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_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 if ((m->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
53 ev.data.fd = m->signal_fd;
55 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_fd, &ev) < 0)
65 void manager_free(Manager *m) {
71 while ((j = hashmap_first(m->transaction_jobs)))
74 while ((u = hashmap_first(m->units)))
77 hashmap_free(m->units);
78 hashmap_free(m->jobs);
79 hashmap_free(m->transaction_jobs);
80 hashmap_free(m->watch_pids);
83 close_nointr(m->epoll_fd);
84 if (m->signal_fd >= 0)
85 close_nointr(m->signal_fd);
90 static void transaction_delete_job(Manager *m, Job *j) {
94 /* Deletes one job from the transaction */
96 manager_transaction_unlink_job(m, j);
102 static void transaction_delete_unit(Manager *m, Unit *u) {
105 /* Deletes all jobs associated with a certain unit from the
108 while ((j = hashmap_get(m->transaction_jobs, u)))
109 transaction_delete_job(m, j);
112 static void transaction_abort(Manager *m) {
117 while ((j = hashmap_first(m->transaction_jobs)))
119 transaction_delete_job(m, j);
123 assert(hashmap_isempty(m->transaction_jobs));
124 assert(!m->transaction_anchor);
127 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
132 /* A recursive sweep through the graph that marks all units
133 * that matter to the anchor job, i.e. are directly or
134 * indirectly a dependency of the anchor job via paths that
135 * are fully marked as mattering. */
140 l = m->transaction_anchor;
142 LIST_FOREACH(subject, l, l) {
144 /* This link does not matter */
148 /* This unit has already been marked */
149 if (l->object->generation == generation)
152 l->object->matters_to_anchor = true;
153 l->object->generation = generation;
155 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
159 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
160 JobDependency *l, *last;
164 assert(j->unit == other->unit);
165 assert(!j->installed);
167 /* Merges 'other' into 'j' and then deletes j. */
170 j->state = JOB_WAITING;
171 j->forced = j->forced || other->forced;
173 j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
175 /* Patch us in as new owner of the JobDependency objects */
177 LIST_FOREACH(subject, l, other->subject_list) {
178 assert(l->subject == other);
183 /* Merge both lists */
185 last->subject_next = j->subject_list;
187 j->subject_list->subject_prev = last;
188 j->subject_list = other->subject_list;
191 /* Patch us in as new owner of the JobDependency objects */
193 LIST_FOREACH(object, l, other->object_list) {
194 assert(l->object == other);
199 /* Merge both lists */
201 last->object_next = j->object_list;
203 j->object_list->object_prev = last;
204 j->object_list = other->object_list;
207 /* Kill the other job */
208 other->subject_list = NULL;
209 other->object_list = NULL;
210 transaction_delete_job(m, other);
213 static int delete_one_unmergeable_job(Manager *m, Job *j) {
218 /* Tries to delete one item in the linked list
219 * j->transaction_next->transaction_next->... that conflicts
220 * whith another one, in an attempt to make an inconsistent
221 * transaction work. */
223 /* We rely here on the fact that if a merged with b does not
224 * merge with c, either a or b merge with c neither */
225 LIST_FOREACH(transaction, j, j)
226 LIST_FOREACH(transaction, k, j->transaction_next) {
229 /* Is this one mergeable? Then skip it */
230 if (job_type_is_mergeable(j->type, k->type))
233 /* Ok, we found two that conflict, let's see if we can
234 * drop one of them */
235 if (!j->matters_to_anchor)
237 else if (!k->matters_to_anchor)
242 /* Ok, we can drop one, so let's do so. */
243 log_debug("Try to fix job merging by deleting job %s/%s", unit_id(d->unit), job_type_to_string(d->type));
244 transaction_delete_job(m, d);
251 static int transaction_merge_jobs(Manager *m) {
258 /* First step, check whether any of the jobs for one specific
259 * task conflict. If so, try to drop one of them. */
260 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
265 LIST_FOREACH(transaction, k, j->transaction_next) {
266 if ((r = job_type_merge(&t, k->type)) >= 0)
