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->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 (UNIT(t)->load_state != UNIT_LOADED)
  68                 return 0;
  69
  70         if (!t->values) {
  71                 log_error("%s lacks value setting. Refusing.", UNIT(t)->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 (UNIT(t)->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->load_state == UNIT_STUB);
 100
 101         if ((r = unit_load_fragment_and_dropin(u)) < 0)
 102                 return r;
 103
 104         if (u->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 (UNIT(t)->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                 "%sResult: %s\n"
 137                 "%sUnit: %s\n",
 138                 prefix, timer_state_to_string(t->state),
 139                 prefix, timer_result_to_string(t->result),
 140                 prefix, UNIT_DEREF(t->unit)->id);
 141
 142         LIST_FOREACH(value, v, t->values)
 143                 fprintf(f,
 144                         "%s%s: %s\n",
 145                         prefix,
 146                         timer_base_to_string(v->base),
 147                         strna(format_timespan(timespan1, sizeof(timespan1), v->value)));
 148 }
 149
 150 static void timer_set_state(Timer *t, TimerState state) {
 151         TimerState old_state;
 152         assert(t);
 153
 154         old_state = t->state;
 155         t->state = state;
 156
 157         if (state != TIMER_WAITING)
 158                 unit_unwatch_timer(UNIT(t), &t->timer_watch);
 159
 160         if (state != old_state)
 161                 log_debug("%s changed %s -> %s",
 162                           UNIT(t)->id,
 163                           timer_state_to_string(old_state),
 164                           timer_state_to_string(state));
 165
 166         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], true);
 167 }
 168
 169 static void timer_enter_waiting(Timer *t, bool initial);
 170
 171 static int timer_coldplug(Unit *u) {
 172         Timer *t = TIMER(u);
 173
 174         assert(t);
 175         assert(t->state == TIMER_DEAD);
 176
 177         if (t->deserialized_state != t->state) {
 178
 179                 if (t->deserialized_state == TIMER_WAITING)
 180                         timer_enter_waiting(t, false);
 181                 else
 182                         timer_set_state(t, t->deserialized_state);
 183         }
 184
 185         return 0;
 186 }
 187
 188 static void timer_enter_dead(Timer *t, TimerResult f) {
 189         assert(t);
 190
 191         if (f != TIMER_SUCCESS)
 192                 t->result = f;
 193
 194         timer_set_state(t, t->result != TIMER_SUCCESS ? TIMER_FAILED : TIMER_DEAD);
 195 }
 196
 197 static void timer_enter_waiting(Timer *t, bool initial) {
 198         TimerValue *v;
 199         usec_t base = 0, delay, n;
 200         bool found = false;
 201         int r;
 202
 203         n = now(CLOCK_MONOTONIC);
 204
 205         LIST_FOREACH(value, v, t->values) {
 206
 207                 if (v->disabled)
 208                         continue;
 209
 210                 switch (v->base) {
 211
 212                 case TIMER_ACTIVE:
 213                         if (state_translation_table[t->state] == UNIT_ACTIVE)
 214                                 base = UNIT(t)->inactive_exit_timestamp.monotonic;
 215                         else
 216                                 base = n;
 217                         break;
 218
 219                 case TIMER_BOOT:
 220                         /* CLOCK_MONOTONIC equals the uptime on Linux */
 221                         base = 0;
 222                         break;
 223
 224                 case TIMER_STARTUP:
 225                         base = UNIT(t)->manager->startup_timestamp.monotonic;
 226                         break;
 227
 228                 case TIMER_UNIT_ACTIVE:
 229
 230                         if (UNIT_DEREF(t->unit)->inactive_exit_timestamp.monotonic <= 0)
 231                                 continue;
 232
 233                         base = UNIT_DEREF(t->unit)->inactive_exit_timestamp.monotonic;
 234                         break;
 235
 236                 case TIMER_UNIT_INACTIVE:
 237
 238                         if (UNIT_DEREF(t->unit)->inactive_enter_timestamp.monotonic <= 0)
 239                                 continue;
 240
 241                         base = UNIT_DEREF(t->unit)->inactive_enter_timestamp.monotonic;
