diff options
Diffstat (limited to 'src/libsystemd/sd-event/sd-event.c')
| -rw-r--r-- | src/libsystemd/sd-event/sd-event.c | 3541 |
1 files changed, 3541 insertions, 0 deletions
diff --git a/src/libsystemd/sd-event/sd-event.c b/src/libsystemd/sd-event/sd-event.c new file mode 100644 index 0000000..04ba7e2 --- /dev/null +++ b/src/libsystemd/sd-event/sd-event.c @@ -0,0 +1,3541 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +#include <sys/epoll.h> +#include <sys/timerfd.h> +#include <sys/wait.h> + +#include "sd-daemon.h" +#include "sd-event.h" +#include "sd-id128.h" + +#include "alloc-util.h" +#include "event-source.h" +#include "fd-util.h" +#include "fs-util.h" +#include "hashmap.h" +#include "list.h" +#include "macro.h" +#include "missing.h" +#include "prioq.h" +#include "process-util.h" +#include "set.h" +#include "signal-util.h" +#include "string-table.h" +#include "string-util.h" +#include "time-util.h" +#include "util.h" + +#define DEFAULT_ACCURACY_USEC (250 * USEC_PER_MSEC) + +static const char* const event_source_type_table[_SOURCE_EVENT_SOURCE_TYPE_MAX] = { + [SOURCE_IO] = "io", + [SOURCE_TIME_REALTIME] = "realtime", + [SOURCE_TIME_BOOTTIME] = "bootime", + [SOURCE_TIME_MONOTONIC] = "monotonic", + [SOURCE_TIME_REALTIME_ALARM] = "realtime-alarm", + [SOURCE_TIME_BOOTTIME_ALARM] = "boottime-alarm", + [SOURCE_SIGNAL] = "signal", + [SOURCE_CHILD] = "child", + [SOURCE_DEFER] = "defer", + [SOURCE_POST] = "post", + [SOURCE_EXIT] = "exit", + [SOURCE_WATCHDOG] = "watchdog", + [SOURCE_INOTIFY] = "inotify", +}; + +DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(event_source_type, int); + +#define EVENT_SOURCE_IS_TIME(t) IN_SET((t), SOURCE_TIME_REALTIME, SOURCE_TIME_BOOTTIME, SOURCE_TIME_MONOTONIC, SOURCE_TIME_REALTIME_ALARM, SOURCE_TIME_BOOTTIME_ALARM) + +struct sd_event { + unsigned n_ref; + + int epoll_fd; + int watchdog_fd; + + Prioq *pending; + Prioq *prepare; + + /* timerfd_create() only supports these five clocks so far. We + * can add support for more clocks when the kernel learns to + * deal with them, too. */ + struct clock_data realtime; + struct clock_data boottime; + struct clock_data monotonic; + struct clock_data realtime_alarm; + struct clock_data boottime_alarm; + + usec_t perturb; + + sd_event_source **signal_sources; /* indexed by signal number */ + Hashmap *signal_data; /* indexed by priority */ + + Hashmap *child_sources; + unsigned n_enabled_child_sources; + + Set *post_sources; + + Prioq *exit; + + Hashmap *inotify_data; /* indexed by priority */ + + /* A list of inode structures that still have an fd open, that we need to close before the next loop iteration */ + LIST_HEAD(struct inode_data, inode_data_to_close); + + /* A list of inotify objects that already have events buffered which aren't processed yet */ + LIST_HEAD(struct inotify_data, inotify_data_buffered); + + pid_t original_pid; + + uint64_t iteration; + triple_timestamp timestamp; + int state; + + bool exit_requested:1; + bool need_process_child:1; + bool watchdog:1; + bool profile_delays:1; + + int exit_code; + + pid_t tid; + sd_event **default_event_ptr; + + usec_t watchdog_last, watchdog_period; + + unsigned n_sources; + + LIST_HEAD(sd_event_source, sources); + + usec_t last_run, last_log; + unsigned delays[sizeof(usec_t) * 8]; +}; + +static thread_local sd_event *default_event = NULL; + +static void source_disconnect(sd_event_source *s); +static void event_gc_inode_data(sd_event *e, struct inode_data *d); + +static sd_event *event_resolve(sd_event *e) { + return e == SD_EVENT_DEFAULT ? default_event : e; +} + +static int pending_prioq_compare(const void *a, const void *b) { + const sd_event_source *x = a, *y = b; + int r; + + assert(x->pending); + assert(y->pending); + + /* Enabled ones first */ + if (x->enabled != SD_EVENT_OFF && y->enabled == SD_EVENT_OFF) + return -1; + if (x->enabled == SD_EVENT_OFF && y->enabled != SD_EVENT_OFF) + return 1; + + /* Lower priority values first */ + r = CMP(x->priority, y->priority); + if (r != 0) + return r; + + /* Older entries first */ + return CMP(x->pending_iteration, y->pending_iteration); +} + +static int prepare_prioq_compare(const void *a, const void *b) { + const sd_event_source *x = a, *y = b; + int r; + + assert(x->prepare); + assert(y->prepare); + + /* Enabled ones first */ + if (x->enabled != SD_EVENT_OFF && y->enabled == SD_EVENT_OFF) + return -1; + if (x->enabled == SD_EVENT_OFF && y->enabled != SD_EVENT_OFF) + return 1; + + /* Move most recently prepared ones last, so that we can stop + * preparing as soon as we hit one that has already been + * prepared in the current iteration */ + r = CMP(x->prepare_iteration, y->prepare_iteration); + if (r != 0) + return r; + + /* Lower priority values first */ + return CMP(x->priority, y->priority); +} + +static int earliest_time_prioq_compare(const void *a, const void *b) { + const sd_event_source *x = a, *y = b; + + assert(EVENT_SOURCE_IS_TIME(x->type)); + assert(x->type == y->type); + + /* Enabled ones first */ + if (x->enabled != SD_EVENT_OFF && y->enabled == SD_EVENT_OFF) + return -1; + if (x->enabled == SD_EVENT_OFF && y->enabled != SD_EVENT_OFF) + return 1; + + /* Move the pending ones to the end */ + if (!x->pending && y->pending) + return -1; + if (x->pending && !y->pending) + return 1; + + /* Order by time */ + return CMP(x->time.next, y->time.next); +} + +static usec_t time_event_source_latest(const sd_event_source *s) { + return usec_add(s->time.next, s->time.accuracy); +} + +static int latest_time_prioq_compare(const void *a, const void *b) { + const sd_event_source *x = a, *y = b; + + assert(EVENT_SOURCE_IS_TIME(x->type)); + assert(x->type == y->type); + + /* Enabled ones first */ + if (x->enabled != SD_EVENT_OFF && y->enabled == SD_EVENT_OFF) + return -1; + if (x->enabled == SD_EVENT_OFF && y->enabled != SD_EVENT_OFF) + return 1; + + /* Move the pending ones to the end */ + if (!x->pending && y->pending) + return -1; + if (x->pending && !y->pending) + return 1; + + /* Order by time */ + return CMP(time_event_source_latest(x), time_event_source_latest(y)); +} + +static int exit_prioq_compare(const void *a, const void *b) { + const sd_event_source *x = a, *y = b; + + assert(x->type == SOURCE_EXIT); + assert(y->type == SOURCE_EXIT); + + /* Enabled ones first */ + if (x->enabled != SD_EVENT_OFF && y->enabled == SD_EVENT_OFF) + return -1; + if (x->enabled == SD_EVENT_OFF && y->enabled != SD_EVENT_OFF) + return 1; + + /* Lower priority values first */ + return CMP(x->priority, y->priority); +} + +static void free_clock_data(struct clock_data *d) { + assert(d); + assert(d->wakeup == WAKEUP_CLOCK_DATA); + + safe_close(d->fd); + prioq_free(d->earliest); + prioq_free(d->latest); +} + +static sd_event *event_free(sd_event *e) { + sd_event_source *s; + + assert(e); + + while ((s = e->sources)) { + assert(s->floating); + source_disconnect(s); + sd_event_source_unref(s); + } + + assert(e->n_sources == 0); + + if (e->default_event_ptr) + *(e->default_event_ptr) = NULL; + + safe_close(e->epoll_fd); + safe_close(e->watchdog_fd); + + free_clock_data(&e->realtime); + free_clock_data(&e->boottime); + free_clock_data(&e->monotonic); + free_clock_data(&e->realtime_alarm); + free_clock_data(&e->boottime_alarm); + + prioq_free(e->pending); + prioq_free(e->prepare); + prioq_free(e->exit); + + free(e->signal_sources); + hashmap_free(e->signal_data); + + hashmap_free(e->inotify_data); + + hashmap_free(e->child_sources); + set_free(e->post_sources); + + return mfree(e); +} + +_public_ int sd_event_new(sd_event** ret) { + sd_event *e; + int r; + + assert_return(ret, -EINVAL); + + e = new(sd_event, 1); + if (!e) + return -ENOMEM; + + *e = (sd_event) { + .n_ref = 1, + .epoll_fd = -1, + .watchdog_fd = -1, + .realtime.wakeup = WAKEUP_CLOCK_DATA, + .realtime.fd = -1, + .realtime.next = USEC_INFINITY, + .boottime.wakeup = WAKEUP_CLOCK_DATA, + .boottime.fd = -1, + .boottime.next = USEC_INFINITY, + .monotonic.wakeup = WAKEUP_CLOCK_DATA, + .monotonic.fd = -1, + .monotonic.next = USEC_INFINITY, + .realtime_alarm.wakeup = WAKEUP_CLOCK_DATA, + .realtime_alarm.fd = -1, + .realtime_alarm.next = USEC_INFINITY, + .boottime_alarm.wakeup = WAKEUP_CLOCK_DATA, + .boottime_alarm.fd = -1, + .boottime_alarm.next = USEC_INFINITY, + .perturb = USEC_INFINITY, + .original_pid = getpid_cached(), + }; + + r = prioq_ensure_allocated(&e->pending, pending_prioq_compare); + if (r < 0) + goto fail; + + e->epoll_fd = epoll_create1(EPOLL_CLOEXEC); + if (e->epoll_fd < 0) { + r = -errno; + goto fail; + } + + e->epoll_fd = fd_move_above_stdio(e->epoll_fd); + + if (secure_getenv("SD_EVENT_PROFILE_DELAYS")) { + log_debug("Event loop profiling enabled. Logarithmic histogram of event loop iterations in the range 2^0 ... 