src/core/timer.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <errno.h>
  23
  24 #include "unit.h"
  25 #include "unit-name.h"
  26 #include "timer.h"
  27 #include "dbus-timer.h"
  28 #include "special.h"
  29 #include "bus-util.h"
  30 #include "bus-error.h"
  31
  32 static const UnitActiveState state_translation_table[_TIMER_STATE_MAX] = {
  33         [TIMER_DEAD] = UNIT_INACTIVE,
  34         [TIMER_WAITING] = UNIT_ACTIVE,
  35         [TIMER_RUNNING] = UNIT_ACTIVE,
  36         [TIMER_ELAPSED] = UNIT_ACTIVE,
  37         [TIMER_FAILED] = UNIT_FAILED
  38 };
  39
  40 static int timer_dispatch(sd_event_source *s, uint64_t usec, void *userdata);
  41
  42 static void timer_init(Unit *u) {
  43         Timer *t = TIMER(u);
  44
  45         assert(u);
  46         assert(u->load_state == UNIT_STUB);
  47
  48         t->next_elapse_monotonic = (usec_t) -1;
  49         t->next_elapse_realtime = (usec_t) -1;
  50         t->accuracy_usec = USEC_PER_MINUTE;
  51 }
  52
  53 void timer_free_values(Timer *t) {
  54         TimerValue *v;
  55
  56         assert(t);
  57
  58         while ((v = t->values)) {
  59                 LIST_REMOVE(value, t->values, v);
  60
  61                 if (v->calendar_spec)
  62                         calendar_spec_free(v->calendar_spec);
  63
  64                 free(v);
  65         }
  66 }
  67
  68 static void timer_done(Unit *u) {
  69         Timer *t = TIMER(u);
  70
  71         assert(t);
  72
  73         timer_free_values(t);
  74
  75         t->monotonic_event_source = sd_event_source_unref(t->monotonic_event_source);
  76         t->realtime_event_source = sd_event_source_unref(t->realtime_event_source);
  77 }
  78
  79 static int timer_verify(Timer *t) {
  80         assert(t);
  81
  82         if (UNIT(t)->load_state != UNIT_LOADED)
  83                 return 0;
  84
  85         if (!t->values) {
  86                 log_error_unit(UNIT(t)->id,
  87                                "%s lacks value setting. Refusing.", UNIT(t)->id);
  88                 return -EINVAL;
  89         }
  90
  91         return 0;
  92 }
  93
  94 static int timer_add_default_dependencies(Timer *t) {
  95         int r;
  96
  97         assert(t);
  98
  99         r = unit_add_dependency_by_name(UNIT(t), UNIT_BEFORE, SPECIAL_TIMERS_TARGET, NULL, true);
 100         if (r < 0)
 101                 return r;
 102
 103         if (UNIT(t)->manager->running_as == SYSTEMD_SYSTEM) {
 104                 r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true);
 105                 if (r < 0)
 106                         return r;
 107         }
 108
 109         return unit_add_two_dependencies_by_name(UNIT(t), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true);
 110 }
 111
 112 static int timer_load(Unit *u) {
 113         Timer *t = TIMER(u);
 114         int r;
 115
 116         assert(u);
 117         assert(u->load_state == UNIT_STUB);
 118
 119         r = unit_load_fragment_and_dropin(u);
 120         if (r < 0)
 121                 return r;
 122
 123         if (u->load_state == UNIT_LOADED) {
 124
 125                 if (set_isempty(u->dependencies[UNIT_TRIGGERS])) {
 126                         Unit *x;
 127
 128                         r = unit_load_related_unit(u, ".service", &x);
 129                         if (r < 0)
 130                                 return r;
 131
 132                         r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, x, true);
 133                         if (r < 0)
 134                                 return r;
 135                 }
 136
 137                 if (UNIT(t)->default_dependencies) {
 138                         r = timer_add_default_dependencies(t);
 139                         if (r < 0)
 140                                 return r;
 141                 }
 142         }
 143
 144         return timer_verify(t);
 145 }
 146
 147 static void timer_dump(Unit *u, FILE *f, const char *prefix) {
 148         char buf[FORMAT_TIMESPAN_MAX];
 149         Timer *t = TIMER(u);
 150         Unit *trigger;
 151         TimerValue *v;
 152
 153         trigger = UNIT_TRIGGER(u);
 154
 155         fprintf(f,
 156                 "%sTimer State: %s\n"
 157                 "%sResult: %s\n"
 158                 "%sUnit: %s\n"
 159                 "%sAccuracy: %s\n",
 160                 prefix, timer_state_to_string(t->state),
 161                 prefix, timer_result_to_string(t->result),
