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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 02:25:50 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 02:25:50 +0000
commit19f4f86bfed21c5326ed2acebe1163f3a83e832b (patch)
treed59b9989ce55ed23693e80974d94c856f1c2c8b1 /src/core/timer.c
parentInitial commit. (diff)
downloadsystemd-upstream.tar.xz
systemd-upstream.zip
Adding upstream version 241.upstream/241upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--src/core/timer.c881
1 files changed, 881 insertions, 0 deletions
diff --git a/src/core/timer.c b/src/core/timer.c
new file mode 100644
index 0000000..d9ba2f7
--- /dev/null
+++ b/src/core/timer.c
@@ -0,0 +1,881 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+
+#include "alloc-util.h"
+#include "bus-error.h"
+#include "bus-util.h"
+#include "dbus-timer.h"
+#include "dbus-unit.h"
+#include "fs-util.h"
+#include "parse-util.h"
+#include "random-util.h"
+#include "serialize.h"
+#include "special.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "timer.h"
+#include "unit-name.h"
+#include "unit.h"
+#include "user-util.h"
+#include "virt.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_FAILED] = UNIT_FAILED
+};
+
+static int timer_dispatch(sd_event_source *s, uint64_t usec, void *userdata);
+
+static void timer_init(Unit *u) {
+ Timer *t = TIMER(u);
+
+ assert(u);
+ assert(u->load_state == UNIT_STUB);
+
+ t->next_elapse_monotonic_or_boottime = USEC_INFINITY;
+ t->next_elapse_realtime = USEC_INFINITY;
+ t->accuracy_usec = u->manager->default_timer_accuracy_usec;
+ t->remain_after_elapse = true;
+}
+
+void timer_free_values(Timer *t) {
+ TimerValue *v;
+
+ assert(t);
+
+ while ((v = t->values)) {
+ LIST_REMOVE(value, t->values, v);
+ calendar_spec_free(v->calendar_spec);
+ free(v);
+ }
+}
+
+static void timer_done(Unit *u) {
+ Timer *t = TIMER(u);
+
+ assert(t);
+
+ timer_free_values(t);
+
+ t->monotonic_event_source = sd_event_source_unref(t->monotonic_event_source);
+ t->realtime_event_source = sd_event_source_unref(t->realtime_event_source);
+
+ free(t->stamp_path);
+}
+
+static int timer_verify(Timer *t) {
+ assert(t);
+
+ if (UNIT(t)->load_state != UNIT_LOADED)
+ return 0;
+
+ if (!t->values) {
+ log_unit_error(UNIT(t), "Timer unit lacks value setting. Refusing.");
+ return -ENOEXEC;
+ }
+
+ return 0;
+}
+
+static int timer_add_default_dependencies(Timer *t) {
+ int r;
+ TimerValue *v;
+
+ assert(t);
+
+ if (!UNIT(t)->default_dependencies)
+ return 0;
+
+ r = unit_add_dependency_by_name(UNIT(t), UNIT_BEFORE, SPECIAL_TIMERS_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
+ if (r < 0)
+ return r;
+
+ if (MANAGER_IS_SYSTEM(UNIT(t)->manager)) {
+ r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
+ if (r < 0)
+ return r;
+
+ LIST_FOREACH(value, v, t->values) {
+ if (v->base == TIMER_CALENDAR) {
+ r = unit_add_dependency_by_name(UNIT(t), UNIT_AFTER, SPECIAL_TIME_SYNC_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
+ if (r < 0)
+ return r;
+ break;
+ }
+ }
+ }
+
