unit: rework trigger dependency logic

Instead of having explicit type-specific callbacks that inform the
triggering unit when a triggered unit changes state, make this generic
so that state changes are forwarded betwee any triggered and triggering
unit.

Also, get rid of UnitRef references from automount, timer, path units,
to the units they trigger and rely exclsuively on UNIT_TRIGGER type
dendencies.

1 files changed, 49 insertions, 56 deletions

diff --git a/src/core/timer.c b/src/core/timer.c
index 107dbb3f21..b5d895f048 100644
--- a/src/core/timer.c
+++ b/src/core/timer.c
@@ -72,8 +72,6 @@ static void timer_done(Unit *u) {
 
         unit_unwatch_timer(u, &t->monotonic_watch);
         unit_unwatch_timer(u, &t->realtime_watch);
-
-        unit_ref_unset(&t->unit);
 }
 
 static int timer_verify(Timer *t) {
@@ -122,20 +120,18 @@ static int timer_load(Unit *u) {
 
         if (u->load_state == UNIT_LOADED) {
 
-                if (!UNIT_DEREF(t->unit)) {
+                if (set_isempty(u->dependencies[UNIT_TRIGGERS])) {
                         Unit *x;
 
                         r = unit_load_related_unit(u, ".service", &x);
                         if (r < 0)
                                 return r;
 
-                        unit_ref_set(&t->unit, x);
+                        r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, x, true);
+                        if (r < 0)
+                                return r;
                 }
 
-                r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, UNIT_DEREF(t->unit), true);
-                if (r < 0)
-                        return r;
-
                 if (UNIT(t)->default_dependencies) {
                         r = timer_add_default_dependencies(t);
                         if (r < 0)
@@ -148,15 +144,18 @@ static int timer_load(Unit *u) {
 
 static void timer_dump(Unit *u, FILE *f, const char *prefix) {
         Timer *t = TIMER(u);
+        Unit *trigger;
         TimerValue *v;
 
+        trigger = UNIT_TRIGGER(u);
+
         fprintf(f,
                 "%sTimer State: %s\n"
                 "%sResult: %s\n"
                 "%sUnit: %s\n",
                 prefix, timer_state_to_string(t->state),
                 prefix, timer_result_to_string(t->result),
-                prefix, UNIT_DEREF(t->unit)->id);
+                prefix, trigger ? trigger->id : "n/a");
 
         LIST_FOREACH(value, v, t->values) {
 
@@ -285,18 +284,18 @@ static void timer_enter_waiting(Timer *t, bool initial) {
 
                         case TIMER_UNIT_ACTIVE:
 
-                                if (UNIT_DEREF(t->unit)->inactive_exit_timestamp.monotonic <= 0)
+                                if (UNIT_TRIGGER(UNIT(t))->inactive_exit_timestamp.monotonic <= 0)
                                         continue;
 
-                                base = UNIT_DEREF(t->unit)->inactive_exit_timestamp.monotonic;
+                                base = UNIT_TRIGGER(UNIT(t))->inactive_exit_timestamp.monotonic;
                                 break;
 
                         case TIMER_UNIT_INACTIVE:
 
-                                if (UNIT_DEREF(t->unit)->inactive_enter_timestamp.monotonic <= 0)
+                                if (UNIT_TRIGGER(UNIT(t))->inactive_enter_timestamp.monotonic <= 0)
                                         continue;
 
-                                base = UNIT_DEREF(t->unit)->inactive_enter_timestamp.monotonic;
+                                base = UNIT_TRIGGER(UNIT(t))->inactive_enter_timestamp.monotonic;
                                 break;
 
                         default:
@@ -369,10 +368,11 @@ static void timer_enter_running(Timer *t) {
         dbus_error_init(&error);
 
         /* Don't start job if we are supposed to go down */
-        if (UNIT(t)->job && UNIT(t)->job->type == JOB_STOP)
+        if (unit_pending_inactive(UNIT(t)))
                 return;
 
