src/core/timer.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4
   5 #include "alloc-util.h"
   6 #include "bus-error.h"
   7 #include "bus-util.h"
   8 #include "dbus-timer.h"
   9 #include "fs-util.h"
  10 #include "parse-util.h"
  11 #include "random-util.h"
  12 #include "serialize.h"
  13 #include "special.h"
  14 #include "string-table.h"
  15 #include "string-util.h"
  16 #include "timer.h"
  17 #include "unit-name.h"
  18 #include "unit.h"
  19 #include "user-util.h"
  20 #include "virt.h"
  21
  22 static const UnitActiveState state_translation_table[_TIMER_STATE_MAX] = {
  23         [TIMER_DEAD] = UNIT_INACTIVE,
  24         [TIMER_WAITING] = UNIT_ACTIVE,
  25         [TIMER_RUNNING] = UNIT_ACTIVE,
  26         [TIMER_ELAPSED] = UNIT_ACTIVE,
  27         [TIMER_FAILED] = UNIT_FAILED
  28 };
  29
  30 static int timer_dispatch(sd_event_source *s, uint64_t usec, void *userdata);
  31
  32 static void timer_init(Unit *u) {
  33         Timer *t = TIMER(u);
  34
  35         assert(u);
  36         assert(u->load_state == UNIT_STUB);
  37
  38         t->next_elapse_monotonic_or_boottime = USEC_INFINITY;
  39         t->next_elapse_realtime = USEC_INFINITY;
  40         t->accuracy_usec = u->manager->default_timer_accuracy_usec;
  41         t->remain_after_elapse = true;
  42 }
  43
  44 void timer_free_values(Timer *t) {
  45         TimerValue *v;
  46
  47         assert(t);
  48
  49         while ((v = t->values)) {
  50                 LIST_REMOVE(value, t->values, v);
  51                 calendar_spec_free(v->calendar_spec);
  52                 free(v);
  53         }
  54 }
  55
  56 static void timer_done(Unit *u) {
  57         Timer *t = TIMER(u);
  58
  59         assert(t);
  60
  61         timer_free_values(t);
  62
  63         t->monotonic_event_source = sd_event_source_unref(t->monotonic_event_source);
  64         t->realtime_event_source = sd_event_source_unref(t->realtime_event_source);
  65
  66         free(t->stamp_path);
  67 }
  68
  69 static int timer_verify(Timer *t) {
  70         assert(t);
  71
  72         if (UNIT(t)->load_state != UNIT_LOADED)
  73                 return 0;
  74
  75         if (!t->values) {
  76                 log_unit_error(UNIT(t), "Timer unit lacks value setting. Refusing.");
  77                 return -ENOEXEC;
  78         }
  79
  80         return 0;
  81 }
  82
  83 static int timer_add_default_dependencies(Timer *t) {
  84         int r;
  85         TimerValue *v;
  86
  87         assert(t);
  88
  89         if (!UNIT(t)->default_dependencies)
  90                 return 0;
  91
  92         r = unit_add_dependency_by_name(UNIT(t), UNIT_BEFORE, SPECIAL_TIMERS_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
  93         if (r < 0)
  94                 return r;
  95
  96         if (MANAGER_IS_SYSTEM(UNIT(t)->manager)) {
  97                 r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
  98                 if (r < 0)
  99                         return r;
 100
 101                 LIST_FOREACH(value, v, t->values) {
 102                         if (v->base == TIMER_CALENDAR) {
 103                                 r = unit_add_dependency_by_name(UNIT(t), UNIT_AFTER, SPECIAL_TIME_SYNC_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
 104                                 if (r < 0)
 105                                         return r;
 106                                 break;
 107                         }
 108                 }
 109         }
 110
 111         return unit_add_two_dependencies_by_name(UNIT(t), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
 112 }
 113
 114 static int timer_add_trigger_dependencies(Timer *t) {
 115         Unit *x;
 116         int r;
 117
 118         assert(t);
 119
 120         if (!hashmap_isempty(UNIT(t)->dependencies[UNIT_TRIGGERS]))
 121                 return 0;
 122
 123         r = unit_load_related_unit(UNIT(t), ".service", &x);
 124         if (r < 0)
 125                 return r;
 126
 127         return unit_add_two_dependencies(UNIT(t), UNIT_BEFORE, UNIT_TRIGGERS, x, true, UNIT_DEPENDENCY_IMPLICIT);
 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", UNIT_DEPENDENCY_FILE);
 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                 r = timer_add_trigger_dependencies(t);