269 /* OK, we could not merge all jobs for this
270 * action. Let's see if we can get rid of one
273 if ((r = delete_one_unmergeable_job(m, j)) >= 0)
274 /* Ok, we managed to drop one, now
275 * let's ask our callers to call us
276 * again after garbage collecting */
279 /* We couldn't merge anything. Failure */
284 /* Second step, merge the jobs. */
285 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
289 /* Merge all transactions */
290 LIST_FOREACH(transaction, k, j->transaction_next)
291 assert_se(job_type_merge(&t, k->type) == 0);
293 /* If an active job is mergeable, merge it too */
294 if (j->unit->meta.job)
295 job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
297 while ((k = j->transaction_next)) {
299 transaction_merge_and_delete_job(m, k, j, t);
302 transaction_merge_and_delete_job(m, j, k, t);
305 assert(!j->transaction_next);
306 assert(!j->transaction_prev);
312 static bool unit_matters_to_anchor(Unit *u, Job *j) {
314 assert(!j->transaction_prev);
316 /* Checks whether at least one of the jobs for this unit
317 * matters to the anchor. */
319 LIST_FOREACH(transaction, j, j)
320 if (j->matters_to_anchor)
326 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
333 assert(!j->transaction_prev);
335 /* Does a recursive sweep through the ordering graph, looking
336 * for a cycle. If we find cycle we try to break it. */
338 /* Did we find a cycle? */
339 if (j->marker && j->generation == generation) {
342 /* So, we already have been here. We have a
343 * cycle. Let's try to break it. We go backwards in
344 * our path and try to find a suitable job to
345 * remove. We use the marker to find our way back,
346 * since smart how we are we stored our way back in
349 for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
352 !unit_matters_to_anchor(k->unit, k)) {
353 /* Ok, we can drop this one, so let's
355 log_debug("Breaking order cycle by deleting job %s/%s", unit_id(k->unit), job_type_to_string(k->type));
356 transaction_delete_unit(m, k->unit);
360 /* Check if this in fact was the beginning of
369 /* Make the marker point to where we come from, so that we can
370 * find our way backwards if we want to break a cycle */
372 j->generation = generation;
374 /* We assume that the the dependencies are bidirectional, and
375 * hence can ignore UNIT_AFTER */
376 SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
379 /* Is there a job for this unit? */
380 if (!(o = hashmap_get(m->transaction_jobs, u)))
382 /* Ok, there is no job for this in the
383 * transaction, but maybe there is already one
385 if (!(o = u->meta.job))
388 if ((r = transaction_verify_order_one(m, o, j, generation)) < 0)
395 static int transaction_verify_order(Manager *m, unsigned *generation) {
403 /* Check if the ordering graph is cyclic. If it is, try to fix
404 * that up by dropping one of the jobs. */
406 HASHMAP_FOREACH(j, m->transaction_jobs, i)
407 if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
413 static void transaction_collect_garbage(Manager *m) {
418 /* Drop jobs that are not required by any other job */
426 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
430 log_debug("Garbage collecting job %s/%s", unit_id(j->unit), job_type_to_string(j->type));
431 transaction_delete_job(m, j);
439 static int transaction_is_destructive(Manager *m, JobMode mode) {
445 /* Checks whether applying this transaction means that
446 * existing jobs would be replaced */
448 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
451 assert(!j->transaction_prev);
452 assert(!j->transaction_next);
454 if (j->unit->meta.job &&
455 j->unit->meta.job != j &&
456 !job_type_is_superset(j->type, j->unit->meta.job->type))
463 static void transaction_minimize_impact(Manager *m) {
467 /* Drops all unnecessary jobs that reverse already active jobs
468 * or that stop a running service. */
476 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
477 LIST_FOREACH(transaction, j, j) {
479 /* If it matters, we shouldn't drop it */
480 if (j->matters_to_anchor)
483 /* Would this stop a running service?
484 * Would this change an existing job?
