+ /* If it matters, we shouldn't drop it */
+ if (j->matters_to_anchor)
+ continue;
+
+ /* Would this stop a running service?
+ * Would this change an existing job?
+ * If so, let's drop this entry */
+
+ stops_running_service =
+ j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit));
+
+ changes_existing_job =
+ j->unit->meta.job && job_type_is_conflicting(j->type, j->unit->meta.job->state);
+
+ if (!stops_running_service && !changes_existing_job)
+ continue;
+
+ if (stops_running_service)
+ log_debug("%s/%s would stop a running service.", unit_id(j->unit), job_type_to_string(j->type));
+
+ if (changes_existing_job)
+ log_debug("%s/%s would change existing job.", unit_id(j->unit), job_type_to_string(j->type));
+
+ /* Ok, let's get rid of this */
+ log_debug("Deleting %s/%s to minimize impact.", unit_id(j->unit), job_type_to_string(j->type));
+
+ transaction_delete_job(m, j, true);
+ again = true;
+ break;
+ }
+
+ if (again)
+ break;
+ }
+
+ } while (again);
+}
+
+static int transaction_apply(Manager *m, JobMode mode) {
+ Iterator i;
+ Job *j;
+ int r;
+
+ /* Moves the transaction jobs to the set of active jobs */
+
+ HASHMAP_FOREACH(j, m->transaction_jobs, i) {
+ /* Assume merged */
+ assert(!j->transaction_prev);
+ assert(!j->transaction_next);
+
+ if (j->installed)
+ continue;
+
+ if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
+ goto rollback;
+ }
+
+ while ((j = hashmap_steal_first(m->transaction_jobs))) {
+ if (j->installed)
+ continue;
+
+ if (j->unit->meta.job)
+ job_free(j->unit->meta.job);
+
+ j->unit->meta.job = j;
+ j->installed = true;
+
+ /* We're fully installed. Now let's free data we don't
+ * need anymore. */
+
+ assert(!j->transaction_next);
+ assert(!j->transaction_prev);
+
+ job_add_to_run_queue(j);
+ job_add_to_dbus_queue(j);
+ }
+
+ /* As last step, kill all remaining job dependencies. */
+ transaction_clean_dependencies(m);
+
+ return 0;
+
+rollback:
+
+ HASHMAP_FOREACH(j, m->transaction_jobs, i) {
+ if (j->installed)
+ continue;
+
+ hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
+ }
+
+ return r;
+}
+
+static int transaction_activate(Manager *m, JobMode mode) {
+ int r;
+ unsigned generation = 1;
+
+ assert(m);
+
+ /* This applies the changes recorded in transaction_jobs to
+ * the actual list of jobs, if possible. */
+
+ /* First step: figure out which jobs matter */
+ transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
+
+ /* Second step: Try not to stop any running services if
+ * we don't have to. Don't try to reverse running
+ * jobs if we don't have to. */
+ transaction_minimize_impact(m);
+
+ /* Third step: Drop redundant jobs */
+ transaction_drop_redundant(m);
+
+ for (;;) {
+ /* Fourth step: Let's remove unneeded jobs that might
+ * be lurking. */
+ transaction_collect_garbage(m);
+
+ /* Fifth step: verify order makes sense and correct
+ * cycles if necessary and possible */
+ if ((r = transaction_verify_order(m, &generation)) >= 0)
+ break;
+
+ if (r != -EAGAIN) {
+ log_debug("Requested transaction contains an unfixable cyclic ordering dependency: %s", strerror(-r));
+ goto rollback;
+ }
+
+ /* Let's see if the resulting transaction ordering
+ * graph is still cyclic... */
+ }
+
+ for (;;) {
+ /* Sixth step: let's drop unmergeable entries if
+ * necessary and possible, merge entries we can
+ * merge */
+ if ((r = transaction_merge_jobs(m)) >= 0)
+ break;
+
+ if (r != -EAGAIN) {
+ log_debug("Requested transaction contains unmergable jobs: %s", strerror(-r));
+ goto rollback;
+ }
+
+ /* Seventh step: an entry got dropped, let's garbage
+ * collect its dependencies. */
