1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
8 #include <sys/signalfd.h>
20 static int manager_setup_signals(Manager *m) {
22 struct epoll_event ev;
26 assert_se(reset_all_signal_handlers() == 0);
28 assert_se(sigemptyset(&mask) == 0);
29 assert_se(sigaddset(&mask, SIGCHLD) == 0);
30 assert_se(sigaddset(&mask, SIGINT) == 0); /* Kernel sends us this on control-alt-del */
31 assert_se(sigaddset(&mask, SIGWINCH) == 0); /* Kernel sends us this on kbrequest (alt-arrowup) */
32 assert_se(sigaddset(&mask, SIGTERM) == 0);
33 assert_se(sigaddset(&mask, SIGHUP) == 0);
34 assert_se(sigaddset(&mask, SIGUSR1) == 0);
35 assert_se(sigaddset(&mask, SIGUSR2) == 0);
36 assert_se(sigaddset(&mask, SIGPIPE) == 0);
37 assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
39 m->signal_watch.type = WATCH_SIGNAL_FD;
40 if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
45 ev.data.ptr = &m->signal_watch;
47 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
53 Manager* manager_new(void) {
56 if (!(m = new0(Manager, 1)))
59 m->signal_watch.fd = m->epoll_fd = -1;
61 if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
64 if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
67 if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
70 if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func)))
73 if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
76 if (manager_setup_signals(m) < 0)
86 void manager_free(Manager *m) {
93 while ((j = hashmap_first(m->transaction_jobs)))
96 while ((u = hashmap_first(m->units)))
99 for (c = 0; c < _UNIT_TYPE_MAX; c++)
100 if (unit_vtable[c]->shutdown)
101 unit_vtable[c]->shutdown(m);
103 hashmap_free(m->units);
104 hashmap_free(m->jobs);
105 hashmap_free(m->transaction_jobs);
106 hashmap_free(m->watch_pids);
108 if (m->epoll_fd >= 0)
109 close_nointr(m->epoll_fd);
110 if (m->signal_watch.fd >= 0)
111 close_nointr(m->signal_watch.fd);
116 int manager_coldplug(Manager *m) {
125 /* First, let's ask every type to load all units from
126 * disk/kernel that it might know */
127 for (c = 0; c < _UNIT_TYPE_MAX; c++)
128 if (unit_vtable[c]->enumerate)
129 if ((r = unit_vtable[c]->enumerate(m)) < 0)
132 manager_dispatch_load_queue(m);
134 /* Then, let's set up their initial state. */
135 HASHMAP_FOREACH_KEY(u, k, m->units, i) {
141 if (UNIT_VTABLE(u)->coldplug)
142 if ((r = UNIT_VTABLE(u)->coldplug(u)) < 0)
149 static void transaction_delete_job(Manager *m, Job *j) {
153 /* Deletes one job from the transaction */
155 manager_transaction_unlink_job(m, j);
161 static void transaction_delete_unit(Manager *m, Unit *u) {
164 /* Deletes all jobs associated with a certain unit from the
167 while ((j = hashmap_get(m->transaction_jobs, u)))
168 transaction_delete_job(m, j);
171 static void transaction_clean_dependencies(Manager *m) {
177 /* Drops all dependencies of all installed jobs */
179 HASHMAP_FOREACH(j, m->jobs, i) {
180 while (j->subject_list)
181 job_dependency_free(j->subject_list);
182 while (j->object_list)
183 job_dependency_free(j->object_list);
186 assert(!m->transaction_anchor);
189 static void transaction_abort(Manager *m) {
194 while ((j = hashmap_first(m->transaction_jobs)))
196 transaction_delete_job(m, j);
200 assert(hashmap_isempty(m->transaction_jobs));
202 transaction_clean_dependencies(m);
205 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
210 /* A recursive sweep through the graph that marks all units
211 * that matter to the anchor job, i.e. are directly or
212 * indirectly a dependency of the anchor job via paths that
213 * are fully marked as mattering. */
218 l = m->transaction_anchor;
220 LIST_FOREACH(subject, l, l) {
222 /* This link does not matter */
226 /* This unit has already been marked */
227 if (l->object->generation == generation)
230 l->object->matters_to_anchor = true;
231 l->object->generation = generation;
233 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
237 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
238 JobDependency *l, *last;
