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 #include "special.h"
  29
  30 static const UnitActiveState state_translation_table[_TIMER_STATE_MAX] = {
  31         [TIMER_DEAD] = UNIT_INACTIVE,
  32         [TIMER_WAITING] = UNIT_ACTIVE,
  33         [TIMER_RUNNING] = UNIT_ACTIVE,
  34         [TIMER_ELAPSED] = UNIT_ACTIVE,
  35         [TIMER_MAINTENANCE] = UNIT_MAINTENANCE
  36 };
  37
  38 static void timer_init(Unit *u) {
  39         Timer *t = TIMER(u);
  40
  41         assert(u);
  42         assert(u->meta.load_state == UNIT_STUB);
  43
  44         t->next_elapse = (usec_t) -1;
  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 (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                 /* Timers shouldn't stay around on shutdown */
  95                 if (t->meta.default_dependencies)
  96                         if ((r = unit_add_two_dependencies_by_name(u, UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true)) < 0)
  97                                 return r;
  98         }
  99
 100         return timer_verify(t);
 101 }
 102
 103 static void timer_dump(Unit *u, FILE *f, const char *prefix) {
 104         Timer *t = TIMER(u);
 105         const char *prefix2;
 106         char *p2;
 107         TimerValue *v;
 108         char
 109                 timespan1[FORMAT_TIMESPAN_MAX];
 110
 111         p2 = strappend(prefix, "\t");
 112         prefix2 = p2 ? p2 : prefix;
 113
 114         fprintf(f,
 115                 "%sTimer State: %s\n"
 116                 "%sUnit: %s\n",
 117                 prefix, timer_state_to_string(t->state),
 118                 prefix, t->unit->meta.id);
 119
 120         LIST_FOREACH(value, v, t->values)
 121                 fprintf(f,
 122                         "%s%s: %s\n",
 123                         prefix,
 124                         timer_base_to_string(v->base),
 125                         strna(format_timespan(timespan1, sizeof(timespan1), v->value)));
 126
 127         free(p2);
 128 }
 129
 130 static void timer_set_state(Timer *t, TimerState state) {
 131         TimerState old_state;
 132         assert(t);
 133
 134         old_state = t->state;
 135         t->state = state;
 136
 137         if (state != TIMER_WAITING)
 138                 unit_unwatch_timer(UNIT(t), &t->timer_watch);
 139
 140         if (state != old_state)
 141                 log_debug("%s changed %s -> %s",
 142                           t->meta.id,
 143                           timer_state_to_string(old_state),
 144                           timer_state_to_string(state));
 145
 146         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state]);
 147 }
 148
 149 static void timer_enter_waiting(Timer *t, bool initial);
 150
 151 static int timer_coldplug(Unit *u) {
 152         Timer *t = TIMER(u);
 153
 154         assert(t);
 155         assert(t->state == TIMER_DEAD);
 156
 157         if (t->deserialized_state != t->state) {
 158
 159                 if (t->deserialized_state == TIMER_WAITING ||
 160                     t->deserialized_state == TIMER_RUNNING ||
 161                     t->deserialized_state == TIMER_ELAPSED)
 162                         timer_enter_waiting(t, false);
 163                 else
 164                         timer_set_state(t, t->deserialized_state);
 165         }
 166
 167         return 0;
 168 }
 169
 170 static void timer_enter_dead(Timer *t, bool success) {
 171         assert(t);
 172
 173         if (!success)
 174                 t->failure = true;
 175
 176         timer_set_state(t, t->failure ? TIMER_MAINTENANCE : TIMER_DEAD);
 177 }
 178
 179 static void timer_enter_waiting(Timer *t, bool initial) {
 180         TimerValue *v;
 181         usec_t base = 0, delay, n;
 182         bool found = false;
 183         int r;
 184
 185         n = now(CLOCK_MONOTONIC);
 186
 187         LIST_FOREACH(value, v, t->values) {
 188
 189                 if (v->disabled)
 190                         continue;
 191
 192                 switch (v->base) {
 193
 194                 case TIMER_ACTIVE:
 195                         if (state_translation_table[t->state] == UNIT_ACTIVE) {
 196                                 base = t->meta.inactive_exit_timestamp.monotonic;
 197                         } else
 198                                 base = n;
 199                         break;
 200
