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-errors.h"
  30
  31 static const UnitActiveState state_translation_table[_TIMER_STATE_MAX] = {
  32         [TIMER_DEAD] = UNIT_INACTIVE,
  33         [TIMER_WAITING] = UNIT_ACTIVE,
  34         [TIMER_RUNNING] = UNIT_ACTIVE,
  35         [TIMER_ELAPSED] = UNIT_ACTIVE,
  36         [TIMER_FAILED] = UNIT_FAILED
  37 };
  38
  39 static void timer_init(Unit *u) {
  40         Timer *t = TIMER(u);
  41
  42         assert(u);
  43         assert(u->load_state == UNIT_STUB);
  44
  45         t->next_elapse_monotonic = (usec_t) -1;
  46         t->next_elapse_realtime = (usec_t) -1;
  47         watch_init(&t->monotonic_watch);
  48         watch_init(&t->realtime_watch);
  49 }
  50
  51 void timer_free_values(Timer *t) {
  52         TimerValue *v;
  53
  54         assert(t);
  55
  56         while ((v = t->values)) {
  57                 LIST_REMOVE(TimerValue, value, t->values, v);
  58
  59                 if (v->calendar_spec)
  60                         calendar_spec_free(v->calendar_spec);
  61
  62                 free(v);
  63         }
  64 }
  65
  66 static void timer_done(Unit *u) {
  67         Timer *t = TIMER(u);
  68
  69         assert(t);
  70
  71         timer_free_values(t);
  72
  73         unit_unwatch_timer(u, &t->monotonic_watch);
  74         unit_unwatch_timer(u, &t->realtime_watch);
  75
  76         unit_ref_unset(&t->unit);
  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         if (UNIT(t)->manager->running_as == SYSTEMD_SYSTEM) {
 100                 r = unit_add_dependency_by_name(UNIT(t), UNIT_BEFORE, SPECIAL_BASIC_TARGET, NULL, true);
 101                 if (r < 0)
 102                         return r;
 103
 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 (!UNIT_DEREF(t->unit)) {
 126                         Unit *x;
 127
 128                         r = unit_load_related_unit(u, ".service", &x);
 129                         if (r < 0)
 130                                 return r;
 131
 132                         unit_ref_set(&t->unit, x);
 133                 }
 134
 135                 r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, UNIT_DEREF(t->unit), true);
 136                 if (r < 0)
 137                         return r;
 138
 139                 if (UNIT(t)->default_dependencies) {
 140                         r = timer_add_default_dependencies(t);
 141                         if (r < 0)
 142                                 return r;
 143                 }
 144         }
 145
 146         return timer_verify(t);
 147 }
 148
 149 static void timer_dump(Unit *u, FILE *f, const char *prefix) {
 150         Timer *t = TIMER(u);
 151         TimerValue *v;
 152
 153         fprintf(f,
 154                 "%sTimer State: %s\n"
 155                 "%sResult: %s\n"
 156                 "%sUnit: %s\n",
 157                 prefix, timer_state_to_string(t->state),
 158                 prefix, timer_result_to_string(t->result),
 159                 prefix, UNIT_DEREF(t->unit)->id);
 160
 161         LIST_FOREACH(value, v, t->values) {
 162
 163                 if (v->base == TIMER_CALENDAR) {
 164                         _cleanup_free_ char *p = NULL;
 165
 166                         calendar_spec_to_string(v->calendar_spec, &p);
 167
 168                         fprintf(f,
 169                                 "%s%s: %s\n",
 170                                 prefix,
 171                                 timer_base_to_string(v->base),
 172                                 strna(p));
 173                 } else  {
 174                         char timespan1[FORMAT_TIMESPAN_MAX];
 175
 176                         fprintf(f,
 177                                 "%s%s: %s\n",
 178                                 prefix,
 179                                 timer_base_to_string(v->base),
 180                                 strna(format_timespan(timespan1, sizeof(timespan1), v->value)));
 181                 }
 182         }
 183 }
 184
 185 static void timer_set_state(Timer *t, TimerState state) {
 186         TimerState old_state;
 187         assert(t);
 188
 189         old_state = t->state;
 190         t->state = state;
 191
 192         if (state != TIMER_WAITING) {
 193                 unit_unwatch_timer(UNIT(t), &t->monotonic_watch);
 194                 unit_unwatch_timer(UNIT(t), &t->realtime_watch);
 195         }
 196
 197         if (state != old_state)
 198                 log_debug_unit(UNIT(t)->id,
 199                                "%s changed %s -> %s", UNIT(t)->id,
 200                                timer_state_to_string(old_state),
