chiark / gitweb /
Remove src/core
[elogind.git] / src / core / transaction.c
diff --git a/src/core/transaction.c b/src/core/transaction.c
deleted file mode 100644 (file)
index 64c2af5..0000000
+++ /dev/null
@@ -1,1145 +0,0 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
-  This file is part of systemd.
-
-  Copyright 2010 Lennart Poettering
-
-  systemd is free software; you can redistribute it and/or modify it
-  under the terms of the GNU Lesser General Public License as published by
-  the Free Software Foundation; either version 2.1 of the License, or
-  (at your option) any later version.
-
-  systemd is distributed in the hope that it will be useful, but
-  WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General Public License
-  along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include <unistd.h>
-#include <fcntl.h>
-
-#include "bus-common-errors.h"
-#include "bus-error.h"
-#include "transaction.h"
-
-static void transaction_unlink_job(Transaction *tr, Job *j, bool delete_dependencies);
-
-static void transaction_delete_job(Transaction *tr, Job *j, bool delete_dependencies) {
-        assert(tr);
-        assert(j);
-
-        /* Deletes one job from the transaction */
-
-        transaction_unlink_job(tr, j, delete_dependencies);
-
-        job_free(j);
-}
-
-static void transaction_delete_unit(Transaction *tr, Unit *u) {
-        Job *j;
-
-        /* Deletes all jobs associated with a certain unit from the
-         * transaction */
-
-        while ((j = hashmap_get(tr->jobs, u)))
-                transaction_delete_job(tr, j, true);
-}
-
-void transaction_abort(Transaction *tr) {
-        Job *j;
-
-        assert(tr);
-
-        while ((j = hashmap_first(tr->jobs)))
-                transaction_delete_job(tr, j, false);
-
-        assert(hashmap_isempty(tr->jobs));
-}
-
-static void transaction_find_jobs_that_matter_to_anchor(Job *j, unsigned generation) {
-        JobDependency *l;
-
-        /* A recursive sweep through the graph that marks all units
-         * that matter to the anchor job, i.e. are directly or
-         * indirectly a dependency of the anchor job via paths that
-         * are fully marked as mattering. */
-
-        j->matters_to_anchor = true;
-        j->generation = generation;
-
-        LIST_FOREACH(subject, l, j->subject_list) {
-
-                /* This link does not matter */
-                if (!l->matters)
-                        continue;
-
-                /* This unit has already been marked */
-                if (l->object->generation == generation)
-                        continue;
-
-                transaction_find_jobs_that_matter_to_anchor(l->object, generation);
-        }
-}
-
-static void transaction_merge_and_delete_job(Transaction *tr, Job *j, Job *other, JobType t) {
-        JobDependency *l, *last;
-
-        assert(j);
-        assert(other);
-        assert(j->unit == other->unit);
-        assert(!j->installed);
-
-        /* Merges 'other' into 'j' and then deletes 'other'. */
-
-        j->type = t;
-        j->state = JOB_WAITING;
-        j->override = j->override || other->override;
-        j->irreversible = j->irreversible || other->irreversible;
-
-        j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
-
-        /* Patch us in as new owner of the JobDependency objects */
-        last = NULL;
-        LIST_FOREACH(subject, l, other->subject_list) {
-                assert(l->subject == other);
-                l->subject = j;
-                last = l;
-        }
-
-        /* Merge both lists */
-        if (last) {
-                last->subject_next = j->subject_list;
-                if (j->subject_list)
-                        j->subject_list->subject_prev = last;
-                j->subject_list = other->subject_list;
-        }
-
-        /* Patch us in as new owner of the JobDependency objects */
-        last = NULL;
-        LIST_FOREACH(object, l, other->object_list) {
-                assert(l->object == other);
-                l->object = j;
-                last = l;
-        }
-
-        /* Merge both lists */
-        if (last) {
-                last->object_next = j->object_list;
-                if (j->object_list)
-                        j->object_list->object_prev = last;
-                j->object_list = other->object_list;
-        }
-
-        /* Kill the other job */
-        other->subject_list = NULL;
-        other->object_list = NULL;
-        transaction_delete_job(tr, other, true);
-}
-
-_pure_ static bool job_is_conflicted_by(Job *j) {
-        JobDependency *l;
-
-        assert(j);
-
-        /* Returns true if this job is pulled in by a least one
-         * ConflictedBy dependency. */
-
-        LIST_FOREACH(object, l, j->object_list)
-                if (l->conflicts)
-                        return true;
-
-        return false;
-}
-
-static int delete_one_unmergeable_job(Transaction *tr, Job *j) {
-        Job *k;
-
-        assert(j);
-
-        /* Tries to delete one item in the linked list
-         * j->transaction_next->transaction_next->... that conflicts
-         * with another one, in an attempt to make an inconsistent
-         * transaction work. */
-
-        /* We rely here on the fact that if a merged with b does not
-         * merge with c, either a or b merge with c neither */
-        LIST_FOREACH(transaction, j, j)
-                LIST_FOREACH(transaction, k, j->transaction_next) {
-                        Job *d;
-
-                        /* Is this one mergeable? Then skip it */
