diff options
Diffstat (limited to 'src/job.c')
-rw-r--r-- | src/job.c | 589 |
1 files changed, 589 insertions, 0 deletions
diff --git a/src/job.c b/src/job.c new file mode 100644 index 0000000000..887de92cad --- /dev/null +++ b/src/job.c @@ -0,0 +1,589 @@ +/*-*- Mode: C; c-basic-offset: 8 -*-*/ + +/*** + 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 General Public License as published by + the Free Software Foundation; either version 2 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 + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <assert.h> +#include <errno.h> + +#include "set.h" +#include "unit.h" +#include "macro.h" +#include "strv.h" +#include "load-fragment.h" +#include "load-dropin.h" +#include "log.h" +#include "dbus-job.h" + +Job* job_new(Manager *m, JobType type, Unit *unit) { + Job *j; + + assert(m); + assert(type < _JOB_TYPE_MAX); + assert(unit); + + if (!(j = new0(Job, 1))) + return NULL; + + j->manager = m; + j->id = m->current_job_id++; + j->type = type; + j->unit = unit; + + /* We don't link it here, that's what job_dependency() is for */ + + return j; +} + +void job_free(Job *j) { + assert(j); + + /* Detach from next 'bigger' objects */ + if (j->installed) { + bus_job_send_removed_signal(j); + + if (j->unit->meta.job == j) { + j->unit->meta.job = NULL; + unit_add_to_gc_queue(j->unit); + } + + hashmap_remove(j->manager->jobs, UINT32_TO_PTR(j->id)); + j->installed = false; + } + + /* Detach from next 'smaller' objects */ + manager_transaction_unlink_job(j->manager, j, true); + + if (j->in_run_queue) + LIST_REMOVE(Job, run_queue, j->manager->run_queue, j); + + if (j->in_dbus_queue) + LIST_REMOVE(Job, dbus_queue, j->manager->dbus_job_queue, j); + + free(j); +} + +JobDependency* job_dependency_new(Job *subject, Job *object, bool matters) { + JobDependency *l; + + assert(object); + + /* Adds a new job link, which encodes that the 'subject' job + * needs the 'object' job in some way. If 'subject' is NULL + * this means the 'anchor' job (i.e. the one the user + * explcitily asked for) is the requester. */ + + if (!(l = new0(JobDependency, 1))) + return NULL; + + l->subject = subject; + l->object = object; + l->matters = matters; + + if (subject) + LIST_PREPEND(JobDependency, subject, subject->subject_list, l); + else + LIST_PREPEND(JobDependency, subject, object->manager->transaction_anchor, l); + + LIST_PREPEND(JobDependency, object, object->object_list, l); + + return l; +} + +void job_dependency_free(JobDependency *l) { + assert(l); + + if (l->subject) + LIST_REMOVE(JobDependency, subject, l->subject->subject_list, l); + else + LIST_REMOVE(JobDependency, subject, l->object->manager->transaction_anchor, l); + + LIST_REMOVE(JobDependency, object, l->object->object_list, l); + + free(l); +} + +void job_dependency_delete(Job *subject, Job *object, bool *matters) { + JobDependency *l; + + assert(object); + + LIST_FOREACH(object, l, object->object_list) { + assert(l->object == object); + + if (l->subject == subject) + break; + } + + if (!l) { + if (matters) + *matters = false; + return; + } + + if (matters) + *matters = l->matters; + + job_dependency_free(l); +} + +void job_dump(Job *j, FILE*f, const char *prefix) { + + + assert(j); + assert(f); + + fprintf(f, + "%s-> Job %u:\n" + "%s\tAction: %s -> %s\n" + "%s\tState: %s\n" + "%s\tForced: %s\n", + prefix, j->id, + prefix, j->unit->meta.id, job_type_to_string(j->type), + prefix, job_state_to_string(j->state), + prefix, yes_no(j->override)); +} + +bool job_is_anchor(Job *j) { + JobDependency *l; + + assert(j); + + LIST_FOREACH(object, l, j->object_list) + if (!l->subject) + return true; + + return false; +} + +static bool types_match(JobType a, JobType b, JobType c, JobType d) { + return + (a == c && b == d) || + (a == d && b == c); +} + +int job_type_merge(JobType *a, JobType b) { + if (*a == b) + return 0; + + /* Merging is associative! a merged with b merged with c is + * the same as a merged with c merged with b. */ + + /* Mergeability is transitive! if a can be merged with b and b + * with c then a also with c */ + + /* Also, if a merged with b cannot be merged with c, then + * either a or b cannot be merged with c either */ + + if (types_match(*a, b, JOB_START, JOB_VERIFY_ACTIVE)) + *a = JOB_START; + else if (types_match(*a, b, JOB_START, JOB_RELOAD) || + types_match(*a, b, JOB_START, JOB_RELOAD_OR_START) || + types_match(*a, b, JOB_VERIFY_ACTIVE, JOB_RELOAD_OR_START) || + types_match(*a, b, JOB_RELOAD, JOB_RELOAD_OR_START)) + *a = JOB_RELOAD_OR_START; + else if (types_match(*a, b, JOB_START, JOB_RESTART) || + types_match(*a, b, JOB_START, JOB_TRY_RESTART) || + types_match(*a, b, JOB_VERIFY_ACTIVE, JOB_RESTART) || + types_match(*a, b, JOB_RELOAD, JOB_RESTART) || + types_match(*a, b, JOB_RELOAD_OR_START, JOB_RESTART) || + types_match(*a, b, JOB_RELOAD_OR_START, JOB_TRY_RESTART) || + types_match(*a, b, JOB_RESTART, JOB_TRY_RESTART)) + *a = JOB_RESTART; + else if (types_match(*a, b, JOB_VERIFY_ACTIVE, JOB_RELOAD)) + *a = JOB_RELOAD; + else if (types_match(*a, b, JOB_VERIFY_ACTIVE, JOB_TRY_RESTART) || + types_match(*a, b, JOB_RELOAD, JOB_TRY_RESTART)) + *a = JOB_TRY_RESTART; + else + return -EEXIST; + + return 0; +} + +bool job_type_is_mergeable(JobType a, JobType b) { + return job_type_merge(&a, b) >= 0; +} + +bool job_type_is_superset(JobType a, JobType b) { + + /* Checks whether operation a is a "superset" of b in its + * actions */ + + if (a == b) + return true; + + switch (a) { + case JOB_START: + return b == JOB_VERIFY_ACTIVE; + + case JOB_RELOAD: + return + b == JOB_VERIFY_ACTIVE; + + case JOB_RELOAD_OR_START: + return + b == JOB_RELOAD || + b == JOB_START || + b == JOB_VERIFY_ACTIVE; + + case JOB_RESTART: + return + b == JOB_START || + b == JOB_VERIFY_ACTIVE || + b == JOB_RELOAD || + b == JOB_RELOAD_OR_START || + b == JOB_TRY_RESTART; + + case JOB_TRY_RESTART: + return + b == JOB_VERIFY_ACTIVE || + b == JOB_RELOAD; + default: + return false; + + } +} + +bool job_type_is_conflicting(JobType a, JobType b) { + assert(a >= 0 && a < _JOB_TYPE_MAX); + assert(b >= 0 && b < _JOB_TYPE_MAX); + + return (a == JOB_STOP) != (b == JOB_STOP); +} + +bool job_type_is_redundant(JobType a, UnitActiveState b) { + switch (a) { + + case JOB_START: + return + b == UNIT_ACTIVE || + b == UNIT_ACTIVE_RELOADING; + + case JOB_STOP: + return + b == UNIT_INACTIVE; + + case JOB_VERIFY_ACTIVE: + return + b == UNIT_ACTIVE || + b == UNIT_ACTIVE_RELOADING; + + case JOB_RELOAD: + return + b == UNIT_ACTIVE_RELOADING; + + case JOB_RELOAD_OR_START: + return + b == UNIT_ACTIVATING || + b == UNIT_ACTIVE_RELOADING; + + case JOB_RESTART: + return + b == UNIT_ACTIVATING; + + case JOB_TRY_RESTART: + return + b == UNIT_ACTIVATING; + + default: + assert_not_reached("Invalid job