+ return unit_add_two_dependencies_by_name(UNIT(t), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
+}
+
+static int timer_add_trigger_dependencies(Timer *t) {
+ Unit *x;
+ int r;
+
+ assert(t);
+
+ if (!hashmap_isempty(UNIT(t)->dependencies[UNIT_TRIGGERS]))
+ return 0;
+
+ r = unit_load_related_unit(UNIT(t), ".service", &x);
+ if (r < 0)
+ return r;
+
+ return unit_add_two_dependencies(UNIT(t), UNIT_BEFORE, UNIT_TRIGGERS, x, true, UNIT_DEPENDENCY_IMPLICIT);
+}
+
+static int timer_setup_persistent(Timer *t) {
+ int r;
+
+ assert(t);
+
+ if (!t->persistent)
+ return 0;
+
+ if (MANAGER_IS_SYSTEM(UNIT(t)->manager)) {
+
+ r = unit_require_mounts_for(UNIT(t), "/var/lib/systemd/timers", UNIT_DEPENDENCY_FILE);
+ if (r < 0)
+ return r;
+
+ t->stamp_path = strappend("/var/lib/systemd/timers/stamp-", UNIT(t)->id);
+ } else {
+ const char *e;
+
+ e = getenv("XDG_DATA_HOME");
+ if (e)
+ t->stamp_path = strjoin(e, "/systemd/timers/stamp-", UNIT(t)->id);
+ else {
+
+ _cleanup_free_ char *h = NULL;
+
+ r = get_home_dir(&h);
+ if (r < 0)
+ return log_unit_error_errno(UNIT(t), r, "Failed to determine home directory: %m");
+
+ t->stamp_path = strjoin(h, "/.local/share/systemd/timers/stamp-", UNIT(t)->id);
+ }
+ }
+
+ if (!t->stamp_path)
+ return log_oom();
+
+ return 0;
+}
+
+static int timer_load(Unit *u) {
+ Timer *t = TIMER(u);
+ int r;
+
+ assert(u);
+ assert(u->load_state == UNIT_STUB);
+
+ r = unit_load_fragment_and_dropin(u);
+ if (r < 0)
+ return r;
+
+ if (u->load_state == UNIT_LOADED) {
+
+ r = timer_add_trigger_dependencies(t);
+ if (r < 0)
+ return r;
+
+ r = timer_setup_persistent(t);
+ if (r < 0)
+ return r;
+
+ r = timer_add_default_dependencies(t);
+ if (r < 0)
+ return r;
+ }
+
+ return timer_verify(t);
+}
+
+static void timer_dump(Unit *u, FILE *f, const char *prefix) {
+ char buf[FORMAT_TIMESPAN_MAX];
+ Timer *t = TIMER(u);
+ Unit *trigger;
+ TimerValue *v;
+
+ trigger = UNIT_TRIGGER(u);
+
+ fprintf(f,
+ "%sTimer State: %s\n"
+ "%sResult: %s\n"
+ "%sUnit: %s\n"
+ "%sPersistent: %s\n"
+ "%sWakeSystem: %s\n"
+ "%sAccuracy: %s\n"
+ "%sRemainAfterElapse: %s\n",
+ prefix, timer_state_to_string(t->state),
+ prefix, timer_result_to_string(t->result),
+ prefix, trigger ? trigger->id : "n/a",
+ prefix, yes_no(t->persistent),
+ prefix, yes_no(t->wake_system),
+ prefix, format_timespan(buf, sizeof(buf), t->accuracy_usec, 1),
+ prefix, yes_no(t->remain_after_elapse));
+
+ LIST_FOREACH(value, v, t->values) {
+
+ if (v->base == TIMER_CALENDAR) {
+ _cleanup_free_ char *p = NULL;
+
+ (void) calendar_spec_to_string(v->calendar_spec, &p);
+
+ fprintf(f,
+ "%s%s: %s\n",
+ prefix,
+ timer_base_to_string(v->base),
+ strna(p));
+ } else {
+ char timespan1[FORMAT_TIMESPAN_MAX];
+
+ fprintf(f,
+ "%s%s: %s\n",
+ prefix,
+ timer_base_to_string(v->base),
+ format_timespan(timespan1, sizeof(timespan1), v->value, 0));
+ }
+ }
+}
+
+static void timer_set_state(Timer *t, TimerState state) {
+ TimerState old_state;
+ assert(t);
+
+ if (t->state != state)
+ bus_unit_send_pending_change_signal(UNIT(t), false);