 201                 case TIMER_BOOT:
 202                         /* CLOCK_MONOTONIC equals the uptime on Linux */
 203                         base = 0;
 204                         break;
 205
 206                 case TIMER_STARTUP:
 207                         base = t->meta.manager->startup_timestamp.monotonic;
 208                         break;
 209
 210                 case TIMER_UNIT_ACTIVE:
 211
 212                         if (t->unit->meta.inactive_exit_timestamp.monotonic <= 0)
 213                                 continue;
 214
 215                         base = t->unit->meta.inactive_exit_timestamp.monotonic;
 216                         break;
 217
 218                 case TIMER_UNIT_INACTIVE:
 219
 220                         if (t->unit->meta.inactive_enter_timestamp.monotonic <= 0)
 221                                 continue;
 222
 223                         base = t->unit->meta.inactive_enter_timestamp.monotonic;
 224                         break;
 225
 226                 default:
 227                         assert_not_reached("Unknown timer base");
 228                 }
 229
 230                 v->next_elapse = base + v->value;
 231
 232                 if (!initial && v->next_elapse < n) {
 233                         v->disabled = true;
 234                         continue;
 235                 }
 236
 237                 if (!found)
 238                         t->next_elapse = v->next_elapse;
 239                 else
 240                         t->next_elapse = MIN(t->next_elapse, v->next_elapse);
 241
 242                 found = true;
 243         }
 244
 245         if (!found) {
 246                 timer_set_state(t, TIMER_ELAPSED);
 247                 return;
 248         }
 249
 250         delay = n < t->next_elapse ? t->next_elapse - n : 0;
 251
 252         if ((r = unit_watch_timer(UNIT(t), delay, &t->timer_watch)) < 0)
 253                 goto fail;
 254
 255         timer_set_state(t, TIMER_WAITING);
 256         return;
 257
 258 fail:
 259         log_warning("%s failed to enter waiting state: %s", t->meta.id, strerror(-r));
 260         timer_enter_dead(t, false);
 261 }
 262
 263 static void timer_enter_running(Timer *t) {
 264         int r;
 265         assert(t);
 266
 267         if ((r = manager_add_job(t->meta.manager, JOB_START, t->unit, JOB_REPLACE, true, NULL)) < 0)
 268                 goto fail;
 269
 270         timer_set_state(t, TIMER_RUNNING);
 271         return;
 272
 273 fail:
 274         log_warning("%s failed to queue unit startup job: %s", t->meta.id, strerror(-r));
 275         timer_enter_dead(t, false);
 276 }
 277
 278 static int timer_start(Unit *u) {
 279         Timer *t = TIMER(u);
 280
 281         assert(t);
 282         assert(t->state == TIMER_DEAD || t->state == TIMER_MAINTENANCE);
 283
 284         if (t->unit->meta.load_state != UNIT_LOADED)
 285                 return -ENOENT;
 286
 287         t->failure = false;
 288         timer_enter_waiting(t, true);
 289         return 0;
 290 }
 291
 292 static int timer_stop(Unit *u) {
 293         Timer *t = TIMER(u);
 294
 295         assert(t);
 296         assert(t->state == TIMER_WAITING || t->state == TIMER_RUNNING || t->state == TIMER_ELAPSED);
 297
 298         timer_enter_dead(t, true);
 299         return 0;
 300 }
 301
 302 static int timer_serialize(Unit *u, FILE *f, FDSet *fds) {
 303         Timer *t = TIMER(u);
 304
 305         assert(u);
 306         assert(f);
 307         assert(fds);
 308
 309         unit_serialize_item(u, f, "state", timer_state_to_string(t->state));
 310
 311         return 0;
 312 }
 313
 314 static int timer_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
 315         Timer *t = TIMER(u);
 316
 317         assert(u);
 318         assert(key);
 319         assert(value);
 320         assert(fds);
 321
 322         if (streq(key, "state")) {
 323                 TimerState state;
 324
 325                 if ((state = timer_state_from_string(value)) < 0)
 326                         log_debug("Failed to parse state value %s", value);
 327                 else
 328                         t->deserialized_state = state;
 329         } else
 330                 log_debug("Unknown serialization key '%s'", key);
 331
 332         return 0;
 333 }
 334
 335 static UnitActiveState timer_active_state(Unit *u) {
