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(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
48 m->signal_watch.type = WATCH_SIGNAL_FD;
49 if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
54 ev.data.ptr = &m->signal_watch;
56 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
66 void manager_free(Manager *m) {
72 while ((j = hashmap_first(m->transaction_jobs)))
75 while ((u = hashmap_first(m->units)))
78 hashmap_free(m->units);
79 hashmap_free(m->jobs);
80 hashmap_free(m->transaction_jobs);
81 hashmap_free(m->watch_pids);
84 close_nointr(m->epoll_fd);
85 if (m->signal_watch.fd >= 0)
86 close_nointr(m->signal_watch.fd);
91 static void transaction_delete_job(Manager *m, Job *j) {
95 /* Deletes one job from the transaction */
97 manager_transaction_unlink_job(m, j);
103 static void transaction_delete_unit(Manager *m, Unit *u) {
106 /* Deletes all jobs associated with a certain unit from the
109 while ((j = hashmap_get(m->transaction_jobs, u)))
110 transaction_delete_job(m, j);
113 static void transaction_clean_dependencies(Manager *m) {
119 /* Drops all dependencies of all installed jobs */
121 HASHMAP_FOREACH(j, m->jobs, i) {
122 while (j->subject_list)
123 job_dependency_free(j->subject_list);
124 while (j->object_list)
125 job_dependency_free(j->object_list);
128 assert(!m->transaction_anchor);
131 static void transaction_abort(Manager *m) {
136 while ((j = hashmap_first(m->transaction_jobs)))
138 transaction_delete_job(m, j);
142 assert(hashmap_isempty(m->transaction_jobs));
144 transaction_clean_dependencies(m);
147 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
152 /* A recursive sweep through the graph that marks all units
153 * that matter to the anchor job, i.e. are directly or
154 * indirectly a dependency of the anchor job via paths that
155 * are fully marked as mattering. */
160 l = m->transaction_anchor;
162 LIST_FOREACH(subject, l, l) {
164 /* This link does not matter */
168 /* This unit has already been marked */
169 if (l->object->generation == generation)
172 l->object->matters_to_anchor = true;
173 l->object->generation = generation;
175 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
179 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
180 JobDependency *l, *last;
184 assert(j->unit == other->unit);
185 assert(!j->installed);
187 /* Merges 'other' into 'j' and then deletes j. */
190 j->state = JOB_WAITING;
191 j->forced = j->forced || other->forced;
193 j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
195 /* Patch us in as new owner of the JobDependency objects */
197 LIST_FOREACH(subject, l, other->subject_list) {
198 assert(l->subject == other);
203 /* Merge both lists */
205 last->subject_next = j->subject_list;
207 j->subject_list->subject_prev = last;
208 j->subject_list = other->subject_list;
211 /* Patch us in as new owner of the JobDependency objects */
213 LIST_FOREACH(object, l, other->object_list) {
214 assert(l->object == other);
219 /* Merge both lists */
221 last->object_next = j->object_list;
223 j->object_list->object_prev = last;
224 j->object_list = other->object_list;
227 /* Kill the other job */
228 other->subject_list = NULL;
229 other->object_list = NULL;
230 transaction_delete_job(m, other);
233 static int delete_one_unmergeable_job(Manager *m, Job *j) {
238 /* Tries to delete one item in the linked list
239 * j->transaction_next->transaction_next->... that conflicts
240 * whith another one, in an attempt to make an inconsistent
241 * transaction work. */
243 /* We rely here on the fact that if a merged with b does not
244 * merge with c, either a or b merge with c neither */
245 LIST_FOREACH(transaction, j, j)
246 LIST_FOREACH(transaction, k, j->transaction_next) {
249 /* Is this one mergeable? Then skip it */
250 if (job_type_is_mergeable(j->type, k->type))
253 /* Ok, we found two that conflict, let's see if we can
254 * drop one of them */
255 if (!j->matters_to_anchor)
257 else if (!k->matters_to_anchor)
262 /* Ok, we can drop one, so let's do so. */
263 log_debug("Try to fix job merging by deleting job %s/%s", unit_id(d->unit), job_type_to_string(d->type));
264 transaction_delete_job(m, d);
271 static int transaction_merge_jobs(Manager *m) {
278 /* First step, check whether any of the jobs for one specific
