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         if (t->result != TIMER_SUCCESS)
 300                 log_unit_warning(UNIT(t), "Failed with result '%s'.", timer_result_to_string(t->result));
 301
 302         timer_set_state(t, t->result != TIMER_SUCCESS ? TIMER_FAILED : TIMER_DEAD);
 303 }
 304
 305 static void timer_enter_elapsed(Timer *t, bool leave_around) {
 306         assert(t);
 307
 308         /* If a unit is marked with RemainAfterElapse=yes we leave it
 309          * around even after it elapsed once, so that starting it
 310          * later again does not necessarily mean immediate
 311          * retriggering. We unconditionally leave units with
 312          * TIMER_UNIT_ACTIVE or TIMER_UNIT_INACTIVE triggers around,
 313          * since they might be restarted automatically at any time
 314          * later on. */
 315
 316         if (t->remain_after_elapse || leave_around)
 317                 timer_set_state(t, TIMER_ELAPSED);
 318         else
 319                 timer_enter_dead(t, TIMER_SUCCESS);
 320 }
 321
 322 static void add_random(Timer *t, usec_t *v) {
 323         char s[FORMAT_TIMESPAN_MAX];
 324         usec_t add;
 325
 326         assert(t);
 327         assert(v);
 328
 329         if (t->random_usec == 0)
 330                 return;
 331         if (*v == USEC_INFINITY)
 332                 return;
 333
 334         add = random_u64() % t->random_usec;
 335
 336         if (*v + add < *v) /* overflow */
 337                 *v = (usec_t) -2; /* Highest possible value, that is not USEC_INFINITY */
 338         else
 339                 *v += add;
 340
 341         log_unit_debug(UNIT(t), "Adding %s random time.", format_timespan(s, sizeof(s), add, 0));
 342 }
 343
 344 static void timer_enter_waiting(Timer *t, bool initial) {
 345         bool found_monotonic = false, found_realtime = false;
 346         bool leave_around = false;
 347         triple_timestamp ts;
 348         usec_t base = 0;
 349         TimerValue *v;
 350         Unit *trigger;
 351         int r;
 352
 353         assert(t);
 354
 355         trigger = UNIT_TRIGGER(UNIT(t));
 356         if (!trigger) {
 357                 log_unit_error(UNIT(t), "Unit to trigger vanished.");
 358                 timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 359                 return;
 360         }
 361
 362         triple_timestamp_get(&ts);
 363         t->next_elapse_monotonic_or_boottime = t->next_elapse_realtime = 0;
 364
 365         LIST_FOREACH(value, v, t->values) {
 366
 367                 if (v->disabled)
 368                         continue;
 369
 370                 if (v->base == TIMER_CALENDAR) {
 371                         usec_t b;
 372
 373                         /* If we know the last time this was
 374                          * triggered, schedule the job based relative
 375                          * to that. If we don't just start from
 376                          * now. */
 377
 378                         b = t->last_trigger.realtime > 0 ? t->last_trigger.realtime : ts.realtime;
 379
 380                         r = calendar_spec_next_usec(v->calendar_spec, b, &v->next_elapse);
 381                         if (r < 0)
 382                                 continue;
 383
 384                         if (!found_realtime)
 385                                 t->next_elapse_realtime = v->next_elapse;
 386                         else
 387                                 t->next_elapse_realtime = MIN(t->next_elapse_realtime, v->next_elapse);
 388
 389                         found_realtime = true;
 390
 391                 } else  {
 392
 393                         switch (v->base) {
 394
 395                         case TIMER_ACTIVE:
 396                                 if (state_translation_table[t->state] == UNIT_ACTIVE)
 397                                         base = UNIT(t)->inactive_exit_timestamp.monotonic;
 398                                 else
 399                                         base = ts.monotonic;
 400                                 break;
 401
 402                         case TIMER_BOOT:
 403                                 if (detect_container() <= 0) {
 404                                         /* CLOCK_MONOTONIC equals the uptime on Linux */
 405                                         base = 0;
 406                                         break;
 407                                 }
 408                                 /* In a container we don't want to include the time the host
 409                                  * was already up when the container started, so count from
 410                                  * our own startup. */
 411                                 /* fall through */
 412                         case TIMER_STARTUP:
 413                                 base = UNIT(t)->manager->userspace_timestamp.monotonic;
 414                                 break;
 415
 416                         case TIMER_UNIT_ACTIVE:
 417                                 leave_around = true;
 418                                 base = trigger->inactive_exit_timestamp.monotonic;
 419
 420                                 if (base <= 0)
 421                                         base = t->last_trigger.monotonic;
 422
 423                                 if (base <= 0)
 424                                         continue;
 425
 426                                 break;
 427
 428                         case TIMER_UNIT_INACTIVE:
 429                                 leave_around = true;
 430                                 base = trigger->inactive_enter_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                         default:
 441                                 assert_not_reached("Unknown timer base");
 442                         }
 443
 444                         v->next_elapse = usec_add(usec_shift_clock(base, CLOCK_MONOTONIC, TIMER_MONOTONIC_CLOCK(t)), v->value);
 445
 446                         if (!initial &&
 447                             v->next_elapse < triple_timestamp_by_clock(&ts, TIMER_MONOTONIC_CLOCK(t)) &&
 448                             IN_SET(v->base, TIMER_ACTIVE, TIMER_BOOT, TIMER_STARTUP)) {
 449                                 /* This is a one time trigger, disable it now */
 450                                 v->disabled = true;
 451                                 continue;
 452                         }
 453
 454                         if (!found_monotonic)
 455                                 t->next_elapse_monotonic_or_boottime = v->next_elapse;
 456                         else
 457                                 t->next_elapse_monotonic_or_boottime = MIN(t->next_elapse_monotonic_or_boottime, v->next_elapse);
 458
 459                         found_monotonic = true;
 460                 }
 461         }
 462
 463         if (!found_monotonic && !found_realtime) {
 464                 log_unit_debug(UNIT(t), "Timer is elapsed.");
 465                 timer_enter_elapsed(t, leave_around);
 466                 return;
 467         }
 468
 469         if (found_monotonic) {
 470                 char buf[FORMAT_TIMESPAN_MAX];
 471                 usec_t left;
 472
 473                 add_random(t, &t->next_elapse_monotonic_or_boottime);
 474
 475                 left = usec_sub_unsigned(t->next_elapse_monotonic_or_boottime, triple_timestamp_by_clock(&ts, TIMER_MONOTONIC_CLOCK(t)));
 476                 log_unit_debug(UNIT(t), "Monotonic timer elapses in %s.", format_timespan(buf, sizeof(buf), left, 0));
 477
 478                 if (t->monotonic_event_source) {
 479                         r = sd_event_source_set_time(t->monotonic_event_source, t->next_elapse_monotonic_or_boottime);
 480                         if (r < 0)
 481                                 goto fail;
 482
 483                         r = sd_event_source_set_enabled(t->monotonic_event_source, SD_EVENT_ONESHOT);
 484                         if (r < 0)
 485                                 goto fail;
 486                 } else {
 487
 488                         r = sd_event_add_time(
 489                                         UNIT(t)->manager->event,
 490                                         &t->monotonic_event_source,
 491                                         t->wake_system ? CLOCK_BOOTTIME_ALARM : CLOCK_MONOTONIC,
 492                                         t->next_elapse_monotonic_or_boottime, t->accuracy_usec,
 493                                         timer_dispatch, t);
 494                         if (r < 0)
 495                                 goto fail;
 496
 497                         (void) sd_event_source_set_description(t->monotonic_event_source, "timer-monotonic");
 498                 }
 499
 500         } else if (t->monotonic_event_source) {
 501
 502                 r = sd_event_source_set_enabled(t->monotonic_event_source, SD_EVENT_OFF);
 503                 if (r < 0)
 504                         goto fail;
 505         }
 506
 507         if (found_realtime) {
 508                 char buf[FORMAT_TIMESTAMP_MAX];
 509
 510                 add_random(t, &t->next_elapse_realtime);
 511
 512                 log_unit_debug(UNIT(t), "Realtime timer elapses at %s.", format_timestamp(buf, sizeof(buf), t->next_elapse_realtime));
 513
 514                 if (t->realtime_event_source) {
 515                         r = sd_event_source_set_time(t->realtime_event_source, t->next_elapse_realtime);
 516                         if (r < 0)
 517                                 goto fail;
 518
 519                         r = sd_event_source_set_enabled(t->realtime_event_source, SD_EVENT_ONESHOT);