2^63 us will be logged every 5s."); + e->profile_delays = true; + } + + *ret = e; + return 0; + +fail: + event_free(e); + return r; +} + +DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_event, sd_event, event_free); + +static bool event_pid_changed(sd_event *e) { + assert(e); + + /* We don't support people creating an event loop and keeping + * it around over a fork(). Let's complain. */ + + return e->original_pid != getpid_cached(); +} + +static void source_io_unregister(sd_event_source *s) { + int r; + + assert(s); + assert(s->type == SOURCE_IO); + + if (event_pid_changed(s->event)) + return; + + if (!s->io.registered) + return; + + r = epoll_ctl(s->event->epoll_fd, EPOLL_CTL_DEL, s->io.fd, NULL); + if (r < 0) + log_debug_errno(errno, "Failed to remove source %s (type %s) from epoll: %m", + strna(s->description), event_source_type_to_string(s->type)); + + s->io.registered = false; +} + +static int source_io_register( + sd_event_source *s, + int enabled, + uint32_t events) { + + struct epoll_event ev; + int r; + + assert(s); + assert(s->type == SOURCE_IO); + assert(enabled != SD_EVENT_OFF); + + ev = (struct epoll_event) { + .events = events | (enabled == SD_EVENT_ONESHOT ? EPOLLONESHOT : 0), + .data.ptr = s, + }; + + if (s->io.registered) + r = epoll_ctl(s->event->epoll_fd, EPOLL_CTL_MOD, s->io.fd, &ev); + else + r = epoll_ctl(s->event->epoll_fd, EPOLL_CTL_ADD, s->io.fd, &ev); + if (r < 0) + return -errno; + + s->io.registered = true; + + return 0; +} + +static clockid_t event_source_type_to_clock(EventSourceType t) { + + switch (t) { + + case SOURCE_TIME_REALTIME: + return CLOCK_REALTIME; + + case SOURCE_TIME_BOOTTIME: + return CLOCK_BOOTTIME; + + case SOURCE_TIME_MONOTONIC: + return CLOCK_MONOTONIC; + + case SOURCE_TIME_REALTIME_ALARM: + return CLOCK_REALTIME_ALARM; + + case SOURCE_TIME_BOOTTIME_ALARM: + return CLOCK_BOOTTIME_ALARM; + + default: + return (clockid_t) -1; + } +} + +static EventSourceType clock_to_event_source_type(clockid_t clock) { + + switch (clock) { + + case CLOCK_REALTIME: + return SOURCE_TIME_REALTIME; + + case CLOCK_BOOTTIME: + return SOURCE_TIME_BOOTTIME; + + case CLOCK_MONOTONIC: + return SOURCE_TIME_MONOTONIC; + + case CLOCK_REALTIME_ALARM: + return SOURCE_TIME_REALTIME_ALARM; + + case CLOCK_BOOTTIME_ALARM: + return SOURCE_TIME_BOOTTIME_ALARM; + + default: + return _SOURCE_EVENT_SOURCE_TYPE_INVALID; + } +} + +static struct clock_data* event_get_clock_data(sd_event *e, EventSourceType t) { + assert(e); + + switch (t) { + + case SOURCE_TIME_REALTIME: + return &e->realtime; + + case SOURCE_TIME_BOOTTIME: + return &e->boottime; + + case SOURCE_TIME_MONOTONIC: + return &e->monotonic; + + case SOURCE_TIME_REALTIME_ALARM: + return &e->realtime_alarm; + + case SOURCE_TIME_BOOTTIME_ALARM: + return &e->boottime_alarm; + + default: + return NULL; + } +} + +static void event_free_signal_data(sd_event *e, struct signal_data *d) { + assert(e); + + if (!d) + return; + + hashmap_remove(e->signal_data, &d->priority); + safe_close(d->fd); + free(d); +} + +static int event_make_signal_data( + sd_event *e, + int sig, + struct signal_data **ret) { + + struct epoll_event ev; + struct signal_data *d; + bool added = false; + sigset_t ss_copy; + int64_t priority; + int r; + + assert(e); + + if (event_pid_changed(e)) + return -ECHILD; + + if (e->signal_sources && e->signal_sources[sig]) + priority = e->signal_sources[sig]->priority; + else + priority = SD_EVENT_PRIORITY_NORMAL; + + d = hashmap_get(e->signal_data, &priority); + if (d) { + if (sigismember(&d->sigset, sig) > 0) { + if (ret) + *ret = d; + return 0; + } + } else { + r = hashmap_ensure_allocated(&e->signal_data, &uint64_hash_ops); + if (r < 0) + return r; + + d = new(struct signal_data, 1); + if (!d) + return -ENOMEM; + + *d = (struct signal_data) { + .wakeup = WAKEUP_SIGNAL_DATA, + .fd = -1, + .priority = priority, + }; + + r = hashmap_put(e->signal_data, &d->priority, d); + if (r < 0) { + free(d); + return r; + } + + added = true; + } + + ss_copy = d->sigset; + assert_se(sigaddset(&ss_copy, sig) >= 0); + + r = signalfd(d->fd, &ss_copy, SFD_NONBLOCK|SFD_CLOEXEC); + if (r < 0) { + r = -errno; + goto fail; + } + + d->sigset = ss_copy; + + if (d->fd >= 0) { + if (ret) + *ret = d; + return 