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