 520                         if (r < 0)
 521                                 goto fail;
 522                 } else {
 523                         r = sd_event_add_time(
 524                                         UNIT(t)->manager->event,
 525                                         &t->realtime_event_source,
 526                                         t->wake_system ? CLOCK_REALTIME_ALARM : CLOCK_REALTIME,
 527                                         t->next_elapse_realtime, t->accuracy_usec,
 528                                         timer_dispatch, t);
 529                         if (r < 0)
 530                                 goto fail;
 531
 532                         (void) sd_event_source_set_description(t->realtime_event_source, "timer-realtime");
 533                 }
 534
 535         } else if (t->realtime_event_source) {
 536
 537                 r = sd_event_source_set_enabled(t->realtime_event_source, SD_EVENT_OFF);
 538                 if (r < 0)
 539                         goto fail;
 540         }
 541
 542         timer_set_state(t, TIMER_WAITING);
 543         return;
 544
 545 fail:
 546         log_unit_warning_errno(UNIT(t), r, "Failed to enter waiting state: %m");
 547         timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 548 }
 549
 550 static void timer_enter_running(Timer *t) {
 551         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
 552         Unit *trigger;
 553         int r;
 554
 555         assert(t);
 556
 557         /* Don't start job if we are supposed to go down */
 558         if (unit_stop_pending(UNIT(t)))
 559                 return;
 560
 561         trigger = UNIT_TRIGGER(UNIT(t));
 562         if (!trigger) {
 563                 log_unit_error(UNIT(t), "Unit to trigger vanished.");
 564                 timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 565                 return;
 566         }
 567
 568         r = manager_add_job(UNIT(t)->manager, JOB_START, trigger, JOB_REPLACE, &error, NULL);
 569         if (r < 0)
 570                 goto fail;
 571
 572         dual_timestamp_get(&t->last_trigger);
 573
 574         if (t->stamp_path)
 575                 touch_file(t->stamp_path, true, t->last_trigger.realtime, UID_INVALID, GID_INVALID, MODE_INVALID);
 576
 577         timer_set_state(t, TIMER_RUNNING);
 578         return;
 579
 580 fail:
 581         log_unit_warning(UNIT(t), "Failed to queue unit startup job: %s", bus_error_message(&error, r));
 582         timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 583 }
 584
 585 static int timer_start(Unit *u) {
 586         Timer *t = TIMER(u);
 587         TimerValue *v;
 588         Unit *trigger;
 589         int r;
 590
 591         assert(t);
 592         assert(t->state == TIMER_DEAD || t->state == TIMER_FAILED);
 593
 594         trigger = UNIT_TRIGGER(u);
 595         if (!trigger || trigger->load_state != UNIT_LOADED) {
 596                 log_unit_error(u, "Refusing to start, unit to trigger not loaded.");
 597                 return -ENOENT;
 598         }
 599
 600         r = unit_start_limit_test(u);
 601         if (r < 0) {
 602                 timer_enter_dead(t, TIMER_FAILURE_START_LIMIT_HIT);
 603                 return r;
 604         }
 605
 606         r = unit_acquire_invocation_id(u);
 607         if (r < 0)
 608                 return r;
 609
 610         t->last_trigger = DUAL_TIMESTAMP_NULL;
 611
 612         /* Reenable all timers that depend on unit activation time */
 613         LIST_FOREACH(value, v, t->values)
 614                 if (v->base == TIMER_ACTIVE)
 615                         v->disabled = false;
 616
 617         if (t->stamp_path) {
 618                 struct stat st;
 619
 620                 if (stat(t->stamp_path, &st) >= 0) {
 621                         usec_t ft;
 622
 623                         /* Load the file timestamp, but only if it is actually in the past. If it is in the future,
 624                          * something is wrong with the system clock. */
 625
 626                         ft = timespec_load(&st.st_mtim);
 627                         if (ft < now(CLOCK_REALTIME))
 628                                 t->last_trigger.realtime = ft;
 629                         else {
 630                                 char z[FORMAT_TIMESTAMP_MAX];
 631
 632                                 log_unit_warning(u, "Not using persistent file timestamp %s as it is in the future.",
 633                                                  format_timestamp(z, sizeof(z), ft));
 634                         }
 635
 636                 } else if (errno == ENOENT)
 637                         /* The timer has never run before,
 638                          * make sure a stamp file exists.