279 * task conflict. If so, try to drop one of them. */
280 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
285 LIST_FOREACH(transaction, k, j->transaction_next) {
286 if ((r = job_type_merge(&t, k->type)) >= 0)
289 /* OK, we could not merge all jobs for this
290 * action. Let's see if we can get rid of one
293 if ((r = delete_one_unmergeable_job(m, j)) >= 0)
294 /* Ok, we managed to drop one, now
295 * let's ask our callers to call us
296 * again after garbage collecting */
299 /* We couldn't merge anything. Failure */
304 /* Second step, merge the jobs. */
305 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
309 /* Merge all transactions */
310 LIST_FOREACH(transaction, k, j->transaction_next)
311 assert_se(job_type_merge(&t, k->type) == 0);
313 /* If an active job is mergeable, merge it too */
314 if (j->unit->meta.job)
315 job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
317 while ((k = j->transaction_next)) {
319 transaction_merge_and_delete_job(m, k, j, t);
322 transaction_merge_and_delete_job(m, j, k, t);
325 assert(!j->transaction_next);
326 assert(!j->transaction_prev);
332 static bool unit_matters_to_anchor(Unit *u, Job *j) {
334 assert(!j->transaction_prev);
336 /* Checks whether at least one of the jobs for this unit
337 * matters to the anchor. */
339 LIST_FOREACH(transaction, j, j)
340 if (j->matters_to_anchor)
346 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
353 assert(!j->transaction_prev);
355 /* Does a recursive sweep through the ordering graph, looking
356 * for a cycle. If we find cycle we try to break it. */
358 /* Did we find a cycle? */
359 if (j->marker && j->generation == generation) {
362 /* So, we already have been here. We have a
363 * cycle. Let's try to break it. We go backwards in
364 * our path and try to find a suitable job to
365 * remove. We use the marker to find our way back,
366 * since smart how we are we stored our way back in
369 for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
372 !unit_matters_to_anchor(k->unit, k)) {
373 /* Ok, we can drop this one, so let's
375 log_debug("Breaking order cycle by deleting job %s/%s", unit_id(k->unit), job_type_to_string(k->type));
376 transaction_delete_unit(m, k->unit);
380 /* Check if this in fact was the beginning of
389 /* Make the marker point to where we come from, so that we can
390 * find our way backwards if we want to break a cycle */
392 j->generation = generation;
394 /* We assume that the the dependencies are bidirectional, and
395 * hence can ignore UNIT_AFTER */
396 SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
399 /* Is there a job for this unit? */
400 if (!(o = hashmap_get(m->transaction_jobs, u)))
402 /* Ok, there is no job for this in the
403 * transaction, but maybe there is already one
405 if (!(o = u->meta.job))
408 if ((r = transaction_verify_order_one(m, o, j, generation)) < 0)
415 static int transaction_verify_order(Manager *m, unsigned *generation) {
423 /* Check if the ordering graph is cyclic. If it is, try to fix
424 * that up by dropping one of the jobs. */
426 HASHMAP_FOREACH(j, m->transaction_jobs, i)
427 if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
433 static void transaction_collect_garbage(Manager *m) {
438 /* Drop jobs that are not required by any other job */
446 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
450 log_debug("Garbage collecting job %s/%s", unit_id(j->unit), job_type_to_string(j->type));
451 transaction_delete_job(m, j);
459 static int transaction_is_destructive(Manager *m, JobMode mode) {
465 /* Checks whether applying this transaction means that
466 * existing jobs would be replaced */
468 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
471 assert(!j->transaction_prev);
472 assert(!j->transaction_next);
474 if (j->unit->meta.job &&
475 j->unit->meta.job != j &&
476 !job_type_is_superset(j->type, j->unit->meta.job->type))
483 static void transaction_minimize_impact(Manager *m) {
487 /* Drops all unnecessary jobs that reverse already active jobs
488 * or that stop a running service. */
496 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
497 LIST_FOREACH(transaction, j, j) {
499 /* If it matters, we shouldn't drop it */
500 if (j->matters_to_anchor)
503 /* Would this stop a running service?
504 * Would this change an existing job?