242 assert(j->unit == other->unit);
243 assert(!j->installed);
245 /* Merges 'other' into 'j' and then deletes j. */
248 j->state = JOB_WAITING;
249 j->forced = j->forced || other->forced;
251 j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
253 /* Patch us in as new owner of the JobDependency objects */
255 LIST_FOREACH(subject, l, other->subject_list) {
256 assert(l->subject == other);
261 /* Merge both lists */
263 last->subject_next = j->subject_list;
265 j->subject_list->subject_prev = last;
266 j->subject_list = other->subject_list;
269 /* Patch us in as new owner of the JobDependency objects */
271 LIST_FOREACH(object, l, other->object_list) {
272 assert(l->object == other);
277 /* Merge both lists */
279 last->object_next = j->object_list;
281 j->object_list->object_prev = last;
282 j->object_list = other->object_list;
285 /* Kill the other job */
286 other->subject_list = NULL;
287 other->object_list = NULL;
288 transaction_delete_job(m, other);
291 static int delete_one_unmergeable_job(Manager *m, Job *j) {
296 /* Tries to delete one item in the linked list
297 * j->transaction_next->transaction_next->... that conflicts
298 * whith another one, in an attempt to make an inconsistent
299 * transaction work. */
301 /* We rely here on the fact that if a merged with b does not
302 * merge with c, either a or b merge with c neither */
303 LIST_FOREACH(transaction, j, j)
304 LIST_FOREACH(transaction, k, j->transaction_next) {
307 /* Is this one mergeable? Then skip it */
308 if (job_type_is_mergeable(j->type, k->type))
311 /* Ok, we found two that conflict, let's see if we can
312 * drop one of them */
313 if (!j->matters_to_anchor)
315 else if (!k->matters_to_anchor)
320 /* Ok, we can drop one, so let's do so. */
321 log_debug("Try to fix job merging by deleting job %s/%s", unit_id(d->unit), job_type_to_string(d->type));
322 transaction_delete_job(m, d);
329 static int transaction_merge_jobs(Manager *m) {
336 /* First step, check whether any of the jobs for one specific
337 * task conflict. If so, try to drop one of them. */
338 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
343 LIST_FOREACH(transaction, k, j->transaction_next) {
344 if ((r = job_type_merge(&t, k->type)) >= 0)
347 /* OK, we could not merge all jobs for this
348 * action. Let's see if we can get rid of one
351 if ((r = delete_one_unmergeable_job(m, j)) >= 0)
352 /* Ok, we managed to drop one, now
353 * let's ask our callers to call us
354 * again after garbage collecting */
357 /* We couldn't merge anything. Failure */
362 /* Second step, merge the jobs. */
363 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
367 /* Merge all transactions */
368 LIST_FOREACH(transaction, k, j->transaction_next)
369 assert_se(job_type_merge(&t, k->type) == 0);
371 /* If an active job is mergeable, merge it too */
372 if (j->unit->meta.job)
373 job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
375 while ((k = j->transaction_next)) {
377 transaction_merge_and_delete_job(m, k, j, t);
380 transaction_merge_and_delete_job(m, j, k, t);
383 assert(!j->transaction_next);
384 assert(!j->transaction_prev);
390 static bool unit_matters_to_anchor(Unit *u, Job *j) {
392 assert(!j->transaction_prev);
394 /* Checks whether at least one of the jobs for this unit
395 * matters to the anchor. */
397 LIST_FOREACH(transaction, j, j)
398 if (j->matters_to_anchor)
404 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
411 assert(!j->transaction_prev);
413 /* Does a recursive sweep through the ordering graph, looking
414 * for a cycle. If we find cycle we try to break it. */
416 /* Did we find a cycle? */
417 if (j->marker && j->generation == generation) {
420 /* So, we already have been here. We have a
421 * cycle. Let's try to break it. We go backwards in
422 * our path and try to find a suitable job to
423 * remove. We use the marker to find our way back,
424 * since smart how we are we stored our way back in
427 for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
