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_dependency_by_name(UNIT(t), UNIT_BEFORE, SPECIAL_BASIC_TARGET, NULL, true)) < 0)
  83                         return r;
  84
  85                 if ((r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true)) < 0)
  86                         return r;
  87         }
  88
  89         return unit_add_two_dependencies_by_name(UNIT(t), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true);
  90 }
  91
  92 static int timer_load(Unit *u) {
  93         Timer *t = TIMER(u);
  94         int r;
  95
  96         assert(u);
  97         assert(u->meta.load_state == UNIT_STUB);
  98
  99         if ((r = unit_load_fragment_and_dropin(u)) < 0)
 100                 return r;
 101
 102         if (u->meta.load_state == UNIT_LOADED) {
 103
 104                 if (!t->unit)
 105                         if ((r = unit_load_related_unit(u, ".service", &t->unit)))
 106                                 return r;
 107
 108                 if ((r = unit_add_dependency(u, UNIT_BEFORE, t->unit, true)) < 0)
 109                         return r;
 110
 111                 if (t->meta.default_dependencies)
 112                         if ((r = timer_add_default_dependencies(t)) < 0)
 113                                 return r;
 114         }
 115
 116         return timer_verify(t);
 117 }
 118
 119 static void timer_dump(Unit *u, FILE *f, const char *prefix) {
 120         Timer *t = TIMER(u);
 121         TimerValue *v;
 122         char
 123                 timespan1[FORMAT_TIMESPAN_MAX];
 124
 125         fprintf(f,
 126                 "%sTimer State: %s\n"
 127                 "%sUnit: %s\n",
 128                 prefix, timer_state_to_string(t->state),
 129                 prefix, t->unit->meta.id);
 130
 131         LIST_FOREACH(value, v, t->values)
 132                 fprintf(f,
 133                         "%s%s: %s\n",
 134                         prefix,
 135                         timer_base_to_string(v->base),
 136                         strna(format_timespan(timespan1, sizeof(timespan1), v->value)));
 137 }
 138
 139 static void timer_set_state(Timer *t, TimerState state) {
 140         TimerState old_state;
 141         assert(t);
 142
 143         old_state = t->state;
 144         t->state = state;
 145
 146         if (state != TIMER_WAITING)
 147                 unit_unwatch_timer(UNIT(t), &t->timer_watch);
 148
 149         if (state != old_state)
 150                 log_debug("%s changed %s -> %s",
 151                           t->meta.id,
 152                           timer_state_to_string(old_state),
 153                           timer_state_to_string(state));
 154
 155         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], true);
 156 }
 157
 158 static void timer_enter_waiting(Timer *t, bool initial);
 159
 160 static int timer_coldplug(Unit *u) {
 161         Timer *t = TIMER(u);
 162
 163         assert(t);
 164         assert(t->state == TIMER_DEAD);
 165
 166         if (t->deserialized_state != t->state) {
 167
 168                 if (t->deserialized_state == TIMER_WAITING)
 169                         timer_enter_waiting(t, false);
 170                 else
 171                         timer_set_state(t, t->deserialized_state);
 172         }
 173
 174         return 0;
 175 }
 176
 177 static void timer_enter_dead(Timer *t, bool success) {
 178         assert(t);
 179
 180         if (!success)
 181                 t->failure = true;
 182
 183         timer_set_state(t, t->failure ? TIMER_FAILED : TIMER_DEAD);
 184 }
 185
 186 static void timer_enter_waiting(Timer *t, bool initial) {
 187         TimerValue *v;
 188         usec_t base = 0, delay, n;
 189         bool found = false;
 190         int r;
 191
 192         n = now(CLOCK_MONOTONIC);
 193
 194         LIST_FOREACH(value, v, t->values) {
 195
 196                 if (v->disabled)
 197                         continue;
 198
 199                 switch (v->base) {
 200
 201                 case TIMER_ACTIVE:
 202                         if (state_translation_table[t->state] == UNIT_ACTIVE)
 203                                 base = t->meta.inactive_exit_timestamp.monotonic;
 204                         else
 205                                 base = n;
 206                         break;
 207
 208                 case TIMER_BOOT:
 209                         /* CLOCK_MONOTONIC equals the uptime on Linux */
 210                         base = 0;
 211                         break;
 212
 213                 case TIMER_STARTUP:
 214                         base = t->meta.manager->startup_timestamp.monotonic;
