src/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 General Public License as published by
  10   the Free Software Foundation; either version 2 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   General Public License for more details.
  17
  18   You should have received a copy of the GNU 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->meta.load_state == UNIT_STUB);
  44
  45         t->next_elapse = (usec_t) -1;
  46 }
  47
  48 static void timer_done(Unit *u) {
  49         Timer *t = TIMER(u);
  50         TimerValue *v;
  51
  52         assert(t);
  53
  54         while ((v = t->values)) {
  55                 LIST_REMOVE(TimerValue, value, t->values, v);
  56                 free(v);
  57         }
  58
  59         unit_unwatch_timer(u, &t->timer_watch);
  60 }
  61
  62 static int timer_verify(Timer *t) {
  63         assert(t);
  64
  65         if (t->meta.load_state != UNIT_LOADED)
  66                 return 0;
  67
  68         if (!t->values) {
  69                 log_error("%s lacks value setting. Refusing.", t->meta.id);
  70                 return -EINVAL;
  71         }
  72
  73         return 0;
  74 }
  75
  76 static int timer_add_default_dependencies(Timer *t) {
  77         int r;
  78
  79         assert(t);
  80
  81         if (t->meta.manager->running_as == MANAGER_SYSTEM)
  82                 if ((r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true)) < 0)
  83                         return r;
  84
  85         return unit_add_two_dependencies_by_name(UNIT(t), UNIT_BEFORE, UNIT_CONFLICTED_BY, SPECIAL_SHUTDOWN_TARGET, NULL, true);
  86 }
  87
  88 static int timer_load(Unit *u) {
  89         Timer *t = TIMER(u);
  90         int r;
  91
  92         assert(u);
  93         assert(u->meta.load_state == UNIT_STUB);
  94
  95         if ((r = unit_load_fragment_and_dropin(u)) < 0)
  96                 return r;
  97
  98         if (u->meta.load_state == UNIT_LOADED) {
  99
 100                 if (!t->unit)
 101                         if ((r = unit_load_related_unit(u, ".service", &t->unit)))
 102                                 return r;
 103
 104                 if ((r = unit_add_dependency(u, UNIT_BEFORE, t->unit, true)) < 0)
 105                         return r;
 106
 107                 if (t->meta.default_dependencies)
 108                         if ((r = timer_add_default_dependencies(t)) < 0)
 109                                 return r;
 110         }
 111
 112         return timer_verify(t);
 113 }
 114
 115 static void timer_dump(Unit *u, FILE *f, const char *prefix) {
 116         Timer *t = TIMER(u);
 117         TimerValue *v;
 118         char
 119                 timespan1[FORMAT_TIMESPAN_MAX];
 120
 121         fprintf(f,
 122                 "%sTimer State: %s\n"
 123                 "%sUnit: %s\n",
 124                 prefix, timer_state_to_string(t->state),
 125                 prefix, t->unit->meta.id);
 126
 127         LIST_FOREACH(value, v, t->values)
 128                 fprintf(f,
 129                         "%s%s: %s\n",
 130                         prefix,
 131                         timer_base_to_string(v->base),
 132                         strna(format_timespan(timespan1, sizeof(timespan1), v->value)));
 133 }
 134
 135 static void timer_set_state(Timer *t, TimerState state) {
 136         TimerState old_state;
 137         assert(t);
 138
 139         old_state = t->state;
 140         t->state = state;
 141
 142         if (state != TIMER_WAITING)
 143                 unit_unwatch_timer(UNIT(t), &t->timer_watch);
 144
 145         if (state != old_state)
 146                 log_debug("%s changed %s -> %s",
 147                           t->meta.id,
 148                           timer_state_to_string(old_state),
 149                           timer_state_to_string(state));
 150
 151         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state]);
 152 }
 153
 154 static void timer_enter_waiting(Timer *t, bool initial);
 155
 156 static int timer_coldplug(Unit *u) {
 157         Timer *t = TIMER(u);
 158
 159         assert(t);
 160         assert(t->state == TIMER_DEAD);
 161
 162         if (t->deserialized_state != t->state) {
 163
 164                 if (t->deserialized_state == TIMER_WAITING ||
 165                     t->deserialized_state == TIMER_RUNNING ||
 166                     t->deserialized_state == TIMER_ELAPSED)
 167                         timer_enter_waiting(t, false);
 168                 else
 169                         timer_set_state(t, t->deserialized_state);
 170         }
 171
 172         return 0;
 173 }
 174
 175 static void timer_enter_dead(Timer *t, bool success) {
 176         assert(t);
 177
 178         if (!success)
 179                 t->failure = true;
 180
 181         timer_set_state(t, t->failure ? TIMER_FAILED : TIMER_DEAD);
 182 }
 183
 184 static void timer_enter_waiting(Timer *t, bool initial) {
 185         TimerValue *v;
 186         usec_t base = 0, delay, n;
 187         bool found = false;
