH(value, v, t->values) {
 363
 364                 if (v->disabled)
 365                         continue;
 366
 367                 if (v->base == TIMER_CALENDAR) {
 368                         usec_t b;
 369
 370                         /* If we know the last time this was
 371                          * triggered, schedule the job based relative
 372                          * to that. If we don't just start from
 373                          * now. */
 374
 375                         b = t->last_trigger.realtime > 0 ? t->last_trigger.realtime : ts.realtime;
 376
 377                         r = calendar_spec_next_usec(v->calendar_spec, b, &v->next_elapse);
 378                         if (r < 0)
 379                                 continue;
 380
 381                         if (!found_realtime)
 382                                 t->next_elapse_realtime = v->next_elapse;
 383                         else
 384                                 t->next_elapse_realtime = MIN(t->next_elapse_realtime, v->next_elapse);
 385
 386                         found_realtime = true;
 387
 388                 } else  {
 389
 390                         switch (v->base) {
 391
 392                         case TIMER_ACTIVE:
 393                                 if (state_translation_table[t->state] == UNIT_ACTIVE)
 394                                         base = UNIT(t)->inactive_exit_timestamp.monotonic;
 395                                 else
 396                                         base = ts.monotonic;
 397                                 break;
 398
 399                         case TIMER_BOOT:
 400                                 if (detect_container() <= 0) {
 401                                         /* CLOCK_MONOTONIC equals the uptime on Linux */
 402                                         base = 0;
 403                                         break;
 404                                 }
 405                                 /* In a container we don't want to include the time the host
 406                                  * was already up when the container started, so count from
 407                                  * our own startup. */
 408                                 /* fall through */
 409                         case TIMER_STARTUP:
 410                                 base = UNIT(t)->manager->userspace_timestamp.monotonic;
 411                                 break;
 412
 413                         case TIMER_UNIT_ACTIVE:
 414                                 leave_around = true;
 415                                 base = trigger->inactive_exit_timestamp.monotonic;
 416
 417                                 if (base <= 0)
 418                                         base = t->last_trigger.monotonic;
 419
 420                                 if (base <= 0)
 421                                         continue;
 422
 423                                 break;
 424
 425                         case TIMER_UNIT_INACTIVE:
 426                                 leave_around = true;
 427                                 base = trigger->inactive_enter_timestamp.monotonic;
 428
 429                                 if (base <= 0)
 430                                         base = t->last_trigger.monotonic;
 431
 432                                 if (base <= 0)
 433                                         continue;
 434
 435                                 break;
 436
 437                         default:
 438                                 assert_not_reached("Unknown timer base");
 439                         }
 440
 441                         v->next_elapse = usec_add(usec_shift_clock(base, CLOCK_MONOTONIC, TIMER_MONOTONIC_CLOCK(t)), v->value);
 442
 443                         if (!initial &&
 444                             v->next_elapse < triple_timestamp_by_clock(&ts, TIMER_MONOTONIC_CLOCK(t)) &&
 445                             IN_SET(v->base, TIMER_ACTIVE, TIMER_BOOT, TIMER_STARTUP)) {
 446                                 /* This is a one time trigger, disable it now */
 447                                 v->disabled = true;
 448                                 continue;
 449                         }
 450
 451                         if (!found_monotonic)
 452                                 t->next_elapse_monotonic_or_boottime = v->next_elapse;
 453                         else
 454                                 t->next_elapse_monotonic_or_boottime = MIN(t->next_elapse_monotonic_or_boottime, v->next_elapse);
 455
 456                         found_monotonic = true;
 457                 }
 458         }
 459
 460         if (!found_monotonic && !found_realtime) {
 461                 log_unit_debug(UNIT(t), "Timer is elapsed.");
 462                 timer_enter_elapsed(t, leave_around);
 463                 return;
 464         }
 465
 466         if (found_monotonic) {