 183                 if (r < 0)
 184                         return r;
 185
 186                 r = timer_setup_persistent(t);
 187                 if (r < 0)
 188                         return r;
 189
 190                 r = timer_add_default_dependencies(t);
 191                 if (r < 0)
 192                         return r;
 193         }
 194
 195         return timer_verify(t);
 196 }
 197
 198 static void timer_dump(Unit *u, FILE *f, const char *prefix) {
 199         char buf[FORMAT_TIMESPAN_MAX];
 200         Timer *t = TIMER(u);
 201         Unit *trigger;
 202         TimerValue *v;
 203
 204         trigger = UNIT_TRIGGER(u);
 205
 206         fprintf(f,
 207                 "%sTimer State: %s\n"
 208                 "%sResult: %s\n"
 209                 "%sUnit: %s\n"
 210                 "%sPersistent: %s\n"
 211                 "%sWakeSystem: %s\n"
 212                 "%sAccuracy: %s\n"
 213                 "%sRemainAfterElapse: %s\n",
 214                 prefix, timer_state_to_string(t->state),
 215                 prefix, timer_result_to_string(t->result),
 216                 prefix, trigger ? trigger->id : "n/a",
 217                 prefix, yes_no(t->persistent),
 218                 prefix, yes_no(t->wake_system),
 219                 prefix, format_timespan(buf, sizeof(buf), t->accuracy_usec, 1),
 220                 prefix, yes_no(t->remain_after_elapse));
 221
 222         LIST_FOREACH(value, v, t->values) {
 223
 224                 if (v->base == TIMER_CALENDAR) {
 225                         _cleanup_free_ char *p = NULL;
 226
 227                         (void) calendar_spec_to_string(v->calendar_spec, &p);
 228
 229                         fprintf(f,
 230                                 "%s%s: %s\n",
 231                                 prefix,
 232                                 timer_base_to_string(v->base),
 233                                 strna(p));
 234                 } else  {
 235                         char timespan1[FORMAT_TIMESPAN_MAX];
 236
 237                         fprintf(f,
 238                                 "%s%s: %s\n",
 239                                 prefix,
 240                                 timer_base_to_string(v->base),
 241                                 format_timespan(timespan1, sizeof(timespan1), v->value, 0));
 242                 }
 243         }
 244 }
 245
 246 static void timer_set_state(Timer *t, TimerState state) {
 247         TimerState old_state;
 248         assert(t);
 249
 250         old_state = t->state;
 251         t->state = state;
 252
 253         if (state != TIMER_WAITING) {
 254                 t->monotonic_event_source = sd_event_source_unref(t->monotonic_event_source);
 255                 t->realtime_event_source = sd_event_source_unref(t->realtime_event_source);
 256                 t->next_elapse_monotonic_or_boottime = USEC_INFINITY;
 257                 t->next_elapse_realtime = USEC_INFINITY;
 258         }
 259
 260         if (state != old_state)
 261                 log_unit_debug(UNIT(t), "Changed %s -> %s", timer_state_to_string(old_state), timer_state_to_string(state));
 262
 263         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], 0);
 264 }
 265
 266 static void timer_enter_waiting(Timer *t, bool initial, bool time_change);
 267
 268 static int timer_coldplug(Unit *u) {
 269         Timer *t = TIMER(u);
 270
 271         assert(t);
 272         assert(t->state == TIMER_DEAD);
 273
 274         if (t->deserialized_state == t->state)
 275                 return 0;
 276
 277         if (t->deserialized_state == TIMER_WAITING)
 278                 timer_enter_waiting(t, false, false);
 279         else
 280                 timer_set_state(t, t->deserialized_state);
 281
 282         return 0;
 283 }
 284
 285 static void timer_enter_dead(Timer *t, TimerResult f) {
 286         assert(t);
 287
 288         if (t->result == TIMER_SUCCESS)
 289                 t->result = f;
 290
 291         if (t->result != TIMER_SUCCESS)
 292                 log_unit_warning(UNIT(t), "Failed with result '%s'.", timer_result_to_string(t->result));
 293
 294         timer_set_state(t, t->result != TIMER_SUCCESS ? TIMER_FAILED : TIMER_DEAD);
 295 }
 296