+ transaction_collect_garbage(m);
+
+ /* Let's see if the resulting transaction still has
+ * unmergeable entries ... */
+ }
+
+ /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */
+ transaction_drop_redundant(m);
+
+ /* Ninth step: check whether we can actually apply this */
+ if (mode == JOB_FAIL)
+ if ((r = transaction_is_destructive(m, mode)) < 0) {
+ log_debug("Requested transaction contradicts existing jobs: %s", strerror(-r));
+ goto rollback;
+ }
+
+ /* Tenth step: apply changes */
+ if ((r = transaction_apply(m, mode)) < 0) {
+ log_debug("Failed to apply transaction: %s", strerror(-r));
+ goto rollback;
+ }
+
+ assert(hashmap_isempty(m->transaction_jobs));
+ assert(!m->transaction_anchor);
+
+ return 0;
+
+rollback:
+ transaction_abort(m);
+ return r;
+}
+
+static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool force, bool *is_new) {
+ Job *j, *f;
+ int r;
+
+ assert(m);
+ assert(unit);
+
+ /* Looks for an axisting prospective job and returns that. If
+ * it doesn't exist it is created and added to the prospective
+ * jobs list. */
+
+ f = hashmap_get(m->transaction_jobs, unit);
+
+ LIST_FOREACH(transaction, j, f) {
+ assert(j->unit == unit);
+
+ if (j->type == type) {
+ if (is_new)
+ *is_new = false;
+ return j;
+ }
+ }
+
+ if (unit->meta.job && unit->meta.job->type == type)
+ j = unit->meta.job;
+ else if (!(j = job_new(m, type, unit)))
+ return NULL;
+
+ j->generation = 0;
+ j->marker = NULL;
+ j->matters_to_anchor = false;
+ j->forced = force;
+
+ LIST_PREPEND(Job, transaction, f, j);
+
+ if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
+ job_free(j);
+ return NULL;
+ }
+
+ if (is_new)
+ *is_new = true;
+
+ log_debug("Added job %s/%s to transaction.", unit_id(unit), job_type_to_string(type));
+
+ return j;
+}
+
+void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies) {
+ assert(m);
+ assert(j);
+
+ if (j->transaction_prev)
+ j->transaction_prev->transaction_next = j->transaction_next;
+ else if (j->transaction_next)
+ hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
+ else
+ hashmap_remove_value(m->transaction_jobs, j->unit, j);
+
+ if (j->transaction_next)
+ j->transaction_next->transaction_prev = j->transaction_prev;
+
+ j->transaction_prev = j->transaction_next = NULL;
+
+ while (j->subject_list)
+ job_dependency_free(j->subject_list);
+
+ while (j->object_list) {
+ Job *other = j->object_list->matters ? j->object_list->subject : NULL;
+
+ job_dependency_free(j->object_list);
+
+ if (other && delete_dependencies) {
+ log_debug("Deleting job %s/%s as dependency of job %s/%s",
+ unit_id(other->unit), job_type_to_string(other->type),
+ unit_id(j->unit), job_type_to_string(j->type));
+ transaction_delete_job(m, other, delete_dependencies);
+ }
+ }
+}
+
+static int transaction_add_job_and_dependencies(Manager *m, JobType type, Unit *unit, Job *by, bool matters, bool force, Job **_ret) {
+ Job *ret;
+ Iterator i;
+ Unit *dep;
+ int r;
+ bool is_new;
+
+ assert(m);
+ assert(type < _JOB_TYPE_MAX);
+ assert(unit);
+
+ if (unit->meta.load_state != UNIT_LOADED)
+ return -EINVAL;
+
+ if (!unit_job_is_applicable(unit, type))
+ return -EBADR;
+
+ /* First add the job. */
+ if (!(ret = transaction_add_one_job(m, type, unit, force, &is_new)))
+ return -ENOMEM;
+
+ /* Then, add a link to the job. */
+ if (!job_dependency_new(by, ret, matters))
+ return -ENOMEM;
+
+ if (is_new) {
+ /* Finally, recursively add in all dependencies. */
+ if (type == JOB_START || type == JOB_RELOAD_OR_START) {
+ SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
+ if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