-                        if (job_type_is_mergeable(j->type, k->type))
-                                continue;
-
-                        /* Ok, we found two that conflict, let's see if we can
-                         * drop one of them */
-                        if (!j->matters_to_anchor && !k->matters_to_anchor) {
-
-                                /* Both jobs don't matter, so let's
-                                 * find the one that is smarter to
-                                 * remove. Let's think positive and
-                                 * rather remove stops then starts --
-                                 * except if something is being
-                                 * stopped because it is conflicted by
-                                 * another unit in which case we
-                                 * rather remove the start. */
-
-                                log_unit_debug(j->unit->id,
-                                               "Looking at job %s/%s conflicted_by=%s",
-                                               j->unit->id, job_type_to_string(j->type),
-                                               yes_no(j->type == JOB_STOP && job_is_conflicted_by(j)));
-                                log_unit_debug(k->unit->id,
-                                               "Looking at job %s/%s conflicted_by=%s",
-                                               k->unit->id, job_type_to_string(k->type),
-                                               yes_no(k->type == JOB_STOP && job_is_conflicted_by(k)));
-
-                                if (j->type == JOB_STOP) {
-
-                                        if (job_is_conflicted_by(j))
-                                                d = k;
-                                        else
-                                                d = j;
-
-                                } else if (k->type == JOB_STOP) {
-
-                                        if (job_is_conflicted_by(k))
-                                                d = j;
-                                        else
-                                                d = k;
-                                } else
-                                        d = j;
-
-                        } else if (!j->matters_to_anchor)
-                                d = j;
-                        else if (!k->matters_to_anchor)
-                                d = k;
-                        else
-                                return -ENOEXEC;
-
-                        /* Ok, we can drop one, so let's do so. */
-                        log_unit_debug(d->unit->id,
-                                       "Fixing conflicting jobs %s/%s,%s/%s by deleting job %s/%s",
-                                       j->unit->id, job_type_to_string(j->type),
-                                       k->unit->id, job_type_to_string(k->type),
-                                       d->unit->id, job_type_to_string(d->type));
-                        transaction_delete_job(tr, d, true);
-                        return 0;
-                }
-
-        return -EINVAL;
-}
-
-static int transaction_merge_jobs(Transaction *tr, sd_bus_error *e) {
-        Job *j;
-        Iterator i;
-        int r;
-
-        assert(tr);
-
-        /* First step, check whether any of the jobs for one specific
-         * task conflict. If so, try to drop one of them. */
-        HASHMAP_FOREACH(j, tr->jobs, i) {
-                JobType t;
-                Job *k;
-
-                t = j->type;
-                LIST_FOREACH(transaction, k, j->transaction_next) {
-                        if (job_type_merge_and_collapse(&t, k->type, j->unit) >= 0)
-                                continue;
-
-                        /* OK, we could not merge all jobs for this
-                         * action. Let's see if we can get rid of one
-                         * of them */
-
-                        r = delete_one_unmergeable_job(tr, j);
-                        if (r >= 0)
-                                /* Ok, we managed to drop one, now
-                                 * let's ask our callers to call us
-                                 * again after garbage collecting */
-                                return -EAGAIN;
-
-                        /* We couldn't merge anything. Failure */
-                        return sd_bus_error_setf(e, BUS_ERROR_TRANSACTION_JOBS_CONFLICTING,
-                                                 "Transaction contains conflicting jobs '%s' and '%s' for %s. "
-                                                 "Probably contradicting requirement dependencies configured.",
-                                                 job_type_to_string(t),
-                                                 job_type_to_string(k->type),
-                                                 k->unit->id);
-                }
-        }
-
-        /* Second step, merge the jobs. */
-        HASHMAP_FOREACH(j, tr->jobs, i) {
-                JobType t = j->type;
-                Job *k;
-
-                /* Merge all transaction jobs for j->unit */
-                LIST_FOREACH(transaction, k, j->transaction_next)
-                        assert_se(job_type_merge_and_collapse(&t, k->type, j->unit) == 0);
-
-                while ((k = j->transaction_next)) {
-                        if (tr->anchor_job == k) {
-                                transaction_merge_and_delete_job(tr, k, j, t);
-                                j = k;
-                        } else