430 !unit_matters_to_anchor(k->unit, k)) {
431 /* Ok, we can drop this one, so let's
433 log_debug("Breaking order cycle by deleting job %s/%s", unit_id(k->unit), job_type_to_string(k->type));
434 transaction_delete_unit(m, k->unit);
438 /* Check if this in fact was the beginning of
447 /* Make the marker point to where we come from, so that we can
448 * find our way backwards if we want to break a cycle */
450 j->generation = generation;
452 /* We assume that the the dependencies are bidirectional, and
453 * hence can ignore UNIT_AFTER */
454 SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
457 /* Is there a job for this unit? */
458 if (!(o = hashmap_get(m->transaction_jobs, u)))
460 /* Ok, there is no job for this in the
461 * transaction, but maybe there is already one
463 if (!(o = u->meta.job))
466 if ((r = transaction_verify_order_one(m, o, j, generation)) < 0)
473 static int transaction_verify_order(Manager *m, unsigned *generation) {
481 /* Check if the ordering graph is cyclic. If it is, try to fix
482 * that up by dropping one of the jobs. */
484 HASHMAP_FOREACH(j, m->transaction_jobs, i)
485 if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
491 static void transaction_collect_garbage(Manager *m) {
496 /* Drop jobs that are not required by any other job */
504 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
508 log_debug("Garbage collecting job %s/%s", unit_id(j->unit), job_type_to_string(j->type));
509 transaction_delete_job(m, j);
517 static int transaction_is_destructive(Manager *m, JobMode mode) {
523 /* Checks whether applying this transaction means that
524 * existing jobs would be replaced */
526 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
529 assert(!j->transaction_prev);
530 assert(!j->transaction_next);
532 if (j->unit->meta.job &&
533 j->unit->meta.job != j &&
534 !job_type_is_superset(j->type, j->unit->meta.job->type))
541 static void transaction_minimize_impact(Manager *m) {
545 /* Drops all unnecessary jobs that reverse already active jobs
546 * or that stop a running service. */
554 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
555 LIST_FOREACH(transaction, j, j) {
557 /* If it matters, we shouldn't drop it */
558 if (j->matters_to_anchor)
561 /* Would this stop a running service?
562 * Would this change an existing job?
563 * If so, let's drop this entry */
564 if ((j->type != JOB_STOP || UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(j->unit))) &&
565 (!j->unit->meta.job || job_type_is_conflicting(j->type, j->unit->meta.job->state)))
568 /* Ok, let's get rid of this */
569 log_debug("Deleting %s/%s to minimize impact", unit_id(j->unit), job_type_to_string(j->type));
570 transaction_delete_job(m, j);
582 static int transaction_apply(Manager *m, JobMode mode) {
587 /* Moves the transaction jobs to the set of active jobs */
589 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
591 assert(!j->transaction_prev);
592 assert(!j->transaction_next);
597 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
601 while ((j = hashmap_steal_first(m->transaction_jobs))) {
605 if (j->unit->meta.job)
606 job_free(j->unit->meta.job);
608 j->unit->meta.job = j;
611 /* We're fully installed. Now let's free data we don't
614 assert(!j->transaction_next);
615 assert(!j->transaction_prev);
620 /* As last step, kill all remaining job dependencies. */
621 transaction_clean_dependencies(m);
627 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
631 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
637 static int transaction_activate(Manager *m, JobMode mode) {
639 unsigned generation = 1;
643 /* This applies the changes recorded in transaction_jobs to
644 * the actual list of jobs, if possible. */
646 /* First step: figure out which jobs matter */
647 transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
649 /* Second step: Try not to stop any running services if
650 * we don't have to. Don't try to reverse running
651 * jobs if we don't have to. */