 215                         break;
 216
 217                 case TIMER_UNIT_ACTIVE:
 218
 219                         if (t->unit->meta.inactive_exit_timestamp.monotonic <= 0)
 220                                 continue;
 221
 222                         base = t->unit->meta.inactive_exit_timestamp.monotonic;
 223                         break;
 224
 225                 case TIMER_UNIT_INACTIVE:
 226
 227                         if (t->unit->meta.inactive_enter_timestamp.monotonic <= 0)
 228                                 continue;
 229
 230                         base = t->unit->meta.inactive_enter_timestamp.monotonic;
 231                         break;
 232
 233                 default:
 234                         assert_not_reached("Unknown timer base");
 235                 }
 236
 237                 v->next_elapse = base + v->value;
 238
 239                 if (!initial && v->next_elapse < n) {
 240                         v->disabled = true;
 241                         continue;
 242                 }
 243
 244                 if (!found)
 245                         t->next_elapse = v->next_elapse;
 246                 else
 247                         t->next_elapse = MIN(t->next_elapse, v->next_elapse);
 248
 249                 found = true;
 250         }
 251
 252         if (!found) {
 253                 timer_set_state(t, TIMER_ELAPSED);
 254                 return;
 255         }
 256
 257         delay = n < t->next_elapse ? t->next_elapse - n : 0;
 258
 259         if ((r = unit_watch_timer(UNIT(t), delay, &t->timer_watch)) < 0)
 260                 goto fail;
 261
 262         timer_set_state(t, TIMER_WAITING);
 263         return;
 264
 265 fail:
 266         log_warning("%s failed to enter waiting state: %s", t->meta.id, strerror(-r));
 267         timer_enter_dead(t, false);
 268 }
 269
 270 static void timer_enter_running(Timer *t) {
 271         DBusError error;
 272         int r;
 273
 274         assert(t);
 275         dbus_error_init(&error);
 276
 277         /* Don't start job if we are supposed to go down */
 278         if (t->meta.job && t->meta.job->type == JOB_STOP)
 279                 return;
 280
 281         if ((r = manager_add_job(t->meta.manager, JOB_START, t->unit, JOB_REPLACE, true, &error, NULL)) < 0)
 282                 goto fail;
 283
 284         timer_set_state(t, TIMER_RUNNING);
 285         return;
 286
 287 fail:
 288         log_warning("%s failed to queue unit startup job: %s", t->meta.id, bus_error(&error, r));
 289         timer_enter_dead(t, false);
 290
 291         dbus_error_free(&error);
 292 }
 293
 294 static int timer_start(Unit *u) {
 295         Timer *t = TIMER(u);
 296
 297         assert(t);
 298         assert(t->state == TIMER_DEAD || t->state == TIMER_FAILED);
 299
 300         if (t->unit->meta.load_state != UNIT_LOADED)
 301                 return -ENOENT;
 302
 303         t->failure = false;
 304         timer_enter_waiting(t, true);
 305         return 0;
 306 }
 307
 308 static int timer_stop(Unit *u) {
 309         Timer *t = TIMER(u);
 310
 311         assert(t);
 312         assert(t->state == TIMER_WAITING || t->state == TIMER_RUNNING || t->state == TIMER_ELAPSED);
 313
 314         timer_enter_dead(t, true);
 315         return 0;
 316 }
 317
 318 static int timer_serialize(Unit *u, FILE *f, FDSet *fds) {
 319         Timer *t = TIMER(u);
 320
 321         assert(u);
 322         assert(f);
 323         assert(fds);
 324
 325         unit_serialize_item(u, f, "state", timer_state_to_string(t->state));
 326
 327         return 0;
 328 }
 329
 330 static int timer_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 331         Timer *t = TIMER(u);
 332
 333         assert(u);
 334         assert(key);
 335         assert(value);
 336         assert(fds);
 337
 338         if (streq(key, "state")) {
 339                 TimerState state;
 340
 341                 if ((state = timer_state_from_string(value)) < 0)
 342                         log_debug("Failed to parse state value %s", value);
 343                 else
 344                         t->deserialized_state = state;
 345         } else
 346                 log_debug("Unknown serialization key '%s'", key);
 347
 348         return 0;
 349 }
 350
 351 static UnitActiveState timer_active_state(Unit *u) {
 352         assert(u);
 353
 354         return state_translation_table[TIMER(u)->state];
 355 }
 356
 357 static const char *timer_sub_state_to_string(Unit *u) {
 358         assert(u);
 359
 360         return timer_state_to_string(TIMER(u)->state);