-                                transaction_merge_and_delete_job(tr, j, k, t);
-                }
-
-                assert(!j->transaction_next);
-                assert(!j->transaction_prev);
-        }
-
-        return 0;
-}
-
-static void transaction_drop_redundant(Transaction *tr) {
-        Job *j;
-        Iterator i;
-
-        /* Goes through the transaction and removes all jobs of the units
-         * whose jobs are all noops. If not all of a unit's jobs are
-         * redundant, they are kept. */
-
-        assert(tr);
-
-rescan:
-        HASHMAP_FOREACH(j, tr->jobs, i) {
-                Job *k;
-
-                LIST_FOREACH(transaction, k, j) {
-
-                        if (tr->anchor_job == k ||
-                            !job_type_is_redundant(k->type, unit_active_state(k->unit)) ||
-                            (k->unit->job && job_type_is_conflicting(k->type, k->unit->job->type)))
-                                goto next_unit;
-                }
-
-                /* log_debug("Found redundant job %s/%s, dropping.", j->unit->id, job_type_to_string(j->type)); */
-                transaction_delete_job(tr, j, false);
-                goto rescan;
-        next_unit:;
-        }
-}
-
-_pure_ static bool unit_matters_to_anchor(Unit *u, Job *j) {
-        assert(u);
-        assert(!j->transaction_prev);
-
-        /* Checks whether at least one of the jobs for this unit
-         * matters to the anchor. */
-
-        LIST_FOREACH(transaction, j, j)
-                if (j->matters_to_anchor)
-                        return true;
-
-        return false;
-}
-
-static int transaction_verify_order_one(Transaction *tr, Job *j, Job *from, unsigned generation, sd_bus_error *e) {
-        Iterator i;
-        Unit *u;
-        int r;
-
-        assert(tr);
-        assert(j);
-        assert(!j->transaction_prev);
-
-        /* Does a recursive sweep through the ordering graph, looking
-         * for a cycle. If we find a cycle we try to break it. */
-
-        /* Have we seen this before? */
-        if (j->generation == generation) {
-                Job *k, *delete;
-
-                /* If the marker is NULL we have been here already and
-                 * decided the job was loop-free from here. Hence
-                 * shortcut things and return right-away. */
-                if (!j->marker)
-                        return 0;
-
-                /* So, the marker is not NULL and we already have been
-                 * here. We have a cycle. Let's try to break it. We go
-                 * backwards in our path and try to find a suitable
-                 * job to remove. We use the marker to find our way
-                 * back, since smart how we are we stored our way back
-                 * in there. */
-                log_unit_warning(j->unit->id,
-                                 "Found ordering cycle on %s/%s",
-                                 j->unit->id, job_type_to_string(j->type));
-
-                delete = NULL;
-                for (k = from; k; k = ((k->generation == generation && k->marker != k) ? k->marker : NULL)) {
-
-                        /* logging for j not k here here to provide consistent narrative */
-                        log_unit_warning(j->unit->id,
-                                         "Found dependency on %s/%s",
-                                         k->unit->id, job_type_to_string(k->type));
-
-                        if (!delete && hashmap_get(tr->jobs, k->unit) &&
-                            !unit_matters_to_anchor(k->unit, k)) {
-                                /* Ok, we can drop this one, so let's
-                                 * do so. */
-                                delete = k;
-                        }
-
-                        /* Check if this in fact was the beginning of
-                         * the cycle */
-                        if (k == j)
-                                break;
-                }
-
-
-                if (delete) {
-                        /* logging for j not k here here to provide consistent narrative */
-                        log_unit_warning(j->unit->id,
-                                         "Breaking ordering cycle by deleting job %s/%s",
-                                         delete->unit->id, job_type_to_string(delete->type));
-                        log_unit_error(delete->unit->id,
-                                       "Job %s/%s deleted to break ordering cycle starting with %s/%s",
-                                       delete->unit->id, job_type_to_string(delete->type),
-                                       j->unit->id, job_type_to_string(j->type));
-                        unit_status_printf(delete->unit, ANSI_HIGHLIGHT_RED_ON " SKIP " ANSI_HIGHLIGHT_OFF,
-                                           "Ordering cycle found, skipping %s");
-                        transaction_delete_unit(tr, delete->unit);
-                        return -EAGAIN;
-                }
-
-                log_error("Unable to break cycle");
-
-                return sd_bus_error_setf(e, BUS_ERROR_TRANSACTION_ORDER_IS_CYCLIC,
-                                         "Transaction order is cyclic. See system logs for details.");
-        }
-
-        /* Make the marker point to where we come from, so that we can
-         * find our way backwards if we want to break a cycle. We use
-         * a special marker for the beginning: we point to
-         * ourselves. */
-        j->marker = from ? from : j;
-        j->generation = generation;
-
