From 0629b78d815ce6a0b65aecc02fb18a122226274c Mon Sep 17 00:00:00 2001 From: Luke Shumaker Date: Wed, 25 May 2016 23:32:14 -0400 Subject: stuff --- src/libcore/timer.c | 851 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 851 insertions(+) create mode 100644 src/libcore/timer.c (limited to 'src/libcore/timer.c') diff --git a/src/libcore/timer.c b/src/libcore/timer.c new file mode 100644 index 0000000000..3d0bae16e5 --- /dev/null +++ b/src/libcore/timer.c @@ -0,0 +1,851 @@ +/*** + 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 Lesser General Public License as published by + the Free Software Foundation; either version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see . +***/ + +#include + +#include "alloc-util.h" +#include "bus-error.h" +#include "bus-util.h" +#include "dbus-timer.h" +#include "fs-util.h" +#include "parse-util.h" +#include "random-util.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 -EINVAL; + } + + 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, NULL, true); + if (r < 0) + return r; + + if (UNIT(t)->manager->running_as == MANAGER_SYSTEM) { + r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true); + 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, NULL, true); + if (r < 0) + return r; + break; + } + } + } + + return unit_add_two_dependencies_by_name(UNIT(t), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true); +} + +static int timer_setup_persistent(Timer *t) { + int r; + + assert(t); + + if (!t->persistent) + return 0; + + if (UNIT(t)->manager->running_as == MANAGER_SYSTEM) { + + r = unit_require_mounts_for(UNIT(t), "/var/lib/systemd/timers"); + 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, NULL); + 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, NULL); + } + } + + 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) { + + if (set_isempty(u->dependencies[UNIT_TRIGGERS])) { + Unit *x; + + r = unit_load_related_unit(u, ".service", &x); + if (r < 0) + return r; + + r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, x, true); + 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; + + 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); + + 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); + } + + 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], true); +} + +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) + 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 (f != TIMER_SUCCESS) + t->result = f; + + 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 usec_t monotonic_to_boottime(usec_t t) { + usec_t a, b; + + if (t <= 0) + return 0; + + a = now(CLOCK_BOOTTIME); + b = now(CLOCK_MONOTONIC); + + if (t + a > b) + return t + a - b; + else + return 0; +} + +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_info(UNIT(t), "Adding %s random time.", format_timespan(s, sizeof(s), add, 0)); +} + +static void timer_enter_waiting(Timer *t, bool initial) { + bool found_monotonic = false, found_realtime = false; + usec_t ts_realtime, ts_monotonic; + usec_t base = 0; + bool leave_around = false; + 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; + } + + /* If we shall wake the system we use the boottime clock + * rather than the monotonic clock. */ + + ts_realtime = now(CLOCK_REALTIME); + ts_monotonic = now(t->wake_system ? CLOCK_BOOTTIME : CLOCK_MONOTONIC); + 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 + * now. */ + + b = t->last_trigger.realtime > 0 ? t->last_trigger.realtime : 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 { + 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. Fall through. */ + case TIMER_STARTUP: + base = UNIT(t)->manager->userspace_timestamp.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; + + 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; + + break; + + default: + assert_not_reached("Unknown timer base"); + } + + if (t->wake_system) + base = monotonic_to_boottime(base); + + v->next_elapse = base + v->value; + + if (!initial && v->next_elapse < ts_monotonic && 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 = t->next_elapse_monotonic_or_boottime > ts_monotonic ? t->next_elapse_monotonic_or_boottime - ts_monotonic : 0; + 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; + + assert(t); + assert(t->state == TIMER_DEAD || t->state == 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; + } + + 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) + t->last_trigger.realtime = timespec_load(&st.st_atim); + else if (errno == ENOENT) + /* The timer has never run before, + * make sure a stamp file exists. + */ + touch_file(t->stamp_path, true, USEC_INFINITY, UID_INVALID, GID_INVALID, MODE_INVALID); + } + + t->result = TIMER_SUCCESS; + timer_enter_waiting(t, true); + return 1; +} + +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, TIMER_SUCCESS); + return 1; +} + +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)); + unit_serialize_item(u, f, "result", timer_result_to_string(t->result)); + + if (t->last_trigger.realtime > 0) + unit_serialize_item_format(u, f, "last-trigger-realtime", "%" PRIu64, t->last_trigger.realtime); + + if (t->last_trigger.monotonic > 0) + unit_serialize_item_format(u, f, "last-trigger-monotonic", "%" PRIu64, 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); + int r; + + 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")) { + + r = safe_atou64(value, &t->last_trigger.realtime); + if (r < 0) + log_unit_debug(u, "Failed to parse last-trigger-realtime value: %s", value); + + } else if (streq(key, "last-trigger-monotonic")) { + + r = safe_atou64(value, &t->last_trigger.monotonic); + if (r < 0) + log_unit_debug(u, "Failed to parse last-trigger-monotonic value: %s", value); + + } 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 (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 (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); + + assert(u); + + if (t->state != TIMER_WAITING) + return; + + log_unit_debug(u, "Time 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" +}; + +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, + + .bus_vtable = bus_timer_vtable, + .bus_set_property = bus_timer_set_property, + + .can_transient = true, +}; -- cgit v1.2.3-54-g00ecf