 242                         break;
 243
 244                 default:
 245                         assert_not_reached("Unknown timer base");
 246                 }
 247
 248                 v->next_elapse = base + v->value;
 249
 250                 if (!initial && v->next_elapse < n) {
 251                         v->disabled = true;
 252                         continue;
 253                 }
 254
 255                 if (!found)
 256                         t->next_elapse = v->next_elapse;
 257                 else
 258                         t->next_elapse = MIN(t->next_elapse, v->next_elapse);
 259
 260                 found = true;
 261         }
 262
 263         if (!found) {
 264                 timer_set_state(t, TIMER_ELAPSED);
 265                 return;
 266         }
 267
 268         delay = n < t->next_elapse ? t->next_elapse - n : 0;
 269
 270         if ((r = unit_watch_timer(UNIT(t), delay, &t->timer_watch)) < 0)
 271                 goto fail;
 272
 273         timer_set_state(t, TIMER_WAITING);
 274         return;
 275
 276 fail:
 277         log_warning("%s failed to enter waiting state: %s", UNIT(t)->id, strerror(-r));
 278         timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 279 }
 280
 281 static void timer_enter_running(Timer *t) {
 282         DBusError error;
 283         int r;
 284
 285         assert(t);
 286         dbus_error_init(&error);
 287
 288         /* Don't start job if we are supposed to go down */
 289         if (UNIT(t)->job && UNIT(t)->job->type == JOB_STOP)
 290                 return;
 291
 292         if ((r = manager_add_job(UNIT(t)->manager, JOB_START, UNIT_DEREF(t->unit), JOB_REPLACE, true, &error, NULL)) < 0)
 293                 goto fail;
 294
 295         timer_set_state(t, TIMER_RUNNING);
 296         return;
 297
 298 fail:
 299         log_warning("%s failed to queue unit startup job: %s", UNIT(t)->id, bus_error(&error, r));
 300         timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
 301
 302         dbus_error_free(&error);
 303 }
 304
 305 static int timer_start(Unit *u) {
 306         Timer *t = TIMER(u);
 307
 308         assert(t);
 309         assert(t->state == TIMER_DEAD || t->state == TIMER_FAILED);
 310
 311         if (UNIT_DEREF(t->unit)->load_state != UNIT_LOADED)
 312                 return -ENOENT;
 313
 314         t->result = TIMER_SUCCESS;
 315         timer_enter_waiting(t, true);
 316         return 0;
 317 }
 318
 319 static int timer_stop(Unit *u) {
 320         Timer *t = TIMER(u);
 321
 322         assert(t);
 323         assert(t->state == TIMER_WAITING || t->state == TIMER_RUNNING || t->state == TIMER_ELAPSED);
 324
 325         timer_enter_dead(t, TIMER_SUCCESS);
 326         return 0;
 327 }
 328
 329 static int timer_serialize(Unit *u, FILE *f, FDSet *fds) {
 330         Timer *t = TIMER(u);
 331
 332         assert(u);
 333         assert(f);
 334         assert(fds);
 335
 336         unit_serialize_item(u, f, "state", timer_state_to_string(t->state));
 337         unit_serialize_item(u, f, "result", timer_result_to_string(t->result));
 338
 339         return 0;
 340 }
 341
 342 static int timer_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 343         Timer *t = TIMER(u);
 344
 345         assert(u);
 346         assert(key);
 347         assert(value);
 348         assert(fds);
 349
 350         if (streq(key, "state")) {
 351                 TimerState state;
 352
 353                 if ((state = timer_state_from_string(value)) < 0)
 354                         log_debug("Failed to parse state value %s", value);
 355                 else
 356                         t->deserialized_state = state;
 357         } else if (streq(key, "result")) {
 358                 TimerResult f;
 359
 360                 f = timer_result_from_string(value);
 361                 if (f < 0)
 362                         log_debug("Failed to parse result value %s", value);
 363                 else if (f != TIMER_SUCCESS)
 364                         t->result = f;
 365
 366         } else
 367                 log_debug("Unknown serialization key '%s'", key);
 368
 369         return 0;
 370 }
 371
 372 static UnitActiveState timer_active_state(Unit *u) {
 373         assert(u);
 374
 375         return state_translation_table[TIMER(u)->state];
 376 }
 377
 378 static const char *timer_sub_state_to_string(Unit *u) {
 379         assert(u);
 380
 381         return timer_state_to_string(TIMER(u)->state);