+
+ old_state = t->state;
+ t->state = state;
+
+ if (state != TIMER_WAITING) {
+ t->monotonic_event_source = sd_event_source_unref(t->monotonic_event_source);
+ t->realtime_event_source = sd_event_source_unref(t->realtime_event_source);
+ t->next_elapse_monotonic_or_boottime = USEC_INFINITY;
+ t->next_elapse_realtime = USEC_INFINITY;
+ }
+
+ if (state != old_state)
+ log_unit_debug(UNIT(t), "Changed %s -> %s", timer_state_to_string(old_state), timer_state_to_string(state));
+
+ unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], 0);
+}
+
+static void timer_enter_waiting(Timer *t, bool time_change);
+
+static int timer_coldplug(Unit *u) {
+ Timer *t = TIMER(u);
+
+ assert(t);
+ assert(t->state == TIMER_DEAD);
+
+ if (t->deserialized_state == t->state)
+ return 0;
+
+ if (t->deserialized_state == TIMER_WAITING)
+ timer_enter_waiting(t, false);
+ else
+ timer_set_state(t, t->deserialized_state);
+
+ return 0;
+}
+
+static void timer_enter_dead(Timer *t, TimerResult f) {
+ assert(t);
+
+ if (t->result == TIMER_SUCCESS)
+ t->result = f;
+
+ unit_log_result(UNIT(t), t->result == TIMER_SUCCESS, timer_result_to_string(t->result));
+ timer_set_state(t, t->result != TIMER_SUCCESS ? TIMER_FAILED : TIMER_DEAD);
+}
+
+static void timer_enter_elapsed(Timer *t, bool leave_around) {
+ assert(t);
+
+ /* If a unit is marked with RemainAfterElapse=yes we leave it
+ * around even after it elapsed once, so that starting it
+ * later again does not necessarily mean immediate
+ * retriggering. We unconditionally leave units with
+ * TIMER_UNIT_ACTIVE or TIMER_UNIT_INACTIVE triggers around,
+ * since they might be restarted automatically at any time
+ * later on. */
+
+ if (t->remain_after_elapse || leave_around)
+ timer_set_state(t, TIMER_ELAPSED);
+ else
+ timer_enter_dead(t, TIMER_SUCCESS);
+}
+
+static void add_random(Timer *t, usec_t *v) {
+ char s[FORMAT_TIMESPAN_MAX];
+ usec_t add;
+
+ assert(t);
+ assert(v);
+
+ if (t->random_usec == 0)
+ return;
+ if (*v == USEC_INFINITY)
+ return;
+
+ add = random_u64() % t->random_usec;
+
+ if (*v + add < *v) /* overflow */
+ *v = (usec_t) -2; /* Highest possible value, that is not USEC_INFINITY */
+ else
+ *v += add;
+
+ log_unit_debug(UNIT(t), "Adding %s random time.", format_timespan(s, sizeof(s), add, 0));
+}
+
+static void timer_enter_waiting(Timer *t, bool time_change) {
+ bool found_monotonic = false, found_realtime = false;
+ bool leave_around = false;
+ triple_timestamp ts;
+ TimerValue *v;
+ Unit *trigger;
+ int r;
+
+ assert(t);
+
+ trigger = UNIT_TRIGGER(UNIT(t));
+ if (!trigger) {
+ log_unit_error(UNIT(t), "Unit to trigger vanished.");
+ timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
+ return;
+ }
+
+ triple_timestamp_get(&ts);
+ t->next_elapse_monotonic_or_boottime = t->next_elapse_realtime = 0;
+
+ LIST_FOREACH(value, v, t->values) {
+ if (v->disabled)
+ continue;
+
+ if (v->base == TIMER_CALENDAR) {
+ usec_t b;
+
+ /* If we know the last time this was
+ * triggered, schedule the job based relative
