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->names = 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 ((n = hashmap_first(m->names)))
74 while ((j = hashmap_steal_first(m->transaction_jobs)))
77 hashmap_free(m->names);
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_name(Manager *m, Name *n) {
105 /* Deletes all jobs associated with a certain name from the
108 while ((j = hashmap_get(m->transaction_jobs, n)))
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 names
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. */
137 for (l = j ? j->subject_list : m->transaction_anchor; l; l = l->subject_next) {
139 /* This link does not matter */
143 /* This name has already been marked */
144 if (l->object->generation == generation)
147 l->object->matters_to_anchor = true;
148 l->object->generation = generation;
150 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
154 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
155 JobDependency *l, *last;
159 assert(j->name == other->name);
162 /* Merges 'other' into 'j' and then deletes j. */
165 j->state = JOB_WAITING;
166 j->forced = j->forced || other->forced;
168 j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
170 /* Patch us in as new owner of the JobDependency objects */
172 for (l = other->subject_list; l; l = l->subject_next) {
173 assert(l->subject == other);
178 /* Merge both lists */
180 last->subject_next = j->subject_list;
182 j->subject_list->subject_prev = last;
183 j->subject_list = other->subject_list;
186 /* Patch us in as new owner of the JobDependency objects */
188 for (l = other->object_list; l; l = l->object_next) {
189 assert(l->object == other);
194 /* Merge both lists */
196 last->object_next = j->object_list;
198 j->object_list->object_prev = last;
199 j->object_list = other->object_list;
202 /* Kill the other job */
203 other->subject_list = NULL;
204 other->object_list = NULL;
205 transaction_delete_job(m, other);
208 static int delete_one_unmergeable_job(Manager *m, Job *j) {
213 /* Tries to delete one item in the linked list
214 * j->transaction_next->transaction_next->... that conflicts
215 * whith another one, in an attempt to make an inconsistent
216 * transaction work. */
218 /* We rely here on the fact that if a merged with b does not
219 * merge with c, either a or b merge with c neither */
220 for (; j; j = j->transaction_next)
221 for (k = j->transaction_next; k; k = k->transaction_next) {
224 /* Is this one mergeable? Then skip it */
225 if (job_type_is_mergeable(j->type, k->type))
228 /* Ok, we found two that conflict, let's see if we can
229 * drop one of them */
230 if (!j->matters_to_anchor)
232 else if (!k->matters_to_anchor)
237 /* Ok, we can drop one, so let's do so. */
238 log_debug("Try to fix job merging by deleting job %s/%s", name_id(d->name), job_type_to_string(d->type));
239 transaction_delete_job(m, d);
246 static int transaction_merge_jobs(Manager *m) {
253 /* First step, check whether any of the jobs for one specific
254 * task conflict. If so, try to drop one of them. */
255 HASHMAP_FOREACH(j, m->transaction_jobs, state) {
260 for (k = j->transaction_next; k; k = k->transaction_next) {
261 if ((r = job_type_merge(&t, k->type)) >= 0)
264 /* OK, we could not merge all jobs for this
265 * action. Let's see if we can get rid of one
268 if ((r = delete_one_unmergeable_job(m, j)) >= 0)
269 /* Ok, we managed to drop one, now
270 * let's ask our callers to call us
271 * again after garbage collecting */
274 /* We couldn't merge anything. Failure */
279 /* Second step, merge the jobs. */
280 HASHMAP_FOREACH(j, m->transaction_jobs, state) {
284 /* Merge all transactions */
