1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
8 #include <sys/signalfd.h>
19 Manager* manager_new(void) {
22 struct epoll_event ev;
24 if (!(m = new0(Manager, 1)))
27 m->signal_watch.fd = m->epoll_fd = -1;
29 if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
32 if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
35 if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
38 if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func)))
41 if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
44 assert_se(sigemptyset(&mask) == 0);
45 assert_se(sigaddset(&mask, SIGCHLD) == 0);
46 assert_se(sigaddset(&mask, SIGINT) == 0);
47 assert_se(sigaddset(&mask, SIGTERM) == 0);
48 assert_se(sigaddset(&mask, SIGWINCH) == 0);
49 assert_se(sigaddset(&mask, SIGHUP) == 0);
50 assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
52 m->signal_watch.type = WATCH_SIGNAL_FD;
53 if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
58 ev.data.ptr = &m->signal_watch;
60 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
70 void manager_free(Manager *m) {
76 while ((j = hashmap_first(m->transaction_jobs)))
79 while ((u = hashmap_first(m->units)))
82 hashmap_free(m->units);
83 hashmap_free(m->jobs);
84 hashmap_free(m->transaction_jobs);
85 hashmap_free(m->watch_pids);
88 close_nointr(m->epoll_fd);
89 if (m->signal_watch.fd >= 0)
90 close_nointr(m->signal_watch.fd);
95 static void transaction_delete_job(Manager *m, Job *j) {
99 /* Deletes one job from the transaction */
101 manager_transaction_unlink_job(m, j);
107 static void transaction_delete_unit(Manager *m, Unit *u) {
110 /* Deletes all jobs associated with a certain unit from the
113 while ((j = hashmap_get(m->transaction_jobs, u)))
114 transaction_delete_job(m, j);
117 static void transaction_clean_dependencies(Manager *m) {
123 /* Drops all dependencies of all installed jobs */
125 HASHMAP_FOREACH(j, m->jobs, i) {
126 while (j->subject_list)
127 job_dependency_free(j->subject_list);
128 while (j->object_list)
129 job_dependency_free(j->object_list);
132 assert(!m->transaction_anchor);
135 static void transaction_abort(Manager *m) {
140 while ((j = hashmap_first(m->transaction_jobs)))
142 transaction_delete_job(m, j);
146 assert(hashmap_isempty(m->transaction_jobs));
148 transaction_clean_dependencies(m);
151 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
156 /* A recursive sweep through the graph that marks all units
157 * that matter to the anchor job, i.e. are directly or
158 * indirectly a dependency of the anchor job via paths that
159 * are fully marked as mattering. */
164 l = m->transaction_anchor;
166 LIST_FOREACH(subject, l, l) {
168 /* This link does not matter */
172 /* This unit has already been marked */
173 if (l->object->generation == generation)
176 l->object->matters_to_anchor = true;
177 l->object->generation = generation;
179 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
183 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
184 JobDependency *l, *last;
188 assert(j->unit == other->unit);
189 assert(!j->installed);
191 /* Merges 'other' into 'j' and then deletes j. */
194 j->state = JOB_WAITING;
195 j->forced = j->forced || other->forced;
197 j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
199 /* Patch us in as new owner of the JobDependency objects */
201 LIST_FOREACH(subject, l, other->subject_list) {
202 assert(l->subject == other);
207 /* Merge both lists */
209 last->subject_next = j->subject_list;
211 j->subject_list->subject_prev = last;
212 j->subject_list = other->subject_list;
215 /* Patch us in as new owner of the JobDependency objects */
217 LIST_FOREACH(object, l, other->object_list) {
218 assert(l->object == other);
223 /* Merge both lists */
225 last->object_next = j->object_list;
227 j->object_list->object_prev = last;
228 j->object_list = other->object_list;
231 /* Kill the other job */
232 other->subject_list = NULL;
233 other->object_list = NULL;
234 transaction_delete_job(m, other);
237 static int delete_one_unmergeable_job(Manager *m, Job *j) {
242 /* Tries to delete one item in the linked list
243 * j->transaction_next->transaction_next->... that conflicts
244 * whith another one, in an attempt to make an inconsistent
245 * transaction work. */
247 /* We rely here on the fact that if a merged with b does not
248 * merge with c, either a or b merge with c neither */
249 LIST_FOREACH(transaction, j, j)
250 LIST_FOREACH(transaction, k, j->transaction_next) {
253 /* Is this one mergeable? Then skip it */
254 if (job_type_is_mergeable(j->type, k->type))
257 /* Ok, we found two that conflict, let's see if we can
258 * drop one of them */
259 if (!j->matters_to_anchor)