485 * If so, let's drop this entry */
486 if ((j->type != JOB_STOP || UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(j->unit))) &&
487 (!j->unit->meta.job || job_type_is_conflicting(j->type, j->unit->meta.job->state)))
490 /* Ok, let's get rid of this */
491 log_debug("Deleting %s/%s to minimize impact", unit_id(j->unit), job_type_to_string(j->type));
492 transaction_delete_job(m, j);
504 static int transaction_apply(Manager *m, JobMode mode) {
509 /* Moves the transaction jobs to the set of active jobs */
511 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
513 assert(!j->transaction_prev);
514 assert(!j->transaction_next);
519 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
523 while ((j = hashmap_steal_first(m->transaction_jobs))) {
527 if (j->unit->meta.job)
528 job_free(j->unit->meta.job);
530 j->unit->meta.job = j;
533 /* We're fully installed. Now let's free data we don't
536 assert(!j->transaction_next);
537 assert(!j->transaction_prev);
541 /* As last step, kill all remaining job dependencies. */
542 HASHMAP_FOREACH(j, m->jobs, i) {
543 while (j->subject_list)
544 job_dependency_free(j->subject_list);
545 while (j->object_list)
546 job_dependency_free(j->object_list);
549 assert(!m->transaction_anchor);
555 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
559 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
565 static int transaction_activate(Manager *m, JobMode mode) {
567 unsigned generation = 1;
571 /* This applies the changes recorded in transaction_jobs to
572 * the actual list of jobs, if possible. */
574 /* First step: figure out which jobs matter */
575 transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
577 /* Second step: Try not to stop any running services if
578 * we don't have to. Don't try to reverse running
579 * jobs if we don't have to. */
580 transaction_minimize_impact(m);
583 /* Third step: Let's remove unneeded jobs that might
585 transaction_collect_garbage(m);
587 /* Fourth step: verify order makes sense and correct
588 * cycles if necessary and possible */
589 if ((r = transaction_verify_order(m, &generation)) >= 0)
595 /* Let's see if the resulting transaction ordering
596 * graph is still cyclic... */
600 /* Fifth step: let's drop unmergeable entries if
601 * necessary and possible, merge entries we can
603 if ((r = transaction_merge_jobs(m)) >= 0)
609 /* Sixth step: an entry got dropped, let's garbage
610 * collect its dependencies. */
611 transaction_collect_garbage(m);
613 /* Let's see if the resulting transaction still has
614 * unmergeable entries ... */
617 /* Seventh step: check whether we can actually apply this */
618 if (mode == JOB_FAIL)
619 if ((r = transaction_is_destructive(m, mode)) < 0)
622 /* Eights step: apply changes */
623 if ((r = transaction_apply(m, mode)) < 0)
626 assert(hashmap_isempty(m->transaction_jobs));
627 assert(!m->transaction_anchor);
632 transaction_abort(m);
636 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool force, bool *is_new) {
643 /* Looks for an axisting prospective job and returns that. If
644 * it doesn't exist it is created and added to the prospective
647 f = hashmap_get(m->transaction_jobs, unit);
649 LIST_FOREACH(transaction, j, f) {
650 assert(j->unit == unit);
652 if (j->type == type) {
659 if (unit->meta.job && unit->meta.job->type == type)
661 else if (!(j = job_new(m, type, unit)))
666 j->matters_to_anchor = false;
669 LIST_PREPEND(Job, transaction, f, j);
671 if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
682 void manager_transaction_unlink_job(Manager *m, Job *j) {
686 if (j->transaction_prev)
687 j->transaction_prev->transaction_next = j->transaction_next;
688 else if (j->transaction_next)
689 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
691 hashmap_remove_value(m->transaction_jobs, j->unit, j);
693 if (j->transaction_next)
694 j->transaction_next->transaction_prev = j->transaction_prev;
696 j->transaction_prev = j->transaction_next = NULL;
698 while (j->subject_list)
699 job_dependency_free(j->subject_list);
701 while (j->object_list) {
702 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
704 job_dependency_free(j->object_list);
707 log_debug("Deleting job %s/%s as dependency of job %s/%s",
708 unit_id(other->unit), job_type_to_string(other->type),
709 unit_id(j->unit), job_type_to_string(j->type));
710 transaction_delete_job(m, other);
715 static int transaction_add_job_and_dependencies(Manager *m, JobType type, Unit *unit, Job *by, bool matters, bool force, Job **_ret) {
723 assert(type < _JOB_TYPE_MAX);
726 if (unit->meta.load_state != UNIT_LOADED)
729 if (!unit_job_is_applicable(unit, type))
732 /* First add the job. */
733 if (!(ret = transaction_add_one_job(m, type, unit, force, &is_new)))
736 /* Then, add a link to the job. */