 467                 char buf[FORMAT_TIMESPAN_MAX];
 468                 usec_t left;
 469
 470                 add_random(t, &t->next_elapse_monotonic_or_boottime);
 471
 472                 left = usec_sub_unsigned(t->next_elapse_monotonic_or_boottime, triple_timestamp_by_clock(&ts, TIMER_MONOTONIC_CLOCK(t)));
 473                 log_unit_debug(UNIT(t), "Monotonic timer elapses in %s.", format_timespan(buf, sizeof(buf), left, 0));
 474
 475                 if (t->monotonic_event_source) {
 476                         r = sd_event_source_set_time(t->monotonic_event_source, t->next_elapse_monotonic_or_boottime);
 477                         if (r < 0)
 478                                 goto fail;
 479
 480                         r = sd_event_source_set_enabled(t->monotonic_event_source, SD_EVENT_ONESHOT);
 481                         if (r < 0)
 482                                 goto fail;
 483                 } else {
 484
 485                         r = sd_event_add_time(
 486                                         UNIT(t)->manager->event,
 487                                         &t->monotonic_event_source,
 488                                         t->wake_system ? CLOCK_BOOTTIME_ALARM : CLOCK_MONOTONIC,
 489                                         t->next_elapse_monotonic_or_boottime, t->accuracy_usec,
 490                                         timer_dispatch, t);
 491                         if (r < 0)
 492                                 goto fail;
 493
 494                         (void) sd_event_source_set_description(t->monotonic_event_source, "timer-monotonic");
 495                 }
 496
 497         } else if (t->monotonic_event_source) {
 498
 499                 r = sd_event_source_set_enabled(t->monotonic_event_source, SD_EVENT_OFF);
 500                 if (r < 0)
 501                         goto fail;
 502         }
 503
 504         if (found_realtime) {
 505                 char buf[FORMAT_TIMESTAMP_MAX];
 506
 507                 add_random(t, &t->next_elapse_realtime);
 508
 509                 log_unit_debug(UNIT(t), "Realtime timer elapses at %s.", format_timestamp(buf, sizeof(buf), t->next_elapse_realtime));
 510
 511                 if (t->realtime_event_source) {
 512                         r = sd_event_source_set_time(t->realtime_event_source, t->next_elapse_realtime);
 513                         if (r < 0)
 514                                 goto fail;
 515
 516                         r = sd_event_source_set_enabled(t->realtime_event_source, SD_EVENT_ONESHOT);
 517                         if (r < 0)
 518                                 goto fail;
 519                 } else {
 520                         r = sd_event_add_time(
 521                                         UNIT(t)->manager->event,
 522                                         &t->realtime_event_source,
 523                                         t->wake_system ? CLOCK_REALTIME_ALARM : CLOCK_REALTIME,
 524                                         t->next_elapse_realtime, t->accuracy_usec,
 525                                         timer_dispatch, t);
 526                         if (r < 0)
 527                                 goto fail;
 528
 529                         (void) sd_event_source_set_description(t->realtime_event_source, "timer-realtime");
 530                 }
 531
 532         } else if (t->realtime_event_source) {
 533
 534                 r = sd_event_source_set_enabled(t->realtime_event_source, SD_EVENT_OFF);
 535                 if (r < 0)
 536                         goto fail;
 537         }
 538
 539         timer_set_state(t, TIMER_WAITING);
 540         return;
 541
 542 fail:
 543         log_unit_warning_errno(UNIT(t), r, "Failed to enter waiting state: %m");
 544         timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 545 }
 546
 547 static void timer_enter_running(Timer *t) {
 548         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 549         Unit *trigger;
 550         int r;
 551
 552         assert(t);
 553
 554         /* Don't start job if we are supposed to go down */
 555         if (unit_stop_pending(UNIT(t)))
 556                 return;
 557
 558         trigger = UNIT_TRIGGER(UNIT(t));
 559         if (!trigger) {
 560                 log_unit_error(UNIT(t), "Unit to trigger vanished.");
 561                 timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 562                 return;
 563         }
 564
 565         r = manager_add_job(UNIT(t)->manager, JOB_START, trigger, JOB_REPLACE, &error, NULL);
 566         if (r < 0)
 567                 goto fail;
 568
 569         dual_timestamp_get(&t->last_trigger);
 570
 571         if (t->stamp_path)
 572                 touch_file(t->stamp_path, true, t->last_trigger.realtime, UID_INVALID, GID_INVALID, MODE_INVALID);
 573
 574         timer_set_state(t, TIMER_RUNNING);
 575         return;
 576
 577 fail:
 578         log_unit_warning(UNIT(t), "Failed to queue unit startup job: %s", bus_error_message(&error, r));
 579         timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 580 }
 581
 582 static int timer_start(Unit *u) {
 583         Timer *t = TIMER(u);
 584         TimerValue *v;
 585         Unit *trigger;
 586         int r;
 587
 588         assert(t);
 589         assert(t->state == TIMER_DEAD || t->state == TIMER_FAILED);
 590
 591         trigger = UNIT_TRIGGER(u);
 592         if (!trigger || trigger->load_state != UNIT_LOADED) {
 593                 log_unit_error(u, "Refusing to start, unit to trigger not loaded.");
 594                 return -ENOENT;
 595         }
 596
 597         r = unit_start_limit_test(u);
 598         if (r < 0) {
 599                 timer_enter_dead(t, TIMER_FAILURE_START_LIMIT_HIT);
 600                 return r;
 601         }
 602
 603         r = unit_acquire_invocation_id(u);
 604         if (r < 0)
 605                 return r;
 606
 607         t->last_trigger = DUAL_TIMESTAMP_NULL;
 608
 609         /* Reenable all timers that depend on unit activation time */
 610         LIST_FOREACH(value, v, t->values)
 611                 if (v->base == TIMER_ACTIVE)
 612                         v->disabled = false;
 613
 614         if (t->stamp_path) {
 615                 struct stat st;
 616
 617                 if (stat(t->stamp_path, &st) >= 0) {
 618                         usec_t ft;
 619
 620                         /* Load the file timestamp, but only if it is actually in the past. If it is in the future,
 621                          * something is wrong with the system clock. */
 622
 623                         ft = timespec_load(&st.st_mtim);
 624                         if (ft < now(CLOCK_REALTIME))
 625                                 t->last_trigger.realtime = ft;
 626                         else {
 627                                 char z[FORMAT_TIMESTAMP_MAX];
 628
 629                                 log_unit_warning(u, "Not using persistent file timestamp %s as it is in the future.",
 630                                                  format_timestamp(z, sizeof(z), ft));
 631                         }
 632
 633                 } else if (errno == ENOENT)
 634                         /* The timer has never run before,
 635                          * make sure a stamp file exists.
 636                          */
 637                         (void) touch_file(t->stamp_path, true, USEC_INFINITY, UID_INVALID, GID_INVALID, MODE_INVALID);
 638         }
 639
 640         t->result = TIMER_SUCCESS;
 641         timer_enter_waiting(t, true);
 642         return 1;
 643 }
 644
 645 static int timer_stop(Unit *u) {
 646         Timer *t = TIMER(u);
 647
 648         assert(t);
 649         assert(t->state == TIMER_WAITING || t->state == TIMER_RUNNING || t->state == TIMER_ELAPSED);
 650
 651         timer_enter_dead(t, TIMER_SUCCESS);
 652         return 1;
 653 }
 654
 655 static int timer_serialize(Unit *u, FILE *f, FDSet *fds) {
 656         Timer *t = TIMER(u);
 657
 658         assert(u);
 659         assert(f);
 660         assert(fds);
 661
 662         unit_serialize_item(u, f, "state", timer_state_to_string(t->state));
 663         unit_serialize_item(u, f, "result", timer_result_to_string(t->result));
 664
 665         if (t->last_trigger.realtime > 0)
 666                 unit_serialize_item_format(u, f, "last-trigger-realtime", "%" PRIu64, t->last_trigger.realtime);
 667
 668         if (t->last_trigger.monotonic > 0)
 669                 unit_serialize_item_format(u, f, "last-trigger-monotonic", "%" PRIu64, t->last_trigger.monotonic);
 670
 671         return 0;
 672 }
 673
 674 static int timer_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 675         Timer *t = TIMER(u);
 676         int r;
 677
 678         assert(u);
 679         assert(key);
 680         assert(value);
 681         assert(fds);
 682
 683         if (streq(key, "state")) {
 684                 TimerState state;
 685
 686                 state = timer_state_from_string(value);
 687                 if (state < 0)
 688                         log_unit_debug(u, "Failed to parse state value: %s", value);
 689                 else
 690                         t->deserialized_state = state;
 691         } else if (streq(key, "result")) {
 692                 TimerResult f;
 693
 694                 f = timer_result_from_string(value);
 695                 if (f < 0)
 696                         log_unit_debug(u, "Failed to parse result value: %s", value);
 697                 else if (f != TIMER_SUCCESS)
 698                         t->result = f;
 699         } else if (streq(key, "last-trigger-realtime")) {
 700
 701                 r = safe_atou64(value, &t->last_trigger.realtime);
 702                 if (r < 0)
 703                         log_unit_debug(u, "Failed to parse last-trigger-realtime value: %s", value);