 201                                timer_state_to_string(state));
 202
 203         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], true);
 204 }
 205
 206 static void timer_enter_waiting(Timer *t, bool initial);
 207
 208 static int timer_coldplug(Unit *u) {
 209         Timer *t = TIMER(u);
 210
 211         assert(t);
 212         assert(t->state == TIMER_DEAD);
 213
 214         if (t->deserialized_state != t->state) {
 215
 216                 if (t->deserialized_state == TIMER_WAITING)
 217                         timer_enter_waiting(t, false);
 218                 else
 219                         timer_set_state(t, t->deserialized_state);
 220         }
 221
 222         return 0;
 223 }
 224
 225 static void timer_enter_dead(Timer *t, TimerResult f) {
 226         assert(t);
 227
 228         if (f != TIMER_SUCCESS)
 229                 t->result = f;
 230
 231         timer_set_state(t, t->result != TIMER_SUCCESS ? TIMER_FAILED : TIMER_DEAD);
 232 }
 233
 234 static void timer_enter_waiting(Timer *t, bool initial) {
 235         TimerValue *v;
 236         usec_t base = 0;
 237         dual_timestamp ts;
 238         bool found_monotonic = false, found_realtime = false;
 239         int r;
 240
 241         dual_timestamp_get(&ts);
 242         t->next_elapse_monotonic = t->next_elapse_realtime = 0;
 243
 244         LIST_FOREACH(value, v, t->values) {
 245
 246                 if (v->disabled)
 247                         continue;
 248
 249                 if (v->base == TIMER_CALENDAR) {
 250
 251                         r = calendar_spec_next_usec(v->calendar_spec, ts.realtime, &v->next_elapse);
 252                         if (r < 0)
 253                                 continue;
 254
 255                         if (!initial && v->next_elapse < ts.realtime) {
 256                                 v->disabled = true;
 257                                 continue;
 258                         }
 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                                 if (UNIT_DEREF(t->unit)->inactive_exit_timestamp.monotonic <= 0)
 289                                         continue;
 290
 291                                 base = UNIT_DEREF(t->unit)->inactive_exit_timestamp.monotonic;
 292                                 break;
 293
 294                         case TIMER_UNIT_INACTIVE:
 295
 296                                 if (UNIT_DEREF(t->unit)->inactive_enter_timestamp.monotonic <= 0)
 297                                         continue;
 298
 299                                 base = UNIT_DEREF(t->unit)->inactive_enter_timestamp.monotonic;
 300                                 break;
 301
 302                         default:
 303                                 assert_not_reached("Unknown timer base");
 304                         }
 305
 306                         v->next_elapse = base + v->value;
 307
 308                         if (!initial && v->next_elapse < ts.monotonic) {
 309                                 v->disabled = true;
 310                                 continue;
 311                         }
 312
 313                         if (!found_monotonic)
 314                                 t->next_elapse_monotonic = v->next_elapse;
 315                         else
 316                                 t->next_elapse_monotonic = MIN(t->next_elapse_monotonic, v->next_elapse);
 317
 318                         found_monotonic = true;
 319                 }
 320         }
 321
 322         if (!found_monotonic && !found_realtime) {
 323                 log_debug_unit(UNIT(t)->id, "%s: Timer is elapsed.", UNIT(t)->id);
 324                 timer_set_state(t, TIMER_ELAPSED);
 325                 return;
 326         }
 327
 328         if (found_monotonic) {
 329                 char buf[FORMAT_TIMESPAN_MAX];
 330                 log_debug_unit(UNIT(t)->id,
 331                                "%s: Monotonic timer elapses in %s.",
 332                                UNIT(t)->id,
 333                                format_timespan(buf, sizeof(buf), t->next_elapse_monotonic > ts.monotonic ? t->next_elapse_monotonic - ts.monotonic : 0));
 334
 335                 r = unit_watch_timer(UNIT(t), CLOCK_MONOTONIC, false, t->next_elapse_monotonic, &t->monotonic_watch);
 336                 if (r < 0)
 337                         goto fail;
 338         } else
 339                 unit_unwatch_timer(UNIT(t), &t->monotonic_watch);
 340
 341         if (found_realtime) {
 342                 char buf[FORMAT_TIMESTAMP_MAX];
 343                 log_debug_unit(UNIT(t)->id,