+ * to that. If we don't, just start from
+ * the activation time. */
+
+ if (t->last_trigger.realtime > 0)
+ b = t->last_trigger.realtime;
+ else {
+ if (state_translation_table[t->state] == UNIT_ACTIVE)
+ b = UNIT(t)->inactive_exit_timestamp.realtime;
+ else
+ b = ts.realtime;
+ }
+
+ r = calendar_spec_next_usec(v->calendar_spec, b, &v->next_elapse);
+ if (r < 0)
+ continue;
+
+ if (!found_realtime)
+ t->next_elapse_realtime = v->next_elapse;
+ else
+ t->next_elapse_realtime = MIN(t->next_elapse_realtime, v->next_elapse);
+
+ found_realtime = true;
+
+ } else {
+ usec_t base;
+
+ switch (v->base) {
+
+ case TIMER_ACTIVE:
+ if (state_translation_table[t->state] == UNIT_ACTIVE)
+ base = UNIT(t)->inactive_exit_timestamp.monotonic;
+ else
+ base = ts.monotonic;
+ break;
+
+ case TIMER_BOOT:
+ if (detect_container() <= 0) {
+ /* CLOCK_MONOTONIC equals the uptime on Linux */
+ base = 0;
+ break;
+ }
+ /* In a container we don't want to include the time the host
+ * was already up when the container started, so count from
+ * our own startup. */
+ _fallthrough_;
+ case TIMER_STARTUP:
+ base = UNIT(t)->manager->timestamps[MANAGER_TIMESTAMP_USERSPACE].monotonic;
+ break;
+
+ case TIMER_UNIT_ACTIVE:
+ leave_around = true;
+ base = trigger->inactive_exit_timestamp.monotonic;
+
+ if (base <= 0)
+ base = t->last_trigger.monotonic;
+
+ if (base <= 0)
+ continue;
+ base = MAX(base, t->last_trigger.monotonic);
+
+ break;
+
+ case TIMER_UNIT_INACTIVE:
+ leave_around = true;
+ base = trigger->inactive_enter_timestamp.monotonic;
+
+ if (base <= 0)
+ base = t->last_trigger.monotonic;
+
+ if (base <= 0)
+ continue;
+ base = MAX(base, t->last_trigger.monotonic);
+
+ break;
+
+ default:
+ assert_not_reached("Unknown timer base");
+ }
+
+ v->next_elapse = usec_add(usec_shift_clock(base, CLOCK_MONOTONIC, TIMER_MONOTONIC_CLOCK(t)), v->value);
+
+ if (dual_timestamp_is_set(&t->last_trigger) &&
+ !time_change &&
+ v->next_elapse < triple_timestamp_by_clock(&ts, TIMER_MONOTONIC_CLOCK(t)) &&
+ IN_SET(v->base, TIMER_ACTIVE, TIMER_BOOT, TIMER_STARTUP)) {
+ /* This is a one time trigger, disable it now */
+ v->disabled = true;
+ continue;
+ }
+
+ if (!found_monotonic)
+ t->next_elapse_monotonic_or_boottime = v->next_elapse;
+ else
+ t->next_elapse_monotonic_or_boottime = MIN(t->next_elapse_monotonic_or_boottime, v->next_elapse);
+
+ found_monotonic = true;
+ }
+ }
+
+ if (!found_monotonic && !found_realtime) {
+ log_unit_debug(UNIT(t), "Timer is elapsed.");
+ timer_enter_elapsed(t, leave_around);
+ return;
+ }
+
+ if (found_monotonic) {
+ char buf[FORMAT_TIMESPAN_MAX];
+ usec_t left;
+
+ add_random(t, &t->next_elapse_monotonic_or_boottime);
+
+ left = usec_sub_unsigned(t->next_elapse_monotonic_or_boottime, triple_timestamp_by_clock(&ts, TIMER_MONOTONIC_CLOCK(t)));
+ log_unit_debug(UNIT(t), "Monotonic timer elapses in %s.", format_timespan(buf, sizeof(buf), left, 0));
+
+ if (t->monotonic_event_source) {
+ r = sd_event_source_set_time(t->monotonic_event_source, t->next_elapse_monotonic_or_boottime);
