src/timer.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   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
  29 static const UnitActiveState state_translation_table[_TIMER_STATE_MAX] = {
  30         [TIMER_DEAD] = UNIT_INACTIVE,
  31         [TIMER_WAITING] = UNIT_ACTIVE,
  32         [TIMER_RUNNING] = UNIT_ACTIVE,
  33         [TIMER_ELAPSED] = UNIT_ACTIVE,
  34         [TIMER_MAINTENANCE] = UNIT_MAINTENANCE
  35 };
  36
  37 static void timer_init(Unit *u) {
  38         Timer *t = TIMER(u);
  39
  40         assert(u);
  41         assert(u->meta.load_state == UNIT_STUB);
  42
  43         t->next_elapse = (usec_t) -1;
  44 }
  45
  46 static void timer_done(Unit *u) {
  47         Timer *t = TIMER(u);
  48         TimerValue *v;
  49
  50         assert(t);
  51
  52         while ((v = t->values)) {
  53                 LIST_REMOVE(TimerValue, value, t->values, v);
  54                 free(v);
  55         }
  56
  57         unit_unwatch_timer(u, &t->timer_watch);
  58 }
  59
  60 static int timer_verify(Timer *t) {
  61         assert(t);
  62
  63         if (t->meta.load_state != UNIT_LOADED)
  64                 return 0;
  65
  66         if (!t->values) {
  67                 log_error("%s lacks value setting. Refusing.", t->meta.id);
  68                 return -EINVAL;
  69         }
  70
  71         return 0;
  72 }
  73
  74 static int timer_load(Unit *u) {
  75         Timer *t = TIMER(u);
  76         int r;
  77
  78         assert(u);
  79         assert(u->meta.load_state == UNIT_STUB);
  80
  81         if ((r = unit_load_fragment_and_dropin(u)) < 0)
  82                 return r;
  83
  84         if (u->meta.load_state == UNIT_LOADED) {
  85
  86                 if (!t->unit)
  87                         if ((r = unit_load_related_unit(u, ".service", &t->unit)))
  88                                 return r;
  89
  90                 if ((r = unit_add_dependency(u, UNIT_BEFORE, t->unit, true)) < 0)
  91                         return r;
  92         }
  93
  94         return timer_verify(t);
  95 }
  96
  97 static void timer_dump(Unit *u, FILE *f, const char *prefix) {
  98         Timer *t = TIMER(u);
  99         const char *prefix2;
 100         char *p2;
 101         TimerValue *v;
 102         char
 103                 timespan1[FORMAT_TIMESPAN_MAX];
 104
 105         p2 = strappend(prefix, "\t");
 106         prefix2 = p2 ? p2 : prefix;
 107
 108         fprintf(f,
 109                 "%sTimer State: %s\n"
 110                 "%sUnit: %s\n",
 111                 prefix, timer_state_to_string(t->state),
 112                 prefix, t->unit->meta.id);
 113
 114         LIST_FOREACH(value, v, t->values)
 115                 fprintf(f,
 116                         "%s%s: %s\n",
 117                         prefix,
 118                         timer_base_to_string(v->base),
 119                         strna(format_timespan(timespan1, sizeof(timespan1), v->value)));
 120
 121         free(p2);
 122 }
 123
 124 static void timer_set_state(Timer *t, TimerState state) {
 125         TimerState old_state;
 126         assert(t);
 127
 128         old_state = t->state;
 129         t->state = state;
 130
 131         if (state != TIMER_WAITING)
 132                 unit_unwatch_timer(UNIT(t), &t->timer_watch);
 133
 134         if (state != old_state)
 135                 log_debug("%s changed %s -> %s",
 136                           t->meta.id,
 137                           timer_state_to_string(old_state),
 138                           timer_state_to_string(state));
 139
 140         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state]);
 141 }
 142
 143 static void timer_enter_waiting(Timer *t, bool initial);
 144
 145 static int timer_coldplug(Unit *u) {
 146         Timer *t = TIMER(u);
 147
 148         assert(t);
 149         assert(t->state == TIMER_DEAD);
 150
 151         if (t->deserialized_state != t->state) {
 152
 153                 if (t->deserialized_state == TIMER_WAITING ||
 154                     t->deserialized_state == TIMER_RUNNING ||
 155                     t->deserialized_state == TIMER_ELAPSED)
 156                         timer_enter_waiting(t, false);
 157                 else
 158                         timer_set_state(t, t->deserialized_state);
 159         }
 160
 161         return 0;
 162 }
 163
 164 static void timer_enter_dead(Timer *t, bool success) {
 165         assert(t);
 166
 167         if (!success)
 168                 t->failure = true;
 169
 170         timer_set_state(t, t->failure ? TIMER_MAINTENANCE : TIMER_DEAD);
 171 }
 172
 173 static void timer_enter_waiting(Timer *t, bool initial) {
 174         TimerValue *v;