505 * If so, let's drop this entry */
506 if ((j->type != JOB_STOP || UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(j->unit))) &&
507 (!j->unit->meta.job || job_type_is_conflicting(j->type, j->unit->meta.job->state)))
510 /* Ok, let's get rid of this */
511 log_debug("Deleting %s/%s to minimize impact", unit_id(j->unit), job_type_to_string(j->type));
512 transaction_delete_job(m, j);
524 static int transaction_apply(Manager *m, JobMode mode) {
529 /* Moves the transaction jobs to the set of active jobs */
531 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
533 assert(!j->transaction_prev);
534 assert(!j->transaction_next);
539 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
543 while ((j = hashmap_steal_first(m->transaction_jobs))) {
547 if (j->unit->meta.job)
548 job_free(j->unit->meta.job);
550 j->unit->meta.job = j;
553 /* We're fully installed. Now let's free data we don't
556 assert(!j->transaction_next);
557 assert(!j->transaction_prev);
562 /* As last step, kill all remaining job dependencies. */
563 transaction_clean_dependencies(m);
569 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
573 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
579 static int transaction_activate(Manager *m, JobMode mode) {
581 unsigned generation = 1;
585 /* This applies the changes recorded in transaction_jobs to
586 * the actual list of jobs, if possible. */
588 /* First step: figure out which jobs matter */
589 transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
591 /* Second step: Try not to stop any running services if
592 * we don't have to. Don't try to reverse running
593 * jobs if we don't have to. */
594 transaction_minimize_impact(m);
597 /* Third step: Let's remove unneeded jobs that might
599 transaction_collect_garbage(m);
601 /* Fourth step: verify order makes sense and correct
602 * cycles if necessary and possible */
603 if ((r = transaction_verify_order(m, &generation)) >= 0)
609 /* Let's see if the resulting transaction ordering
610 * graph is still cyclic... */
614 /* Fifth step: let's drop unmergeable entries if
615 * necessary and possible, merge entries we can
617 if ((r = transaction_merge_jobs(m)) >= 0)
623 /* Sixth step: an entry got dropped, let's garbage
624 * collect its dependencies. */
625 transaction_collect_garbage(m);
627 /* Let's see if the resulting transaction still has
628 * unmergeable entries ... */
631 /* Seventh step: check whether we can actually apply this */
632 if (mode == JOB_FAIL)
633 if ((r = transaction_is_destructive(m, mode)) < 0)
636 /* Eights step: apply changes */
637 if ((r = transaction_apply(m, mode)) < 0)
640 assert(hashmap_isempty(m->transaction_jobs));
641 assert(!m->transaction_anchor);
646 transaction_abort(m);
650 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool force, bool *is_new) {
657 /* Looks for an axisting prospective job and returns that. If
658 * it doesn't exist it is created and added to the prospective
661 f = hashmap_get(m->transaction_jobs, unit);
663 LIST_FOREACH(transaction, j, f) {
664 assert(j->unit == unit);
666 if (j->type == type) {
673 if (unit->meta.job && unit->meta.job->type == type)
675 else if (!(j = job_new(m, type, unit)))
680 j->matters_to_anchor = false;
683 LIST_PREPEND(Job, transaction, f, j);
685 if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
696 void manager_transaction_unlink_job(Manager *m, Job *j) {
700 if (j->transaction_prev)
701 j->transaction_prev->transaction_next = j->transaction_next;
702 else if (j->transaction_next)
703 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
705 hashmap_remove_value(m->transaction_jobs, j->unit, j);
707 if (j->transaction_next)
708 j->transaction_next->transaction_prev = j->transaction_prev;
710 j->transaction_prev = j->transaction_next = NULL;
712 while (j->subject_list)
713 job_dependency_free(j->subject_list);
715 while (j->object_list) {
716 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
718 job_dependency_free(j->object_list);
721 log_debug("Deleting job %s/%s as dependency of job %s/%s",
722 unit_id(other->unit), job_type_to_string(other->type),
723 unit_id(j->unit), job_type_to_string(j->type));
724 transaction_delete_job(m, other);
729 static int transaction_add_job_and_dependencies(Manager *m, JobType type, Unit *unit, Job *by, bool matters, bool force, Job **_ret) {
737 assert(type < _JOB_TYPE_MAX);
740 if (unit->meta.load_state != UNIT_LOADED)
743 if (!unit_job_is_applicable(unit, type))
746 /* First add the job. */
747 if (!(ret = transaction_add_one_job(m, type, unit, force, &is_new)))
750 /* Then, add a link to the job. */
751 if (!job_dependency_new(by, ret, matters))
755 /* Finally, recursively add in all dependencies. */
