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