 639                          */
 640                         (void) touch_file(t->stamp_path, true, USEC_INFINITY, UID_INVALID, GID_INVALID, MODE_INVALID);
 641         }
 642
 643         t->result = TIMER_SUCCESS;
 644         timer_enter_waiting(t, true);
 645         return 1;
 646 }
 647
 648 static int timer_stop(Unit *u) {
 649         Timer *t = TIMER(u);
 650
 651         assert(t);
 652         assert(t->state == TIMER_WAITING || t->state == TIMER_RUNNING || t->state == TIMER_ELAPSED);
 653
 654         timer_enter_dead(t, TIMER_SUCCESS);
 655         return 1;
 656 }
 657
 658 static int timer_serialize(Unit *u, FILE *f, FDSet *fds) {
 659         Timer *t = TIMER(u);
 660
 661         assert(u);
 662         assert(f);
 663         assert(fds);
 664
 665         unit_serialize_item(u, f, "state", timer_state_to_string(t->state));
 666         unit_serialize_item(u, f, "result", timer_result_to_string(t->result));
 667
 668         if (t->last_trigger.realtime > 0)
 669                 unit_serialize_item_format(u, f, "last-trigger-realtime", "%" PRIu64, t->last_trigger.realtime);
 670
 671         if (t->last_trigger.monotonic > 0)
 672                 unit_serialize_item_format(u, f, "last-trigger-monotonic", "%" PRIu64, t->last_trigger.monotonic);
 673
 674         return 0;
 675 }
 676
 677 static int timer_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 678         Timer *t = TIMER(u);
 679         int r;
 680
 681         assert(u);
 682         assert(key);
 683         assert(value);
 684         assert(fds);
 685
 686         if (streq(key, "state")) {
 687                 TimerState state;
 688
 689                 state = timer_state_from_string(value);
 690                 if (state < 0)
 691                         log_unit_debug(u, "Failed to parse state value: %s", value);
 692                 else
 693                         t->deserialized_state = state;
 694         } else if (streq(key, "result")) {
 695                 TimerResult f;
 696
 697                 f = timer_result_from_string(value);
 698                 if (f < 0)
 699                         log_unit_debug(u, "Failed to parse result value: %s", value);
 700                 else if (f != TIMER_SUCCESS)
 701                         t->result = f;
 702         } else if (streq(key, "last-trigger-realtime")) {
 703
 704                 r = safe_atou64(value, &t->last_trigger.realtime);
 705                 if (r < 0)
 706                         log_unit_debug(u, "Failed to parse last-trigger-realtime value: %s", value);
 707
 708         } else if (streq(key, "last-trigger-monotonic")) {
 709
 710                 r = safe_atou64(value, &t->last_trigger.monotonic);
 711                 if (r < 0)
 712                         log_unit_debug(u, "Failed to parse last-trigger-monotonic value: %s", value);
 713
 714         } else
 715                 log_unit_debug(u, "Unknown serialization key: %s", key);
 716
 717         return 0;
 718 }
 719
 720 _pure_ static UnitActiveState timer_active_state(Unit *u) {
 721         assert(u);
 722
 723         return state_translation_table[TIMER(u)->state];
 724 }
 725
 726 _pure_ static const char *timer_sub_state_to_string(Unit *u) {
 727         assert(u);
 728
 729         return timer_state_to_string(TIMER(u)->state);
 730 }
 731
 732 static int timer_dispatch(sd_event_source *s, uint64_t usec, void *userdata) {
 733         Timer *t = TIMER(userdata);
 734
 735         assert(t);
 736
 737         if (t->state != TIMER_WAITING)
 738                 return 0;
 739
 740         log_unit_debug(UNIT(t), "Timer elapsed.");
 741         timer_enter_running(t);
 742         return 0;
 743 }
 744