+ if (r < 0)
+ goto fail;
+
+ r = sd_event_source_set_enabled(t->monotonic_event_source, SD_EVENT_ONESHOT);
+ if (r < 0)
+ goto fail;
+ } else {
+
+ r = sd_event_add_time(
+ UNIT(t)->manager->event,
+ &t->monotonic_event_source,
+ t->wake_system ? CLOCK_BOOTTIME_ALARM : CLOCK_MONOTONIC,
+ t->next_elapse_monotonic_or_boottime, t->accuracy_usec,
+ timer_dispatch, t);
+ if (r < 0)
+ goto fail;
+
+ (void) sd_event_source_set_description(t->monotonic_event_source, "timer-monotonic");
+ }
+
+ } else if (t->monotonic_event_source) {
+
+ r = sd_event_source_set_enabled(t->monotonic_event_source, SD_EVENT_OFF);
+ if (r < 0)
+ goto fail;
+ }
+
+ if (found_realtime) {
+ char buf[FORMAT_TIMESTAMP_MAX];
+
+ add_random(t, &t->next_elapse_realtime);
+
+ log_unit_debug(UNIT(t), "Realtime timer elapses at %s.", format_timestamp(buf, sizeof(buf), t->next_elapse_realtime));
+
+ if (t->realtime_event_source) {
+ r = sd_event_source_set_time(t->realtime_event_source, t->next_elapse_realtime);
+ if (r < 0)
+ goto fail;
+
+ r = sd_event_source_set_enabled(t->realtime_event_source, SD_EVENT_ONESHOT);
+ if (r < 0)
+ goto fail;
+ } else {
+ r = sd_event_add_time(
+ UNIT(t)->manager->event,
+ &t->realtime_event_source,
+ t->wake_system ? CLOCK_REALTIME_ALARM : CLOCK_REALTIME,
+ t->next_elapse_realtime, t->accuracy_usec,
+ timer_dispatch, t);
+ if (r < 0)
+ goto fail;
+
+ (void) sd_event_source_set_description(t->realtime_event_source, "timer-realtime");
+ }
+
+ } else if (t->realtime_event_source) {
+
+ r = sd_event_source_set_enabled(t->realtime_event_source, SD_EVENT_OFF);
+ if (r < 0)
+ goto fail;
+ }
+
+ timer_set_state(t, TIMER_WAITING);
+ return;
+
+fail:
+ log_unit_warning_errno(UNIT(t), r, "Failed to enter waiting state: %m");
+ timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
+}
+
+static void timer_enter_running(Timer *t) {
+ _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+ Unit *trigger;
+ int r;
+
+ assert(t);
+
+ /* Don't start job if we are supposed to go down */
+ if (unit_stop_pending(UNIT(t)))
+ return;
+
+ trigger = UNIT_TRIGGER(UNIT(t));
+ if (!trigger) {
+ log_unit_error(UNIT(t), "Unit to trigger vanished.");
+ timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
+ return;
+ }
+
+ r = manager_add_job(UNIT(t)->manager, JOB_START, trigger, JOB_REPLACE, &error, NULL);
+ if (r < 0)
+ goto fail;
+
+ dual_timestamp_get(&t->last_trigger);
+
+ if (t->stamp_path)
+ touch_file(t->stamp_path, true, t->last_trigger.realtime, UID_INVALID, GID_INVALID, MODE_INVALID);
+
+ timer_set_state(t, TIMER_RUNNING);
+ return;
+
+fail:
+ log_unit_warning(UNIT(t), "Failed to queue unit startup job: %s", bus_error_message(&error, r));
+ timer_enter_dead(t, TIMER_FAILURE_RESOURCES);
+}
+
+static int timer_start(Unit *u) {
+ Timer *t = TIMER(u);
+ TimerValue *v;
+ Unit *trigger;
+ int r;
+
+ assert(t);
+ assert(IN_SET(t->state, TIMER_DEAD, TIMER_FAILED));
+
+ trigger = UNIT_TRIGGER(u);
+ if (!trigger || trigger->load_state != UNIT_LOADED) {