 175         usec_t base = 0, delay, n;
 176         bool found = false;
 177         int r;
 178
 179         n = now(CLOCK_MONOTONIC);
 180
 181         LIST_FOREACH(value, v, t->values) {
 182
 183                 if (v->disabled)
 184                         continue;
 185
 186                 switch (v->base) {
 187
 188                 case TIMER_ACTIVE:
 189                         if (state_translation_table[t->state] == UNIT_ACTIVE) {
 190                                 base = t->meta.inactive_exit_timestamp.monotonic;
 191                         } else
 192                                 base = n;
 193                         break;
 194
 195                 case TIMER_BOOT:
 196                         /* CLOCK_MONOTONIC equals the uptime on Linux */
 197                         base = 0;
 198                         break;
 199
 200                 case TIMER_STARTUP:
 201                         base = t->meta.manager->startup_timestamp.monotonic;
 202                         break;
 203
 204                 case TIMER_UNIT_ACTIVE:
 205
 206                         if (t->unit->meta.inactive_exit_timestamp.monotonic <= 0)
 207                                 continue;
 208
 209                         base = t->unit->meta.inactive_exit_timestamp.monotonic;
 210                         break;
 211
 212                 case TIMER_UNIT_INACTIVE:
 213
 214                         if (t->unit->meta.inactive_enter_timestamp.monotonic <= 0)
 215                                 continue;
 216
 217                         base = t->unit->meta.inactive_enter_timestamp.monotonic;
 218                         break;
 219
 220                 default:
 221                         assert_not_reached("Unknown timer base");
 222                 }
 223
 224                 v->next_elapse = base + v->value;
 225
 226                 if (!initial && v->next_elapse < n) {
 227                         v->disabled = true;
 228                         continue;
 229                 }
 230
 231                 if (!found)
 232                         t->next_elapse = v->next_elapse;
 233                 else
 234                         t->next_elapse = MIN(t->next_elapse, v->next_elapse);
 235
 236                 found = true;
 237         }
 238
 239         if (!found) {
 240                 timer_set_state(t, TIMER_ELAPSED);
 241                 return;
 242         }
 243
 244         delay = n < t->next_elapse ? t->next_elapse - n : 0;
 245
 246         if ((r = unit_watch_timer(UNIT(t), delay, &t->timer_watch)) < 0)
 247                 goto fail;
 248
 249         timer_set_state(t, TIMER_WAITING);
 250         return;
 251
 252 fail:
 253         log_warning("%s failed to enter waiting state: %s", t->meta.id, strerror(-r));
 254         timer_enter_dead(t, false);
 255 }
 256
 257 static void timer_enter_running(Timer *t) {
 258         int r;
 259         assert(t);
 260
 261         if ((r = manager_add_job(t->meta.manager, JOB_START, t->unit, JOB_REPLACE, true, NULL)) < 0)
 262                 goto fail;
 263
 264         timer_set_state(t, TIMER_RUNNING);
 265         return;
 266
 267 fail:
 268         log_warning("%s failed to queue unit startup job: %s", t->meta.id, strerror(-r));
 269         timer_enter_dead(t, false);
 270 }
 271
 272 static int timer_start(Unit *u) {
 273         Timer *t = TIMER(u);
 274
 275         assert(t);
 276         assert(t->state == TIMER_DEAD || t->state == TIMER_MAINTENANCE);
 277
 278         if (t->unit->meta.load_state != UNIT_LOADED)
 279                 return -ENOENT;
 280
 281         t->failure = false;
 282         timer_enter_waiting(t, true);
 283         return 0;
 284 }
 285
 286 static int timer_stop(Unit *u) {
 287         Timer *t = TIMER(u);
 288
 289         assert(t);
 290         assert(t->state == TIMER_WAITING || t->state == TIMER_RUNNING || t->state == TIMER_ELAPSED);
 291
 292         timer_enter_dead(t, true);
 293         return 0;
 294 }
 295
 296 static int timer_serialize(Unit *u, FILE *f, FDSet *fds) {
 297         Timer *t = TIMER(u);
 298
 299         assert(u);
 300         assert(f);
 301         assert(fds);
 302
 303         unit_serialize_item(u, f, "state", timer_state_to_string(t->state));
 304
 305         return 0;
 306 }
 307
 308 static int timer_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 309         Timer *t = TIMER(u);
 310
 311         assert(u);
 312         assert(key);
 313         assert(value);
 314         assert(fds);
 315
 316         if (streq(key, "state")) {
 317                 TimerState state;
 318
 319                 if ((state = timer_state_from_string(value)) < 0)