 162                 prefix, trigger ? trigger->id : "n/a",
 163                 prefix, format_timespan(buf, sizeof(buf), t->accuracy_usec, 1));
 164
 165         LIST_FOREACH(value, v, t->values) {
 166
 167                 if (v->base == TIMER_CALENDAR) {
 168                         _cleanup_free_ char *p = NULL;
 169
 170                         calendar_spec_to_string(v->calendar_spec, &p);
 171
 172                         fprintf(f,
 173                                 "%s%s: %s\n",
 174                                 prefix,
 175                                 timer_base_to_string(v->base),
 176                                 strna(p));
 177                 } else  {
 178                         char timespan1[FORMAT_TIMESPAN_MAX];
 179
 180                         fprintf(f,
 181                                 "%s%s: %s\n",
 182                                 prefix,
 183                                 timer_base_to_string(v->base),
 184                                 strna(format_timespan(timespan1, sizeof(timespan1), v->value, 0)));
 185                 }
 186         }
 187 }
 188
 189 static void timer_set_state(Timer *t, TimerState state) {
 190         TimerState old_state;
 191         assert(t);
 192
 193         old_state = t->state;
 194         t->state = state;
 195
 196         if (state != TIMER_WAITING) {
 197                 t->monotonic_event_source = sd_event_source_unref(t->monotonic_event_source);
 198                 t->realtime_event_source = sd_event_source_unref(t->realtime_event_source);
 199         }
 200
 201         if (state != old_state)
 202                 log_debug_unit(UNIT(t)->id,
 203                                "%s changed %s -> %s", UNIT(t)->id,
 204                                timer_state_to_string(old_state),
 205                                timer_state_to_string(state));
 206
 207         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], true);
 208 }
 209
 210 static void timer_enter_waiting(Timer *t, bool initial);
 211
 212 static int timer_coldplug(Unit *u) {
 213         Timer *t = TIMER(u);
 214
 215         assert(t);
 216         assert(t->state == TIMER_DEAD);
 217
 218         if (t->deserialized_state != t->state) {
 219
 220                 if (t->deserialized_state == TIMER_WAITING)
 221                         timer_enter_waiting(t, false);
 222                 else
 223                         timer_set_state(t, t->deserialized_state);
 224         }
 225
 226         return 0;
 227 }
 228
 229 static void timer_enter_dead(Timer *t, TimerResult f) {
 230         assert(t);
 231
 232         if (f != TIMER_SUCCESS)
 233                 t->result = f;
 234
 235         timer_set_state(t, t->result != TIMER_SUCCESS ? TIMER_FAILED : TIMER_DEAD);
 236 }
 237
 238
 239 static void timer_enter_waiting(Timer *t, bool initial) {
 240         TimerValue *v;
 241         usec_t base = 0;
 242         dual_timestamp ts;
 243         bool found_monotonic = false, found_realtime = false;
 244         int r;
 245
 246         dual_timestamp_get(&ts);
 247         t->next_elapse_monotonic = t->next_elapse_realtime = 0;
 248
 249         LIST_FOREACH(value, v, t->values) {
 250
 251                 if (v->disabled)
 252                         continue;
 253
 254                 if (v->base == TIMER_CALENDAR) {
 255
 256                         r = calendar_spec_next_usec(v->calendar_spec, ts.realtime, &v->next_elapse);
 257                         if (r < 0)
 258                                 continue;
 259
 260                         if (!found_realtime)
 261                                 t->next_elapse_realtime = v->next_elapse;
 262                         else
 263                                 t->next_elapse_realtime = MIN(t->next_elapse_realtime, v->next_elapse);
 264
 265                         found_realtime = true;
 266
 267                 } else  {
 268                         switch (v->base) {
 269
 270                         case TIMER_ACTIVE:
 271                                 if (state_translation_table[t->state] == UNIT_ACTIVE)
 272                                         base = UNIT(t)->inactive_exit_timestamp.monotonic;
 273                                 else
 274                                         base = ts.monotonic;
 275                                 break;
 276
 277                         case TIMER_BOOT:
 278                                 /* CLOCK_MONOTONIC equals the uptime on Linux */