-        /* We assume that the dependencies are bidirectional, and
-         * hence can ignore UNIT_AFTER */
-        SET_FOREACH(u, j->unit->dependencies[UNIT_BEFORE], i) {
-                Job *o;
-
-                /* Is there a job for this unit? */
-                o = hashmap_get(tr->jobs, u);
-                if (!o) {
-                        /* Ok, there is no job for this in the
-                         * transaction, but maybe there is already one
-                         * running? */
-                        o = u->job;
-                        if (!o)
-                                continue;
-                }
-
-                r = transaction_verify_order_one(tr, o, j, generation, e);
-                if (r < 0)
-                        return r;
-        }
-
-        /* Ok, let's backtrack, and remember that this entry is not on
-         * our path anymore. */
-        j->marker = NULL;
-
-        return 0;
-}
-
-static int transaction_verify_order(Transaction *tr, unsigned *generation, sd_bus_error *e) {
-        Job *j;
-        int r;
-        Iterator i;
-        unsigned g;
-
-        assert(tr);
-        assert(generation);
-
-        /* Check if the ordering graph is cyclic. If it is, try to fix
-         * that up by dropping one of the jobs. */
-
-        g = (*generation)++;
-
-        HASHMAP_FOREACH(j, tr->jobs, i)
-                if ((r = transaction_verify_order_one(tr, j, NULL, g, e)) < 0)
-                        return r;
-
-        return 0;
-}
-
-static void transaction_collect_garbage(Transaction *tr) {
-        Iterator i;
-        Job *j;
-
-        assert(tr);
-
-        /* Drop jobs that are not required by any other job */
-
-rescan:
-        HASHMAP_FOREACH(j, tr->jobs, i) {
-                if (tr->anchor_job == j || j->object_list) {
-                        /* log_debug("Keeping job %s/%s because of %s/%s", */
-                        /*           j->unit->id, job_type_to_string(j->type), */
-                        /*           j->object_list->subject ? j->object_list->subject->unit->id : "root", */
-                        /*           j->object_list->subject ? job_type_to_string(j->object_list->subject->type) : "root"); */
-                        continue;
-                }
-
-                /* log_debug("Garbage collecting job %s/%s", j->unit->id, job_type_to_string(j->type)); */
-                transaction_delete_job(tr, j, true);
-                goto rescan;
-        }
-}
-
-static int transaction_is_destructive(Transaction *tr, JobMode mode, sd_bus_error *e) {
-        Iterator i;
-        Job *j;
-
-        assert(tr);
-
-        /* Checks whether applying this transaction means that
-         * existing jobs would be replaced */
-
-        HASHMAP_FOREACH(j, tr->jobs, i) {
-
-                /* Assume merged */
-                assert(!j->transaction_prev);
-                assert(!j->transaction_next);
-
-                if (j->unit->job && (mode == JOB_FAIL || j->unit->job->irreversible) &&
-                    job_type_is_conflicting(j->unit->job->type, j->type))
-                        return sd_bus_error_setf(e, BUS_ERROR_TRANSACTION_IS_DESTRUCTIVE,
-                                                 "Transaction is destructive.");
-        }
-
-        return 0;
-}
-
-static void transaction_minimize_impact(Transaction *tr) {
-        Job *j;
-        Iterator i;
-
-        assert(tr);
-
-        /* Drops all unnecessary jobs that reverse already active jobs
-         * or that stop a running service. */
-
-rescan:
-        HASHMAP_FOREACH(j, tr->jobs, i) {
-                LIST_FOREACH(transaction, j, j) {
-                        bool stops_running_service, changes_existing_job;
-
-                        /* 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->job &&
-                                job_type_is_conflicting(j->type, j->unit->job->type);
-
-                        if (!stops_running_service && !changes_existing_job)
-                                continue;
-
-                        if (stops_running_service)
-                                log_unit_debug(j->unit->id,
-                                               "%s/%s would stop a running service.",
-                                               j->unit->id, job_type_to_string(j->type));
-
-                        if (changes_existing_job)
-                                log_unit_debug(j->unit->id,
-                                               "%s/%s would change existing job.",
-                                               j->unit->id, job_type_to_string(j->type));
-
-                        /* Ok, let's get rid of this */
-                        log_unit_debug(j->unit->id,
-                                       "Deleting %s/%s to minimize impact.",
-                                       j->unit->id, job_type_to_string(j->type));
-
-                        transaction_delete_job(tr, j, true);
-                        goto rescan;
-                }
-        }
-}
-
-static int transaction_apply(Transaction *tr, Manager *m, JobMode mode) {
-        Iterator i;
-        Job *j;
-        int r;
-
-        /* Moves the transaction jobs to the set of active jobs */
-
-        if (mode == JOB_ISOLATE || mode == JOB_FLUSH) {
-
-                /* When isolating first kill all installed jobs which
-                 * aren't part of the new transaction */
-                HASHMAP_FOREACH(j, m->jobs, i) {
-                        assert(j->installed);
-
-                        if (hashmap_get(tr->jobs, j->unit))
-                                continue;