737 if (!job_dependency_new(by, ret, matters))
741 /* Finally, recursively add in all dependencies. */
742 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
743 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
744 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
746 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUIRES], i)
747 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
749 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
750 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, force, NULL)) < 0 && r != -EBADR)
752 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
753 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
755 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUISITE], i)
756 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
758 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
759 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
762 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
764 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
765 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
769 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
778 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool force, Job **_ret) {
783 assert(type < _JOB_TYPE_MAX);
785 assert(mode < _JOB_MODE_MAX);
787 if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, force, &ret))) {
788 transaction_abort(m);
792 if ((r = transaction_activate(m, mode)) < 0)
801 Job *manager_get_job(Manager *m, uint32_t id) {
804 return hashmap_get(m->jobs, UINT32_TO_PTR(id));
807 Unit *manager_get_unit(Manager *m, const char *name) {
811 return hashmap_get(m->units, name);
814 static void dispatch_load_queue(Manager *m) {
819 /* Make sure we are not run recursively */
820 if (m->dispatching_load_queue)
823 m->dispatching_load_queue = true;
825 /* Dispatches the load queue. Takes a unit from the queue and
826 * tries to load its data until the queue is empty */
828 while ((meta = m->load_queue)) {
829 assert(meta->in_load_queue);
831 unit_load(UNIT(meta));
834 m->dispatching_load_queue = false;
837 int manager_load_unit(Manager *m, const char *path, Unit **_ret) {
846 /* This will load the service information files, but not actually
847 * start any services or anything. */
849 name = file_name_from_path(path);
851 if ((ret = manager_get_unit(m, name))) {
856 if (!(ret = unit_new(m)))
860 if (!(ret->meta.load_path = strdup(path))) {
866 if ((r = unit_add_name(ret, name)) < 0) {
871 unit_add_to_load_queue(ret);
872 dispatch_load_queue(m);
878 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
885 HASHMAP_FOREACH(j, s->jobs, i)
886 job_dump(j, f, prefix);
889 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
897 HASHMAP_FOREACH_KEY(u, t, s->units, i)
899 unit_dump(u, f, prefix);
902 void manager_clear_jobs(Manager *m) {
907 transaction_abort(m);
909 while ((j = hashmap_first(m->jobs)))
913 void manager_dispatch_run_queue(Manager *m) {
916 if (m->dispatching_run_queue)
919 m->dispatching_run_queue = true;
921 while ((j = m->run_queue)) {
922 assert(j->installed);
923 assert(j->in_run_queue);
925 job_run_and_invalidate(j);
928 m->dispatching_run_queue = false;
931 static int manager_dispatch_sigchld(Manager *m) {
939 if (waitid(P_ALL, 0, &si, WNOHANG) < 0)
945 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
948 if (!(u = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
951 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
957 static int manager_process_signal_fd(Manager *m) {
959 struct signalfd_siginfo sfsi;
960 bool sigchld = false;
965 if ((n = read(m->signal_fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
976 if (sfsi.ssi_signo == SIGCHLD)
981 return manager_dispatch_sigchld(m);
986 static int process_event(Manager *m, struct epoll_event *ev) {
992 switch (ev->data.u32) {
995 assert(ev->data.fd == m->signal_fd);
997 /* An incoming signal? */
998 if (ev->events != POLLIN)
1001 if ((r = manager_process_signal_fd(m)) < 0)
1009 /* Some fd event, to be dispatched to the units */
1010 assert_se(u = ev->data.ptr);
1011 UNIT_VTABLE(u)->fd_event(u, ev->data.fd, ev->events);
1015 case MANAGER_TIMER: {
1020 /* Some timer event, to be dispatched to the units */
1021 if ((k = read(ev->data.fd, &v, sizeof(v))) != sizeof(v)) {
1023 if (k < 0 && (errno == EINTR || errno == EAGAIN))
1026 return k < 0 ? -errno : -EIO;
1029 assert_se(u = ev->data.ptr);
1030 UNIT_VTABLE(u)->timer_event(u, ev->data.fd, v);
1035 assert_not_reached("Unknown epoll event type.");
1041 int manager_loop(Manager *m) {
1047 struct epoll_event events[32];
1050 manager_dispatch_run_queue(m);
1052 if ((n = epoll_wait(m->epoll_fd, events, ELEMENTSOF(events), -1)) < 0) {
1054 if (errno == -EINTR)
1060 for (i = 0; i < n; i++)
1061 if ((r = process_event(m, events + i)) < 0)