chiark / gitweb /
logind: make sure we hand out write fd, and keep read fd for session end detection
[elogind.git] / 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_dependency_by_name(UNIT(t), UNIT_BEFORE, SPECIAL_BASIC_TARGET, NULL, true)) < 0)
83                         return r;
84
85                 if ((r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true)) < 0)
86                         return r;
87         }
88
89         return unit_add_two_dependencies_by_name(UNIT(t), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true);
90 }
91
92 static int timer_load(Unit *u) {
93         Timer *t = TIMER(u);
94         int r;
95
96         assert(u);
97         assert(u->meta.load_state == UNIT_STUB);
98
99         if ((r = unit_load_fragment_and_dropin(u)) < 0)
100                 return r;
101
102         if (u->meta.load_state == UNIT_LOADED) {
103
104                 if (!t->unit)
105                         if ((r = unit_load_related_unit(u, ".service", &t->unit)))
106                                 return r;
107
108                 if ((r = unit_add_dependency(u, UNIT_BEFORE, t->unit, true)) < 0)
109                         return r;
110
111                 if (t->meta.default_dependencies)
112                         if ((r = timer_add_default_dependencies(t)) < 0)
113                                 return r;
114         }
115
116         return timer_verify(t);
117 }
118
119 static void timer_dump(Unit *u, FILE *f, const char *prefix) {
120         Timer *t = TIMER(u);
121         TimerValue *v;
122         char
123                 timespan1[FORMAT_TIMESPAN_MAX];
124
125         fprintf(f,
126                 "%sTimer State: %s\n"
127                 "%sUnit: %s\n",
128                 prefix, timer_state_to_string(t->state),
129                 prefix, t->unit->meta.id);
130
131         LIST_FOREACH(value, v, t->values)
132                 fprintf(f,
133                         "%s%s: %s\n",
134                         prefix,
135                         timer_base_to_string(v->base),
136                         strna(format_timespan(timespan1, sizeof(timespan1), v->value)));
137 }
138
139 static void timer_set_state(Timer *t, TimerState state) {
140         TimerState old_state;
141         assert(t);
142
143         old_state = t->state;
144         t->state = state;
145
146         if (state != TIMER_WAITING)
147                 unit_unwatch_timer(UNIT(t), &t->timer_watch);
148
149         if (state != old_state)
150                 log_debug("%s changed %s -> %s",
151                           t->meta.id,
152                           timer_state_to_string(old_state),
153                           timer_state_to_string(state));
154
155         unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], true);
156 }
157
158 static void timer_enter_waiting(Timer *t, bool initial);
159
160 static int timer_coldplug(Unit *u) {
161         Timer *t = TIMER(u);
162
163         assert(t);
164         assert(t->state == TIMER_DEAD);
165
166         if (t->deserialized_state != t->state) {
167
168                 if (t->deserialized_state == TIMER_WAITING)
169                         timer_enter_waiting(t, false);
170                 else
171                         timer_set_state(t, t->deserialized_state);
172         }
173
174         return 0;
175 }
176
177 static void timer_enter_dead(Timer *t, bool success) {
178         assert(t);
179
180         if (!success)
181                 t->failure = true;
182
183         timer_set_state(t, t->failure ? TIMER_FAILED : TIMER_DEAD);
184 }
185
186 static void timer_enter_waiting(Timer *t, bool initial) {
187         TimerValue *v;
188         usec_t base = 0, delay, n;
189         bool found = false;
190         int r;
191
192         n = now(CLOCK_MONOTONIC);
193
194         LIST_FOREACH(value, v, t->values) {
195
196                 if (v->disabled)
197                         continue;
198
199                 switch (v->base) {
200
201                 case TIMER_ACTIVE:
202                         if (state_translation_table[t->state] == UNIT_ACTIVE)
203                                 base = t->meta.inactive_exit_timestamp.monotonic;
204                         else
205                                 base = n;
206                         break;
207
208                 case TIMER_BOOT:
209                         /* CLOCK_MONOTONIC equals the uptime on Linux */
210                         base = 0;
211                         break;
212