+ log_unit_error(u, "Refusing to start, unit to trigger not loaded.");
+ return -ENOENT;
+ }
+
+ r = unit_start_limit_test(u);
+ if (r < 0) {
+ timer_enter_dead(t, TIMER_FAILURE_START_LIMIT_HIT);
+ return r;
+ }
+
+ r = unit_acquire_invocation_id(u);
+ if (r < 0)
+ return r;
+
+ t->last_trigger = DUAL_TIMESTAMP_NULL;
+
+ /* Reenable all timers that depend on unit activation time */
+ LIST_FOREACH(value, v, t->values)
+ if (v->base == TIMER_ACTIVE)
+ v->disabled = false;
+
+ if (t->stamp_path) {
+ struct stat st;
+
+ if (stat(t->stamp_path, &st) >= 0) {
+ usec_t ft;
+
+ /* Load the file timestamp, but only if it is actually in the past. If it is in the future,
+ * something is wrong with the system clock. */
+
+ ft = timespec_load(&st.st_mtim);
+ if (ft < now(CLOCK_REALTIME))
+ t->last_trigger.realtime = ft;
+ else {
+ char z[FORMAT_TIMESTAMP_MAX];
+
+ log_unit_warning(u, "Not using persistent file timestamp %s as it is in the future.",
+ format_timestamp(z, sizeof(z), ft));
+ }
+
+ } else if (errno == ENOENT)
+ /* The timer has never run before,
+ * make sure a stamp file exists.
+ */
+ (void) touch_file(t->stamp_path, true, USEC_INFINITY, UID_INVALID, GID_INVALID, MODE_INVALID);
+ }
+
+ t->result = TIMER_SUCCESS;
+ timer_enter_waiting(t, false);
+ return 1;
+}
+
+static int timer_stop(Unit *u) {
+ Timer *t = TIMER(u);
+
+ assert(t);
+ assert(IN_SET(t->state, TIMER_WAITING, TIMER_RUNNING, TIMER_ELAPSED));
+
+ timer_enter_dead(t, TIMER_SUCCESS);
+ return 1;
+}
+
+static int timer_serialize(Unit *u, FILE *f, FDSet *fds) {
+ Timer *t = TIMER(u);
+
+ assert(u);
+ assert(f);
+ assert(fds);
+
+ (void) serialize_item(f, "state", timer_state_to_string(t->state));
+ (void) serialize_item(f, "result", timer_result_to_string(t->result));
+
+ if (t->last_trigger.realtime > 0)
+ (void) serialize_usec(f, "last-trigger-realtime", t->last_trigger.realtime);
+
+ if (t->last_trigger.monotonic > 0)
+ (void) serialize_usec(f, "last-trigger-monotonic", t->last_trigger.monotonic);
+
+ 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;
+
+ state = timer_state_from_string(value);
+ if (state < 0)
+ log_unit_debug(u, "Failed to parse state value: %s", value);
+ else
+ t->deserialized_state = state;
+
+ } else if (streq(key, "result")) {
+ TimerResult f;
+
+ f = timer_result_from_string(value);
+ if (f < 0)
+ log_unit_debug(u, "Failed to parse result value: %s", value);
+ else if (f != TIMER_SUCCESS)
+ t->result = f;
+
+ } else if (streq(key, "last-trigger-realtime"))
+ (void) deserialize_usec(value, &t->last_trigger.realtime);
+ else if (streq(key, "last-trigger-monotonic"))
+ (void) deserialize_usec(value, &t->last_trigger.monotonic);
+ else
+ log_unit_debug(u, "Unknown serialization key: %s", key);
+
+ return 0;
+}
+
+_pure_ static UnitActiveState timer_active_state(Unit *u) {
+ assert(u);
+
+ return state_translation_table[TIMER(u)->state];
+}
+
+_pure_ static const char *timer_sub_state_to_string(Unit *u) {
+ assert(u);
+
+ return timer_state_to_string(TIMER(u)->state);
+}
+