-
-                        /* Not invalidating recursively. Avoids triggering
-                         * OnFailure= actions of dependent jobs. Also avoids
-                         * invalidating our iterator. */
-                        job_finish_and_invalidate(j, JOB_CANCELED, false);
-                }
-        }
-
-        HASHMAP_FOREACH(j, tr->jobs, i) {
-                /* Assume merged */
-                assert(!j->transaction_prev);
-                assert(!j->transaction_next);
-
-                r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j);
-                if (r < 0)
-                        goto rollback;
-        }
-
-        while ((j = hashmap_steal_first(tr->jobs))) {
-                Job *installed_job;
-
-                /* Clean the job dependencies */
-                transaction_unlink_job(tr, j, false);
-
-                installed_job = job_install(j);
-                if (installed_job != j) {
-                        /* j has been merged into a previously installed job */
-                        if (tr->anchor_job == j)
-                                tr->anchor_job = installed_job;
-                        hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
-                        job_free(j);
-                        j = installed_job;
-                }
-
-                job_add_to_run_queue(j);
-                job_add_to_dbus_queue(j);
-                job_start_timer(j);
-                job_shutdown_magic(j);
-        }
-
-        return 0;
-
-rollback:
-
-        HASHMAP_FOREACH(j, tr->jobs, i)
-                hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
-
-        return r;
-}
-
-int transaction_activate(Transaction *tr, Manager *m, JobMode mode, sd_bus_error *e) {
-        Iterator i;
-        Job *j;
-        int r;
-        unsigned generation = 1;
-
-        assert(tr);
-
-        /* This applies the changes recorded in tr->jobs to
-         * the actual list of jobs, if possible. */
-
-        /* Reset the generation counter of all installed jobs. The detection of cycles
-         * looks at installed jobs. If they had a non-zero generation from some previous
-         * walk of the graph, the algorithm would break. */
-        HASHMAP_FOREACH(j, m->jobs, i)
-                j->generation = 0;
-
-        /* First step: figure out which jobs matter */
-        transaction_find_jobs_that_matter_to_anchor(tr->anchor_job, 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. */
-        if (mode == JOB_FAIL)
-                transaction_minimize_impact(tr);
-
-        /* Third step: Drop redundant jobs */
-        transaction_drop_redundant(tr);
-
-        for (;;) {
-                /* Fourth step: Let's remove unneeded jobs that might
-                 * be lurking. */
-                if (mode != JOB_ISOLATE)
-                        transaction_collect_garbage(tr);
-
-                /* Fifth step: verify order makes sense and correct
-                 * cycles if necessary and possible */
-                r = transaction_verify_order(tr, &generation, e);
-                if (r >= 0)
-                        break;
-
-                if (r != -EAGAIN) {
-                        log_warning("Requested transaction contains an unfixable cyclic ordering dependency: %s", bus_error_message(e, r));
-                        return r;
-                }
-
-                /* 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 */
-                r = transaction_merge_jobs(tr, e);
-                if (r >= 0)
-                        break;
-
-                if (r != -EAGAIN) {
-                        log_warning("Requested transaction contains unmergeable jobs: %s", bus_error_message(e, r));
-                        return r;
-                }
-
-                /* Seventh step: an entry got dropped, let's garbage
-                 * collect its dependencies. */
-                if (mode != JOB_ISOLATE)
-                        transaction_collect_garbage(tr);
-
-                /* 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(tr);
-
-        /* Ninth step: check whether we can actually apply this */
-        r = transaction_is_destructive(tr, mode, e);
-        if (r < 0) {
-                log_notice("Requested transaction contradicts existing jobs: %s", bus_error_message(e, r));
-                return r;
-        }
-
-        /* Tenth step: apply changes */
-        r = transaction_apply(tr, m, mode);
-        if (r < 0)
-                return log_warning_errno(r, "Failed to apply transaction: %m");
-
-        assert(hashmap_isempty(tr->jobs));
-
-        if (!hashmap_isempty(m->jobs)) {
-                /* Are there any jobs now? Then make sure we have the
-                 * idle pipe around. We don't really care too much
-                 * whether this works or not, as the idle pipe is a
-                 * feature for cosmetics, not actually useful for
-                 * anything beyond that. */
-
-                if (m->idle_pipe[0] < 0 && m->idle_pipe[1] < 0 &&
-                    m->idle_pipe[2] < 0 && m->idle_pipe[3] < 0) {
-                        pipe2(m->idle_pipe, O_NONBLOCK|O_CLOEXEC);
-                        pipe2(m->idle_pipe + 2, O_NONBLOCK|O_CLOEXEC);
-                }
-        }
-
-        return 0;
-}
-
-static Job* transaction_add_one_job(Transaction *tr, JobType type, Unit *unit, bool override, bool *is_new) {
-        Job *j, *f;
-
-        assert(tr);
-        assert(unit);
-
-        /* Looks for an existing prospective job and returns that. If