213                 case TIMER_STARTUP:
214                         base = t->meta.manager->startup_timestamp.monotonic;
215                         break;
216
217                 case TIMER_UNIT_ACTIVE:
218
219                         if (t->unit->meta.inactive_exit_timestamp.monotonic <= 0)
220                                 continue;
221
222                         base = t->unit->meta.inactive_exit_timestamp.monotonic;
223                         break;
224
225                 case TIMER_UNIT_INACTIVE:
226
227                         if (t->unit->meta.inactive_enter_timestamp.monotonic <= 0)
228                                 continue;
229
230                         base = t->unit->meta.inactive_enter_timestamp.monotonic;
231                         break;
232
233                 default:
234                         assert_not_reached("Unknown timer base");
235                 }
236
237                 v->next_elapse = base + v->value;
238
239                 if (!initial && v->next_elapse < n) {
240                         v->disabled = true;
241                         continue;
242                 }
243
244                 if (!found)
245                         t->next_elapse = v->next_elapse;
246                 else
247                         t->next_elapse = MIN(t->next_elapse, v->next_elapse);
248
249                 found = true;
250         }
251
252         if (!found) {
253                 timer_set_state(t, TIMER_ELAPSED);
254                 return;
255         }
256
257         delay = n < t->next_elapse ? t->next_elapse - n : 0;
258
259         if ((r = unit_watch_timer(UNIT(t), delay, &t->timer_watch)) < 0)
260                 goto fail;
261
262         timer_set_state(t, TIMER_WAITING);
263         return;
264
265 fail:
266         log_warning("%s failed to enter waiting state: %s", t->meta.id, strerror(-r));
267         timer_enter_dead(t, false);
268 }
269
270 static void timer_enter_running(Timer *t) {
271         DBusError error;
272         int r;
273
274         assert(t);
275         dbus_error_init(&error);
276
277         /* Don't start job if we are supposed to go down */
278         if (t->meta.job && t->meta.job->type == JOB_STOP)
279                 return;
280
281         if ((r = manager_add_job(t->meta.manager, JOB_START, t->unit, JOB_REPLACE, true, &error, NULL)) < 0)
282                 goto fail;
283
284         timer_set_state(t, TIMER_RUNNING);
285         return;
286
287 fail:
288         log_warning("%s failed to queue unit startup job: %s", t->meta.id, bus_error(&error, r));
289         timer_enter_dead(t, false);
290
291         dbus_error_free(&error);
292 }
293
294 static int timer_start(Unit *u) {
295         Timer *t = TIMER(u);
296
297         assert(t);
298         assert(t->state == TIMER_DEAD || t->state == TIMER_FAILED);
299
300         if (t->unit->meta.load_state != UNIT_LOADED)
301                 return -ENOENT;
302
303         t->failure = false;
304         timer_enter_waiting(t, true);
305         return 0;
306 }
307
308 static int timer_stop(Unit *u) {
309         Timer *t = TIMER(u);
310
311         assert(t);
312         assert(t->state == TIMER_WAITING || t->state == TIMER_RUNNING || t->state == TIMER_ELAPSED);
313
314         timer_enter_dead(t, true);
315         return 0;
316 }
317
318 static int timer_serialize(Unit *u, FILE *f, FDSet *fds) {
319         Timer *t = TIMER(u);
320
321         assert(u);
322         assert(f);
323         assert(fds);
324
325         unit_serialize_item(u, f, "state", timer_state_to_string(t->state));
326
327         return 0;
328 }
329
330 static int timer_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
331         Timer *t = TIMER(u);
332
333         assert(u);
334         assert(key);
335         assert(value);
336         assert(fds);
337
338         if (streq(key, "state")) {
339                 TimerState state;
340
341                 if ((state = timer_state_from_string(value)) < 0)
342                         log_debug("Failed to parse state value %s", value);
343                 else
344                         t->deserialized_state = state;
345         } else
346                 log_debug("Unknown serialization key '%s'", key);
347
348         return 0;
349 }
350
351 static UnitActiveState timer_active_state(Unit *u) {
352         assert(u);
353
354         return state_translation_table[TIMER(u)->state];
355 }
356
357 static const char *timer_sub_state_to_string(Unit *u) {
358         assert(u);
359