261 else if (!k->matters_to_anchor)
266 /* Ok, we can drop one, so let's do so. */
267 log_debug("Try to fix job merging by deleting job %s/%s", unit_id(d->unit), job_type_to_string(d->type));
268 transaction_delete_job(m, d);
275 static int transaction_merge_jobs(Manager *m) {
282 /* First step, check whether any of the jobs for one specific
283 * task conflict. If so, try to drop one of them. */
284 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
289 LIST_FOREACH(transaction, k, j->transaction_next) {
290 if ((r = job_type_merge(&t, k->type)) >= 0)
293 /* OK, we could not merge all jobs for this
294 * action. Let's see if we can get rid of one
297 if ((r = delete_one_unmergeable_job(m, j)) >= 0)
298 /* Ok, we managed to drop one, now
299 * let's ask our callers to call us
300 * again after garbage collecting */
303 /* We couldn't merge anything. Failure */
308 /* Second step, merge the jobs. */
309 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
313 /* Merge all transactions */
314 LIST_FOREACH(transaction, k, j->transaction_next)
315 assert_se(job_type_merge(&t, k->type) == 0);
317 /* If an active job is mergeable, merge it too */
318 if (j->unit->meta.job)
319 job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
321 while ((k = j->transaction_next)) {
323 transaction_merge_and_delete_job(m, k, j, t);
326 transaction_merge_and_delete_job(m, j, k, t);
329 assert(!j->transaction_next);
330 assert(!j->transaction_prev);
336 static bool unit_matters_to_anchor(Unit *u, Job *j) {
338 assert(!j->transaction_prev);
340 /* Checks whether at least one of the jobs for this unit
341 * matters to the anchor. */
343 LIST_FOREACH(transaction, j, j)
344 if (j->matters_to_anchor)
350 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
357 assert(!j->transaction_prev);
359 /* Does a recursive sweep through the ordering graph, looking
360 * for a cycle. If we find cycle we try to break it. */
362 /* Did we find a cycle? */
363 if (j->marker && j->generation == generation) {
366 /* So, we already have been here. We have a
367 * cycle. Let's try to break it. We go backwards in
368 * our path and try to find a suitable job to
369 * remove. We use the marker to find our way back,
370 * since smart how we are we stored our way back in
373 for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
376 !unit_matters_to_anchor(k->unit, k)) {
377 /* Ok, we can drop this one, so let's
379 log_debug("Breaking order cycle by deleting job %s/%s", unit_id(k->unit), job_type_to_string(k->type));
380 transaction_delete_unit(m, k->unit);
384 /* Check if this in fact was the beginning of
393 /* Make the marker point to where we come from, so that we can
394 * find our way backwards if we want to break a cycle */
396 j->generation = generation;
398 /* We assume that the the dependencies are bidirectional, and
399 * hence can ignore UNIT_AFTER */
400 SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
403 /* Is there a job for this unit? */
404 if (!(o = hashmap_get(m->transaction_jobs, u)))
406 /* Ok, there is no job for this in the
407 * transaction, but maybe there is already one
409 if (!(o = u->meta.job))
412 if ((r = transaction_verify_order_one(m, o, j, generation)) < 0)
419 static int transaction_verify_order(Manager *m, unsigned *generation) {
427 /* Check if the ordering graph is cyclic. If it is, try to fix
428 * that up by dropping one of the jobs. */
430 HASHMAP_FOREACH(j, m->transaction_jobs, i)
431 if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
437 static void transaction_collect_garbage(Manager *m) {
442 /* Drop jobs that are not required by any other job */
450 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
454 log_debug("Garbage collecting job %s/%s", unit_id(j->unit), job_type_to_string(j->type));
455 transaction_delete_job(m, j);
463 static int transaction_is_destructive(Manager *m, JobMode mode) {
469 /* Checks whether applying this transaction means that
470 * existing jobs would be replaced */
472 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
475 assert(!j->transaction_prev);
476 assert(!j->transaction_next);
478 if (j->unit->meta.job &&
479 j->unit->meta.job != j &&
480 !job_type_is_superset(j->type, j->unit->meta.job->type))
487 static void transaction_minimize_impact(Manager *m) {
491 /* Drops all unnecessary jobs that reverse already active jobs
492 * or that stop a running service. */
500 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
501 LIST_FOREACH(transaction, j, j) {
503 /* If it matters, we shouldn't drop it */
504 if (j->matters_to_anchor)
507 /* Would this stop a running service?
508 * Would this change an existing job?
