1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
8 #include <sys/signalfd.h>
20 Manager* manager_new(void) {
23 struct epoll_event ev;
25 if (!(m = new0(Manager, 1)))
28 m->signal_watch.fd = m->epoll_fd = -1;
30 if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
33 if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
36 if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
39 if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func)))
42 if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
45 assert_se(reset_all_signal_handlers() == 0);
47 assert_se(sigemptyset(&mask) == 0);
48 assert_se(sigaddset(&mask, SIGCHLD) == 0);
49 assert_se(sigaddset(&mask, SIGINT) == 0);
50 assert_se(sigaddset(&mask, SIGTERM) == 0);
51 assert_se(sigaddset(&mask, SIGWINCH) == 0);
52 assert_se(sigaddset(&mask, SIGHUP) == 0);
53 assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
55 m->signal_watch.type = WATCH_SIGNAL_FD;
56 if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
61 ev.data.ptr = &m->signal_watch;
63 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
73 void manager_free(Manager *m) {
79 while ((j = hashmap_first(m->transaction_jobs)))
82 while ((u = hashmap_first(m->units)))
85 hashmap_free(m->units);
86 hashmap_free(m->jobs);
87 hashmap_free(m->transaction_jobs);
88 hashmap_free(m->watch_pids);
91 close_nointr(m->epoll_fd);
92 if (m->signal_watch.fd >= 0)
93 close_nointr(m->signal_watch.fd);
98 static void transaction_delete_job(Manager *m, Job *j) {
102 /* Deletes one job from the transaction */
104 manager_transaction_unlink_job(m, j);
110 static void transaction_delete_unit(Manager *m, Unit *u) {
113 /* Deletes all jobs associated with a certain unit from the
116 while ((j = hashmap_get(m->transaction_jobs, u)))
117 transaction_delete_job(m, j);
120 static void transaction_clean_dependencies(Manager *m) {
126 /* Drops all dependencies of all installed jobs */
128 HASHMAP_FOREACH(j, m->jobs, i) {
129 while (j->subject_list)
130 job_dependency_free(j->subject_list);
131 while (j->object_list)
132 job_dependency_free(j->object_list);
135 assert(!m->transaction_anchor);
138 static void transaction_abort(Manager *m) {
143 while ((j = hashmap_first(m->transaction_jobs)))
145 transaction_delete_job(m, j);
149 assert(hashmap_isempty(m->transaction_jobs));
151 transaction_clean_dependencies(m);
154 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
159 /* A recursive sweep through the graph that marks all units
160 * that matter to the anchor job, i.e. are directly or
161 * indirectly a dependency of the anchor job via paths that
162 * are fully marked as mattering. */
167 l = m->transaction_anchor;
169 LIST_FOREACH(subject, l, l) {
171 /* This link does not matter */
175 /* This unit has already been marked */
176 if (l->object->generation == generation)
179 l->object->matters_to_anchor = true;
180 l->object->generation = generation;
182 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
186 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
187 JobDependency *l, *last;
191 assert(j->unit == other->unit);
192 assert(!j->installed);
194 /* Merges 'other' into 'j' and then deletes j. */
197 j->state = JOB_WAITING;
198 j->forced = j->forced || other->forced;
200 j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
202 /* Patch us in as new owner of the JobDependency objects */
204 LIST_FOREACH(subject, l, other->subject_list) {
205 assert(l->subject == other);
210 /* Merge both lists */
212 last->subject_next = j->subject_list;
214 j->subject_list->subject_prev = last;
215 j->subject_list = other->subject_list;
218 /* Patch us in as new owner of the JobDependency objects */
220 LIST_FOREACH(object, l, other->object_list) {
221 assert(l->object == other);
226 /* Merge both lists */
228 last->object_next = j->object_list;
230 j->object_list->object_prev = last;
231 j->object_list = other->object_list;
234 /* Kill the other job */
235 other->subject_list = NULL;
236 other->object_list = NULL;
237 transaction_delete_job(m, other);
240 static int delete_one_unmergeable_job(Manager *m, Job *j) {
245 /* Tries to delete one item in the linked list
246 * j->transaction_next->transaction_next->... that conflicts
247 * whith another one, in an attempt to make an inconsistent
248 * transaction work. */
250 /* We rely here on the fact that if a merged with b does not
251 * merge with c, either a or b merge with c neither */
252 LIST_FOREACH(transaction, j, j)
253 LIST_FOREACH(transaction, k, j->transaction_next) {
256 /* Is this one mergeable? Then skip it */
257 if (job_type_is_mergeable(j->type, k->type))
260 /* Ok, we found two that conflict, let's see if we can
261 * drop one of them */