 745 static void timer_trigger_notify(Unit *u, Unit *other) {
 746         Timer *t = TIMER(u);
 747         TimerValue *v;
 748
 749         assert(u);
 750         assert(other);
 751
 752         if (other->load_state != UNIT_LOADED)
 753                 return;
 754
 755         /* Reenable all timers that depend on unit state */
 756         LIST_FOREACH(value, v, t->values)
 757                 if (v->base == TIMER_UNIT_ACTIVE ||
 758                     v->base == TIMER_UNIT_INACTIVE)
 759                         v->disabled = false;
 760
 761         switch (t->state) {
 762
 763         case TIMER_WAITING:
 764         case TIMER_ELAPSED:
 765
 766                 /* Recalculate sleep time */
 767                 timer_enter_waiting(t, false);
 768                 break;
 769
 770         case TIMER_RUNNING:
 771
 772                 if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other))) {
 773                         log_unit_debug(UNIT(t), "Got notified about unit deactivation.");
 774                         timer_enter_waiting(t, false);
 775                 }
 776                 break;
 777
 778         case TIMER_DEAD:
 779         case TIMER_FAILED:
 780                 break;
 781
 782         default:
 783                 assert_not_reached("Unknown timer state");
 784         }
 785 }
 786
 787 static void timer_reset_failed(Unit *u) {
 788         Timer *t = TIMER(u);
 789
 790         assert(t);
 791
 792         if (t->state == TIMER_FAILED)
 793                 timer_set_state(t, TIMER_DEAD);
 794
 795         t->result = TIMER_SUCCESS;
 796 }
 797
 798 static void timer_time_change(Unit *u) {
 799         Timer *t = TIMER(u);
 800
 801         assert(u);
 802
 803         if (t->state != TIMER_WAITING)
 804                 return;
 805
 806         log_unit_debug(u, "Time change, recalculating next elapse.");
 807         timer_enter_waiting(t, false);
 808 }
 809
 810 static const char* const timer_base_table[_TIMER_BASE_MAX] = {
 811         [TIMER_ACTIVE] = "OnActiveSec",
 812         [TIMER_BOOT] = "OnBootSec",
 813         [TIMER_STARTUP] = "OnStartupSec",
 814         [TIMER_UNIT_ACTIVE] = "OnUnitActiveSec",
 815         [TIMER_UNIT_INACTIVE] = "OnUnitInactiveSec",
 816         [TIMER_CALENDAR] = "OnCalendar"
 817 };
 818
 819 DEFINE_STRING_TABLE_LOOKUP(timer_base, TimerBase);
 820
 821 static const char* const timer_result_table[_TIMER_RESULT_MAX] = {
 822         [TIMER_SUCCESS] = "success",
 823         [TIMER_FAILURE_RESOURCES] = "resources",
 824         [TIMER_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
 825 };
 826
 827 DEFINE_STRING_TABLE_LOOKUP(timer_result, TimerResult);
 828
 829 const UnitVTable timer_vtable = {
 830         .object_size = sizeof(Timer),
 831
 832         .sections =
 833                 "Unit\0"
 834                 "Timer\0"
 835                 "Install\0",
 836         .private_section = "Timer",
 837
 838         .init = timer_init,
 839         .done = timer_done,
 840         .load = timer_load,
 841
 842         .coldplug = timer_coldplug,
 843
 844         .dump = timer_dump,
 845
 846         .start = timer_start,
 847         .stop = timer_stop,
 848
 849         .serialize = timer_serialize,
 850         .deserialize_item = timer_deserialize_item,
 851
 852         .active_state = timer_active_state,
 853         .sub_state_to_string = timer_sub_state_to_string,
 854
 855         .trigger_notify = timer_trigger_notify,
 856
 857         .reset_failed = timer_reset_failed,
 858         .time_change = timer_time_change,
 859
 860         .bus_vtable = bus_timer_vtable,
 861         .bus_set_property = bus_timer_set_property,
 862
 863         .can_transient = true,
 864 };