+static int timer_dispatch(sd_event_source *s, uint64_t usec, void *userdata) {
+ Timer *t = TIMER(userdata);
+
+ assert(t);
+
+ if (t->state != TIMER_WAITING)
+ return 0;
+
+ log_unit_debug(UNIT(t), "Timer elapsed.");
+ timer_enter_running(t);
+ return 0;
+}
+
+static void timer_trigger_notify(Unit *u, Unit *other) {
+ Timer *t = TIMER(u);
+ TimerValue *v;
+
+ assert(u);
+ assert(other);
+
+ if (other->load_state != UNIT_LOADED)
+ return;
+
+ /* Reenable all timers that depend on unit state */
+ LIST_FOREACH(value, v, t->values)
+ if (IN_SET(v->base, TIMER_UNIT_ACTIVE, 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 (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other))) {
+ log_unit_debug(UNIT(t), "Got notified about unit deactivation.");
+ timer_enter_waiting(t, false);
+ }
+ break;
+
+ case TIMER_DEAD:
+ case TIMER_FAILED:
+ break;
+
+ default:
+ assert_not_reached("Unknown timer state");
+ }
+}
+
+static void timer_reset_failed(Unit *u) {
+ Timer *t = TIMER(u);
+
+ assert(t);
+
+ if (t->state == TIMER_FAILED)
+ timer_set_state(t, TIMER_DEAD);
+
+ t->result = TIMER_SUCCESS;
+}
+
+static void timer_time_change(Unit *u) {
+ Timer *t = TIMER(u);
+ usec_t ts;
+
+ assert(u);
+
+ if (t->state != TIMER_WAITING)
+ return;
+
+ /* If we appear to have triggered in the future, the system clock must
+ * have been set backwards. So let's rewind our own clock and allow
+ * the future trigger(s) to happen again :). Exactly the same as when
+ * you start a timer unit with Persistent=yes. */
+ ts = now(CLOCK_REALTIME);
+ if (t->last_trigger.realtime > ts)
+ t->last_trigger.realtime = ts;
+
+ log_unit_debug(u, "Time change, recalculating next elapse.");
+ timer_enter_waiting(t, true);
+}
+
+static void timer_timezone_change(Unit *u) {
+ Timer *t = TIMER(u);
+
+ assert(u);
+
+ if (t->state != TIMER_WAITING)
+ return;
+
+ log_unit_debug(u, "Timezone change, recalculating next elapse.");
+ timer_enter_waiting(t, false);
+}
+
+static const char* const timer_base_table[_TIMER_BASE_MAX] = {
+ [TIMER_ACTIVE] = "OnActiveSec",
+ [TIMER_BOOT] = "OnBootSec",
+ [TIMER_STARTUP] = "OnStartupSec",
+ [TIMER_UNIT_ACTIVE] = "OnUnitActiveSec",
+ [TIMER_UNIT_INACTIVE] = "OnUnitInactiveSec",
+ [TIMER_CALENDAR] = "OnCalendar"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(timer_base, TimerBase);
+
+static const char* const timer_result_table[_TIMER_RESULT_MAX] = {
+ [TIMER_SUCCESS] = "success",
+ [TIMER_FAILURE_RESOURCES] = "resources",
+ [TIMER_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(timer_result, TimerResult);
+
+const UnitVTable timer_vtable = {
+ .object_size = sizeof(Timer),
+
+ .sections =
+ "Unit\0"
+ "Timer\0"
+ "Install\0",
+ .private_section = "Timer",
+
+ .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,
+
+ .trigger_notify = timer_trigger_notify,
+
+ .reset_failed = timer_reset_failed,
+ .time_change = timer_time_change,
+ .timezone_change = timer_timezone_change,
+
+ .bus_vtable = bus_timer_vtable,
+ .bus_set_property = bus_timer_set_property,
+
+ .can_transient = true,
+};