type"); + } +} + +bool job_is_runnable(Job *j) { + Iterator i; + Unit *other; + + assert(j); + assert(j->installed); + + /* Checks whether there is any job running for the units this + * job needs to be running after (in the case of a 'positive' + * job type) or before (in the case of a 'negative' job type + * . */ + + if (j->type == JOB_START || + j->type == JOB_VERIFY_ACTIVE || + j->type == JOB_RELOAD || + j->type == JOB_RELOAD_OR_START) { + + /* Immediate result is that the job is or might be + * started. In this case lets wait for the + * dependencies, regardless whether they are + * starting or stopping something. */ + + SET_FOREACH(other, j->unit->meta.dependencies[UNIT_AFTER], i) + if (other->meta.job) + return false; + } + + /* Also, if something else is being stopped and we should + * change state after it, then lets wait. */ + + SET_FOREACH(other, j->unit->meta.dependencies[UNIT_BEFORE], i) + if (other->meta.job && + (other->meta.job->type == JOB_STOP || + other->meta.job->type == JOB_RESTART || + other->meta.job->type == JOB_TRY_RESTART)) + return false; + + /* This means that for a service a and a service b where b + * shall be started after a: + * + * start a + start b → 1st step start a, 2nd step start b + * start a + stop b → 1st step stop b, 2nd step start a + * stop a + start b → 1st step stop a, 2nd step start b + * stop a + stop b → 1st step stop b, 2nd step stop a + * + * This has the side effect that restarts are properly + * synchronized too. */ + + return true; +} + +int job_run_and_invalidate(Job *j) { + int r; + + assert(j); + assert(j->installed); + + if (j->in_run_queue) { + LIST_REMOVE(Job, run_queue, j->manager->run_queue, j); + j->in_run_queue = false; + } + + if (j->state != JOB_WAITING) + return 0; + + if (!job_is_runnable(j)) + return -EAGAIN; + + j->state = JOB_RUNNING; + job_add_to_dbus_queue(j); + + switch (j->type) { + + case JOB_START: + r = unit_start(j->unit); + if (r == -EBADR) + r = 0; + break; + + case JOB_VERIFY_ACTIVE: { + UnitActiveState t = unit_active_state(j->unit); + if (UNIT_IS_ACTIVE_OR_RELOADING(t)) + r = -EALREADY; + else if (t == UNIT_ACTIVATING) + r = -EAGAIN; + else + r = -ENOEXEC; + break; + } + + case JOB_STOP: + r = unit_stop(j->unit); + break; + + case JOB_RELOAD: + r = unit_reload(j->unit); + break; + + case JOB_RELOAD_OR_START: + if (unit_active_state(j->unit) == UNIT_ACTIVE) + r = unit_reload(j->unit); + else + r = unit_start(j->unit); + break; + + case JOB_RESTART: { + UnitActiveState t = unit_active_state(j->unit); + if (t == UNIT_INACTIVE || t == UNIT_ACTIVATING) { + j->type = JOB_START; + r = unit_start(j->unit); + } else + r = unit_stop(j->unit); + break; + } + + case JOB_TRY_RESTART: { + UnitActiveState t = unit_active_state(j->unit); + if (t == UNIT_INACTIVE || t == UNIT_DEACTIVATING) + r = -ENOEXEC; + else if (t == UNIT_ACTIVATING) { + j->type = JOB_START; + r = unit_start(j->unit); + } else + r = unit_stop(j->unit); + break; + } + + default: + assert_not_reached("Unknown job type"); + } + + if (r == -EALREADY) + r = job_finish_and_invalidate(j, true); + else if (r == -EAGAIN) { + j->state = JOB_WAITING; + return -EAGAIN; + } else if (r < 0) + r = job_finish_and_invalidate(j, false); + + return r; +} + +int job_finish_and_invalidate(Job *j, bool success) { + Unit *u; + Unit *other; + JobType t; + Iterator i; + + assert(j); + assert(j->installed); + + log_debug("Job %s/%s finished, success=%s", j->unit->meta.id, job_type_to_string(j->type), yes_no(success)); + job_add_to_dbus_queue(j); + + /* Patch restart jobs so that they become normal start jobs */ + if (success && (j->type == JOB_RESTART || j->type == JOB_TRY_RESTART)) { + + log_debug("Converting job %s/%s -> %s/%s", + j->unit->meta.id, job_type_to_string(j->type), + j->unit->meta.id, job_type_to_string(JOB_START)); + + j->state = JOB_RUNNING; + j->type = JOB_START; + + job_add_to_run_queue(j); + return 0; + } + + u = j->unit; + t = j->type; + job_free(j); + + /* Fail depending jobs on failure */ + if (!success) { + + if (t == JOB_START || + t == JOB_VERIFY_ACTIVE || + t == JOB_RELOAD_OR_START) { + + SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY], i) + if (other->meta.job && + (other->meta.job->type == JOB_START || + other->meta.job->type == JOB_VERIFY_ACTIVE || + other->meta.job->type == JOB_RELOAD_OR_START)) + job_finish_and_invalidate(other->meta.job, false); + + SET_FOREACH(other, u->meta.dependencies[UNIT_REQUIRED_BY_OVERRIDABLE], i) + if (other->meta.job && + !other->meta.job->override && + (other->meta.job->type == JOB_START || + other->meta.job->type == JOB_VERIFY_ACTIVE || + other->meta.job->type == JOB_RELOAD_OR_START)) + job_finish_and_invalidate(other->meta.job, false); + + } else if (t == JOB_STOP) { + + SET_FOREACH(other, u->meta.dependencies[UNIT_CONFLICTS], i) + if (other->meta.job && + (other->meta.job->type == JOB_START || + other->meta.job->type == JOB_VERIFY_ACTIVE || + other->meta.job->type == JOB_RELOAD_OR_START)) + job_finish_and_invalidate(other->meta.job, false); + } + } + + /* Try to start the next jobs that can be started */ + SET_FOREACH(other, u->meta.dependencies[UNIT_AFTER], i) + if (other->meta.job) + job_add_to_run_queue(other->meta.job); + SET_FOREACH(other, u->meta.dependencies[UNIT_BEFORE], i) + if (other->meta.job) + job_add_to_run_queue(other->meta.job); + + return 0; +} + +void job_add_to_run_queue(Job *j) { + assert(j); + assert(j->installed); + + if (j->in_run_queue) + return; + + LIST_PREPEND(Job, run_queue, j->manager->run_queue, j); + j->in_run_queue = true; +} + +void job_add_to_dbus_queue(Job *j) { + assert(j); + assert(j->installed); + + if (j->in_dbus_queue) + return; + + if (set_isempty(j->manager->subscribed)) { + j->sent_dbus_new_signal = true; + return; + } + + LIST_PREPEND(Job, dbus_queue, j->manager->dbus_job_queue, j); + j->in_dbus_queue = true; +} + +char *job_dbus_path(Job *j) { + char *p; + + assert(j); + + if (asprintf(&p, "/org/freedesktop/systemd1/job/%lu", (unsigned long) j->id) < 0) + return NULL; + + return p; +} + +static const char* const job_state_table[_JOB_STATE_MAX] = { + [JOB_WAITING] = "waiting", + [JOB_RUNNING] = "running" +}; + +DEFINE_STRING_TABLE_LOOKUP(job_state, JobState); + +static const char* const job_type_table[_JOB_TYPE_MAX] = { + [JOB_START] = "start", + [JOB_VERIFY_ACTIVE] = "verify-active", + [JOB_STOP] = "stop", + [JOB_RELOAD] = "reload", + [JOB_RELOAD_OR_START] = "reload-or-start", + [JOB_RESTART] = "restart", + [JOB_TRY_RESTART] = "try-restart", +}; + +DEFINE_STRING_TABLE_LOOKUP(job_type, JobType); + +static const char* const job_mode_table[_JOB_MODE_MAX] = { + [JOB_FAIL] = "fail", + [JOB_REPLACE] = "replace", + [JOB_ISOLATE] = "isolate" +}; + +DEFINE_STRING_TABLE_LOOKUP(job_mode, JobMode); |