 188         int r;
 189
 190         n = now(CLOCK_MONOTONIC);
 191
 192         LIST_FOREACH(value, v, t->values) {
 193
 194                 if (v->disabled)
 195                         continue;
 196
 197                 switch (v->base) {
 198
 199                 case TIMER_ACTIVE:
 200                         if (state_translation_table[t->state] == UNIT_ACTIVE) {
 201                                 base = t->meta.inactive_exit_timestamp.monotonic;
 202                         } else
 203                                 base = n;
 204                         break;
 205
 206                 case TIMER_BOOT:
 207                         /* CLOCK_MONOTONIC equals the uptime on Linux */
 208                         base = 0;
 209                         break;
 210
 211                 case TIMER_STARTUP:
 212                         base = t->meta.manager->startup_timestamp.monotonic;
 213                         break;
 214
 215                 case TIMER_UNIT_ACTIVE:
 216
 217                         if (t->unit->meta.inactive_exit_timestamp.monotonic <= 0)
 218                                 continue;
 219
 220                         base = t->unit->meta.inactive_exit_timestamp.monotonic;
 221                         break;
 222
 223                 case TIMER_UNIT_INACTIVE:
 224
 225                         if (t->unit->meta.inactive_enter_timestamp.monotonic <= 0)
 226                                 continue;
 227
 228                         base = t->unit->meta.inactive_enter_timestamp.monotonic;
 229                         break;
 230
 231                 default:
 232                         assert_not_reached("Unknown timer base");
 233                 }
 234
 235                 v->next_elapse = base + v->value;
 236
 237                 if (!initial && v->next_elapse < n) {
 238                         v->disabled = true;
 239                         continue;
 240                 }
 241
 242                 if (!found)
 243                         t->next_elapse = v->next_elapse;
 244                 else
 245                         t->next_elapse = MIN(t->next_elapse, v->next_elapse);
 246
 247                 found = true;
 248         }
 249
 250         if (!found) {
 251                 timer_set_state(t, TIMER_ELAPSED);
 252                 return;
 253         }
 254
 255         delay = n < t->next_elapse ? t->next_elapse - n : 0;
 256
 257         if ((r = unit_watch_timer(UNIT(t), delay, &t->timer_watch)) < 0)
 258                 goto fail;
 259
 260         timer_set_state(t, TIMER_WAITING);
 261         return;
 262
 263 fail:
 264         log_warning("%s failed to enter waiting state: %s", t->meta.id, strerror(-r));
 265         timer_enter_dead(t, false);
 266 }
 267
 268 static void timer_enter_running(Timer *t) {
 269         DBusError error;
 270         int r;
 271
 272         assert(t);
 273         dbus_error_init(&error);
 274
 275         /* Don't start job if we are supposed to go down */
 276         if (t->meta.job && t->meta.job->type == JOB_STOP)
 277                 return;
 278
 279         if ((r = manager_add_job(t->meta.manager, JOB_START, t->unit, JOB_REPLACE, true, &error, NULL)) < 0)
 280                 goto fail;
 281
 282         timer_set_state(t, TIMER_RUNNING);
 283         return;
 284
 285 fail:
 286         log_warning("%s failed to queue unit startup job: %s", t->meta.id, bus_error(&error, r));
 287         timer_enter_dead(t, false);
 288
 289         dbus_error_free(&error);
 290 }
 291
 292 static int timer_start(Unit *u) {
 293         Timer *t = TIMER(u);
 294
 295         assert(t);
 296         assert(t->state == TIMER_DEAD || t->state == TIMER_FAILED);
 297
 298         if (t->unit->meta.load_state != UNIT_LOADED)
 299                 return -ENOENT;
 300
 301         t->failure = false;
 302         timer_enter_waiting(t, true);
 303         return 0;
 304 }
 305
 306 static int timer_stop(Unit *u) {
 307         Timer *t = TIMER(u);
 308
 309         assert(t);
 310         assert(t->state == TIMER_WAITING || t->state == TIMER_RUNNING || t->state == TIMER_ELAPSED);
 311
 312         timer_enter_dead(t, true);
 313         return 0;
 314 }
 315
 316 static int timer_serialize(Unit *u, FILE *f, FDSet *fds) {
 317         Timer *t = TIMER(u);
 318
 319         assert(u);
 320         assert(f);
 321         assert(fds);
 322
 323         unit_serialize_item(u, f, "state", timer_state_to_string(t->state));
 324
 325         return 0;
 326 }
 327
 328 static int timer_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 329         Timer *t = TIMER(u);
 330
 331         assert(u);
 332         assert(key);
 333         assert(value);
 334         assert(fds);
 335
 336         if (streq(key, "state")) {
 337                 TimerState state;
 338
 339                 if ((state = timer_state_from_string(value)) < 0)
 340                         log_debug("Failed to parse state value %s", value);
 341                 else
 342                         t->deserialized_state = state;