0; + } + + d->fd = fd_move_above_stdio(r); + + ev = (struct epoll_event) { + .events = EPOLLIN, + .data.ptr = d, + }; + + r = epoll_ctl(e->epoll_fd, EPOLL_CTL_ADD, d->fd, &ev); + if (r < 0) { + r = -errno; + goto fail; + } + + if (ret) + *ret = d; + + return 0; + +fail: + if (added) + event_free_signal_data(e, d); + + return r; +} + +static void event_unmask_signal_data(sd_event *e, struct signal_data *d, int sig) { + assert(e); + assert(d); + + /* Turns off the specified signal in the signal data + * object. If the signal mask of the object becomes empty that + * way removes it. */ + + if (sigismember(&d->sigset, sig) == 0) + return; + + assert_se(sigdelset(&d->sigset, sig) >= 0); + + if (sigisemptyset(&d->sigset)) { + /* If all the mask is all-zero we can get rid of the structure */ + event_free_signal_data(e, d); + return; + } + + assert(d->fd >= 0); + + if (signalfd(d->fd, &d->sigset, SFD_NONBLOCK|SFD_CLOEXEC) < 0) + log_debug_errno(errno, "Failed to unset signal bit, ignoring: %m"); +} + +static void event_gc_signal_data(sd_event *e, const int64_t *priority, int sig) { + struct signal_data *d; + static const int64_t zero_priority = 0; + + assert(e); + + /* Rechecks if the specified signal is still something we are + * interested in. If not, we'll unmask it, and possibly drop + * the signalfd for it. */ + + if (sig == SIGCHLD && + e->n_enabled_child_sources > 0) + return; + + if (e->signal_sources && + e->signal_sources[sig] && + e->signal_sources[sig]->enabled != SD_EVENT_OFF) + return; + + /* + * The specified signal might be enabled in three different queues: + * + * 1) the one that belongs to the priority passed (if it is non-NULL) + * 2) the one that belongs to the priority of the event source of the signal (if there is one) + * 3) the 0 priority (to cover the SIGCHLD case) + * + * Hence, let's remove it from all three here. + */ + + if (priority) { + d = hashmap_get(e->signal_data, priority); + if (d) + event_unmask_signal_data(e, d, sig); + } + + if (e->signal_sources && e->signal_sources[sig]) { + d = hashmap_get(e->signal_data, &e->signal_sources[sig]->priority); + if (d) + event_unmask_signal_data(e, d, sig); + } + + d = hashmap_get(e->signal_data, &zero_priority); + if (d) + event_unmask_signal_data(e, d, sig); +} + +static void source_disconnect(sd_event_source *s) { + sd_event *event; + + assert(s); + + if (!s->event) + return; + + assert(s->event->n_sources > 0); + + switch (s->type) { + + case SOURCE_IO: + if (s->io.fd >= 0) + source_io_unregister(s); + + break; + + case SOURCE_TIME_REALTIME: + case SOURCE_TIME_BOOTTIME: + case SOURCE_TIME_MONOTONIC: + case SOURCE_TIME_REALTIME_ALARM: + case SOURCE_TIME_BOOTTIME_ALARM: { + struct clock_data *d; + + d = event_get_clock_data(s->event, s->type); + assert(d); + + prioq_remove(d->earliest, s, &s->time.earliest_index); + prioq_remove(d->latest, s, &s->time.latest_index); + d->needs_rearm = true; + break; + } + + case SOURCE_SIGNAL: + if (s->signal.sig > 0) { + + if (s->event->signal_sources) + s->event->signal_sources[s->signal.sig] = NULL; + + event_gc_signal_data(s->event, &s->priority, s->signal.sig); + } + + break; + + case SOURCE_CHILD: + if (s->child.pid > 0) { + if (s->enabled != SD_EVENT_OFF) { + assert(s->event->n_enabled_child_sources > 0); + s->event->n_enabled_child_sources--; + } + + (void) hashmap_remove(s->event->child_sources, PID_TO_PTR(s->child.pid)); + event_gc_signal_data(s->event, &s->priority, SIGCHLD); + } + + break; + + case SOURCE_DEFER: + /* nothing */ + break; + + case SOURCE_POST: + set_remove(s->event->post_sources, s); + break; + + case SOURCE_EXIT: + prioq_remove(s->event->exit, s, &s->exit.prioq_index); + break; + + case SOURCE_INOTIFY: { + struct inode_data *inode_data; + + inode_data = s->inotify.inode_data; + if (inode_data) { + struct inotify_data *inotify_data; + assert_se(inotify_data = inode_data->inotify_data); + + /* Detach this event source from the inode object */ + LIST_REMOVE(inotify.by_inode_data, inode_data->event_sources, s); + s->inotify.inode_data = NULL; + + if (s->pending) { + assert(inotify_data->n_pending > 0); + inotify_data->n_pending--; + } + + /* Note that we don't reduce the inotify mask for the watch descriptor here if the inode is + * continued to being watched. That's because inotify doesn't really have an API for