262 if (!j->matters_to_anchor)
264 else if (!k->matters_to_anchor)
269 /* Ok, we can drop one, so let's do so. */
270 log_debug("Try to fix job merging by deleting job %s/%s", unit_id(d->unit), job_type_to_string(d->type));
271 transaction_delete_job(m, d);
278 static int transaction_merge_jobs(Manager *m) {
285 /* First step, check whether any of the jobs for one specific
286 * task conflict. If so, try to drop one of them. */
287 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
292 LIST_FOREACH(transaction, k, j->transaction_next) {
293 if ((r = job_type_merge(&t, k->type)) >= 0)
296 /* OK, we could not merge all jobs for this
297 * action. Let's see if we can get rid of one
300 if ((r = delete_one_unmergeable_job(m, j)) >= 0)
301 /* Ok, we managed to drop one, now
302 * let's ask our callers to call us
303 * again after garbage collecting */
306 /* We couldn't merge anything. Failure */
311 /* Second step, merge the jobs. */
312 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
316 /* Merge all transactions */
317 LIST_FOREACH(transaction, k, j->transaction_next)
318 assert_se(job_type_merge(&t, k->type) == 0);
320 /* If an active job is mergeable, merge it too */
321 if (j->unit->meta.job)
322 job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
324 while ((k = j->transaction_next)) {
326 transaction_merge_and_delete_job(m, k, j, t);
329 transaction_merge_and_delete_job(m, j, k, t);
332 assert(!j->transaction_next);
333 assert(!j->transaction_prev);
339 static bool unit_matters_to_anchor(Unit *u, Job *j) {
341 assert(!j->transaction_prev);
343 /* Checks whether at least one of the jobs for this unit
344 * matters to the anchor. */
346 LIST_FOREACH(transaction, j, j)
347 if (j->matters_to_anchor)
353 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
360 assert(!j->transaction_prev);
362 /* Does a recursive sweep through the ordering graph, looking
363 * for a cycle. If we find cycle we try to break it. */
365 /* Did we find a cycle? */
366 if (j->marker && j->generation == generation) {
369 /* So, we already have been here. We have a
370 * cycle. Let's try to break it. We go backwards in
371 * our path and try to find a suitable job to
372 * remove. We use the marker to find our way back,
373 * since smart how we are we stored our way back in
376 for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
379 !unit_matters_to_anchor(k->unit, k)) {
380 /* Ok, we can drop this one, so let's
382 log_debug("Breaking order cycle by deleting job %s/%s", unit_id(k->unit), job_type_to_string(k->type));
383 transaction_delete_unit(m, k->unit);
387 /* Check if this in fact was the beginning of
396 /* Make the marker point to where we come from, so that we can
397 * find our way backwards if we want to break a cycle */
399 j->generation = generation;
401 /* We assume that the the dependencies are bidirectional, and
402 * hence can ignore UNIT_AFTER */
403 SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
406 /* Is there a job for this unit? */
407 if (!(o = hashmap_get(m->transaction_jobs, u)))
409 /* Ok, there is no job for this in the
410 * transaction, but maybe there is already one
412 if (!(o = u->meta.job))
415 if ((r = transaction_verify_order_one(m, o, j, generation)) < 0)
422 static int transaction_verify_order(Manager *m, unsigned *generation) {
430 /* Check if the ordering graph is cyclic. If it is, try to fix
431 * that up by dropping one of the jobs. */
433 HASHMAP_FOREACH(j, m->transaction_jobs, i)
434 if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
440 static void transaction_collect_garbage(Manager *m) {
445 /* Drop jobs that are not required by any other job */
453 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
457 log_debug("Garbage collecting job %s/%s", unit_id(j->unit), job_type_to_string(j->type));
458 transaction_delete_job(m, j);
466 static int transaction_is_destructive(Manager *m, JobMode mode) {
472 /* Checks whether applying this transaction means that
473 * existing jobs would be replaced */
475 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
478 assert(!j->transaction_prev);
479 assert(!j->transaction_next);
481 if (j->unit->meta.job &&
482 j->unit->meta.job != j &&
483 !job_type_is_superset(j->type, j->unit->meta.job->type))
490 static void transaction_minimize_impact(Manager *m) {
494 /* Drops all unnecessary jobs that reverse already active jobs
495 * or that stop a running service. */
503 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
504 LIST_FOREACH(transaction, j, j) {
506 /* If it matters, we shouldn't drop it */
507 if (j->matters_to_anchor)
510 /* Would this stop a running service?
511 * Would this change an existing job?