 343         } else
 344                 log_debug("Unknown serialization key '%s'", key);
 345
 346         return 0;
 347 }
 348
 349 static UnitActiveState timer_active_state(Unit *u) {
 350         assert(u);
 351
 352         return state_translation_table[TIMER(u)->state];
 353 }
 354
 355 static const char *timer_sub_state_to_string(Unit *u) {
 356         assert(u);
 357
 358         return timer_state_to_string(TIMER(u)->state);
 359 }
 360
 361 static void timer_timer_event(Unit *u, uint64_t elapsed, Watch *w) {
 362         Timer *t = TIMER(u);
 363
 364         assert(t);
 365         assert(elapsed == 1);
 366
 367         if (t->state != TIMER_WAITING)
 368                 return;
 369
 370         log_debug("Timer elapsed on %s", u->meta.id);
 371         timer_enter_running(t);
 372 }
 373
 374 void timer_unit_notify(Unit *u, UnitActiveState new_state) {
 375         char *n;
 376         int r;
 377         Iterator i;
 378
 379         if (u->meta.type == UNIT_TIMER)
 380                 return;
 381
 382         SET_FOREACH(n, u->meta.names, i) {
 383                 char *k;
 384                 Unit *p;
 385                 Timer *t;
 386                 TimerValue *v;
 387
 388                 if (!(k = unit_name_change_suffix(n, ".timer"))) {
 389                         r = -ENOMEM;
 390                         goto fail;
 391                 }
 392
 393                 p = manager_get_unit(u->meta.manager, k);
 394                 free(k);
 395
 396                 if (!p)
 397                         continue;
 398
 399                 if (p->meta.load_state != UNIT_LOADED)
 400                         continue;
 401
 402                 t = TIMER(p);
 403
 404                 if (t->unit != u)
 405                         continue;
 406
 407                 /* Reenable all timers that depend on unit state */
 408                 LIST_FOREACH(value, v, t->values)
 409                         if (v->base == TIMER_UNIT_ACTIVE ||
 410                             v->base == TIMER_UNIT_INACTIVE)
 411                                 v->disabled = false;
 412
 413                 switch (t->state) {
 414
 415                 case TIMER_WAITING:
 416                 case TIMER_ELAPSED:
 417
 418                         /* Recalculate sleep time */
 419                         timer_enter_waiting(t, false);
 420                         break;
 421
 422                 case TIMER_RUNNING:
 423
 424                         if (UNIT_IS_INACTIVE_OR_FAILED(new_state)) {
 425                                 log_debug("%s got notified about unit deactivation.", t->meta.id);
 426                                 timer_enter_waiting(t, false);
 427                         }
 428
 429                         break;
 430
 431                 case TIMER_DEAD:
 432                 case TIMER_FAILED:
 433                         ;
 434
 435                 default:
 436                         assert_not_reached("Unknown timer state");
 437                 }
 438         }
 439
 440         return;
 441
 442 fail:
 443         log_error("Failed find timer unit: %s", strerror(-r));
 444 }
 445
 446 static void timer_reset_failed(Unit *u) {
 447         Timer *t = TIMER(u);
 448
 449         assert(t);
 450
 451         if (t->state == TIMER_FAILED)
 452                 timer_set_state(t, TIMER_DEAD);
 453
 454         t->failure = false;
 455 }
 456
 457 static const char* const timer_state_table[_TIMER_STATE_MAX] = {
 458         [TIMER_DEAD] = "dead",
 459         [TIMER_WAITING] = "waiting",
 460         [TIMER_RUNNING] = "running",
 461         [TIMER_ELAPSED] = "elapsed",
 462         [TIMER_FAILED] = "failed"
 463 };
 464
 465 DEFINE_STRING_TABLE_LOOKUP(timer_state, TimerState);
 466
 467 static const char* const timer_base_table[_TIMER_BASE_MAX] = {
 468         [TIMER_ACTIVE] = "OnActiveSec",
 469         [TIMER_BOOT] = "OnBootSec",
 470         [TIMER_STARTUP] = "OnStartupSec",
 471         [TIMER_UNIT_ACTIVE] = "OnUnitActiveSec",
 472         [TIMER_UNIT_INACTIVE] = "OnUnitInactiveSec"
 473 };
 474
 475 DEFINE_STRING_TABLE_LOOKUP(timer_base, TimerBase);
 476
 477 const UnitVTable timer_vtable = {
 478         .suffix = ".timer",
 479
 480         .init = timer_init,
 481         .done = timer_done,
 482         .load = timer_load,
 483
 484         .coldplug = timer_coldplug,
 485
 486         .dump = timer_dump,
 487
 488         .start = timer_start,
 489         .stop = timer_stop,
 490
 491         .serialize = timer_serialize,
 492         .deserialize_item = timer_deserialize_item,
 493
 494         .active_state = timer_active_state,
 495         .sub_state_to_string = timer_sub_state_to_string,
 496
 497         .timer_event = timer_timer_event,
 498
 499         .reset_failed = timer_reset_failed,
 500
 501         .bus_interface = "org.freedesktop.systemd1.Timer",
 502         .bus_message_handler = bus_timer_message_handler,
 503         .bus_invalidating_properties =  bus_timer_invalidating_properties
 504 };