285 for (k = j->transaction_next; k; k = k->transaction_next)
286 assert_se(job_type_merge(&t, k->type) == 0);
288 /* If an active job is mergeable, merge it too */
289 if (j->name->meta.job)
290 job_type_merge(&t, j->name->meta.job->type); /* Might fail. Which is OK */
292 while ((k = j->transaction_next)) {
294 transaction_merge_and_delete_job(m, k, j, t);
297 transaction_merge_and_delete_job(m, j, k, t);
300 assert(!j->transaction_next);
301 assert(!j->transaction_prev);
307 static bool name_matters_to_anchor(Name *n, Job *j) {
309 assert(!j->transaction_prev);
311 /* Checks whether at least one of the jobs for this name
312 * matters to the anchor. */
314 for (; j; j = j->transaction_next)
315 if (j->matters_to_anchor)
321 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
328 assert(!j->transaction_prev);
330 /* Does a recursive sweep through the ordering graph, looking
331 * for a cycle. If we find cycle we try to break it. */
333 /* Did we find a cycle? */
334 if (j->marker && j->generation == generation) {
337 /* So, we already have been here. We have a
338 * cycle. Let's try to break it. We go backwards in
339 * our path and try to find a suitable job to
340 * remove. We use the marker to find our way back,
341 * since smart how we are we stored our way back in
344 for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
347 !name_matters_to_anchor(k->name, k)) {
348 /* Ok, we can drop this one, so let's
350 log_debug("Breaking order cycle by deleting job %s/%s", name_id(k->name), job_type_to_string(k->type));
351 transaction_delete_name(m, k->name);
355 /* Check if this in fact was the beginning of
364 /* Make the marker point to where we come from, so that we can
365 * find our way backwards if we want to break a cycle */
367 j->generation = generation;
369 /* We assume that the the dependencies are bidirectional, and
370 * hence can ignore NAME_AFTER */
371 SET_FOREACH(n, j->name->meta.dependencies[NAME_BEFORE], state) {
374 /* Is there a job for this name? */
375 if (!(o = hashmap_get(m->transaction_jobs, n)))
377 /* Ok, there is no job for this in the
378 * transaction, but maybe there is already one
380 if (!(o = n->meta.job))
383 if ((r = transaction_verify_order_one(m, o, j, generation)) < 0)
390 static int transaction_verify_order(Manager *m, unsigned *generation) {
398 /* Check if the ordering graph is cyclic. If it is, try to fix
399 * that up by dropping one of the jobs. */
401 HASHMAP_FOREACH(j, m->transaction_jobs, state)
402 if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
408 static void transaction_collect_garbage(Manager *m) {
413 /* Drop jobs that are not required by any other job */
421 HASHMAP_FOREACH(j, m->transaction_jobs, state) {
425 log_debug("Garbage collecting job %s/%s", name_id(j->name), job_type_to_string(j->type));
426 transaction_delete_job(m, j);
434 static int transaction_is_destructive(Manager *m, JobMode mode) {
440 /* Checks whether applying this transaction means that
441 * existing jobs would be replaced */
443 HASHMAP_FOREACH(j, m->transaction_jobs, state) {
446 assert(!j->transaction_prev);
447 assert(!j->transaction_next);
449 if (j->name->meta.job &&
450 j->name->meta.job != j &&
451 !job_type_is_superset(j->type, j->name->meta.job->type))
458 static void transaction_minimize_impact(Manager *m) {
462 /* Drops all unnecessary jobs that reverse already active jobs
463 * or that stop a running service. */
471 HASHMAP_FOREACH(j, m->transaction_jobs, state) {
472 for (; j; j = j->transaction_next) {
474 /* If it matters, we shouldn't drop it */
475 if (j->matters_to_anchor)
478 /* Would this stop a running service?
479 * Would this change an existing job?