512 * If so, let's drop this entry */
513 if ((j->type != JOB_STOP || UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(j->unit))) &&
514 (!j->unit->meta.job || job_type_is_conflicting(j->type, j->unit->meta.job->state)))
517 /* Ok, let's get rid of this */
518 log_debug("Deleting %s/%s to minimize impact", unit_id(j->unit), job_type_to_string(j->type));
519 transaction_delete_job(m, j);
531 static int transaction_apply(Manager *m, JobMode mode) {
536 /* Moves the transaction jobs to the set of active jobs */
538 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
540 assert(!j->transaction_prev);
541 assert(!j->transaction_next);
546 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
550 while ((j = hashmap_steal_first(m->transaction_jobs))) {
554 if (j->unit->meta.job)
555 job_free(j->unit->meta.job);
557 j->unit->meta.job = j;
560 /* We're fully installed. Now let's free data we don't
563 assert(!j->transaction_next);
564 assert(!j->transaction_prev);
569 /* As last step, kill all remaining job dependencies. */
570 transaction_clean_dependencies(m);
576 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
580 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
586 static int transaction_activate(Manager *m, JobMode mode) {
588 unsigned generation = 1;
592 /* This applies the changes recorded in transaction_jobs to
593 * the actual list of jobs, if possible. */
595 /* First step: figure out which jobs matter */
596 transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
598 /* Second step: Try not to stop any running services if
599 * we don't have to. Don't try to reverse running
600 * jobs if we don't have to. */
601 transaction_minimize_impact(m);
604 /* Third step: Let's remove unneeded jobs that might
606 transaction_collect_garbage(m);
608 /* Fourth step: verify order makes sense and correct
609 * cycles if necessary and possible */
610 if ((r = transaction_verify_order(m, &generation)) >= 0)
616 /* Let's see if the resulting transaction ordering
617 * graph is still cyclic... */
621 /* Fifth step: let's drop unmergeable entries if
622 * necessary and possible, merge entries we can
624 if ((r = transaction_merge_jobs(m)) >= 0)
630 /* Sixth step: an entry got dropped, let's garbage
631 * collect its dependencies. */
632 transaction_collect_garbage(m);
634 /* Let's see if the resulting transaction still has
635 * unmergeable entries ... */
638 /* Seventh step: check whether we can actually apply this */
639 if (mode == JOB_FAIL)
640 if ((r = transaction_is_destructive(m, mode)) < 0)
643 /* Eights step: apply changes */
644 if ((r = transaction_apply(m, mode)) < 0)
647 assert(hashmap_isempty(m->transaction_jobs));
648 assert(!m->transaction_anchor);
653 transaction_abort(m);
657 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool force, bool *is_new) {
664 /* Looks for an axisting prospective job and returns that. If
665 * it doesn't exist it is created and added to the prospective
668 f = hashmap_get(m->transaction_jobs, unit);
670 LIST_FOREACH(transaction, j, f) {
671 assert(j->unit == unit);
673 if (j->type == type) {
680 if (unit->meta.job && unit->meta.job->type == type)
682 else if (!(j = job_new(m, type, unit)))
687 j->matters_to_anchor = false;
690 LIST_PREPEND(Job, transaction, f, j);
692 if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
703 void manager_transaction_unlink_job(Manager *m, Job *j) {
707 if (j->transaction_prev)
708 j->transaction_prev->transaction_next = j->transaction_next;
709 else if (j->transaction_next)
710 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
712 hashmap_remove_value(m->transaction_jobs, j->unit, j);
714 if (j->transaction_next)
715 j->transaction_next->transaction_prev = j->transaction_prev;
717 j->transaction_prev = j->transaction_next = NULL;
719 while (j->subject_list)
720 job_dependency_free(j->subject_list);
722 while (j->object_list) {
723 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
725 job_dependency_free(j->object_list);
728 log_debug("Deleting job %s/%s as dependency of job %s/%s",
729 unit_id(other->unit), job_type_to_string(other->type),
730 unit_id(j->unit), job_type_to_string(j->type));
731 transaction_delete_job(m, other);
736 static int transaction_add_job_and_dependencies(Manager *m, JobType type, Unit *unit, Job *by, bool matters, bool force, Job **_ret) {
744 assert(type < _JOB_TYPE_MAX);
747 if (unit->meta.load_state != UNIT_LOADED)
750 if (!unit_job_is_applicable(unit, type))
753 /* First add the job. */
754 if (!(ret = transaction_add_one_job(m, type, unit, force, &is_new)))
757 /* Then, add a link to the job. */
758 if (!job_dependency_new(by, ret, matters))
762 /* Finally, recursively add in all dependencies. */
763 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
764 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