-        r = manager_add_job(UNIT(t)->manager, JOB_START, UNIT_DEREF(t->unit), JOB_REPLACE, true, &error, NULL);
+        r = manager_add_job(UNIT(t)->manager, JOB_START, UNIT_TRIGGER(UNIT(t)),
+                            JOB_REPLACE, true, &error, NULL);
         if (r < 0)
                 goto fail;
 
@@ -394,7 +394,7 @@ static int timer_start(Unit *u) {
         assert(t);
         assert(t->state == TIMER_DEAD || t->state == TIMER_FAILED);
 
-        if (UNIT_DEREF(t->unit)->load_state != UNIT_LOADED)
+        if (UNIT_TRIGGER(u)->load_state != UNIT_LOADED)
                 return -ENOENT;
 
         t->result = TIMER_SUCCESS;
@@ -481,58 +481,49 @@ static void timer_timer_event(Unit *u, uint64_t elapsed, Watch *w) {
         timer_enter_running(t);
 }
 
-void timer_unit_notify(Unit *u, UnitActiveState new_state) {
-        Iterator i;
-        Unit *k;
+static void timer_trigger_notify(Unit *u, Unit *other) {
+        Timer *t = TIMER(u);
+        TimerValue *v;
 
-        if (u->type == UNIT_TIMER)
-                return;
+        assert(u);
+        assert(other);
 
-        SET_FOREACH(k, u->dependencies[UNIT_TRIGGERED_BY], i) {
-                Timer *t;
-                TimerValue *v;
+        log_error("NOTIFY!");
 
-                if (k->type != UNIT_TIMER)
-                        continue;
+        if (other->load_state != UNIT_LOADED)
+                return;
 
-                if (k->load_state != UNIT_LOADED)
-                        continue;
+        /* Reenable all timers that depend on unit state */
+        LIST_FOREACH(value, v, t->values)
+                if (v->base == TIMER_UNIT_ACTIVE ||
+                    v->base == TIMER_UNIT_INACTIVE)
+                        v->disabled = false;
 
-                t = TIMER(k);
+        switch (t->state) {
 
-                /* Reenable all timers that depend on unit state */
-                LIST_FOREACH(value, v, t->values)
-                        if (v->base == TIMER_UNIT_ACTIVE ||
-                            v->base == TIMER_UNIT_INACTIVE)
-                                v->disabled = false;
+        case TIMER_WAITING:
+        case TIMER_ELAPSED:
 
-                switch (t->state) {
+                /* Recalculate sleep time */
+                timer_enter_waiting(t, false);
+                break;
 
-                case TIMER_WAITING:
-                case TIMER_ELAPSED:
+        case TIMER_RUNNING:
 
-                        /* Recalculate sleep time */
+                if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other))) {
+                        log_debug_unit(UNIT(t)->id,
+                                       "%s got notified about unit deactivation.",
+                                       UNIT(t)->id);
                         timer_enter_waiting(t, false);
-                        break;
-
-                case TIMER_RUNNING:
-
-                        if (UNIT_IS_INACTIVE_OR_FAILED(new_state)) {
-                                log_debug_unit(UNIT(t)->id,
-                                               "%s got notified about unit deactivation.",
-                                               UNIT(t)->id);
-                                timer_enter_waiting(t, false);
-                        }
-
-                        break;
+                }
+                break;
 
-                case TIMER_DEAD:
-                case TIMER_FAILED:
-                        break;
+        case TIMER_DEAD:
+        case TIMER_FAILED:
+                break;
 
-                default:
-                        assert_not_reached("Unknown timer state");
-                }
+        default:
+                assert_not_reached("Unknown timer state");
         }
 }
 
@@ -614,6 +605,8 @@ const UnitVTable timer_vtable = {
 
         .timer_event = timer_timer_event,
 
+        .trigger_notify = timer_trigger_notify,
+
         .reset_failed = timer_reset_failed,
         .time_change = timer_time_change,