 344                                "%s: Realtime timer elapses at %s.",
 345                                UNIT(t)->id,
 346                                format_timestamp(buf, sizeof(buf), t->next_elapse_realtime));
 347
 348                 r = unit_watch_timer(UNIT(t), CLOCK_REALTIME, false, t->next_elapse_realtime, &t->realtime_watch);
 349                 if (r < 0)
 350                         goto fail;
 351         } else
 352                 unit_unwatch_timer(UNIT(t), &t->realtime_watch);
 353
 354         timer_set_state(t, TIMER_WAITING);
 355         return;
 356
 357 fail:
 358         log_warning_unit(UNIT(t)->id,
 359                          "%s failed to enter waiting state: %s",
 360                          UNIT(t)->id, strerror(-r));
 361         timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 362 }
 363
 364 static void timer_enter_running(Timer *t) {
 365         DBusError error;
 366         int r;
 367
 368         assert(t);
 369         dbus_error_init(&error);
 370
 371         /* Don't start job if we are supposed to go down */
 372         if (UNIT(t)->job && UNIT(t)->job->type == JOB_STOP)
 373                 return;
 374
 375         r = manager_add_job(UNIT(t)->manager, JOB_START, UNIT_DEREF(t->unit), JOB_REPLACE, true, &error, NULL);
 376         if (r < 0)
 377                 goto fail;
 378
 379         timer_set_state(t, TIMER_RUNNING);
 380         return;
 381
 382 fail:
 383         log_warning_unit(UNIT(t)->id,
 384                          "%s failed to queue unit startup job: %s",
 385                          UNIT(t)->id, bus_error(&error, r));
 386         timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 387
 388         dbus_error_free(&error);
 389 }
 390
 391 static int timer_start(Unit *u) {
 392         Timer *t = TIMER(u);
 393
 394         assert(t);
 395         assert(t->state == TIMER_DEAD || t->state == TIMER_FAILED);
 396
 397         if (UNIT_DEREF(t->unit)->load_state != UNIT_LOADED)
 398                 return -ENOENT;
 399
 400         t->result = TIMER_SUCCESS;
 401         timer_enter_waiting(t, true);
 402         return 0;
 403 }
 404
 405 static int timer_stop(Unit *u) {
 406         Timer *t = TIMER(u);
 407
 408         assert(t);
 409         assert(t->state == TIMER_WAITING || t->state == TIMER_RUNNING || t->state == TIMER_ELAPSED);
 410
 411         timer_enter_dead(t, TIMER_SUCCESS);
 412         return 0;
 413 }
 414
 415 static int timer_serialize(Unit *u, FILE *f, FDSet *fds) {
 416         Timer *t = TIMER(u);
 417
 418         assert(u);
 419         assert(f);
 420         assert(fds);
 421
 422         unit_serialize_item(u, f, "state", timer_state_to_string(t->state));
 423         unit_serialize_item(u, f, "result", timer_result_to_string(t->result));
 424
 425         return 0;
 426 }
 427
 428 static int timer_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 429         Timer *t = TIMER(u);
 430
 431         assert(u);
 432         assert(key);
 433         assert(value);
 434         assert(fds);
 435
 436         if (streq(key, "state")) {
 437                 TimerState state;
 438
 439                 state = timer_state_from_string(value);
 440                 if (state < 0)
 441                         log_debug_unit(u->id, "Failed to parse state value %s", value);
 442                 else
 443                         t->deserialized_state = state;
 444         } else if (streq(key, "result")) {
 445                 TimerResult f;
 446
 447                 f = timer_result_from_string(value);
 448                 if (f < 0)
 449                         log_debug_unit(u->id, "Failed to parse result value %s", value);
 450                 else if (f != TIMER_SUCCESS)
 451                         t->result = f;
 452
 453         } else
 454                 log_debug_unit(u->id, "Unknown serialization key '%s'", key);
 455
 456         return 0;
 457 }
 458
 459 static UnitActiveState timer_active_state(Unit *u) {
 460         assert(u);
 461
 462         return state_translation_table[TIMER(u)->state];
 463 }
 464
 465 static const char *timer_sub_state_to_string(Unit *u) {
 466         assert(u);
 467
 468         return timer_state_to_string(TIMER(u)->state);
 469 }
 470
 471 static void timer_timer_event(Unit *u, uint64_t elapsed, Watch *w) {
 472         Timer *t = TIMER(u);
 473
 474         assert(t);
 475         assert(elapsed == 1);
 476
 477         if (t->state != TIMER_WAITING)
 478                 return;
 479
 480         log_debug_unit(u->id, "Timer elapsed on %s", u->id);
 481         timer_enter_running(t);
 482 }
 483