 382 }
 383
 384 static void timer_timer_event(Unit *u, uint64_t elapsed, Watch *w) {
 385         Timer *t = TIMER(u);
 386
 387         assert(t);
 388         assert(elapsed == 1);
 389
 390         if (t->state != TIMER_WAITING)
 391                 return;
 392
 393         log_debug("Timer elapsed on %s", u->id);
 394         timer_enter_running(t);
 395 }
 396
 397 void timer_unit_notify(Unit *u, UnitActiveState new_state) {
 398         Iterator i;
 399         Unit *k;
 400
 401         if (u->type == UNIT_TIMER)
 402                 return;
 403
 404         SET_FOREACH(k, u->dependencies[UNIT_TRIGGERED_BY], i) {
 405                 Timer *t;
 406                 TimerValue *v;
 407
 408                 if (k->type != UNIT_TIMER)
 409                         continue;
 410
 411                 if (k->load_state != UNIT_LOADED)
 412                         continue;
 413
 414                 t = TIMER(k);
 415
 416                 /* Reenable all timers that depend on unit state */
 417                 LIST_FOREACH(value, v, t->values)
 418                         if (v->base == TIMER_UNIT_ACTIVE ||
 419                             v->base == TIMER_UNIT_INACTIVE)
 420                                 v->disabled = false;
 421
 422                 switch (t->state) {
 423
 424                 case TIMER_WAITING:
 425                 case TIMER_ELAPSED:
 426
 427                         /* Recalculate sleep time */
 428                         timer_enter_waiting(t, false);
 429                         break;
 430
 431                 case TIMER_RUNNING:
 432
 433                         if (UNIT_IS_INACTIVE_OR_FAILED(new_state)) {
 434                                 log_debug("%s got notified about unit deactivation.", UNIT(t)->id);
 435                                 timer_enter_waiting(t, false);
 436                         }
 437
 438                         break;
 439
 440                 case TIMER_DEAD:
 441                 case TIMER_FAILED:
 442                         break;
 443
 444                 default:
 445                         assert_not_reached("Unknown timer state");
 446                 }
 447         }
 448 }
 449
 450 static void timer_reset_failed(Unit *u) {
 451         Timer *t = TIMER(u);
 452
 453         assert(t);
 454
 455         if (t->state == TIMER_FAILED)
 456                 timer_set_state(t, TIMER_DEAD);
 457
 458         t->result = TIMER_SUCCESS;
 459 }
 460
 461 static const char* const timer_state_table[_TIMER_STATE_MAX] = {
 462         [TIMER_DEAD] = "dead",
 463         [TIMER_WAITING] = "waiting",
 464         [TIMER_RUNNING] = "running",
 465         [TIMER_ELAPSED] = "elapsed",
 466         [TIMER_FAILED] = "failed"
 467 };
 468
 469 DEFINE_STRING_TABLE_LOOKUP(timer_state, TimerState);
 470
 471 static const char* const timer_base_table[_TIMER_BASE_MAX] = {
 472         [TIMER_ACTIVE] = "OnActiveSec",
 473         [TIMER_BOOT] = "OnBootSec",
 474         [TIMER_STARTUP] = "OnStartupSec",
 475         [TIMER_UNIT_ACTIVE] = "OnUnitActiveSec",
 476         [TIMER_UNIT_INACTIVE] = "OnUnitInactiveSec"
 477 };
 478
 479 DEFINE_STRING_TABLE_LOOKUP(timer_base, TimerBase);
 480
 481 static const char* const timer_result_table[_TIMER_RESULT_MAX] = {
 482         [TIMER_SUCCESS] = "success",
 483         [TIMER_FAILURE_RESOURCES] = "resources"
 484 };
 485
 486 DEFINE_STRING_TABLE_LOOKUP(timer_result, TimerResult);
 487
 488 const UnitVTable timer_vtable = {
 489         .suffix = ".timer",
 490         .object_size = sizeof(Timer),
 491         .sections =
 492                 "Unit\0"
 493                 "Timer\0"
 494                 "Install\0",
 495
 496         .init = timer_init,
 497         .done = timer_done,
 498         .load = timer_load,
 499
 500         .coldplug = timer_coldplug,
 501
 502         .dump = timer_dump,
 503
 504         .start = timer_start,
 505         .stop = timer_stop,
 506
 507         .serialize = timer_serialize,
 508         .deserialize_item = timer_deserialize_item,
 509
 510         .active_state = timer_active_state,
 511         .sub_state_to_string = timer_sub_state_to_string,
 512
 513         .timer_event = timer_timer_event,
 514
 515         .reset_failed = timer_reset_failed,
 516
 517         .bus_interface = "org.freedesktop.systemd1.Timer",
 518         .bus_message_handler = bus_timer_message_handler,
 519         .bus_invalidating_properties =  bus_timer_invalidating_properties
 520 };