765 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
767 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUIRES], i)
768 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
770 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
771 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, force, NULL)) < 0 && r != -EBADR)
773 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
774 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
776 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUISITE], i)
777 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
779 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
780 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
783 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
785 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
786 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
790 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
799 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool force, Job **_ret) {
804 assert(type < _JOB_TYPE_MAX);
806 assert(mode < _JOB_MODE_MAX);
808 if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, force, &ret))) {
809 transaction_abort(m);
813 if ((r = transaction_activate(m, mode)) < 0)
822 Job *manager_get_job(Manager *m, uint32_t id) {
825 return hashmap_get(m->jobs, UINT32_TO_PTR(id));
828 Unit *manager_get_unit(Manager *m, const char *name) {
832 return hashmap_get(m->units, name);
835 static void dispatch_load_queue(Manager *m) {
840 /* Make sure we are not run recursively */
841 if (m->dispatching_load_queue)
844 m->dispatching_load_queue = true;
846 /* Dispatches the load queue. Takes a unit from the queue and
847 * tries to load its data until the queue is empty */
849 while ((meta = m->load_queue)) {
850 assert(meta->in_load_queue);
852 unit_load(UNIT(meta));
855 m->dispatching_load_queue = false;
858 int manager_load_unit(Manager *m, const char *path, Unit **_ret) {
867 /* This will load the service information files, but not actually
868 * start any services or anything. */
870 name = file_name_from_path(path);
872 if ((ret = manager_get_unit(m, name))) {
877 if (!(ret = unit_new(m)))
881 if (!(ret->meta.load_path = strdup(path))) {
887 if ((r = unit_add_name(ret, name)) < 0) {
892 unit_add_to_load_queue(ret);
893 dispatch_load_queue(m);
899 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
906 HASHMAP_FOREACH(j, s->jobs, i)
907 job_dump(j, f, prefix);
910 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
918 HASHMAP_FOREACH_KEY(u, t, s->units, i)
920 unit_dump(u, f, prefix);
923 void manager_clear_jobs(Manager *m) {
928 transaction_abort(m);
930 while ((j = hashmap_first(m->jobs)))
934 void manager_dispatch_run_queue(Manager *m) {
937 if (m->dispatching_run_queue)
940 m->dispatching_run_queue = true;
942 while ((j = m->run_queue)) {
943 assert(j->installed);
944 assert(j->in_run_queue);
946 job_run_and_invalidate(j);
949 m->dispatching_run_queue = false;
952 static int manager_dispatch_sigchld(Manager *m) {
955 log_debug("dispatching SIGCHLD");
962 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG) < 0) {
973 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
976 log_debug("child %llu died (code=%s, status=%i)", (long long unsigned) si.si_pid, sigchld_code(si.si_code), si.si_status);
978 if (!(u = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
981 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
987 static int manager_process_signal_fd(Manager *m, bool *quit) {
989 struct signalfd_siginfo sfsi;
990 bool sigchld = false;
995 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
1000 if (errno == EAGAIN)
1006 switch (sfsi.ssi_signo) {
1018 log_info("Got unhandled signal <%s>.", strsignal(sfsi.ssi_signo));
1023 return manager_dispatch_sigchld(m);
1028 static int process_event(Manager *m, struct epoll_event *ev, bool *quit) {
1035 assert(w = ev->data.ptr);
1039 case WATCH_SIGNAL_FD:
1041 /* An incoming signal? */
1042 if (ev->events != POLLIN)
1045 if ((r = manager_process_signal_fd(m, quit)) < 0)
1052 /* Some fd event, to be dispatched to the units */
1053 UNIT_VTABLE(w->unit)->fd_event(w->unit, w->fd, ev->events, w);
1060 /* Some timer event, to be dispatched to the units */
1061 if ((k = read(ev->data.fd, &v, sizeof(v))) != sizeof(v)) {
1063 if (k < 0 && (errno == EINTR || errno == EAGAIN))
1066 return k < 0 ? -errno : -EIO;
1069 UNIT_VTABLE(w->unit)->timer_event(w->unit, v, w);
1074 assert_not_reached("Unknown epoll event type.");
1080 int manager_loop(Manager *m) {
1087 struct epoll_event events[32];
1090 manager_dispatch_run_queue(m);
1092 if ((n = epoll_wait(m->epoll_fd, events, ELEMENTSOF(events), -1)) < 0) {
1094 if (errno == -EINTR)
1100 for (i = 0; i < n; i++) {
1101 if ((r = process_event(m, events + i, &quit)) < 0)