 279                                 base = 0;
 280                                 break;
 281
 282                         case TIMER_STARTUP:
 283                                 base = UNIT(t)->manager->userspace_timestamp.monotonic;
 284                                 break;
 285
 286                         case TIMER_UNIT_ACTIVE:
 287
 288                                 base = UNIT_TRIGGER(UNIT(t))->inactive_exit_timestamp.monotonic;
 289
 290                                 if (base <= 0)
 291                                         base = t->last_trigger_monotonic;
 292
 293                                 if (base <= 0)
 294                                         continue;
 295
 296                                 break;
 297
 298                         case TIMER_UNIT_INACTIVE:
 299
 300                                 base = UNIT_TRIGGER(UNIT(t))->inactive_enter_timestamp.monotonic;
 301
 302                                 if (base <= 0)
 303                                         base = t->last_trigger_monotonic;
 304
 305                                 if (base <= 0)
 306                                         continue;
 307
 308                                 break;
 309
 310                         default:
 311                                 assert_not_reached("Unknown timer base");
 312                         }
 313
 314                         v->next_elapse = base + v->value;
 315
 316                         if (!initial &&
 317                             v->next_elapse < ts.monotonic &&
 318                             (v->base == TIMER_ACTIVE || v->base == TIMER_BOOT || v->base == TIMER_STARTUP)) {
 319                                 /* This is a one time trigger, disable it now */
 320                                 v->disabled = true;
 321                                 continue;
 322                         }
 323
 324                         if (!found_monotonic)
 325                                 t->next_elapse_monotonic = v->next_elapse;
 326                         else
 327                                 t->next_elapse_monotonic = MIN(t->next_elapse_monotonic, v->next_elapse);
 328
 329                         found_monotonic = true;
 330                 }
 331         }
 332
 333         if (!found_monotonic && !found_realtime) {
 334                 log_debug_unit(UNIT(t)->id, "%s: Timer is elapsed.", UNIT(t)->id);
 335                 timer_set_state(t, TIMER_ELAPSED);
 336                 return;
 337         }
 338
 339         if (found_monotonic) {
 340                 char buf[FORMAT_TIMESPAN_MAX];
 341                 log_debug_unit(UNIT(t)->id,
 342                                "%s: Monotonic timer elapses in %s.",
 343                                UNIT(t)->id,
 344                                format_timespan(buf, sizeof(buf), t->next_elapse_monotonic > ts.monotonic ? t->next_elapse_monotonic - ts.monotonic : 0, 0));
 345
 346                 if (t->monotonic_event_source) {
 347                         r = sd_event_source_set_time(t->monotonic_event_source, t->next_elapse_monotonic);
 348                         if (r < 0)
 349                                 goto fail;
 350
 351                         r = sd_event_source_set_enabled(t->monotonic_event_source, SD_EVENT_ONESHOT);
 352                 } else
 353                         r = sd_event_add_monotonic(UNIT(t)->manager->event, t->next_elapse_monotonic, t->accuracy_usec, timer_dispatch, t, &t->monotonic_event_source);
 354
 355                 if (r < 0)
 356                         goto fail;
 357
 358         } else if (t->monotonic_event_source) {
 359                 r = sd_event_source_set_enabled(t->monotonic_event_source, SD_EVENT_OFF);
 360
 361                 if (r < 0)
 362                         goto fail;
 363         }
 364
 365         if (found_realtime) {
 366                 char buf[FORMAT_TIMESTAMP_MAX];
 367                 log_debug_unit(UNIT(t)->id,
 368                                "%s: Realtime timer elapses at %s.",
 369                                UNIT(t)->id,
 370                                format_timestamp(buf, sizeof(buf), t->next_elapse_realtime));
 371
 372                 if (t->realtime_event_source) {
 373                         r = sd_event_source_set_time(t->realtime_event_source, t->next_elapse_realtime);
 374                         if (r < 0)
 375                                 goto fail;
