timer: fully implement timer units

1 files changed, 420 insertions, 8 deletions

diff --git a/src/timer.c b/src/timer.c
index 41aeb7f3a5..e95b4d66e1 100644
--- a/src/timer.c
+++ b/src/timer.c
@@ -22,30 +22,442 @@
 #include <errno.h>
 
 #include "unit.h"
+#include "unit-name.h"
 #include "timer.h"
+#include "dbus-timer.h"
+
+static const UnitActiveState state_translation_table[_TIMER_STATE_MAX] = {
+        [TIMER_DEAD] = UNIT_INACTIVE,
+        [TIMER_WAITING] = UNIT_ACTIVE,
+        [TIMER_RUNNING] = UNIT_ACTIVE,
+        [TIMER_ELAPSED] = UNIT_ACTIVE,
+        [TIMER_MAINTAINANCE] = UNIT_INACTIVE
+};
+
+static void timer_init(Unit *u) {
+        Timer *t = TIMER(u);
+
+        assert(u);
+        assert(u->meta.load_state == UNIT_STUB);
+
+        t->next_elapse = (usec_t) -1;
+        t->timer_watch.type = WATCH_INVALID;
+}
 
 static void timer_done(Unit *u) {
         Timer *t = TIMER(u);
+        TimerValue *v;
+
+        assert(t);
+
+        while ((v = t->values)) {
+                LIST_REMOVE(TimerValue, value, t->values, v);
+                free(v);
+        }
+
+        unit_unwatch_timer(u, &t->timer_watch);
+}
+
+static int timer_verify(Timer *t) {
+        assert(t);
+
+        if (UNIT(t)->meta.load_state != UNIT_LOADED)
+                return 0;
+
+        if (!t->values) {
+                log_error("%s lacks value setting. Refusing.", t->meta.id);
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+static int timer_load(Unit *u) {
+        Timer *t = TIMER(u);
+        int r;
+
+        assert(u);
+        assert(u->meta.load_state == UNIT_STUB);
+
+        if ((r = unit_load_fragment_and_dropin(u)) < 0)
+                return r;
+
+        if (u->meta.load_state == UNIT_LOADED) {
+
+                if (!t->unit)
+                        if ((r = unit_load_related_unit(u, ".service", &t->unit)))
+                                return r;
+
+                if ((r = unit_add_dependency(u, UNIT_BEFORE, t->unit, true)) < 0)
+                        return r;
+        }
+
+        return timer_verify(t);
+}
+
+static void timer_dump(Unit *u, FILE *f, const char *prefix) {
+        Timer *t = TIMER(u);
+        const char *prefix2;
+        char *p2;
+        TimerValue *v;
+        char
+                timespan1[FORMAT_TIMESPAN_MAX];
 