that: we + * can only change watch masks with access to the original inode either by fd or by path. But + * paths aren't stable, and keeping an O_PATH fd open all the time would mean wasting an fd + * continuously and keeping the mount busy which we can't really do. We could reconstruct the + * original inode from /proc/self/fdinfo/$INOTIFY_FD (as all watch descriptors are listed + * there), but given the need for open_by_handle_at() which is privileged and not universally + * available this would be quite an incomplete solution. Hence we go the other way, leave the + * mask set, even if it is not minimized now, and ignore all events we aren't interested in + * anymore after reception. Yes, this sucks, but … Linux … */ + + /* Maybe release the inode data (and its inotify) */ + event_gc_inode_data(s->event, inode_data); + } + + break; + } + + default: + assert_not_reached("Wut? I shouldn't exist."); + } + + if (s->pending) + prioq_remove(s->event->pending, s, &s->pending_index); + + if (s->prepare) + prioq_remove(s->event->prepare, s, &s->prepare_index); + + event = s->event; + + s->type = _SOURCE_EVENT_SOURCE_TYPE_INVALID; + s->event = NULL; + LIST_REMOVE(sources, event->sources, s); + event->n_sources--; + + if (!s->floating) + sd_event_unref(event); +} + +static void source_free(sd_event_source *s) { + assert(s); + + source_disconnect(s); + + if (s->type == SOURCE_IO && s->io.owned) + s->io.fd = safe_close(s->io.fd); + + if (s->destroy_callback) + s->destroy_callback(s->userdata); + + free(s->description); + free(s); +} +DEFINE_TRIVIAL_CLEANUP_FUNC(sd_event_source*, source_free); + +static int source_set_pending(sd_event_source *s, bool b) { + int r; + + assert(s); + assert(s->type != SOURCE_EXIT); + + if (s->pending == b) + return 0; + + s->pending = b; + + if (b) { + s->pending_iteration = s->event->iteration; + + r = prioq_put(s->event->pending, s, &s->pending_index); + if (r < 0) { + s->pending = false; + return r; + } + } else + assert_se(prioq_remove(s->event->pending, s, &s->pending_index)); + + if (EVENT_SOURCE_IS_TIME(s->type)) { + struct clock_data *d; + + d = event_get_clock_data(s->event, s->type); + assert(d); + + prioq_reshuffle(d->earliest, s, &s->time.earliest_index); + prioq_reshuffle(d->latest, s, &s->time.latest_index); + d->needs_rearm = true; + } + + if (s->type == SOURCE_SIGNAL && !b) { + struct signal_data *d; + + d = hashmap_get(s->event->signal_data, &s->priority); + if (d && d->current == s) + d->current = NULL; + } + + if (s->type == SOURCE_INOTIFY) { + + assert(s->inotify.inode_data); + assert(s->inotify.inode_data->inotify_data); + + if (b) + s->inotify.inode_data->inotify_data->n_pending ++; + else { + assert(s->inotify.inode_data->inotify_data->n_pending > 0); + s->inotify.inode_data->inotify_data->n_pending --; + } + } + + return 0; +} + +static sd_event_source *source_new(sd_event *e, bool floating, EventSourceType type) { + sd_event_source *s; + + assert(e); + + s = new(sd_event_source, 1); + if (!s) + return NULL; + + *s = (struct sd_event_source) { + .n_ref = 1, + .event = e, + .floating = floating, + .type = type, + .pending_index = PRIOQ_IDX_NULL, + .prepare_index = PRIOQ_IDX_NULL, + }; + + if (!floating) + sd_event_ref(e); + + LIST_PREPEND(sources, e->sources, s); + e->n_sources++; + + return s; +} + +_public_ int sd_event_add_io( + sd_event *e, + sd_event_source **ret, + int fd, + uint32_t events, + sd_event_io_handler_t callback, + void *userdata) { + + _cleanup_(source_freep) sd_event_source *s = NULL; + int r; + + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(fd >= 0, -EBADF); + assert_return(!(events & ~(EPOLLIN|EPOLLOUT|EPOLLRDHUP|EPOLLPRI|EPOLLERR|EPOLLHUP|EPOLLET)), -EINVAL); + assert_return(callback, -EINVAL); + assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(!event_pid_changed(e), -ECHILD); + + s = source_new(e, !ret, SOURCE_IO); + if (!s) + return -ENOMEM; + + s->wakeup = WAKEUP_EVENT_SOURCE; + s->io.fd = fd; + s->io.events = events; + s->io.callback = callback; + s->userdata = userdata; + s->enabled = SD_EVENT_ON; + + r = source_io_register(s, s->enabled, events); + if (r < 0) + return r; + + if (ret) + *ret = s; + TAKE_PTR(s); + + return 0; +} + +static void initialize_perturb(sd_event *e) { + sd_id128_t bootid = {}; + + /* When we sleep for longer, we try to realign