chiark / gitweb /
add basic (and not very useful) D-Bus support
[elogind.git] / job.c
diff --git a/job.c b/job.c
index 87bcd28..d02551a 100644 (file)
--- a/job.c
+++ b/job.c
@@ -1,16 +1,22 @@
 /*-*- Mode: C; c-basic-offset: 8 -*-*/
 
 #include <assert.h>
+#include <errno.h>
 
+#include "set.h"
+#include "unit.h"
 #include "macro.h"
-#include "job.h"
+#include "strv.h"
+#include "load-fragment.h"
+#include "load-dropin.h"
+#include "log.h"
 
-Job* job_new(Manager *m, JobType type, Name *name) {
+Job* job_new(Manager *m, JobType type, Unit *unit) {
         Job *j;
 
         assert(m);
         assert(type < _JOB_TYPE_MAX);
-        assert(name);
+        assert(unit);
 
         if (!(j = new0(Job, 1)))
                 return NULL;
@@ -18,73 +24,471 @@ Job* job_new(Manager *m, JobType type, Name *name) {
         j->manager = m;
         j->id = m->current_job_id++;
         j->type = type;
-        j->name = name;
+        j->unit = unit;
 
-        /* We don't link it here, that's what job_link() is for */
+        /* We don't link it here, that's what job_dependency() is for */
 
         return j;
 }
 
-int job_link(Job *j) {
-        int r;
+void job_free(Job *j) {
+        assert(j);
+
+        /* Detach from next 'bigger' objects */
+        if (j->installed) {
+                if (j->unit->meta.job == j)
+                        j->unit->meta.job = NULL;
+
+                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);
+
+        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, unit_id(j->unit), job_type_to_string(j->type),
+                prefix, job_state_to_string(j->state),
+                prefix, yes_no(j->forced));
+}
+
+bool job_is_anchor(Job *j) {
+        JobDependency *l;
 
         assert(j);
-        assert(!j->linked);
 
-        if ((r = hashmap_put(j->manager->jobs, UINT32_TO_PTR(j->id), j)) < 0)
-                return r;
+        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. */
 
-        j->name->meta.job = j;
+        /* Mergeability is transitive! if a can be merged with b and b
+         * with c then a also with c */
 
-        j->linked = true;
+        /* 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;
 }
 
-void job_free(Job *j) {
+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_is_runnable(Job *j) {
+        Iterator i;
+        Unit *other;
+
         assert(j);
+        assert(j->installed);
 
-        /* Detach from next 'bigger' objects */
+        /* 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->linked) {
-                assert(j->name);
-                assert(j->name->meta.job == j);
-                j->name->meta.job = NULL;
+        if (j->type == JOB_START ||
+            j->type == JOB_VERIFY_ACTIVE ||
+            j->type == JOB_RELOAD ||
+            j->type == JOB_RELOAD_OR_START) {
 
-                hashmap_remove(j->manager->jobs, UINT32_TO_PTR(j->id));
+                /* 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;
         }
 
-        hashmap_remove(j->manager->jobs_to_add, j->name);
-        set_remove(j->manager->jobs_to_remove, j);
+        /* Also, if something else is being stopped and we should
+         * change state after it, then lets wait. */
 
-        /* Free data and next 'smaller' objects */
-        free(j);
+        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;
 }
 
-void job_dump(Job *j, FILE*f) {
+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;
+
+        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;
 
-        static const char* const job_type_table[_JOB_TYPE_MAX] = {
-                [JOB_START] = "START",
-                [JOB_STOP] = "STOP",
-                [JOB_VERIFY_STARTED] = "VERIFY_STARTED",
-                [JOB_RELOAD] = "RELOAD",
-                [JOB_RESTART] = "RESTART",
-                [JOB_TRY_RESTART] = "TRY_RESTART",
-                [JOB_RESTART_FINISH] = "RESTART_FINISH"
-        };
+                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;
 
-        static const char* const job_state_table[_JOB_STATE_MAX] = {
-                [JOB_WAITING] = "WAITING",
-                [JOB_RUNNING] = "RUNNING",
-                [JOB_DONE] = "DONE"
-        };
+                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;
+        UnitType t;
+        Iterator i;
 
         assert(j);
-        assert(f);
+        assert(j->installed);
 
-        fprintf(f, "Job %u: %s → %s in state %s\n",
-                j->id,
-                name_id(j->name),
-                job_type_table[j->type],
-                job_state_table[j->state]);
+        log_debug("Job %s/%s finished, success=%s", unit_id(j->unit), job_type_to_string(j->type), yes_no(success));
+
+        /* 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",
+                          unit_id(j->unit), job_type_to_string(j->type),
+                          unit_id(j->unit), job_type_to_string(JOB_START));
+
+                j->state = JOB_RUNNING;
+                j->type = JOB_START;
+
+                job_schedule_run(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.type == JOB_START ||
+                                     other->meta.type == JOB_VERIFY_ACTIVE ||
+                                     other->meta.type == JOB_RELOAD_OR_START))
+                                        job_finish_and_invalidate(other->meta.job, false);
+
+                        SET_FOREACH(other, u->meta.dependencies[UNIT_SOFT_REQUIRED_BY], i)
+                                if (other->meta.job &&
+                                    !other->meta.job->forced &&
+                                    (other->meta.type == JOB_START ||
+                                     other->meta.type == JOB_VERIFY_ACTIVE ||
+                                     other->meta.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 &&
+                                    (t == JOB_START ||
+                                     t == JOB_VERIFY_ACTIVE ||
+                                     t == 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_schedule_run(other->meta.job);
+        SET_FOREACH(other, u->meta.dependencies[UNIT_BEFORE], i)
+                if (other->meta.job)
+                        job_schedule_run(other->meta.job);
+
+        return 0;
 }
+
+void job_schedule_run(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;
+}
+
+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);