+        p2 = strappend(prefix, "\t");
+        prefix2 = p2 ? p2 : prefix;
+
+        fprintf(f,
+                "%sTimer State: %s\n"
+                "%sUnit: %s\n",
+                prefix, timer_state_to_string(t->state),
+                prefix, t->unit->meta.id);
+
+        LIST_FOREACH(value, v, t->values)
+                fprintf(f,
+                        "%s%s: %s\n",
+                        prefix,
+                        timer_base_to_string(v->base),
+                        strna(format_timespan(timespan1, sizeof(timespan1), v->value)));
+
+        free(p2);
+}
+
+static void timer_set_state(Timer *t, TimerState state) {
+        TimerState old_state;
         assert(t);
+
+        old_state = t->state;
+        t->state = state;
+
+        if (state != TIMER_WAITING)
+                unit_unwatch_timer(UNIT(t), &t->timer_watch);
+
+        if (state != old_state)
+                log_debug("%s changed %s -> %s",
+                          t->meta.id,
+                          timer_state_to_string(old_state),
+                          timer_state_to_string(state));
+
+        unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state]);
+}
+
+static void timer_enter_waiting(Timer *t, bool initial);
+
+static int timer_coldplug(Unit *u) {
+        Timer *t = TIMER(u);
+
+        assert(t);
+        assert(t->state == TIMER_DEAD);
+
+        if (t->deserialized_state != t->state) {
+
+                if (t->deserialized_state == TIMER_WAITING ||
+                    t->deserialized_state == TIMER_RUNNING ||
+                    t->deserialized_state == TIMER_ELAPSED)
+                        timer_enter_waiting(t, false);
+                else
+                        timer_set_state(t, t->deserialized_state);
+        }
+
+        return 0;
+}
+
+static void timer_enter_dead(Timer *t, bool success) {
+        assert(t);
+
+        if (!success)
+                t->failure = true;
+
+        timer_set_state(t, t->failure ? TIMER_MAINTAINANCE : TIMER_DEAD);
+}
+
+static void timer_enter_waiting(Timer *t, bool initial) {
+        TimerValue *v;
+        usec_t base = 0, delay, n;
+        bool found = false;
+        int r;
+
+        n = now(CLOCK_MONOTONIC);
+
+        LIST_FOREACH(value, v, t->values) {
+
+                if (v->disabled)
+                        continue;
+
+                switch (v->base) {
+
+                case TIMER_ACTIVE:
+                        if (state_translation_table[t->state] == UNIT_ACTIVE) {
+                                base = t->meta.inactive_exit_timestamp.monotonic;
+                        } else
+                                base = n;
+                        break;
+
+                case TIMER_BOOT:
+                        /* CLOCK_MONOTONIC equals the uptime on Linux */
+                        base = 0;
+                        break;
+
+                case TIMER_STARTUP:
+                        base = t->meta.manager->startup_timestamp.monotonic;
+                        break;
+
+                case TIMER_UNIT_ACTIVE:
+
+                        if (t->unit->meta.inactive_exit_timestamp.monotonic <= 0)
+                                continue;
+
+                        base = t->unit->meta.inactive_exit_timestamp.monotonic;
+                        break;
+
+                case TIMER_UNIT_INACTIVE:
+
+                        if (t->unit->meta.inactive_enter_timestamp.monotonic <= 0)
+                                continue;
+
+                        base = t->unit->meta.inactive_enter_timestamp.monotonic;
+                        break;
+
+                default:
+                        assert_not_reached("Unknown timer base");
+                }
+
+                v->next_elapse = base + v->value;
+
+                if (!initial && v->next_elapse < n) {
+                        v->disabled = true;
+                        continue;
+                }
+
+                if (!found)
+                        t->next_elapse = v->next_elapse;
+                else
+                        t->next_elapse = MIN(t->next_elapse, v->next_elapse);
+
+                found = true;
+        }
+
+        if (!found) {
+                timer_set_state(t, TIMER_ELAPSED);
+                return;
+        }
+
+        delay = n < t->next_elapse ? t->next_elapse - n : 0;
+
+        if ((r = unit_watch_timer(UNIT(t), delay, &t->timer_watch)) < 0)
+                goto fail;
+
+        timer_set_state(t, TIMER_WAITING);
+        return;
+
+fail:
+        log_warning("%s failed to enter waiting state: %s", t->meta.id, strerror(-r));
+        timer_enter_dead(t, false);
+}
+
+static void timer_enter_running(Timer *t) {
+        int r;
+        assert(t);
+
+        if ((r = manager_add_job(UNIT(t)->meta.manager, JOB_START, t->unit, JOB_REPLACE, true, NULL)) < 0)
+                goto fail;
+
+        timer_set_state(t, TIMER_RUNNING);
+        return;
+
+fail:
+        log_warning("%s failed to queue unit startup job: %s", t->meta.id, strerror(-r));
+        timer_enter_dead(t, false);
+}
+
+static int timer_start(Unit *u) {
+        Timer *t = TIMER(u);
+
+        assert(t);
+        assert(t->state == TIMER_DEAD);
+
+        timer_enter_waiting(t, true);
+        return 0;
+}
+
+static int timer_stop(Unit *u) {
+        Timer *t = TIMER(u);
+
+        assert(t);
+        assert(t->state == TIMER_WAITING || t->state == TIMER_RUNNING || t->state == TIMER_ELAPSED);
+
+        timer_enter_dead(t, true);
+        return 0;
+}
+
+static int timer_serialize(Unit *u, FILE *f, FDSet *fds) {
+        Timer *t = TIMER(u);
+
+        assert(u);
+        assert(f);
+        assert(fds);
+
+        unit_serialize_item(u, f, "state", timer_state_to_string(t->state));
+
+        return 0;
+}
+
+static int timer_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
+        Timer *t = TIMER(u);
+
+        assert(u);
+        assert(key);
+        assert(value);
+        assert(fds);
+
+        if (streq(key, "state")) {
+                TimerState state;
+
+                if ((state = timer_state_from_string(value)) < 0)
+                        log_debug("Failed to parse state value %s", value);
+                else
+                        t->deserialized_state = state;
+        } else
+                log_debug("Unknown serialization key '%s'", key);
+
+        return 0;
 }
 