the wakeup to + the same time within each minute/second/250ms, so that + events all across the system can be coalesced into a single + CPU wakeup. However, let's take some system-specific + randomness for this value, so that in a network of systems + with synced clocks timer events are distributed a + bit. Here, we calculate a perturbation usec offset from the + boot ID. */ + + if (_likely_(e->perturb != USEC_INFINITY)) + return; + + if (sd_id128_get_boot(&bootid) >= 0) + e->perturb = (bootid.qwords[0] ^ bootid.qwords[1]) % USEC_PER_MINUTE; +} + +static int event_setup_timer_fd( + sd_event *e, + struct clock_data *d, + clockid_t clock) { + + struct epoll_event ev; + int r, fd; + + assert(e); + assert(d); + + if (_likely_(d->fd >= 0)) + return 0; + + fd = timerfd_create(clock, TFD_NONBLOCK|TFD_CLOEXEC); + if (fd < 0) + return -errno; + + fd = fd_move_above_stdio(fd); + + ev = (struct epoll_event) { + .events = EPOLLIN, + .data.ptr = d, + }; + + r = epoll_ctl(e->epoll_fd, EPOLL_CTL_ADD, fd, &ev); + if (r < 0) { + safe_close(fd); + return -errno; + } + + d->fd = fd; + return 0; +} + +static int time_exit_callback(sd_event_source *s, uint64_t usec, void *userdata) { + assert(s); + + return sd_event_exit(sd_event_source_get_event(s), PTR_TO_INT(userdata)); +} + +_public_ int sd_event_add_time( + sd_event *e, + sd_event_source **ret, + clockid_t clock, + uint64_t usec, + uint64_t accuracy, + sd_event_time_handler_t callback, + void *userdata) { + + EventSourceType type; + _cleanup_(source_freep) sd_event_source *s = NULL; + struct clock_data *d; + int r; + + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(accuracy != (uint64_t) -1, -EINVAL); + assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(!event_pid_changed(e), -ECHILD); + + if (!clock_supported(clock)) /* Checks whether the kernel supports the clock */ + return -EOPNOTSUPP; + + type = clock_to_event_source_type(clock); /* checks whether sd-event supports this clock */ + if (type < 0) + return -EOPNOTSUPP; + + if (!callback) + callback = time_exit_callback; + + d = event_get_clock_data(e, type); + assert(d); + + r = prioq_ensure_allocated(&d->earliest, earliest_time_prioq_compare); + if (r < 0) + return r; + + r = prioq_ensure_allocated(&d->latest, latest_time_prioq_compare); + if (r < 0) + return r; + + if (d->fd < 0) { + r = event_setup_timer_fd(e, d, clock); + if (r < 0) + return r; + } + + s = source_new(e, !ret, type); + if (!s) + return -ENOMEM; + + s->time.next = usec; + s->time.accuracy = accuracy == 0 ? DEFAULT_ACCURACY_USEC : accuracy; + s->time.callback = callback; + s->time.earliest_index = s->time.latest_index = PRIOQ_IDX_NULL; + s->userdata = userdata; + s->enabled = SD_EVENT_ONESHOT; + + d->needs_rearm = true; + + r = prioq_put(d->earliest, s, &s->time.earliest_index); + if (r < 0) + return r; + + r = prioq_put(d->latest, s, &s->time.latest_index); + if (r < 0) + return r; + + if (ret) + *ret = s; + TAKE_PTR(s); + + return 0; +} + +static int signal_exit_callback(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) { + assert(s); + + return sd_event_exit(sd_event_source_get_event(s), PTR_TO_INT(userdata)); +} + +_public_ int sd_event_add_signal( + sd_event *e, + sd_event_source **ret, + int sig, + sd_event_signal_handler_t callback, + void *userdata) { + + _cleanup_(source_freep) sd_event_source *s = NULL; + struct signal_data *d; + sigset_t ss; + int r; + + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(SIGNAL_VALID(sig), -EINVAL); + assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(!event_pid_changed(e), -ECHILD); + + if (!callback) + callback = signal_exit_callback; + + r = pthread_sigmask(SIG_SETMASK, NULL, &ss); + if (r != 0) + return -r; + + if (!sigismember(&ss, sig)) + return -EBUSY; + + if (!e->signal_sources) { + e->signal_sources = new0(sd_event_source*, _NSIG); + if (!e->signal_sources) + return -ENOMEM; + } else if (e->signal_sources[sig]) + return -EBUSY; + + s = source_new(e, !ret, SOURCE_SIGNAL); + if (!s) + return -ENOMEM; + + s->signal.sig = sig; + s->signal.callback = callback; + s->userdata = userdata; + s->enabled = SD_EVENT_ON; + + e->signal_sources[sig] = s; + + r = event_make_signal_data(e, sig, &d); + if (r < 0) + return r; + + /* Use the signal name as description for the event source by default */ + (void) sd_event_source_set_description(s, signal_to_string(sig)); + + if (ret) + *ret = s; + TAKE_PTR(s); + + return 0; +} + +_public_ int sd_event_add_child( + sd_event *e, + sd_event_source **ret, + pid_t pid, + int options, + sd_event_child_handler_t callback, + void *userdata) { + + _cleanup_(source_freep) sd_event_source *s = NULL; + int r; + + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(pid > 1, -EINVAL); + assert_return(!