 336         assert(u);
 337
 338         return state_translation_table[TIMER(u)->state];
 339 }
 340
 341 static const char *timer_sub_state_to_string(Unit *u) {
 342         assert(u);
 343
 344         return timer_state_to_string(TIMER(u)->state);
 345 }
 346
 347 static void timer_timer_event(Unit *u, uint64_t elapsed, Watch *w) {
 348         Timer *t = TIMER(u);
 349
 350         assert(t);
 351         assert(elapsed == 1);
 352
 353         if (t->state != TIMER_WAITING)
 354                 return;
 355
 356         log_debug("Timer elapsed on %s", u->meta.id);
 357         timer_enter_running(t);
 358 }
 359
 360 void timer_unit_notify(Unit *u, UnitActiveState new_state) {
 361         char *n;
 362         int r;
 363         Iterator i;
 364
 365         if (u->meta.type == UNIT_TIMER)
 366                 return;
 367
 368         SET_FOREACH(n, u->meta.names, i) {
 369                 char *k;
 370                 Unit *p;
 371                 Timer *t;
 372                 TimerValue *v;
 373
 374                 if (!(k = unit_name_change_suffix(n, ".timer"))) {
 375                         r = -ENOMEM;
 376                         goto fail;
 377                 }
 378
 379                 p = manager_get_unit(u->meta.manager, k);
 380                 free(k);
 381
 382                 if (!p)
 383                         continue;
 384
 385                 if (p->meta.load_state != UNIT_LOADED)
 386                         continue;
 387
 388                 t = TIMER(p);
 389
 390                 if (t->unit != u)
 391                         continue;
 392
 393                 /* Reenable all timers that depend on unit state */
 394                 LIST_FOREACH(value, v, t->values)
 395                         if (v->base == TIMER_UNIT_ACTIVE ||
 396                             v->base == TIMER_UNIT_INACTIVE)
 397                                 v->disabled = false;
 398
 399                 switch (t->state) {
 400
 401                 case TIMER_WAITING:
 402                 case TIMER_ELAPSED:
 403
 404                         /* Recalculate sleep time */
 405                         timer_enter_waiting(t, false);
 406                         break;
 407
 408                 case TIMER_RUNNING:
 409
 410                         if (UNIT_IS_INACTIVE_OR_MAINTENANCE(new_state)) {
 411                                 log_debug("%s got notified about unit deactivation.", t->meta.id);
 412                                 timer_enter_waiting(t, false);
 413                         }
 414
 415                         break;
 416
 417                 case TIMER_DEAD:
 418                 case TIMER_MAINTENANCE:
 419                         ;
 420
 421                 default:
 422                         assert_not_reached("Unknown timer state");
 423                 }
 424         }
 425
 426         return;
 427
 428 fail:
 429         log_error("Failed find timer unit: %s", strerror(-r));
 430 }
 431
 432 static const char* const timer_state_table[_TIMER_STATE_MAX] = {
 433         [TIMER_DEAD] = "dead",
 434         [TIMER_WAITING] = "waiting",
 435         [TIMER_RUNNING] = "running",
 436         [TIMER_ELAPSED] = "elapsed",
 437         [TIMER_MAINTENANCE] = "maintenance"
 438 };
 439
 440 DEFINE_STRING_TABLE_LOOKUP(timer_state, TimerState);
 441
 442 static const char* const timer_base_table[_TIMER_BASE_MAX] = {
 443         [TIMER_ACTIVE] = "OnActive",
 444         [TIMER_BOOT] = "OnBoot",
 445         [TIMER_STARTUP] = "OnStartup",
 446         [TIMER_UNIT_ACTIVE] = "OnUnitActive",
 447         [TIMER_UNIT_INACTIVE] = "OnUnitInactive"
 448 };
 449
 450 DEFINE_STRING_TABLE_LOOKUP(timer_base, TimerBase);
 451
 452 const UnitVTable timer_vtable = {
 453         .suffix = ".timer",
 454
 455         .init = timer_init,
 456         .done = timer_done,
 457         .load = timer_load,
 458
 459         .coldplug = timer_coldplug,
 460
 461         .dump = timer_dump,
 462
 463         .start = timer_start,
 464         .stop = timer_stop,
 465
 466         .serialize = timer_serialize,
 467         .deserialize_item = timer_deserialize_item,
 468
 469         .active_state = timer_active_state,
 470         .sub_state_to_string = timer_sub_state_to_string,
 471
 472         .timer_event = timer_timer_event,
 473
 474         .bus_message_handler = bus_timer_message_handler
 475 };