 static UnitActiveState timer_active_state(Unit *u) {
+        assert(u);
+
+        return state_translation_table[TIMER(u)->state];
+}
+
+static const char *timer_sub_state_to_string(Unit *u) {
+        assert(u);
+
+        return timer_state_to_string(TIMER(u)->state);
+}
+
+static void timer_timer_event(Unit *u, uint64_t elapsed, Watch *w) {
+        Timer *t = TIMER(u);
+
+        assert(t);
+        assert(elapsed == 1);
 
-        static const UnitActiveState table[_TIMER_STATE_MAX] = {
-                [TIMER_DEAD] = UNIT_INACTIVE,
-                [TIMER_WAITING] = UNIT_ACTIVE,
-                [TIMER_RUNNING] = UNIT_ACTIVE
-        };
+        if (t->state != TIMER_WAITING)
+                return;
 
-        return table[TIMER(u)->state];
+        log_debug("Timer elapsed on %s", u->meta.id);
+        timer_enter_running(t);
 }
 
+void timer_unit_notify(Unit *u, UnitActiveState new_state) {
+        char *n;
+        int r;
+        Iterator i;
+
+        if (u->meta.type == UNIT_TIMER)
+                return;
+
+        SET_FOREACH(n, u->meta.names, i) {
+                char *k;
+                Unit *p;
+                Timer *t;
+                TimerValue *v;
+
+                if (!(k = unit_name_change_suffix(n, ".timer"))) {
+                        r = -ENOMEM;
+                        goto fail;
+                }
+
+                p = manager_get_unit(u->meta.manager, k);
+                free(k);
+
+                if (!p)
+                        continue;
+
+                t = TIMER(p);
+
+                if (t->meta.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;
+
+                switch (t->state) {
+
+                case TIMER_WAITING:
+                case TIMER_ELAPSED:
+
+                        /* Recalculate sleep time */
+                        timer_enter_waiting(t, false);
+                        break;
+
+                case TIMER_RUNNING:
+
+                        if (new_state == UNIT_INACTIVE) {
+                                log_debug("%s got notified about unit deactivation.", t->meta.id);
+                                timer_enter_waiting(t, false);
+                        }
+
+                        break;
+
+                case TIMER_DEAD:
+                case TIMER_MAINTAINANCE:
+                        ;
+
+                default:
+                        assert_not_reached("Unknown timer state");
+                }
+        }
+
+        return;
+
+fail:
+        log_error("Failed find timer unit: %s", strerror(-r));
+}
+
+static const char* const timer_state_table[_TIMER_STATE_MAX] = {
+        [TIMER_DEAD] = "dead",
+        [TIMER_WAITING] = "waiting",
+        [TIMER_RUNNING] = "running",
+        [TIMER_ELAPSED] = "elapsed",
+        [TIMER_MAINTAINANCE] = "maintainance"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(timer_state, TimerState);
+
+static const char* const timer_base_table[_TIMER_BASE_MAX] = {
+        [TIMER_ACTIVE] = "OnActive",
+        [TIMER_BOOT] = "OnBoot",
+        [TIMER_STARTUP] = "OnStartup",
+        [TIMER_UNIT_ACTIVE] = "OnUnitActive",
+        [TIMER_UNIT_INACTIVE] = "OnUnitInactive"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(timer_base, TimerBase);
+
 const UnitVTable timer_vtable = {
         .suffix = ".timer",
 
-        .load = unit_load_fragment_and_dropin,
+        .init = timer_init,
         .done = timer_done,
+        .load = timer_load,
+
+        .coldplug = timer_coldplug,
+
+        .dump = timer_dump,
+
+        .start = timer_start,
+        .stop = timer_stop,
+
+        .serialize = timer_serialize,
+        .deserialize_item = timer_deserialize_item,
+
+        .active_state = timer_active_state,
+        .sub_state_to_string = timer_sub_state_to_string,
+
+        .timer_event = timer_timer_event,
 
-        .active_state = timer_active_state
+        .bus_message_handler = bus_timer_message_handler
 };