 297 static void timer_enter_elapsed(Timer *t, bool leave_around) {
 298         assert(t);
 299
 300         /* If a unit is marked with RemainAfterElapse=yes we leave it
 301          * around even after it elapsed once, so that starting it
 302          * later again does not necessarily mean immediate
 303          * retriggering. We unconditionally leave units with
 304          * TIMER_UNIT_ACTIVE or TIMER_UNIT_INACTIVE triggers around,
 305          * since they might be restarted automatically at any time
 306          * later on. */
 307
 308         if (t->remain_after_elapse || leave_around)
 309                 timer_set_state(t, TIMER_ELAPSED);
 310         else
 311                 timer_enter_dead(t, TIMER_SUCCESS);
 312 }
 313
 314 static void add_random(Timer *t, usec_t *v) {
 315         char s[FORMAT_TIMESPAN_MAX];
 316         usec_t add;
 317
 318         assert(t);
 319         assert(v);
 320
 321         if (t->random_usec == 0)
 322                 return;
 323         if (*v == USEC_INFINITY)
 324                 return;
 325
 326         add = random_u64() % t->random_usec;
 327
 328         if (*v + add < *v) /* overflow */
 329                 *v = (usec_t) -2; /* Highest possible value, that is not USEC_INFINITY */
 330         else
 331                 *v += add;
 332
 333         log_unit_debug(UNIT(t), "Adding %s random time.", format_timespan(s, sizeof(s), add, 0));
 334 }
 335
 336 static void timer_enter_waiting(Timer *t, bool initial, bool time_change) {
 337         bool found_monotonic = false, found_realtime = false;
 338         bool leave_around = false;
 339         triple_timestamp ts;
 340         TimerValue *v;
 341         Unit *trigger;
 342         int r;
 343
 344         assert(t);
 345
 346         trigger = UNIT_TRIGGER(UNIT(t));
 347         if (!trigger) {
 348                 log_unit_error(UNIT(t), "Unit to trigger vanished.");
 349                 timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 350                 return;
 351         }
 352
 353         triple_timestamp_get(&ts);
 354         t->next_elapse_monotonic_or_boottime = t->next_elapse_realtime = 0;
 355
 356         LIST_FOREACH(value, v, t->values) {
 357                 if (v->disabled)
 358                         continue;
 359
 360                 if (v->base == TIMER_CALENDAR) {
 361                         usec_t b;
 362
 363                         /* If we know the last time this was
 364                          * triggered, schedule the job based relative
 365                          * to that. If we don't, just start from
 366                          * the activation time. */
 367
 368                         if (t->last_trigger.realtime > 0)
 369                                 b = t->last_trigger.realtime;
 370                         else {
 371                                 if (state_translation_table[t->state] == UNIT_ACTIVE)
 372                                         b = UNIT(t)->inactive_exit_timestamp.realtime;
 373                                 else
 374                                         b = ts.realtime;
 375                         }
 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                         usec_t base;
 390
 391                         switch (v->base) {
 392
 393                         case TIMER_ACTIVE:
 394                                 if (state_translation_table[t->state] == UNIT_ACTIVE)
 395                                         base = UNIT(t)->inactive_exit_timestamp.monotonic;
 396                                 else
 397                                         base = ts.monotonic;
 398                                 break;
 399
 400                         case TIMER_BOOT:
 401                                 if (detect_container() <= 0) {
 402                                         /* CLOCK_MONOTONIC equals the uptime on Linux */
 403                                         base = 0;
 404                                         break;
 405                                 }
 406                                 /* In a container we don't want to include the time the host
 407                                  * was already up when the container started, so count from
 408                                  * our own startup. */