652 transaction_minimize_impact(m);
655 /* Third step: Let's remove unneeded jobs that might
657 transaction_collect_garbage(m);
659 /* Fourth step: verify order makes sense and correct
660 * cycles if necessary and possible */
661 if ((r = transaction_verify_order(m, &generation)) >= 0)
667 /* Let's see if the resulting transaction ordering
668 * graph is still cyclic... */
672 /* Fifth step: let's drop unmergeable entries if
673 * necessary and possible, merge entries we can
675 if ((r = transaction_merge_jobs(m)) >= 0)
681 /* Sixth step: an entry got dropped, let's garbage
682 * collect its dependencies. */
683 transaction_collect_garbage(m);
685 /* Let's see if the resulting transaction still has
686 * unmergeable entries ... */
689 /* Seventh step: check whether we can actually apply this */
690 if (mode == JOB_FAIL)
691 if ((r = transaction_is_destructive(m, mode)) < 0)
694 /* Eights step: apply changes */
695 if ((r = transaction_apply(m, mode)) < 0)
698 assert(hashmap_isempty(m->transaction_jobs));
699 assert(!m->transaction_anchor);
704 transaction_abort(m);
708 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool force, bool *is_new) {
715 /* Looks for an axisting prospective job and returns that. If
716 * it doesn't exist it is created and added to the prospective
719 f = hashmap_get(m->transaction_jobs, unit);
721 LIST_FOREACH(transaction, j, f) {
722 assert(j->unit == unit);
724 if (j->type == type) {
731 if (unit->meta.job && unit->meta.job->type == type)
733 else if (!(j = job_new(m, type, unit)))
738 j->matters_to_anchor = false;
741 LIST_PREPEND(Job, transaction, f, j);
743 if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
754 void manager_transaction_unlink_job(Manager *m, Job *j) {
758 if (j->transaction_prev)
759 j->transaction_prev->transaction_next = j->transaction_next;
760 else if (j->transaction_next)
761 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
763 hashmap_remove_value(m->transaction_jobs, j->unit, j);
765 if (j->transaction_next)
766 j->transaction_next->transaction_prev = j->transaction_prev;
768 j->transaction_prev = j->transaction_next = NULL;
770 while (j->subject_list)
771 job_dependency_free(j->subject_list);
773 while (j->object_list) {
774 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
776 job_dependency_free(j->object_list);
779 log_debug("Deleting job %s/%s as dependency of job %s/%s",
780 unit_id(other->unit), job_type_to_string(other->type),
781 unit_id(j->unit), job_type_to_string(j->type));
782 transaction_delete_job(m, other);
787 static int transaction_add_job_and_dependencies(Manager *m, JobType type, Unit *unit, Job *by, bool matters, bool force, Job **_ret) {
795 assert(type < _JOB_TYPE_MAX);
798 if (unit->meta.load_state != UNIT_LOADED)
801 if (!unit_job_is_applicable(unit, type))
804 /* First add the job. */
805 if (!(ret = transaction_add_one_job(m, type, unit, force, &is_new)))
808 /* Then, add a link to the job. */
809 if (!job_dependency_new(by, ret, matters))
813 /* Finally, recursively add in all dependencies. */
814 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
815 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
816 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
818 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUIRES], i)
819 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
821 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
822 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, force, NULL)) < 0 && r != -EBADR)
824 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
825 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
827 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUISITE], i)
828 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
830 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
831 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
834 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
836 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
837 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