509 * If so, let's drop this entry */
510 if ((j->type != JOB_STOP || UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(j->unit))) &&
511 (!j->unit->meta.job || job_type_is_conflicting(j->type, j->unit->meta.job->state)))
514 /* Ok, let's get rid of this */
515 log_debug("Deleting %s/%s to minimize impact", unit_id(j->unit), job_type_to_string(j->type));
516 transaction_delete_job(m, j);
528 static int transaction_apply(Manager *m, JobMode mode) {
533 /* Moves the transaction jobs to the set of active jobs */
535 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
537 assert(!j->transaction_prev);
538 assert(!j->transaction_next);
543 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
547 while ((j = hashmap_steal_first(m->transaction_jobs))) {
551 if (j->unit->meta.job)
552 job_free(j->unit->meta.job);
554 j->unit->meta.job = j;
557 /* We're fully installed. Now let's free data we don't
560 assert(!j->transaction_next);
561 assert(!j->transaction_prev);
566 /* As last step, kill all remaining job dependencies. */
567 transaction_clean_dependencies(m);
573 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
577 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
583 static int transaction_activate(Manager *m, JobMode mode) {
585 unsigned generation = 1;
589 /* This applies the changes recorded in transaction_jobs to
590 * the actual list of jobs, if possible. */
592 /* First step: figure out which jobs matter */
593 transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
595 /* Second step: Try not to stop any running services if
596 * we don't have to. Don't try to reverse running
597 * jobs if we don't have to. */
598 transaction_minimize_impact(m);
601 /* Third step: Let's remove unneeded jobs that might
603 transaction_collect_garbage(m);
605 /* Fourth step: verify order makes sense and correct
606 * cycles if necessary and possible */
607 if ((r = transaction_verify_order(m, &generation)) >= 0)
613 /* Let's see if the resulting transaction ordering
614 * graph is still cyclic... */
618 /* Fifth step: let's drop unmergeable entries if
619 * necessary and possible, merge entries we can
621 if ((r = transaction_merge_jobs(m)) >= 0)
627 /* Sixth step: an entry got dropped, let's garbage
628 * collect its dependencies. */
629 transaction_collect_garbage(m);
631 /* Let's see if the resulting transaction still has
632 * unmergeable entries ... */
635 /* Seventh step: check whether we can actually apply this */
636 if (mode == JOB_FAIL)
637 if ((r = transaction_is_destructive(m, mode)) < 0)
640 /* Eights step: apply changes */
641 if ((r = transaction_apply(m, mode)) < 0)
644 assert(hashmap_isempty(m->transaction_jobs));
645 assert(!m->transaction_anchor);
650 transaction_abort(m);
654 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool force, bool *is_new) {
661 /* Looks for an axisting prospective job and returns that. If
662 * it doesn't exist it is created and added to the prospective
665 f = hashmap_get(m->transaction_jobs, unit);
667 LIST_FOREACH(transaction, j, f) {
668 assert(j->unit == unit);
670 if (j->type == type) {
677 if (unit->meta.job && unit->meta.job->type == type)
679 else if (!(j = job_new(m, type, unit)))
684 j->matters_to_anchor = false;
687 LIST_PREPEND(Job, transaction, f, j);
689 if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
700 void manager_transaction_unlink_job(Manager *m, Job *j) {
704 if (j->transaction_prev)
705 j->transaction_prev->transaction_next = j->transaction_next;
706 else if (j->transaction_next)
707 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
709 hashmap_remove_value(m->transaction_jobs, j->unit, j);
711 if (j->transaction_next)
712 j->transaction_next->transaction_prev = j->transaction_prev;
714 j->transaction_prev = j->transaction_next = NULL;
716 while (j->subject_list)
717 job_dependency_free(j->subject_list);
719 while (j->object_list) {
720 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
722 job_dependency_free(j->object_list);
725 log_debug("Deleting job %s/%s as dependency of job %s/%s",
726 unit_id(other->unit), job_type_to_string(other->type),
727 unit_id(j->unit), job_type_to_string(j->type));
728 transaction_delete_job(m, other);
733 static int transaction_add_job_and_dependencies(Manager *m, JobType type, Unit *unit, Job *by, bool matters, bool force, Job **_ret) {
741 assert(type < _JOB_TYPE_MAX);
744 if (unit->meta.load_state != UNIT_LOADED)
747 if (!unit_job_is_applicable(unit, type))
750 /* First add the job. */
751 if (!(ret = transaction_add_one_job(m, type, unit, force, &is_new)))
754 /* Then, add a link to the job. */
755 if (!job_dependency_new(by, ret, matters))
759 /* Finally, recursively add in all dependencies. */
760 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