480 * If so, let's drop this entry */
481 if ((j->type != JOB_STOP || NAME_IS_INACTIVE_OR_DEACTIVATING(name_active_state(j->name))) &&
482 (!j->name->meta.job || job_type_is_conflicting(j->type, j->name->meta.job->state)))
485 /* Ok, let's get rid of this */
486 log_debug("Deleting %s/%s to minimize impact", name_id(j->name), job_type_to_string(j->type));
487 transaction_delete_job(m, j);
499 static int transaction_apply(Manager *m, JobMode mode) {
504 /* Moves the transaction jobs to the set of active jobs */
506 HASHMAP_FOREACH(j, m->transaction_jobs, state) {
508 assert(!j->transaction_prev);
509 assert(!j->transaction_next);
514 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
518 while ((j = hashmap_steal_first(m->transaction_jobs))) {
522 if (j->name->meta.job)
523 job_free(j->name->meta.job);
525 j->name->meta.job = j;
528 /* We're fully installed. Now let's free data we don't
531 assert(!j->transaction_next);
532 assert(!j->transaction_prev);
534 while (j->subject_list)
535 job_dependency_free(j->subject_list);
536 while (j->object_list)
537 job_dependency_free(j->object_list);
540 m->transaction_anchor = NULL;
546 HASHMAP_FOREACH(j, m->transaction_jobs, state) {
550 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
556 static int transaction_activate(Manager *m, JobMode mode) {
558 unsigned generation = 1;
562 /* This applies the changes recorded in transaction_jobs to
563 * the actual list of jobs, if possible. */
565 /* First step: figure out which jobs matter */
566 transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
568 /* Second step: Try not to stop any running services if
569 * we don't have to. Don't try to reverse running
570 * jobs if we don't have to. */
571 transaction_minimize_impact(m);
574 /* Third step: Let's remove unneeded jobs that might
576 transaction_collect_garbage(m);
578 /* Fourth step: verify order makes sense and correct
579 * cycles if necessary and possible */
580 if ((r = transaction_verify_order(m, &generation)) >= 0)
586 /* Let's see if the resulting transaction ordering
587 * graph is still cyclic... */
591 /* Fifth step: let's drop unmergeable entries if
592 * necessary and possible, merge entries we can
594 if ((r = transaction_merge_jobs(m)) >= 0)
600 /* Sixth step: an entry got dropped, let's garbage
601 * collect its dependencies. */
602 transaction_collect_garbage(m);
604 /* Let's see if the resulting transaction still has
605 * unmergeable entries ... */
608 /* Seventh step: check whether we can actually apply this */
609 if (mode == JOB_FAIL)
610 if ((r = transaction_is_destructive(m, mode)) < 0)
613 /* Eights step: apply changes */
614 if ((r = transaction_apply(m, mode)) < 0)
617 assert(hashmap_isempty(m->transaction_jobs));
618 assert(!m->transaction_anchor);
623 transaction_abort(m);
627 static Job* transaction_add_one_job(Manager *m, JobType type, Name *name, bool force, bool *is_new) {
634 /* Looks for an axisting prospective job and returns that. If
635 * it doesn't exist it is created and added to the prospective
638 f = hashmap_get(m->transaction_jobs, name);
640 for (j = f; j; j = j->transaction_next) {
641 assert(j->name == name);
643 if (j->type == type) {
650 if (name->meta.job && name->meta.job->type == type)
652 else if (!(j = job_new(m, type, name)))
655 if ((r = hashmap_replace(m->transaction_jobs, name, j)) < 0) {
660 j->transaction_next = f;
663 f->transaction_prev = j;
667 j->matters_to_anchor = false;
676 void manager_transaction_unlink_job(Manager *m, Job *j) {
680 if (j->transaction_prev)
681 j->transaction_prev->transaction_next = j->transaction_next;
682 else if (j->transaction_next)
683 hashmap_replace(m->transaction_jobs, j->name, j->transaction_next);
685 hashmap_remove_value(m->transaction_jobs, j->name, j);
687 if (j->transaction_next)
688 j->transaction_next->transaction_prev = j->transaction_prev;
690 j->transaction_prev = j->transaction_next = NULL;
692 while (j->subject_list)
693 job_dependency_free(j->subject_list);
695 while (j->object_list) {
696 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
698 job_dependency_free(j->object_list);
701 log_debug("Deleting job %s/%s as dependency of job %s/%s",
702 name_id(other->name), job_type_to_string(other->type),
703 name_id(j->name), job_type_to_string(j->type));
704 transaction_delete_job(m, other);
709 static int transaction_add_job_and_dependencies(Manager *m, JobType type, Name *name, Job *by, bool matters, bool force, Job **_ret) {
717 assert(type < _JOB_TYPE_MAX);