360         return timer_state_to_string(TIMER(u)->state);
361 }
362
363 static void timer_timer_event(Unit *u, uint64_t elapsed, Watch *w) {
364         Timer *t = TIMER(u);
365
366         assert(t);
367         assert(elapsed == 1);
368
369         if (t->state != TIMER_WAITING)
370                 return;
371
372         log_debug("Timer elapsed on %s", u->meta.id);
373         timer_enter_running(t);
374 }
375
376 void timer_unit_notify(Unit *u, UnitActiveState new_state) {
377         char *n;
378         int r;
379         Iterator i;
380
381         if (u->meta.type == UNIT_TIMER)
382                 return;
383
384         SET_FOREACH(n, u->meta.names, i) {
385                 char *k;
386                 Unit *p;
387                 Timer *t;
388                 TimerValue *v;
389
390                 if (!(k = unit_name_change_suffix(n, ".timer"))) {
391                         r = -ENOMEM;
392                         goto fail;
393                 }
394
395                 p = manager_get_unit(u->meta.manager, k);
396                 free(k);
397
398                 if (!p)
399                         continue;
400
401                 if (p->meta.load_state != UNIT_LOADED)
402                         continue;
403
404                 t = TIMER(p);
405
406                 if (t->unit != u)
407                         continue;
408
409                 /* Reenable all timers that depend on unit state */
410                 LIST_FOREACH(value, v, t->values)
411                         if (v->base == TIMER_UNIT_ACTIVE ||
412                             v->base == TIMER_UNIT_INACTIVE)
413                                 v->disabled = false;
414
415                 switch (t->state) {
416
417                 case TIMER_WAITING:
418                 case TIMER_ELAPSED:
419
420                         /* Recalculate sleep time */
421                         timer_enter_waiting(t, false);
422                         break;
423
424                 case TIMER_RUNNING:
425
426                         if (UNIT_IS_INACTIVE_OR_FAILED(new_state)) {
427                                 log_debug("%s got notified about unit deactivation.", t->meta.id);
428                                 timer_enter_waiting(t, false);
429                         }
430
431                         break;
432
433                 case TIMER_DEAD:
434                 case TIMER_FAILED:
435                         break;
436
437                 default:
438                         assert_not_reached("Unknown timer state");
439                 }
440         }
441
442         return;
443
444 fail:
445         log_error("Failed find timer unit: %s", strerror(-r));
446 }
447
448 static void timer_reset_failed(Unit *u) {
449         Timer *t = TIMER(u);
450
451         assert(t);
452
453         if (t->state == TIMER_FAILED)
454                 timer_set_state(t, TIMER_DEAD);
455
456         t->failure = false;
457 }
458
459 static const char* const timer_state_table[_TIMER_STATE_MAX] = {
460         [TIMER_DEAD] = "dead",
461         [TIMER_WAITING] = "waiting",
462         [TIMER_RUNNING] = "running",
463         [TIMER_ELAPSED] = "elapsed",
464         [TIMER_FAILED] = "failed"
465 };
466
467 DEFINE_STRING_TABLE_LOOKUP(timer_state, TimerState);
468
469 static const char* const timer_base_table[_TIMER_BASE_MAX] = {
470         [TIMER_ACTIVE] = "OnActiveSec",
471         [TIMER_BOOT] = "OnBootSec",
472         [TIMER_STARTUP] = "OnStartupSec",
473         [TIMER_UNIT_ACTIVE] = "OnUnitActiveSec",
474         [TIMER_UNIT_INACTIVE] = "OnUnitInactiveSec"
475 };
476
477 DEFINE_STRING_TABLE_LOOKUP(timer_base, TimerBase);
478
479 const UnitVTable timer_vtable = {
480         .suffix = ".timer",
481
482         .init = timer_init,
483         .done = timer_done,
484         .load = timer_load,
485
486         .coldplug = timer_coldplug,
487
488         .dump = timer_dump,
489
490         .start = timer_start,
491         .stop = timer_stop,
492
493         .serialize = timer_serialize,
494         .deserialize_item = timer_deserialize_item,
495
496         .active_state = timer_active_state,
497         .sub_state_to_string = timer_sub_state_to_string,
498
499         .timer_event = timer_timer_event,
500
501         .reset_failed = timer_reset_failed,
502
503         .bus_interface = "org.freedesktop.systemd1.Timer",
504         .bus_message_handler = bus_timer_message_handler,
505         .bus_invalidating_properties =  bus_timer_invalidating_properties
506 };