 704
 705         } else if (streq(key, "last-trigger-monotonic")) {
 706
 707                 r = safe_atou64(value, &t->last_trigger.monotonic);
 708                 if (r < 0)
 709                         log_unit_debug(u, "Failed to parse last-trigger-monotonic value: %s", value);
 710
 711         } else
 712                 log_unit_debug(u, "Unknown serialization key: %s", key);
 713
 714         return 0;
 715 }
 716
 717 _pure_ static UnitActiveState timer_active_state(Unit *u) {
 718         assert(u);
 719
 720         return state_translation_table[TIMER(u)->state];
 721 }
 722
 723 _pure_ static const char *timer_sub_state_to_string(Unit *u) {
 724         assert(u);
 725
 726         return timer_state_to_string(TIMER(u)->state);
 727 }
 728
 729 static int timer_dispatch(sd_event_source *s, uint64_t usec, void *userdata) {
 730         Timer *t = TIMER(userdata);
 731
 732         assert(t);
 733
 734         if (t->state != TIMER_WAITING)
 735                 return 0;
 736
 737         log_unit_debug(UNIT(t), "Timer elapsed.");
 738         timer_enter_running(t);
 739         return 0;
 740 }
 741
 742 static void timer_trigger_notify(Unit *u, Unit *other) {
 743         Timer *t = TIMER(u);
 744         TimerValue *v;
 745
 746         assert(u);
 747         assert(other);
 748
 749         if (other->load_state != UNIT_LOADED)
 750                 return;
 751
 752         /* Reenable all timers that depend on unit state */
 753         LIST_FOREACH(value, v, t->values)
 754                 if (v->base == TIMER_UNIT_ACTIVE ||
 755                     v->base == TIMER_UNIT_INACTIVE)
 756                         v->disabled = false;
 757
 758         switch (t->state) {
 759
 760         case TIMER_WAITING:
 761         case TIMER_ELAPSED:
 762
 763                 /* Recalculate sleep time */
 764                 timer_enter_waiting(t, false);
 765                 break;
 766
 767         case TIMER_RUNNING:
 768
 769                 if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other))) {
 770                         log_unit_debug(UNIT(t), "Got notified about unit deactivation.");
 771                         timer_enter_waiting(t, false);
 772                 }
 773                 break;
 774
 775         case TIMER_DEAD:
 776         case TIMER_FAILED:
 777                 break;
 778
 779         default:
 780                 assert_not_reached("Unknown timer state");
 781         }
 782 }
 783
 784 static void timer_reset_failed(Unit *u) {
 785         Timer *t = TIMER(u);
 786
 787         assert(t);
 788
 789         if (t->state == TIMER_FAILED)
 790                 timer_set_state(t, TIMER_DEAD);
 791
 792         t->result = TIMER_SUCCESS;
 793 }
 794
 795 static void timer_time_change(Unit *u) {
 796         Timer *t = TIMER(u);
 797
 798         assert(u);
 799
 800         if (t->state != TIMER_WAITING)
 801                 return;
 802
 803         log_unit_debug(u, "Time change, recalculating next elapse.");
 804         timer_enter_waiting(t, false);
 805 }
 806
 807 static const char* const timer_base_table[_TIMER_BASE_MAX] = {
 808         [TIMER_ACTIVE] = "OnActiveSec",
 809         [TIMER_BOOT] = "OnBootSec",
 810         [TIMER_STARTUP] = "OnStartupSec",
 811         [TIMER_UNIT_ACTIVE] = "OnUnitActiveSec",
 812         [TIMER_UNIT_INACTIVE] = "OnUnitInactiveSec",
 813         [TIMER_CALENDAR] = "OnCalendar"
 814 };
 815
 816 DEFINE_STRING_TABLE_LOOKUP(timer_base, TimerBase);
 817
 818 static const char* const timer_result_table[_TIMER_RESULT_MAX] = {
 819         [TIMER_SUCCESS] = "success",
 820         [TIMER_FAILURE_RESOURCES] = "resources",
 821         [TIMER_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
 822 };
 823
 824 DEFINE_STRING_TABLE_LOOKUP(timer_result, TimerResult);
 825
 826 const UnitVTable timer_vtable = {
 827         .object_size = sizeof(Timer),
 828
 829         .sections =
 830                 "Unit\0"
 831                 "Timer\0"
 832                 "Install\0",
 833         .private_section = "Timer",
 834
 835         .init = timer_init,
 836         .done = timer_done,
 837         .load = timer_load,
 838
 839         .coldplug = timer_coldplug,
 840
 841         .dump = timer_dump,
 842
 843         .start = timer_start,
 844         .stop = timer_stop,
 845
 846         .serialize = timer_serialize,
 847         .deserialize_item = timer_deserialize_item,
 848
 849         .active_state = timer_active_state,
 850         .sub_state_to_string = timer_sub_state_to_string,
 851
 852         .trigger_notify = timer_trigger_notify,
 853
 854         .reset_failed = timer_reset_failed,
 855         .time_change = timer_time_change,
 856
 857         .bus_vtable = bus_timer_vtable,
 858         .bus_set_property = bus_timer_set_property,
 859
 860         .can_transient = true,
 861 };