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