+ goto fail;
+ SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUIRES], i)
+ if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
+ goto fail;
+ SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
+ if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, force, NULL)) < 0)
+ log_warning("Cannot add dependency job for unit %s, ignoring: %s", unit_id(dep), strerror(-r));
+ SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
+ if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
+ goto fail;
+ SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUISITE], i)
+ if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
+ goto fail;
+ SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
+ if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
+ goto fail;
+
+ } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
+
+ SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
+ if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
+ goto fail;
+ }
+
+ /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
+ }
+
+ if (_ret)
+ *_ret = ret;
+
+ return 0;
+
+fail:
+ return r;
+}
+
+int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool force, Job **_ret) {
+ int r;
+ Job *ret;
+
+ assert(m);
+ assert(type < _JOB_TYPE_MAX);
+ assert(unit);
+ assert(mode < _JOB_MODE_MAX);
+
+ log_debug("Trying to enqueue job %s/%s", unit_id(unit), job_type_to_string(type));
+
+ if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, force, &ret)) < 0) {
+ transaction_abort(m);
+ return r;
+ }
+
+ if ((r = transaction_activate(m, mode)) < 0)
+ return r;
+
+ log_debug("Enqueued job %s/%s as %u", unit_id(unit), job_type_to_string(type), (unsigned) ret->id);
+
+ if (_ret)
+ *_ret = ret;
+
+ return 0;
+}
+
+Job *manager_get_job(Manager *m, uint32_t id) {
+ assert(m);
+
+ return hashmap_get(m->jobs, UINT32_TO_PTR(id));
+}
+
+Unit *manager_get_unit(Manager *m, const char *name) {
+ assert(m);
+ assert(name);
+
+ return hashmap_get(m->units, name);
+}
+
+unsigned manager_dispatch_load_queue(Manager *m) {
+ Meta *meta;
+ unsigned n = 0;
+
+ assert(m);
+
+ /* Make sure we are not run recursively */
+ if (m->dispatching_load_queue)
+ return 0;
+
+ m->dispatching_load_queue = true;
+
+ /* Dispatches the load queue. Takes a unit from the queue and
+ * tries to load its data until the queue is empty */
+
+ while ((meta = m->load_queue)) {
+ assert(meta->in_load_queue);
+
+ unit_load(UNIT(meta));
+ n++;
+ }
+
+ m->dispatching_load_queue = false;
+ return n;
+}
+
+int manager_load_unit(Manager *m, const char *path, Unit **_ret) {
+ Unit *ret;
+ int r;
+ const char *name;
+
+ assert(m);
+ assert(path);
+ assert(_ret);
+
+ /* This will load the service information files, but not actually
+ * start any services or anything. */
+
+ name = file_name_from_path(path);
+
+ if ((ret = manager_get_unit(m, name))) {
+ *_ret = ret;
+ return 0;
+ }
+
+ if (!(ret = unit_new(m)))
+ return -ENOMEM;
+
+ if (is_path(path)) {
+ if (!(ret->meta.fragment_path = strdup(path))) {
+ unit_free(ret);
+ return -ENOMEM;
+ }
+ }
+
+ if ((r = unit_add_name(ret, name)) < 0) {
+ unit_free(ret);
+ return r;
+ }
+
+ unit_add_to_load_queue(ret);
+ unit_add_to_dbus_queue(ret);
+
+ manager_dispatch_load_queue(m);
+
+ *_ret = unit_follow_merge(ret);
+ return 0;
+}
+
+void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
+ Iterator i;
+ Job *j;
+
+ assert(s);
+ assert(f);
+
+ HASHMAP_FOREACH(j, s->jobs, i)
+ job_dump(j, f, prefix);
+}
+
+void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
+ Iterator i;
+ Unit *u;
+ const char *t;
+
+ assert(s);
+ assert(f);
+