 376
 377                         r = sd_event_source_set_enabled(t->realtime_event_source, SD_EVENT_ONESHOT);
 378                 } else
 379                         r = sd_event_add_realtime(UNIT(t)->manager->event, t->next_elapse_realtime, t->accuracy_usec, timer_dispatch, t, &t->realtime_event_source);
 380
 381                 if (r < 0)
 382                         goto fail;
 383
 384         } else if (t->realtime_event_source) {
 385                 r = sd_event_source_set_enabled(t->realtime_event_source, SD_EVENT_OFF);
 386
 387                 if (r < 0)
 388                         goto fail;
 389         }
 390
 391         timer_set_state(t, TIMER_WAITING);
 392         return;
 393
 394 fail:
 395         log_warning_unit(UNIT(t)->id,
 396                          "%s failed to enter waiting state: %s",
 397                          UNIT(t)->id, strerror(-r));
 398         timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 399 }
 400
 401 static void timer_enter_running(Timer *t) {
 402         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
 403         int r;
 404
 405         assert(t);
 406
 407         /* Don't start job if we are supposed to go down */
 408         if (unit_stop_pending(UNIT(t)))
 409                 return;
 410
 411         r = manager_add_job(UNIT(t)->manager, JOB_START, UNIT_TRIGGER(UNIT(t)),
 412                             JOB_REPLACE, true, &error, NULL);
 413         if (r < 0)
 414                 goto fail;
 415
 416         t->last_trigger_monotonic = now(CLOCK_MONOTONIC);
 417
 418         timer_set_state(t, TIMER_RUNNING);
 419         return;
 420
 421 fail:
 422         log_warning_unit(UNIT(t)->id,
 423                          "%s failed to queue unit startup job: %s",
 424                          UNIT(t)->id, bus_error_message(&error, r));
 425         timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 426 }
 427
 428 static int timer_start(Unit *u) {
 429         Timer *t = TIMER(u);
 430
 431         assert(t);
 432         assert(t->state == TIMER_DEAD || t->state == TIMER_FAILED);
 433
 434         if (UNIT_TRIGGER(u)->load_state != UNIT_LOADED)
 435                 return -ENOENT;
 436
 437         t->result = TIMER_SUCCESS;
 438         timer_enter_waiting(t, true);
 439         return 0;
 440 }
 441
 442 static int timer_stop(Unit *u) {
 443         Timer *t = TIMER(u);
 444
 445         assert(t);
 446         assert(t->state == TIMER_WAITING || t->state == TIMER_RUNNING || t->state == TIMER_ELAPSED);
 447
 448         timer_enter_dead(t, TIMER_SUCCESS);
 449         return 0;
 450 }
 451
 452 static int timer_serialize(Unit *u, FILE *f, FDSet *fds) {
 453         Timer *t = TIMER(u);
 454
 455         assert(u);
 456         assert(f);
 457         assert(fds);
 458
 459         unit_serialize_item(u, f, "state", timer_state_to_string(t->state));
 460         unit_serialize_item(u, f, "result", timer_result_to_string(t->result));
 461
 462         return 0;
 463 }
 464
 465 static int timer_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 466         Timer *t = TIMER(u);
 467
 468         assert(u);
 469         assert(key);
 470         assert(value);
 471         assert(fds);
 472
 473         if (streq(key, "state")) {
 474                 TimerState state;
 475
 476                 state = timer_state_from_string(value);
 477                 if (state < 0)
 478                         log_debug_unit(u->id, "Failed to parse state value %s", value);
 479                 else
 480                         t->deserialized_state = state;
 481         } else if (streq(key, "result")) {
 482                 TimerResult f;
 483
 484                 f = timer_result_from_string(value);
 485                 if (f < 0)
 486                         log_debug_unit(u->id, "Failed to parse result value %s", value);
 487                 else if (f != TIMER_SUCCESS)
 488                         t->result = f;
 489
 490         } else
 491                 log_debug_unit(u->id, "Unknown serialization key '%s'", key);
 492
 493         return 0;
 494 }
 495
 496 _pure_ static UnitActiveState timer_active_state(Unit *u) {
 497         assert(u);
 498
 499         return state_translation_table[TIMER(u)->state];
 500 }
 501
 502 _pure_ static const char *timer_sub_state_to_string(Unit *u) {
 503         assert(u);
 504
 505         return timer_state_to_string(TIMER(u)->state);
 506 }
 507