720 if (name->meta.load_state != NAME_LOADED)
723 if (!job_type_is_applicable(type, name->meta.type))
726 /* First add the job. */
727 if (!(ret = transaction_add_one_job(m, type, name, force, &is_new)))
730 /* Then, add a link to the job. */
731 if (!job_dependency_new(by, ret, matters))
735 /* Finally, recursively add in all dependencies. */
736 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
737 SET_FOREACH(dep, ret->name->meta.dependencies[NAME_REQUIRES], state)
738 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
740 SET_FOREACH(dep, ret->name->meta.dependencies[NAME_SOFT_REQUIRES], state)
741 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
743 SET_FOREACH(dep, ret->name->meta.dependencies[NAME_WANTS], state)
744 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, force, NULL)) < 0 && r != -EBADR)
746 SET_FOREACH(dep, ret->name->meta.dependencies[NAME_REQUISITE], state)
747 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
749 SET_FOREACH(dep, ret->name->meta.dependencies[NAME_SOFT_REQUISITE], state)
750 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
752 SET_FOREACH(dep, ret->name->meta.dependencies[NAME_CONFLICTS], state)
753 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
756 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
758 SET_FOREACH(dep, ret->name->meta.dependencies[NAME_REQUIRED_BY], state)
759 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
763 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
772 int manager_add_job(Manager *m, JobType type, Name *name, JobMode mode, bool force, Job **_ret) {
777 assert(type < _JOB_TYPE_MAX);
779 assert(mode < _JOB_MODE_MAX);
781 if ((r = transaction_add_job_and_dependencies(m, type, name, NULL, true, force, &ret))) {
782 transaction_abort(m);
786 if ((r = transaction_activate(m, mode)) < 0)
795 Job *manager_get_job(Manager *m, uint32_t id) {
798 return hashmap_get(m->jobs, UINT32_TO_PTR(id));
801 Name *manager_get_name(Manager *m, const char *name) {
805 return hashmap_get(m->names, name);
808 static int dispatch_load_queue(Manager *m) {
813 /* Make sure we are not run recursively */
814 if (m->dispatching_load_queue)
817 m->dispatching_load_queue = true;
819 /* Dispatches the load queue. Takes a name from the queue and
820 * tries to load its data until the queue is empty */
822 while ((meta = m->load_queue)) {
823 name_load(NAME(meta));
824 LIST_REMOVE(Meta, m->load_queue, meta);
827 m->dispatching_load_queue = false;
832 int manager_load_name(Manager *m, const char *name, Name **_ret) {
842 if (!name_is_valid(name))
845 /* This will load the service information files, but not actually
846 * start any services or anything */
848 if ((ret = manager_get_name(m, name)))
851 if ((t = name_type_from_string(name)) == _NAME_TYPE_INVALID)
854 if (!(ret = name_new(m)))
859 if (!(n = strdup(name))) {
864 if ((r = set_put(ret->meta.names, n)) < 0) {
870 if ((r = name_link(ret)) < 0) {
875 /* At this point the new entry is created and linked. However,
876 * not loaded. Now load this entry and all its dependencies
879 dispatch_load_queue(m);
887 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
894 HASHMAP_FOREACH(j, s->jobs, state)
895 job_dump(j, f, prefix);
898 void manager_dump_names(Manager *s, FILE *f, const char *prefix) {
906 HASHMAP_FOREACH_KEY(n, t, s->names, state)
908 name_dump(n, f, prefix);
911 void manager_clear_jobs(Manager *m) {
916 transaction_abort(m);
918 while ((j = hashmap_first(m->jobs)))
922 void manager_run_jobs(Manager *m) {
927 HASHMAP_FOREACH(j, m->jobs, state) {
928 r = job_run_and_invalidate(j);
930 /* FIXME... the list of jobs might have changed */
934 int manager_dispatch_sigchld(Manager *m) {
942 if (waitid(P_ALL, 0, &si, WNOHANG) < 0)
948 if (!(n = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
951 NAME_VTABLE(n)->sigchld_event(n, si.si_pid, si.si_code, si.si_status);
957 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 manager_dispatch_sigchld(m);
986 int manager_loop(Manager *m) {
988 struct epoll_event events[32];
995 if ((n = epoll_wait(m->epoll_fd, events, ELEMENTSOF(events), -1)) < 0) {
1003 for (i = 0; i < n; i++) {
1005 if (events[i].data.fd == m->signal_fd) {
1007 /* An incoming signal? */
1008 if (events[i].events != POLLIN)
1011 if ((r = manager_process_signal_fd(m)) < 0)
1016 /* Some other fd event, to be dispatched to the names */
1017 assert_se(n = events[i].data.ptr);
1018 NAME_VTABLE(n)->fd_event(n, events[i].data.fd, events[i].events);