841 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
850 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool force, Job **_ret) {
855 assert(type < _JOB_TYPE_MAX);
857 assert(mode < _JOB_MODE_MAX);
859 if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, force, &ret))) {
860 transaction_abort(m);
864 if ((r = transaction_activate(m, mode)) < 0)
867 log_debug("Enqueued job %s/%s", unit_id(unit), job_type_to_string(type));
875 Job *manager_get_job(Manager *m, uint32_t id) {
878 return hashmap_get(m->jobs, UINT32_TO_PTR(id));
881 Unit *manager_get_unit(Manager *m, const char *name) {
885 return hashmap_get(m->units, name);
888 void manager_dispatch_load_queue(Manager *m) {
893 /* Make sure we are not run recursively */
894 if (m->dispatching_load_queue)
897 m->dispatching_load_queue = true;
899 /* Dispatches the load queue. Takes a unit from the queue and
900 * tries to load its data until the queue is empty */
902 while ((meta = m->load_queue)) {
903 assert(meta->in_load_queue);
905 unit_load(UNIT(meta));
908 m->dispatching_load_queue = false;
911 int manager_load_unit(Manager *m, const char *path, Unit **_ret) {
920 /* This will load the service information files, but not actually
921 * start any services or anything. */
923 name = file_name_from_path(path);
925 if ((ret = manager_get_unit(m, name))) {
930 if (!(ret = unit_new(m)))
934 if (!(ret->meta.load_path = strdup(path))) {
940 if ((r = unit_add_name(ret, name)) < 0) {
945 unit_add_to_load_queue(ret);
946 manager_dispatch_load_queue(m);
952 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
959 HASHMAP_FOREACH(j, s->jobs, i)
960 job_dump(j, f, prefix);
963 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
971 HASHMAP_FOREACH_KEY(u, t, s->units, i)
973 unit_dump(u, f, prefix);
976 void manager_clear_jobs(Manager *m) {
981 transaction_abort(m);
983 while ((j = hashmap_first(m->jobs)))
987 void manager_dispatch_run_queue(Manager *m) {
990 if (m->dispatching_run_queue)
993 m->dispatching_run_queue = true;
995 while ((j = m->run_queue)) {
996 assert(j->installed);
997 assert(j->in_run_queue);
999 job_run_and_invalidate(j);
1002 m->dispatching_run_queue = false;
1005 static int manager_dispatch_sigchld(Manager *m) {
1008 log_debug("dispatching SIGCHLD");
1015 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG) < 0) {
1017 if (errno == ECHILD)
1026 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
1029 log_debug("child %llu died (code=%s, status=%i)", (long long unsigned) si.si_pid, sigchld_code(si.si_code), si.si_status);
1031 if (!(u = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
1034 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
1040 static int manager_process_signal_fd(Manager *m, bool *quit) {
1042 struct signalfd_siginfo sfsi;
1043 bool sigchld = false;
1048 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
1053 if (errno == EAGAIN)
1059 switch (sfsi.ssi_signo) {
1071 log_info("Got unhandled signal <%s>.", strsignal(sfsi.ssi_signo));
1076 return manager_dispatch_sigchld(m);
1081 static int process_event(Manager *m, struct epoll_event *ev, bool *quit) {
1088 assert(w = ev->data.ptr);
1092 case WATCH_SIGNAL_FD:
1094 /* An incoming signal? */
1095 if (ev->events != POLLIN)
1098 if ((r = manager_process_signal_fd(m, quit)) < 0)
1105 /* Some fd event, to be dispatched to the units */
1106 UNIT_VTABLE(w->unit)->fd_event(w->unit, w->fd, ev->events, w);
1113 /* Some timer event, to be dispatched to the units */
1114 if ((k = read(ev->data.fd, &v, sizeof(v))) != sizeof(v)) {
1116 if (k < 0 && (errno == EINTR || errno == EAGAIN))
1119 return k < 0 ? -errno : -EIO;
1122 UNIT_VTABLE(w->unit)->timer_event(w->unit, v, w);
1127 assert_not_reached("Unknown epoll event type.");
1133 int manager_loop(Manager *m) {
1140 struct epoll_event event;
1143 manager_dispatch_run_queue(m);
1145 if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
1147 if (errno == -EINTR)
1155 if ((r = process_event(m, &event, &quit)) < 0)