 320                         log_debug("Failed to parse state value %s", value);
 321                 else
 322                         t->deserialized_state = state;
 323         } else
 324                 log_debug("Unknown serialization key '%s'", key);
 325
 326         return 0;
 327 }
 328
 329 static UnitActiveState timer_active_state(Unit *u) {
 330         assert(u);
 331
 332         return state_translation_table[TIMER(u)->state];
 333 }
 334
 335 static const char *timer_sub_state_to_string(Unit *u) {
 336         assert(u);
 337
 338         return timer_state_to_string(TIMER(u)->state);
 339 }
 340
 341 static void timer_timer_event(Unit *u, uint64_t elapsed, Watch *w) {
 342         Timer *t = TIMER(u);
 343
 344         assert(t);
 345         assert(elapsed == 1);
 346
 347         if (t->state != TIMER_WAITING)
 348                 return;
 349
 350         log_debug("Timer elapsed on %s", u->meta.id);
 351         timer_enter_running(t);
 352 }
 353
 354 void timer_unit_notify(Unit *u, UnitActiveState new_state) {
 355         char *n;
 356         int r;
 357         Iterator i;
 358
 359         if (u->meta.type == UNIT_TIMER)
 360                 return;
 361
 362         SET_FOREACH(n, u->meta.names, i) {
 363                 char *k;
 364                 Unit *p;
 365                 Timer *t;
 366                 TimerValue *v;
 367
 368                 if (!(k = unit_name_change_suffix(n, ".timer"))) {
 369                         r = -ENOMEM;
 370                         goto fail;
 371                 }
 372
 373                 p = manager_get_unit(u->meta.manager, k);
 374                 free(k);
 375
 376                 if (!p)
 377                         continue;
 378
 379                 if (p->meta.load_state != UNIT_LOADED)
 380                         continue;
 381
 382                 t = TIMER(p);
 383
 384                 if (t->unit != u)
 385                         continue;
 386
 387                 /* Reenable all timers that depend on unit state */
 388                 LIST_FOREACH(value, v, t->values)
 389                         if (v->base == TIMER_UNIT_ACTIVE ||
 390                             v->base == TIMER_UNIT_INACTIVE)
 391                                 v->disabled = false;
 392
 393                 switch (t->state) {
 394
 395                 case TIMER_WAITING:
 396                 case TIMER_ELAPSED:
 397
 398                         /* Recalculate sleep time */
 399                         timer_enter_waiting(t, false);
 400                         break;
 401
 402                 case TIMER_RUNNING:
 403
 404                         if (UNIT_IS_INACTIVE_OR_MAINTENANCE(new_state)) {
 405                                 log_debug("%s got notified about unit deactivation.", t->meta.id);
 406                                 timer_enter_waiting(t, false);
 407                         }
 408
 409                         break;
 410
 411                 case TIMER_DEAD:
 412                 case TIMER_MAINTENANCE:
 413                         ;
 414
 415                 default:
 416                         assert_not_reached("Unknown timer state");
 417                 }
 418         }
 419
 420         return;
 421
 422 fail:
 423         log_error("Failed find timer unit: %s", strerror(-r));
 424 }
 425
 426 static const char* const timer_state_table[_TIMER_STATE_MAX] = {
 427         [TIMER_DEAD] = "dead",
 428         [TIMER_WAITING] = "waiting",
 429         [TIMER_RUNNING] = "running",
 430         [TIMER_ELAPSED] = "elapsed",
 431         [TIMER_MAINTENANCE] = "maintenance"
 432 };
 433
 434 DEFINE_STRING_TABLE_LOOKUP(timer_state, TimerState);
 435
 436 static const char* const timer_base_table[_TIMER_BASE_MAX] = {
 437         [TIMER_ACTIVE] = "OnActive",
 438         [TIMER_BOOT] = "OnBoot",
 439         [TIMER_STARTUP] = "OnStartup",
 440         [TIMER_UNIT_ACTIVE] = "OnUnitActive",
 441         [TIMER_UNIT_INACTIVE] = "OnUnitInactive"
 442 };
 443
 444 DEFINE_STRING_TABLE_LOOKUP(timer_base, TimerBase);
 445
 446 const UnitVTable timer_vtable = {
 447         .suffix = ".timer",
 448
 449         .init = timer_init,
 450         .done = timer_done,
 451         .load = timer_load,
 452
 453         .coldplug = timer_coldplug,
 454
 455         .dump = timer_dump,
 456
 457         .start = timer_start,
 458         .stop = timer_stop,
 459
 460         .serialize = timer_serialize,
 461         .deserialize_item = timer_deserialize_item,
 462
 463         .active_state = timer_active_state,
 464         .sub_state_to_string = timer_sub_state_to_string,
 465
 466         .timer_event = timer_timer_event,
 467
 468         .bus_message_handler = bus_timer_message_handler
 469 };