-         * it doesn't exist it is created and added to the prospective
-         * jobs list. */
-
-        f = hashmap_get(tr->jobs, unit);
-
-        LIST_FOREACH(transaction, j, f) {
-                assert(j->unit == unit);
-
-                if (j->type == type) {
-                        if (is_new)
-                                *is_new = false;
-                        return j;
-                }
-        }
-
-        j = job_new(unit, type);
-        if (!j)
-                return NULL;
-
-        j->generation = 0;
-        j->marker = NULL;
-        j->matters_to_anchor = false;
-        j->override = override;
-        j->irreversible = tr->irreversible;
-
-        LIST_PREPEND(transaction, f, j);
-
-        if (hashmap_replace(tr->jobs, unit, f) < 0) {
-                LIST_REMOVE(transaction, f, j);
-                job_free(j);
-                return NULL;
-        }
-
-        if (is_new)
-                *is_new = true;
-
-        /* log_debug("Added job %s/%s to transaction.", unit->id, job_type_to_string(type)); */
-
-        return j;
-}
-
-static void transaction_unlink_job(Transaction *tr, Job *j, bool delete_dependencies) {
-        assert(tr);
-        assert(j);
-
-        if (j->transaction_prev)
-                j->transaction_prev->transaction_next = j->transaction_next;
-        else if (j->transaction_next)
-                hashmap_replace(tr->jobs, j->unit, j->transaction_next);
-        else
-                hashmap_remove_value(tr->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_unit_debug(other->unit->id,
-                                       "Deleting job %s/%s as dependency of job %s/%s",
-                                       other->unit->id, job_type_to_string(other->type),
-                                       j->unit->id, job_type_to_string(j->type));
-                        transaction_delete_job(tr, other, delete_dependencies);
-                }
-        }
-}
-
-int transaction_add_job_and_dependencies(
-                Transaction *tr,
-                JobType type,
-                Unit *unit,
-                Job *by,
-                bool matters,
-                bool override,
-                bool conflicts,
-                bool ignore_requirements,
-                bool ignore_order,
-                sd_bus_error *e) {
-        Job *ret;
-        Iterator i;
-        Unit *dep;
-        int r;
-        bool is_new;
-
-        assert(tr);
-        assert(type < _JOB_TYPE_MAX);
-        assert(type < _JOB_TYPE_MAX_IN_TRANSACTION);
-        assert(unit);
-
-        /* log_debug("Pulling in %s/%s from %s/%s", */
-        /*           unit->id, job_type_to_string(type), */
-        /*           by ? by->unit->id : "NA", */
-        /*           by ? job_type_to_string(by->type) : "NA"); */
-
-        if (!IN_SET(unit->load_state, UNIT_LOADED, UNIT_ERROR, UNIT_NOT_FOUND, UNIT_MASKED))
-                return sd_bus_error_setf(e, BUS_ERROR_LOAD_FAILED,
-                                         "Unit %s is not loaded properly.", unit->id);
-
-        if (type != JOB_STOP && unit->load_state == UNIT_ERROR) {
-                if (unit->load_error == -ENOENT || unit->manager->test_run)
-                        return sd_bus_error_setf(e, BUS_ERROR_LOAD_FAILED,
-                                                 "Unit %s failed to load: %s.",
-                                                 unit->id,
-                                                 strerror(-unit->load_error));
-                else
-                        return sd_bus_error_setf(e, BUS_ERROR_LOAD_FAILED,
-                                                 "Unit %s failed to load: %s. "
-                                                 "See system logs and 'systemctl status %s' for details.",
-                                                 unit->id,
-                                                 strerror(-unit->load_error),
-                                                 unit->id);
-        }
-
-        if (type != JOB_STOP && unit->load_state == UNIT_NOT_FOUND)
-                return sd_bus_error_setf(e, BUS_ERROR_LOAD_FAILED,
-                                         "Unit %s failed to load: %s.",
-                                         unit->id, strerror(-unit->load_error));
-
-        if (type != JOB_STOP && unit->load_state == UNIT_MASKED)
-                return sd_bus_error_setf(e, BUS_ERROR_UNIT_MASKED,
-                                         "Unit %s is masked.", unit->id);
-
-        if (!unit_job_is_applicable(unit, type))
-                return sd_bus_error_setf(e, BUS_ERROR_JOB_TYPE_NOT_APPLICABLE,
-                                         "Job type %s is not applicable for unit %s.",
-                                         job_type_to_string(type), unit->id);
-
-
-        /* First add the job. */
-        ret = transaction_add_one_job(tr, type, unit, override, &is_new);
-        if (!ret)
-                return -ENOMEM;
-
-        ret->ignore_order = ret->ignore_order || ignore_order;
-
-        /* Then, add a link to the job. */
-        if (by) {
-                if (!job_dependency_new(by, ret, matters, conflicts))
-                        return -ENOMEM;
-        } else {
-                /* If the job has no parent job, it is the anchor job. */
-                assert(!tr->anchor_job);
-                tr->anchor_job = ret;
-        }
-
-        if (is_new && !ignore_requirements && type != JOB_NOP) {
-                Set *following;
-
-                /* If we are following some other unit, make sure we