 484 void timer_unit_notify(Unit *u, UnitActiveState new_state) {
 485         Iterator i;
 486         Unit *k;
 487
 488         if (u->type == UNIT_TIMER)
 489                 return;
 490
 491         SET_FOREACH(k, u->dependencies[UNIT_TRIGGERED_BY], i) {
 492                 Timer *t;
 493                 TimerValue *v;
 494
 495                 if (k->type != UNIT_TIMER)
 496                         continue;
 497
 498                 if (k->load_state != UNIT_LOADED)
 499                         continue;
 500
 501                 t = TIMER(k);
 502
 503                 /* Reenable all timers that depend on unit state */
 504                 LIST_FOREACH(value, v, t->values)
 505                         if (v->base == TIMER_UNIT_ACTIVE ||
 506                             v->base == TIMER_UNIT_INACTIVE)
 507                                 v->disabled = false;
 508
 509                 switch (t->state) {
 510
 511                 case TIMER_WAITING:
 512                 case TIMER_ELAPSED:
 513
 514                         /* Recalculate sleep time */
 515                         timer_enter_waiting(t, false);
 516                         break;
 517
 518                 case TIMER_RUNNING:
 519
 520                         if (UNIT_IS_INACTIVE_OR_FAILED(new_state)) {
 521                                 log_debug_unit(UNIT(t)->id,
 522                                                "%s got notified about unit deactivation.",
 523                                                UNIT(t)->id);
 524                                 timer_enter_waiting(t, false);
 525                         }
 526
 527                         break;
 528
 529                 case TIMER_DEAD:
 530                 case TIMER_FAILED:
 531                         break;
 532
 533                 default:
 534                         assert_not_reached("Unknown timer state");
 535                 }
 536         }
 537 }
 538
 539 static void timer_reset_failed(Unit *u) {
 540         Timer *t = TIMER(u);
 541
 542         assert(t);
 543
 544         if (t->state == TIMER_FAILED)
 545                 timer_set_state(t, TIMER_DEAD);
 546
 547         t->result = TIMER_SUCCESS;
 548 }
 549
 550 static void timer_time_change(Unit *u) {
 551         Timer *t = TIMER(u);
 552
 553         assert(u);
 554
 555         if (t->state != TIMER_WAITING)
 556                 return;
 557
 558         log_info_unit(u->id,
 559                       "%s: time change, recalculating next elapse.", u->id);
 560         timer_enter_waiting(t, false);
 561 }
 562
 563 static const char* const timer_state_table[_TIMER_STATE_MAX] = {
 564         [TIMER_DEAD] = "dead",
 565         [TIMER_WAITING] = "waiting",
 566         [TIMER_RUNNING] = "running",
 567         [TIMER_ELAPSED] = "elapsed",
 568         [TIMER_FAILED] = "failed"
 569 };
 570
 571 DEFINE_STRING_TABLE_LOOKUP(timer_state, TimerState);
 572
 573 static const char* const timer_base_table[_TIMER_BASE_MAX] = {
 574         [TIMER_ACTIVE] = "OnActiveSec",
 575         [TIMER_BOOT] = "OnBootSec",
 576         [TIMER_STARTUP] = "OnStartupSec",
 577         [TIMER_UNIT_ACTIVE] = "OnUnitActiveSec",
 578         [TIMER_UNIT_INACTIVE] = "OnUnitInactiveSec",
 579         [TIMER_CALENDAR] = "OnCalendar"
 580 };
 581
 582 DEFINE_STRING_TABLE_LOOKUP(timer_base, TimerBase);
 583
 584 static const char* const timer_result_table[_TIMER_RESULT_MAX] = {
 585         [TIMER_SUCCESS] = "success",
 586         [TIMER_FAILURE_RESOURCES] = "resources"
 587 };
 588
 589 DEFINE_STRING_TABLE_LOOKUP(timer_result, TimerResult);
 590
 591 const UnitVTable timer_vtable = {
 592         .object_size = sizeof(Timer),
 593         .sections =
 594                 "Unit\0"
 595                 "Timer\0"
 596                 "Install\0",
 597
 598         .init = timer_init,
 599         .done = timer_done,
 600         .load = timer_load,
 601
 602         .coldplug = timer_coldplug,
 603
 604         .dump = timer_dump,
 605
 606         .start = timer_start,
 607         .stop = timer_stop,
 608
 609         .serialize = timer_serialize,
 610         .deserialize_item = timer_deserialize_item,
 611
 612         .active_state = timer_active_state,
 613         .sub_state_to_string = timer_sub_state_to_string,
 614
 615         .timer_event = timer_timer_event,
 616
 617         .reset_failed = timer_reset_failed,
 618         .time_change = timer_time_change,
 619
 620         .bus_interface = "org.freedesktop.systemd1.Timer",
 621         .bus_message_handler = bus_timer_message_handler,
 622         .bus_invalidating_properties =  bus_timer_invalidating_properties
 623 };