 508 static int timer_dispatch(sd_event_source *s, uint64_t usec, void *userdata) {
 509         Timer *t = TIMER(userdata);
 510
 511         assert(t);
 512
 513         if (t->state != TIMER_WAITING)
 514                 return 0;
 515
 516         log_debug_unit(UNIT(t)->id, "Timer elapsed on %s", UNIT(t)->id);
 517         timer_enter_running(t);
 518         return 0;
 519 }
 520
 521 static void timer_trigger_notify(Unit *u, Unit *other) {
 522         Timer *t = TIMER(u);
 523         TimerValue *v;
 524
 525         assert(u);
 526         assert(other);
 527
 528         if (other->load_state != UNIT_LOADED)
 529                 return;
 530
 531         /* Reenable all timers that depend on unit state */
 532         LIST_FOREACH(value, v, t->values)
 533                 if (v->base == TIMER_UNIT_ACTIVE ||
 534                     v->base == TIMER_UNIT_INACTIVE)
 535                         v->disabled = false;
 536
 537         switch (t->state) {
 538
 539         case TIMER_WAITING:
 540         case TIMER_ELAPSED:
 541
 542                 /* Recalculate sleep time */
 543                 timer_enter_waiting(t, false);
 544                 break;
 545
 546         case TIMER_RUNNING:
 547
 548                 if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other))) {
 549                         log_debug_unit(UNIT(t)->id,
 550                                        "%s got notified about unit deactivation.",
 551                                        UNIT(t)->id);
 552                         timer_enter_waiting(t, false);
 553                 }
 554                 break;
 555
 556         case TIMER_DEAD:
 557         case TIMER_FAILED:
 558                 break;
 559
 560         default:
 561                 assert_not_reached("Unknown timer state");
 562         }
 563 }
 564
 565 static void timer_reset_failed(Unit *u) {
 566         Timer *t = TIMER(u);
 567
 568         assert(t);
 569
 570         if (t->state == TIMER_FAILED)
 571                 timer_set_state(t, TIMER_DEAD);
 572
 573         t->result = TIMER_SUCCESS;
 574 }
 575
 576 static void timer_time_change(Unit *u) {
 577         Timer *t = TIMER(u);
 578
 579         assert(u);
 580
 581         if (t->state != TIMER_WAITING)
 582                 return;
 583
 584         log_debug_unit(u->id,
 585                        "%s: time change, recalculating next elapse.", u->id);
 586         timer_enter_waiting(t, false);
 587 }
 588
 589 static const char* const timer_state_table[_TIMER_STATE_MAX] = {
 590         [TIMER_DEAD] = "dead",
 591         [TIMER_WAITING] = "waiting",
 592         [TIMER_RUNNING] = "running",
 593         [TIMER_ELAPSED] = "elapsed",
 594         [TIMER_FAILED] = "failed"
 595 };
 596
 597 DEFINE_STRING_TABLE_LOOKUP(timer_state, TimerState);
 598
 599 static const char* const timer_base_table[_TIMER_BASE_MAX] = {
 600         [TIMER_ACTIVE] = "OnActiveSec",
 601         [TIMER_BOOT] = "OnBootSec",
 602         [TIMER_STARTUP] = "OnStartupSec",
 603         [TIMER_UNIT_ACTIVE] = "OnUnitActiveSec",
 604         [TIMER_UNIT_INACTIVE] = "OnUnitInactiveSec",
 605         [TIMER_CALENDAR] = "OnCalendar"
 606 };
 607
 608 DEFINE_STRING_TABLE_LOOKUP(timer_base, TimerBase);
 609
 610 static const char* const timer_result_table[_TIMER_RESULT_MAX] = {
 611         [TIMER_SUCCESS] = "success",
 612         [TIMER_FAILURE_RESOURCES] = "resources"
 613 };
 614
 615 DEFINE_STRING_TABLE_LOOKUP(timer_result, TimerResult);
 616
 617 const UnitVTable timer_vtable = {
 618         .object_size = sizeof(Timer),
 619
 620         .sections =
 621                 "Unit\0"
 622                 "Timer\0"
 623                 "Install\0",
 624
 625         .init = timer_init,
 626         .done = timer_done,
 627         .load = timer_load,
 628
 629         .coldplug = timer_coldplug,
 630
 631         .dump = timer_dump,
 632
 633         .start = timer_start,
 634         .stop = timer_stop,
 635
 636         .serialize = timer_serialize,
 637         .deserialize_item = timer_deserialize_item,
 638
 639         .active_state = timer_active_state,
 640         .sub_state_to_string = timer_sub_state_to_string,
 641
 642         .trigger_notify = timer_trigger_notify,
 643
 644         .reset_failed = timer_reset_failed,
 645         .time_change = timer_time_change,
 646
 647         .bus_interface = "org.freedesktop.systemd1.Timer",
 648         .bus_vtable = bus_timer_vtable,
 649 };