-                 * add all dependencies of everybody following. */
-                if (unit_following_set(ret->unit, &following) > 0) {
-                        SET_FOREACH(dep, following, i) {
-                                r = transaction_add_job_and_dependencies(tr, type, dep, ret, false, override, false, false, ignore_order, e);
-                                if (r < 0) {
-                                        log_unit_warning(dep->id,
-                                                         "Cannot add dependency job for unit %s, ignoring: %s",
-                                                         dep->id, bus_error_message(e, r));
-
-                                        if (e)
-                                                sd_bus_error_free(e);
-                                }
-                        }
-
-                        set_free(following);
-                }
-
-                /* Finally, recursively add in all dependencies. */
-                if (type == JOB_START || type == JOB_RESTART) {
-                        SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUIRES], i) {
-                                r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, true, override, false, false, ignore_order, e);
-                                if (r < 0) {
-                                        if (r != -EBADR)
-                                                goto fail;
-
-                                        if (e)
-                                                sd_bus_error_free(e);
-                                }
-                        }
-
-                        SET_FOREACH(dep, ret->unit->dependencies[UNIT_BINDS_TO], i) {
-                                r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, true, override, false, false, ignore_order, e);
-                                if (r < 0) {
-                                        if (r != -EBADR)
-                                                goto fail;
-
-                                        if (e)
-                                                sd_bus_error_free(e);
-                                }
-                        }
-
-                        SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUIRES_OVERRIDABLE], i) {
-                                r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, !override, override, false, false, ignore_order, e);
-                                if (r < 0) {
-                                        log_unit_full(dep->id,
-                                                      r == -EADDRNOTAVAIL ? LOG_DEBUG : LOG_WARNING,
-                                                      "Cannot add dependency job for unit %s, ignoring: %s",
-                                                      dep->id, bus_error_message(e, r));
-
-                                        if (e)
-                                                sd_bus_error_free(e);
-                                }
-                        }
-
-                        SET_FOREACH(dep, ret->unit->dependencies[UNIT_WANTS], i) {
-                                r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, false, false, false, false, ignore_order, e);
-                                if (r < 0) {
-                                        log_unit_full(dep->id,
-                                                      r == -EADDRNOTAVAIL ? LOG_DEBUG : LOG_WARNING,
-                                                      "Cannot add dependency job for unit %s, ignoring: %s",
-                                                      dep->id, bus_error_message(e, r));
-
-                                        if (e)
-                                                sd_bus_error_free(e);
-                                }
-                        }
-
-                        SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUISITE], i) {
-                                r = transaction_add_job_and_dependencies(tr, JOB_VERIFY_ACTIVE, dep, ret, true, override, false, false, ignore_order, e);
-                                if (r < 0) {
-                                        if (r != -EBADR)
-                                                goto fail;
-
-                                        if (e)
-                                                sd_bus_error_free(e);
-                                }
-                        }
-
-                        SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUISITE_OVERRIDABLE], i) {
-                                r = transaction_add_job_and_dependencies(tr, JOB_VERIFY_ACTIVE, dep, ret, !override, override, false, false, ignore_order, e);
-                                if (r < 0) {
-                                        log_unit_full(dep->id,
-                                                      r == -EADDRNOTAVAIL ? LOG_DEBUG : LOG_WARNING,
-                                                      "Cannot add dependency job for unit %s, ignoring: %s",
-                                                      dep->id, bus_error_message(e, r));
-
-                                        if (e)
-                                                sd_bus_error_free(e);
-                                }
-                        }
-
-                        SET_FOREACH(dep, ret->unit->dependencies[UNIT_CONFLICTS], i) {
-                                r = transaction_add_job_and_dependencies(tr, JOB_STOP, dep, ret, true, override, true, false, ignore_order, e);