 361 }
 362
 363 static void timer_timer_event(Unit *u, uint64_t elapsed, Watch *w) {
 364         Timer *t = TIMER(u);
 365
 366         assert(t);
 367         assert(elapsed == 1);
 368
 369         if (t->state != TIMER_WAITING)
 370                 return;
 371
 372         log_debug("Timer elapsed on %s", u->meta.id);
 373         timer_enter_running(t);
 374 }
 375
 376 void timer_unit_notify(Unit *u, UnitActiveState new_state) {
 377         char *n;
 378         int r;
 379         Iterator i;
 380
 381         if (u->meta.type == UNIT_TIMER)
 382                 return;
 383
 384         SET_FOREACH(n, u->meta.names, i) {
 385                 char *k;
 386                 Unit *p;
 387                 Timer *t;
 388                 TimerValue *v;
 389
 390                 if (!(k = unit_name_change_suffix(n, ".timer"))) {
 391                         r = -ENOMEM;
 392                         goto fail;
 393                 }
 394
 395                 p = manager_get_unit(u->meta.manager, k);
 396                 free(k);
 397
 398                 if (!p)
 399                         continue;
 400
 401                 if (p->meta.load_state != UNIT_LOADED)
 402                         continue;
 403
 404                 t = TIMER(p);
 405
 406                 if (t->unit != u)
 407                         continue;
 408
 409                 /* Reenable all timers that depend on unit state */
 410                 LIST_FOREACH(value, v, t->values)
 411                         if (v->base == TIMER_UNIT_ACTIVE ||
 412                             v->base == TIMER_UNIT_INACTIVE)
 413                                 v->disabled = false;
 414
 415                 switch (t->state) {
 416
 417                 case TIMER_WAITING:
 418                 case TIMER_ELAPSED:
 419
 420                         /* Recalculate sleep time */
 421                         timer_enter_waiting(t, false);
 422                         break;
 423
 424                 case TIMER_RUNNING:
 425
 426                         if (UNIT_IS_INACTIVE_OR_FAILED(new_state)) {
 427                                 log_debug("%s got notified about unit deactivation.", t->meta.id);
 428                                 timer_enter_waiting(t, false);
 429                         }
 430
 431                         break;
 432
 433                 case TIMER_DEAD:
 434                 case TIMER_FAILED:
 435                         break;
 436
 437                 default:
 438                         assert_not_reached("Unknown timer state");
 439                 }
 440         }
 441
 442         return;
 443
 444 fail:
 445         log_error("Failed find timer unit: %s", strerror(-r));
 446 }
 447
 448 static void timer_reset_failed(Unit *u) {
 449         Timer *t = TIMER(u);
 450
 451         assert(t);
 452
 453         if (t->state == TIMER_FAILED)
 454                 timer_set_state(t, TIMER_DEAD);
 455
 456         t->failure = false;
 457 }
 458
 459 static const char* const timer_state_table[_TIMER_STATE_MAX] = {
 460         [TIMER_DEAD] = "dead",
 461         [TIMER_WAITING] = "waiting",
 462         [TIMER_RUNNING] = "running",
 463         [TIMER_ELAPSED] = "elapsed",
 464         [TIMER_FAILED] = "failed"
 465 };
 466
 467 DEFINE_STRING_TABLE_LOOKUP(timer_state, TimerState);
 468
 469 static const char* const timer_base_table[_TIMER_BASE_MAX] = {
 470         [TIMER_ACTIVE] = "OnActiveSec",
 471         [TIMER_BOOT] = "OnBootSec",
 472         [TIMER_STARTUP] = "OnStartupSec",
 473         [TIMER_UNIT_ACTIVE] = "OnUnitActiveSec",
 474         [TIMER_UNIT_INACTIVE] = "OnUnitInactiveSec"
 475 };
 476
 477 DEFINE_STRING_TABLE_LOOKUP(timer_base, TimerBase);
 478
 479 const UnitVTable timer_vtable = {
 480         .suffix = ".timer",
 481
 482         .init = timer_init,
 483         .done = timer_done,
 484         .load = timer_load,
 485
 486         .coldplug = timer_coldplug,
 487
 488         .dump = timer_dump,
 489
 490         .start = timer_start,
 491         .stop = timer_stop,
 492
 493         .serialize = timer_serialize,
 494         .deserialize_item = timer_deserialize_item,
 495
 496         .active_state = timer_active_state,
 497         .sub_state_to_string = timer_sub_state_to_string,
 498
 499         .timer_event = timer_timer_event,
 500
 501         .reset_failed = timer_reset_failed,
 502
 503         .bus_interface = "org.freedesktop.systemd1.Timer",
 504         .bus_message_handler = bus_timer_message_handler,
 505         .bus_invalidating_properties =  bus_timer_invalidating_properties
 506 };