756 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
757 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
758 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
760 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUIRES], i)
761 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
763 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
764 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, force, NULL)) < 0 && r != -EBADR)
766 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
767 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
769 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUISITE], i)
770 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
772 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
773 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
776 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
778 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
779 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
783 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
792 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool force, Job **_ret) {
797 assert(type < _JOB_TYPE_MAX);
799 assert(mode < _JOB_MODE_MAX);
801 if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, force, &ret))) {
802 transaction_abort(m);
806 if ((r = transaction_activate(m, mode)) < 0)
815 Job *manager_get_job(Manager *m, uint32_t id) {
818 return hashmap_get(m->jobs, UINT32_TO_PTR(id));
821 Unit *manager_get_unit(Manager *m, const char *name) {
825 return hashmap_get(m->units, name);
828 static void dispatch_load_queue(Manager *m) {
833 /* Make sure we are not run recursively */
834 if (m->dispatching_load_queue)
837 m->dispatching_load_queue = true;
839 /* Dispatches the load queue. Takes a unit from the queue and
840 * tries to load its data until the queue is empty */
842 while ((meta = m->load_queue)) {
843 assert(meta->in_load_queue);
845 unit_load(UNIT(meta));
848 m->dispatching_load_queue = false;
851 int manager_load_unit(Manager *m, const char *path, Unit **_ret) {
860 /* This will load the service information files, but not actually
861 * start any services or anything. */
863 name = file_name_from_path(path);
865 if ((ret = manager_get_unit(m, name))) {
870 if (!(ret = unit_new(m)))
874 if (!(ret->meta.load_path = strdup(path))) {
880 if ((r = unit_add_name(ret, name)) < 0) {
885 unit_add_to_load_queue(ret);
886 dispatch_load_queue(m);
892 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
899 HASHMAP_FOREACH(j, s->jobs, i)
900 job_dump(j, f, prefix);
903 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
911 HASHMAP_FOREACH_KEY(u, t, s->units, i)
913 unit_dump(u, f, prefix);
916 void manager_clear_jobs(Manager *m) {
921 transaction_abort(m);
923 while ((j = hashmap_first(m->jobs)))
927 void manager_dispatch_run_queue(Manager *m) {
930 if (m->dispatching_run_queue)
933 m->dispatching_run_queue = true;
935 while ((j = m->run_queue)) {
936 assert(j->installed);
937 assert(j->in_run_queue);
939 job_run_and_invalidate(j);
942 m->dispatching_run_queue = false;
945 static int manager_dispatch_sigchld(Manager *m) {
948 log_debug("dispatching SIGCHLD");
955 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG) < 0) {
966 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
969 log_debug("child %llu died (code=%s, status=%i)", (long long unsigned) si.si_pid, sigchld_code(si.si_code), si.si_status);
971 if (!(u = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
974 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
980 static int manager_process_signal_fd(Manager *m) {
982 struct signalfd_siginfo sfsi;
983 bool sigchld = false;
988 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
999 if (sfsi.ssi_signo == SIGCHLD)
1004 return manager_dispatch_sigchld(m);
1009 static int process_event(Manager *m, struct epoll_event *ev) {
1016 assert(w = ev->data.ptr);
1020 case WATCH_SIGNAL_FD:
1022 /* An incoming signal? */
1023 if (ev->events != POLLIN)
1026 if ((r = manager_process_signal_fd(m)) < 0)
1033 /* Some fd event, to be dispatched to the units */
1034 UNIT_VTABLE(w->unit)->fd_event(w->unit, w->fd, ev->events, w);
1041 /* Some timer event, to be dispatched to the units */
1042 if ((k = read(ev->data.fd, &v, sizeof(v))) != sizeof(v)) {
1044 if (k < 0 && (errno == EINTR || errno == EAGAIN))
1047 return k < 0 ? -errno : -EIO;
1050 UNIT_VTABLE(w->unit)->timer_event(w->unit, v, w);
1055 assert_not_reached("Unknown epoll event type.");
1061 int manager_loop(Manager *m) {
1067 struct epoll_event events[32];
1070 manager_dispatch_run_queue(m);
1072 if ((n = epoll_wait(m->epoll_fd, events, ELEMENTSOF(events), -1)) < 0) {
1074 if (errno == -EINTR)
1080 for (i = 0; i < n; i++)
1081 if ((r = process_event(m, events + i)) < 0)