-                                if (r < 0) {
-                                        if (r != -EBADR)
-                                                goto fail;
-
-                                        if (e)
-                                                sd_bus_error_free(e);
-                                }
-                        }
-
-                        SET_FOREACH(dep, ret->unit->dependencies[UNIT_CONFLICTED_BY], i) {
-                                r = transaction_add_job_and_dependencies(tr, JOB_STOP, dep, ret, false, override, false, false, ignore_order, e);
-                                if (r < 0) {
-                                        log_unit_warning(dep->id,
-                                                         "Cannot add dependency job for unit %s, ignoring: %s",
-                                                         dep->id, bus_error_message(e, r));
-
-                                        if (e)
-                                                sd_bus_error_free(e);
-                                }
-                        }
-
-                }
-
-                if (type == JOB_STOP || type == JOB_RESTART) {
-
-                        SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUIRED_BY], i) {
-                                r = transaction_add_job_and_dependencies(tr, type, dep, ret, true, override, false, false, ignore_order, e);
-                                if (r < 0) {
-                                        if (r != -EBADR)
-                                                goto fail;
-
-                                        if (e)
-                                                sd_bus_error_free(e);
-                                }
-                        }
-
-                        SET_FOREACH(dep, ret->unit->dependencies[UNIT_BOUND_BY], i) {
-                                r = transaction_add_job_and_dependencies(tr, type, dep, ret, true, override, false, false, ignore_order, e);
-                                if (r < 0) {
-                                        if (r != -EBADR)
-                                                goto fail;
-
-                                        if (e)
-                                                sd_bus_error_free(e);
-                                }
-                        }
-
-                        SET_FOREACH(dep, ret->unit->dependencies[UNIT_CONSISTS_OF], i) {
-                                r = transaction_add_job_and_dependencies(tr, type, dep, ret, true, override, false, false, ignore_order, e);
-                                if (r < 0) {
-                                        if (r != -EBADR)
-                                                goto fail;
-
-                                        if (e)
-                                                sd_bus_error_free(e);
-                                }
-                        }
-
-                }
-
-                if (type == JOB_RELOAD) {
-
-                        SET_FOREACH(dep, ret->unit->dependencies[UNIT_PROPAGATES_RELOAD_TO], i) {
-                                r = transaction_add_job_and_dependencies(tr, JOB_RELOAD, dep, ret, false, override, false, false, ignore_order, e);
-                                if (r < 0) {
-                                        log_unit_warning(dep->id,
-                                                         "Cannot add dependency reload job for unit %s, ignoring: %s",
-                                                         dep->id, bus_error_message(e, r));
-
-                                        if (e)
-                                                sd_bus_error_free(e);
-                                }
-                        }
-                }
-
-                /* JOB_VERIFY_STARTED require no dependency handling */
-        }
-
-        return 0;
-
-fail:
-        return r;
-}
-
-int transaction_add_isolate_jobs(Transaction *tr, Manager *m) {
-        Iterator i;
-        Unit *u;
-        char *k;
-        int r;
-
-        assert(tr);
-        assert(m);
-
-        HASHMAP_FOREACH_KEY(u, k, m->units, i) {
-
-                /* ignore aliases */
-                if (u->id != k)
-                        continue;
-
-                if (u->ignore_on_isolate)
-                        continue;
-
-                /* No need to stop inactive jobs */
-                if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(u)) && !u->job)
-                        continue;
-
-                /* Is there already something listed for this? */
-                if (hashmap_get(tr->jobs, u))
-                        continue;
-
-                r = transaction_add_job_and_dependencies(tr, JOB_STOP, u, tr->anchor_job, true, false, false, false, false, NULL);
-                if (r < 0)
-                        log_unit_warning(u->id,
-                                         "Cannot add isolate job for unit %s, ignoring: %s",
-                                         u->id, strerror(-r));
-        }
-
-        return 0;
-}
-
-Transaction *transaction_new(bool irreversible) {
-        Transaction *tr;
-
-        tr = new0(Transaction, 1);
-        if (!tr)
-                return NULL;
-
-        tr->jobs = hashmap_new(NULL);
-        if (!tr->jobs) {
-                free(tr);
-                return NULL;
-        }
-
-        tr->irreversible = irreversible;
-
-        return tr;
-}
-
-void transaction_free(Transaction *tr) {
-        assert(hashmap_isempty(tr->jobs));
-        hashmap_free(tr->jobs);
-        free(tr);
-}