 409                                 _fallthrough_;
 410                         case TIMER_STARTUP:
 411                                 base = UNIT(t)->manager->timestamps[MANAGER_TIMESTAMP_USERSPACE].monotonic;
 412                                 break;
 413
 414                         case TIMER_UNIT_ACTIVE:
 415                                 leave_around = true;
 416                                 base = trigger->inactive_exit_timestamp.monotonic;
 417
 418                                 if (base <= 0)
 419                                         base = t->last_trigger.monotonic;
 420
 421                                 if (base <= 0)
 422                                         continue;
 423                                 base = MAX(base, t->last_trigger.monotonic);
 424
 425                                 break;
 426
 427                         case TIMER_UNIT_INACTIVE:
 428                                 leave_around = true;
 429                                 base = trigger->inactive_enter_timestamp.monotonic;
 430
 431                                 if (base <= 0)
 432                                         base = t->last_trigger.monotonic;
 433
 434                                 if (base <= 0)
 435                                         continue;
 436                                 base = MAX(base, t->last_trigger.monotonic);
 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 && !time_change &&
 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(IN_SET(t->state, TIMER_DEAD, 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, false);
 645         return 1;
 646 }
 647
 648 static int timer_stop(Unit *u) {
 649         Timer *t = TIMER(u);
 650
 651         assert(t);
 652         assert(IN_SET(t->state, TIMER_WAITING, TIMER_RUNNING, 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         (void) serialize_item(f, "state", timer_state_to_string(t->state));
 666         (void) serialize_item(f, "result", timer_result_to_string(t->result));
 667
 668         if (t->last_trigger.realtime > 0)
 669                 (void) serialize_usec(f, "last-trigger-realtime", t->last_trigger.realtime);
 670
 671         if (t->last_trigger.monotonic > 0)
 672                 (void) serialize_usec(f, "last-trigger-monotonic", 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
 680         assert(u);
 681         assert(key);
 682         assert(value);
 683         assert(fds);
 684
 685         if (streq(key, "state")) {
 686                 TimerState state;
 687
 688                 state = timer_state_from_string(value);
 689                 if (state < 0)
 690                         log_unit_debug(u, "Failed to parse state value: %s", value);
 691                 else
 692                         t->deserialized_state = state;
 693
 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
 703         } else if (streq(key, "last-trigger-realtime"))
 704                 (void) deserialize_usec(value, &t->last_trigger.realtime);
 705         else if (streq(key, "last-trigger-monotonic"))
 706                 (void) deserialize_usec(value, &t->last_trigger.monotonic);
 707         else
 708                 log_unit_debug(u, "Unknown serialization key: %s", key);
 709
 710         return 0;
 711 }
 712
 713 _pure_ static UnitActiveState timer_active_state(Unit *u) {
 714         assert(u);
 715
 716         return state_translation_table[TIMER(u)->state];
 717 }
 718
 719 _pure_ static const char *timer_sub_state_to_string(Unit *u) {
 720         assert(u);
 721
 722         return timer_state_to_string(TIMER(u)->state);
 723 }
 724
 725 static int timer_dispatch(sd_event_source *s, uint64_t usec, void *userdata) {
 726         Timer *t = TIMER(userdata);
 727
 728         assert(t);
 729
 730         if (t->state != TIMER_WAITING)
 731                 return 0;
 732
 733         log_unit_debug(UNIT(t), "Timer elapsed.");
 734         timer_enter_running(t);
 735         return 0;
 736 }
 737
 738 static void timer_trigger_notify(Unit *u, Unit *other) {
 739         Timer *t = TIMER(u);
 740         TimerValue *v;
 741
 742         assert(u);
 743         assert(other);
 744
 745         if (other->load_state != UNIT_LOADED)
 746                 return;
 747