761 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
762 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
764 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUIRES], i)
765 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
767 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
768 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, force, NULL)) < 0 && r != -EBADR)
770 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
771 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
773 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUISITE], i)
774 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
776 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
777 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
780 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
782 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
783 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
787 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
796 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool force, Job **_ret) {
801 assert(type < _JOB_TYPE_MAX);
803 assert(mode < _JOB_MODE_MAX);
805 if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, force, &ret))) {
806 transaction_abort(m);
810 if ((r = transaction_activate(m, mode)) < 0)
819 Job *manager_get_job(Manager *m, uint32_t id) {
822 return hashmap_get(m->jobs, UINT32_TO_PTR(id));
825 Unit *manager_get_unit(Manager *m, const char *name) {
829 return hashmap_get(m->units, name);
832 static void dispatch_load_queue(Manager *m) {
837 /* Make sure we are not run recursively */
838 if (m->dispatching_load_queue)
841 m->dispatching_load_queue = true;
843 /* Dispatches the load queue. Takes a unit from the queue and
844 * tries to load its data until the queue is empty */
846 while ((meta = m->load_queue)) {
847 assert(meta->in_load_queue);
849 unit_load(UNIT(meta));
852 m->dispatching_load_queue = false;
855 int manager_load_unit(Manager *m, const char *path, Unit **_ret) {
864 /* This will load the service information files, but not actually
865 * start any services or anything. */
867 name = file_name_from_path(path);
869 if ((ret = manager_get_unit(m, name))) {
874 if (!(ret = unit_new(m)))
878 if (!(ret->meta.load_path = strdup(path))) {
884 if ((r = unit_add_name(ret, name)) < 0) {
889 unit_add_to_load_queue(ret);
890 dispatch_load_queue(m);
896 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
903 HASHMAP_FOREACH(j, s->jobs, i)
904 job_dump(j, f, prefix);
907 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
915 HASHMAP_FOREACH_KEY(u, t, s->units, i)
917 unit_dump(u, f, prefix);
920 void manager_clear_jobs(Manager *m) {
925 transaction_abort(m);
927 while ((j = hashmap_first(m->jobs)))
931 void manager_dispatch_run_queue(Manager *m) {
934 if (m->dispatching_run_queue)
937 m->dispatching_run_queue = true;
939 while ((j = m->run_queue)) {
940 assert(j->installed);
941 assert(j->in_run_queue);
943 job_run_and_invalidate(j);
946 m->dispatching_run_queue = false;
949 static int manager_dispatch_sigchld(Manager *m) {
952 log_debug("dispatching SIGCHLD");
959 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG) < 0) {
970 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
973 log_debug("child %llu died (code=%s, status=%i)", (long long unsigned) si.si_pid, sigchld_code(si.si_code), si.si_status);
975 if (!(u = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
978 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
984 static int manager_process_signal_fd(Manager *m, bool *quit) {
986 struct signalfd_siginfo sfsi;
987 bool sigchld = false;
992 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
1003 switch (sfsi.ssi_signo) {
1015 log_info("Got unhandled signal <%s>.", strsignal(sfsi.ssi_signo));
1020 return manager_dispatch_sigchld(m);
1025 static int process_event(Manager *m, struct epoll_event *ev, bool *quit) {
1032 assert(w = ev->data.ptr);
1036 case WATCH_SIGNAL_FD:
1038 /* An incoming signal? */
1039 if (ev->events != POLLIN)
1042 if ((r = manager_process_signal_fd(m, quit)) < 0)
1049 /* Some fd event, to be dispatched to the units */
1050 UNIT_VTABLE(w->unit)->fd_event(w->unit, w->fd, ev->events, w);
1057 /* Some timer event, to be dispatched to the units */
1058 if ((k = read(ev->data.fd, &v, sizeof(v))) != sizeof(v)) {
1060 if (k < 0 && (errno == EINTR || errno == EAGAIN))
1063 return k < 0 ? -errno : -EIO;
1066 UNIT_VTABLE(w->unit)->timer_event(w->unit, v, w);
1071 assert_not_reached("Unknown epoll event type.");
1077 int manager_loop(Manager *m) {
1084 struct epoll_event events[32];
1087 manager_dispatch_run_queue(m);
1089 if ((n = epoll_wait(m->epoll_fd, events, ELEMENTSOF(events), -1)) < 0) {
1091 if (errno == -EINTR)
1097 for (i = 0; i < n; i++) {
1098 if ((r = process_event(m, events + i, &quit)) < 0)