+ HASHMAP_FOREACH_KEY(u, t, s->units, i)
+ if (unit_id(u) == t)
+ unit_dump(u, f, prefix);
+}
+
+void manager_clear_jobs(Manager *m) {
+ Job *j;
+
+ assert(m);
+
+ transaction_abort(m);
+
+ while ((j = hashmap_first(m->jobs)))
+ job_free(j);
+}
+
+unsigned manager_dispatch_run_queue(Manager *m) {
+ Job *j;
+ unsigned n = 0;
+
+ if (m->dispatching_run_queue)
+ return 0;
+
+ m->dispatching_run_queue = true;
+
+ while ((j = m->run_queue)) {
+ assert(j->installed);
+ assert(j->in_run_queue);
+
+ job_run_and_invalidate(j);
+ n++;
+ }
+
+ m->dispatching_run_queue = false;
+ return n;
+}
+
+unsigned manager_dispatch_dbus_queue(Manager *m) {
+ Job *j;
+ Meta *meta;
+ unsigned n = 0;
+
+ assert(m);
+
+ if (m->dispatching_dbus_queue)
+ return 0;
+
+ m->dispatching_dbus_queue = true;
+
+ while ((meta = m->dbus_unit_queue)) {
+ assert(meta->in_dbus_queue);
+
+ bus_unit_send_change_signal(UNIT(meta));
+ n++;
+ }
+
+ while ((j = m->dbus_job_queue)) {
+ assert(j->in_dbus_queue);
+
+ bus_job_send_change_signal(j);
+ n++;
+ }
+
+ m->dispatching_dbus_queue = false;
+ return n;
+}
+
+static int manager_dispatch_sigchld(Manager *m) {
+ assert(m);
+
+ for (;;) {
+ siginfo_t si;
+ Unit *u;
+
+ zero(si);
+ if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG) < 0) {
+
+ if (errno == ECHILD)
+ break;
+
+ return -errno;
+ }
+
+ if (si.si_pid == 0)
+ break;
+
+ if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
+ continue;
+
+ log_debug("child %llu died (code=%s, status=%i)", (long long unsigned) si.si_pid, sigchld_code_to_string(si.si_code), si.si_status);
+
+ if (!(u = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
+ continue;
+
+ log_debug("child %llu belongs to %s", (long long unsigned) si.si_pid, unit_id(u));
+
+ UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
+ }
+
+ return 0;
+}
+
+static int manager_process_signal_fd(Manager *m, bool *quit) {
+ ssize_t n;
+ struct signalfd_siginfo sfsi;
+ bool sigchld = false;
+
+ assert(m);
+
+ for (;;) {
+ if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
+
+ if (n >= 0)
+ return -EIO;
+
+ if (errno == EAGAIN)
+ break;
+
+ return -errno;
+ }
+
+ switch (sfsi.ssi_signo) {
+
+ case SIGCHLD: {
+ char *name = NULL;
+
+ get_process_name(sfsi.ssi_pid, &name);
+ log_debug("Got SIGCHLD for process %llu (%s)", (unsigned long long) sfsi.ssi_pid, strna(name));
+ free(name);
+
+ sigchld = true;
+ break;
+ }
+
+ case SIGINT:
+ case SIGTERM:
+
+ if (m->running_as != MANAGER_INIT) {
+ *quit = true;
+ return 0;
+
+ } else {
+ Unit *target;
+ int r;
+
+ if ((r = manager_load_unit(m, SPECIAL_CTRL_ALT_DEL_TARGET, &target)) < 0)
+ log_error("Failed to load ctrl-alt-del target: %s", strerror(-r));
+ else if ((r = manager_add_job(m, JOB_START, target, JOB_REPLACE, true, NULL)) < 0)
+ log_error("Failed to enqueue ctrl-alt-del job: %s", strerror(-r));
+
+ break;
+ }
+
+ case SIGWINCH:
+
+ if (m->running_as == MANAGER_INIT) {
+ Unit *target;
+ int r;
+
+ if ((r = manager_load_unit(m, SPECIAL_KBREQUEST_TARGET, &target)) < 0)
+ log_error("Failed to load kbrequest target: %s", strerror(-r));
+ else if ((r = manager_add_job(m, JOB_START, target, JOB_REPLACE, true, NULL)) < 0)
+ log_error("Failed to enqueue kbrequest job: %s", strerror(-r));
+
+ break;
+ }
+
+ /* This is a nop on non-init systemd's */
+
+ break;
+
+ case SIGUSR1:
+
+ printf("→ By units:\n");
+ manager_dump_units(m, stdout, "\t");
+
+ printf("→ By jobs:\n");
+ manager_dump_jobs(m, stdout, "\t");
+
+ break;
+
+ default:
+ log_info("Got unhandled signal <%s>.", strsignal(sfsi.ssi_signo));
+ }
+ }
+
+ if (sigchld)
+ return manager_dispatch_sigchld(m);
+
+ return 0;