 748         /* Reenable all timers that depend on unit state */
 749         LIST_FOREACH(value, v, t->values)
 750                 if (IN_SET(v->base, TIMER_UNIT_ACTIVE, TIMER_UNIT_INACTIVE))
 751                         v->disabled = false;
 752
 753         switch (t->state) {
 754
 755         case TIMER_WAITING:
 756         case TIMER_ELAPSED:
 757
 758                 /* Recalculate sleep time */
 759                 timer_enter_waiting(t, false, false);
 760                 break;
 761
 762         case TIMER_RUNNING:
 763
 764                 if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other))) {
 765                         log_unit_debug(UNIT(t), "Got notified about unit deactivation.");
 766                         timer_enter_waiting(t, false, false);
 767                 }
 768                 break;
 769
 770         case TIMER_DEAD:
 771         case TIMER_FAILED:
 772                 break;
 773
 774         default:
 775                 assert_not_reached("Unknown timer state");
 776         }
 777 }
 778
 779 static void timer_reset_failed(Unit *u) {
 780         Timer *t = TIMER(u);
 781
 782         assert(t);
 783
 784         if (t->state == TIMER_FAILED)
 785                 timer_set_state(t, TIMER_DEAD);
 786
 787         t->result = TIMER_SUCCESS;
 788 }
 789
 790 static void timer_time_change(Unit *u) {
 791         Timer *t = TIMER(u);
 792         usec_t ts;
 793
 794         assert(u);
 795
 796         if (t->state != TIMER_WAITING)
 797                 return;
 798
 799         /* If we appear to have triggered in the future, the system clock must
 800          * have been set backwards.  So let's rewind our own clock and allow
 801          * the future trigger(s) to happen again :).  Exactly the same as when
 802          * you start a timer unit with Persistent=yes. */
 803         ts = now(CLOCK_REALTIME);
 804         if (t->last_trigger.realtime > ts)
 805                 t->last_trigger.realtime = ts;
 806
 807         log_unit_debug(u, "Time change, recalculating next elapse.");
 808         timer_enter_waiting(t, false, true);
 809 }
 810
 811 static void timer_timezone_change(Unit *u) {
 812         Timer *t = TIMER(u);
 813
 814         assert(u);
 815
 816         if (t->state != TIMER_WAITING)
 817                 return;
 818
 819         log_unit_debug(u, "Timezone change, recalculating next elapse.");
 820         timer_enter_waiting(t, false, false);
 821 }
 822
 823 static const char* const timer_base_table[_TIMER_BASE_MAX] = {
 824         [TIMER_ACTIVE] = "OnActiveSec",
 825         [TIMER_BOOT] = "OnBootSec",
 826         [TIMER_STARTUP] = "OnStartupSec",
 827         [TIMER_UNIT_ACTIVE] = "OnUnitActiveSec",
 828         [TIMER_UNIT_INACTIVE] = "OnUnitInactiveSec",
 829         [TIMER_CALENDAR] = "OnCalendar"
 830 };
 831
 832 DEFINE_STRING_TABLE_LOOKUP(timer_base, TimerBase);
 833
 834 static const char* const timer_result_table[_TIMER_RESULT_MAX] = {
 835         [TIMER_SUCCESS] = "success",
 836         [TIMER_FAILURE_RESOURCES] = "resources",
 837         [TIMER_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
 838 };
 839
 840 DEFINE_STRING_TABLE_LOOKUP(timer_result, TimerResult);
 841
 842 const UnitVTable timer_vtable = {
 843         .object_size = sizeof(Timer),
 844
 845         .sections =
 846                 "Unit\0"
 847                 "Timer\0"
 848                 "Install\0",
 849         .private_section = "Timer",
 850
 851         .init = timer_init,
 852         .done = timer_done,
 853         .load = timer_load,
 854
 855         .coldplug = timer_coldplug,
 856
 857         .dump = timer_dump,
 858
 859         .start = timer_start,
 860         .stop = timer_stop,
 861
 862         .serialize = timer_serialize,
 863         .deserialize_item = timer_deserialize_item,
 864
 865         .active_state = timer_active_state,
 866         .sub_state_to_string = timer_sub_state_to_string,
 867
 868         .trigger_notify = timer_trigger_notify,
 869
 870         .reset_failed = timer_reset_failed,
 871         .time_change = timer_time_change,
 872         .timezone_change = timer_timezone_change,
 873
 874         .bus_vtable = bus_timer_vtable,
 875         .bus_set_property = bus_timer_set_property,
 876
 877         .can_transient = true,
 878 };