(options & ~(WEXITED|WSTOPPED|WCONTINUED)), -EINVAL); + assert_return(options != 0, -EINVAL); + assert_return(callback, -EINVAL); + assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(!event_pid_changed(e), -ECHILD); + + r = hashmap_ensure_allocated(&e->child_sources, NULL); + if (r < 0) + return r; + + if (hashmap_contains(e->child_sources, PID_TO_PTR(pid))) + return -EBUSY; + + s = source_new(e, !ret, SOURCE_CHILD); + if (!s) + return -ENOMEM; + + s->child.pid = pid; + s->child.options = options; + s->child.callback = callback; + s->userdata = userdata; + s->enabled = SD_EVENT_ONESHOT; + + r = hashmap_put(e->child_sources, PID_TO_PTR(pid), s); + if (r < 0) + return r; + + e->n_enabled_child_sources++; + + r = event_make_signal_data(e, SIGCHLD, NULL); + if (r < 0) { + e->n_enabled_child_sources--; + return r; + } + + e->need_process_child = true; + + if (ret) + *ret = s; + TAKE_PTR(s); + + return 0; +} + +_public_ int sd_event_add_defer( + sd_event *e, + sd_event_source **ret, + sd_event_handler_t callback, + void *userdata) { + + _cleanup_(source_freep) sd_event_source *s = NULL; + int r; + + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(callback, -EINVAL); + assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(!event_pid_changed(e), -ECHILD); + + s = source_new(e, !ret, SOURCE_DEFER); + if (!s) + return -ENOMEM; + + s->defer.callback = callback; + s->userdata = userdata; + s->enabled = SD_EVENT_ONESHOT; + + r = source_set_pending(s, true); + if (r < 0) + return r; + + if (ret) + *ret = s; + TAKE_PTR(s); + + return 0; +} + +_public_ int sd_event_add_post( + sd_event *e, + sd_event_source **ret, + sd_event_handler_t callback, + void *userdata) { + + _cleanup_(source_freep) sd_event_source *s = NULL; + int r; + + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(callback, -EINVAL); + assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(!event_pid_changed(e), -ECHILD); + + r = set_ensure_allocated(&e->post_sources, NULL); + if (r < 0) + return r; + + s = source_new(e, !ret, SOURCE_POST); + if (!s) + return -ENOMEM; + + s->post.callback = callback; + s->userdata = userdata; + s->enabled = SD_EVENT_ON; + + r = set_put(e->post_sources, s); + if (r < 0) + return r; + + if (ret) + *ret = s; + TAKE_PTR(s); + + return 0; +} + +_public_ int sd_event_add_exit( + sd_event *e, + sd_event_source **ret, + sd_event_handler_t callback, + void *userdata) { + + _cleanup_(source_freep) sd_event_source *s = NULL; + int r; + + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(callback, -EINVAL); + assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(!event_pid_changed(e), -ECHILD); + + r = prioq_ensure_allocated(&e->exit, exit_prioq_compare); + if (r < 0) + return r; + + s = source_new(e, !ret, SOURCE_EXIT); + if (!s) + return -ENOMEM; + + s->exit.callback = callback; + s->userdata = userdata; + s->exit.prioq_index = PRIOQ_IDX_NULL; + s->enabled = SD_EVENT_ONESHOT; + + r = prioq_put(s->event->exit, s, &s->exit.prioq_index); + if (r < 0) + return r; + + if (ret) + *ret = s; + TAKE_PTR(s); + + return 0; +} + +static void event_free_inotify_data(sd_event *e, struct inotify_data *d) { + assert(e); + + if (!d) + return; + + assert(hashmap_isempty(d->inodes)); + assert(hashmap_isempty(d->wd)); + + if (d->buffer_filled > 0) + LIST_REMOVE(buffered, e->inotify_data_buffered, d); + + hashmap_free(d->inodes); + hashmap_free(d->wd); + + assert_se(hashmap_remove(e->inotify_data, &d->priority) == d); + + if (d->fd >= 0) { + if (epoll_ctl(e->epoll_fd, EPOLL_CTL_DEL, d->fd, NULL) < 0) + log_debug_errno(errno, "Failed to remove inotify fd from epoll, ignoring: %m"); + + safe_close(d->fd); + } + free(d); +} + +static int event_make_inotify_data( + sd_event *e, + int64_t priority, + struct inotify_data **ret) { + + _cleanup_close_ int fd = -1; + struct inotify_data *d; + struct epoll_event ev; + int r; + + assert(e); + + d = hashmap_get(e->inotify_data, &priority); + if (d) { + if (ret) + *ret = d; + return 0; + } + + fd = inotify_init1(IN_NONBLOCK|O_CLOEXEC); + if (fd < 0) + return -errno; + + fd = fd_move_above_stdio(fd); + + r = hashmap_ensure_allocated(&e->inotify_data, &uint64_hash_ops); + if (r < 0) + return r; + + d = new(struct inotify_data, 1); + if (!d) + return -ENOMEM; + + *d = (struct inotify_data) { + .wakeup = WAKEUP_INOTIFY_DATA, + .fd = TAKE_FD(fd), + .priority = priority, + }; + + r = hashmap_put(e->inotify_data, &d->priority, d); + if (r < 0) { + d->fd = safe_close(d->fd); + free(d); + return r; + } + + ev = (struct epoll_event) { + .events = EPOLLIN, + .data.ptr = d, + }; + + if (epoll_ctl(e->epoll_fd, EPOLL_CTL_ADD, d->fd, &ev) < 0) { + r = -errno; + d->fd = safe_close(d->fd); /* let's close this ourselves, as event_free_inotify_data() would otherwise + * remove the fd from the epoll first, which we don't want as we couldn't + * add it in the first place. */ + event_free_inotify_data(e, d); + return r; + } + + if (ret) + *ret = d; + + return 1; +} + +static int inode_data_compare(const struct inode_data *x, const struct inode_data *y) { + int r; + + assert(x); + assert(y); + + r = CMP(x->dev, y->dev); + if (r != 0) + return r; + + return CMP(x->ino, y->ino); +} + +static void inode_data_hash_func(const struct inode_data *d, struct siphash *state) { + assert(d); + + siphash24_compress(&d->dev, sizeof(d->dev), state); + siphash24_compress(&d->ino, sizeof(d->ino), state); +} + +DEFINE_PRIVATE_HASH_OPS(inode_data_hash_ops, struct inode_data, inode_data_hash_func, inode_data_compare); + +static void event_free_inode_data( + sd_event *e, + struct inode_data *d) { + + assert(e); + + if (!d) + return; + + assert(!d->event_sources); + + if (d->fd >= 0) { + LIST_REMOVE(to_close, e->inode_data_to_close, d); + safe_close(d->fd); + } + + if (d->inotify_data) { + + if (d->wd >= 0) { + if (d->inotify_data->fd >= 0) { + /* So here's a problem. At the time this runs the watch descriptor might already be + * invalidated, because an IN_IGNORED event might be queued right the moment we enter + * the syscall. Hence, whenever we get EINVAL, ignore it entirely, since it's a very + * likely case to happen. */ + + if (inotify_rm_watch(d->inotify_data->fd, d->wd) < 0 && errno != EINVAL) + log_debug_errno(errno, "Failed to remove watch descriptor %i from inotify, ignoring: %m", d->wd); + } + + assert_se(hashmap_remove(d->inotify_data->wd, INT_TO_PTR(d->wd)) == d); + } + + assert_se(hashmap_remove(d->inotify_data->inodes, d) == d); + } + + free(d); +} + +static void event_gc_inode_data( + sd_event *e, + struct inode_data *d) { + + struct inotify_data *inotify_data; + + assert(e); + + if (!d) + return; + + if (d->event_sources) + return; + + inotify_data = d->inotify_data; + event_free_inode_data(e, d); + + if (inotify_data && hashmap_isempty(inotify_data->inodes)) + event_free_inotify_data(e, inotify_data); +} + +static int event_make_inode_data( + sd_event *e, + struct inotify_data *inotify_data, + dev_t dev, + ino_t ino, + struct inode_data **ret) { + + struct inode_data *d, key; + int r; + + assert(e); + assert(inotify_data); + + key = (struct inode_data) { + .ino = ino, + .dev = dev, + }; + + d = hashmap_get(inotify_data->inodes, &key); + if (d) { + if (ret) + *ret = d; + + return 0; + } + + r = hashmap_ensure_allocated(&inotify_data->inodes, &inode_data_hash_ops); + if (r < 0) + return r; + + d = new(struct inode_data, 1); + if (!d) + return -ENOMEM; + + *d = (struct inode_data) { + .dev = dev, + .ino = ino, + .wd = -1, + .fd = -1, + .inotify_data = inotify_data, + }; + + r = hashmap_put(inotify_data->inodes, d, d); + if (r < 0) { + free(d); + return r; + } + + if (ret) + *ret = d; + + return 1; +} + +static uint32_t inode_data_determine_mask(struct inode_data *d) { + bool excl_unlink = true; + uint32_t combined = 0; + sd_event_source *s; + + assert(d); + + /* Combines the watch masks of all event sources watching this inode. We generally just OR them together, but + * the IN_EXCL_UNLINK flag is ANDed instead. + * + * Note that we add all sources to the mask here, regardless whether enabled, disabled or oneshot. That's + * because we cannot change the mask anymore after the event source was created once, since the kernel has no + * API for that. Hence we need to subscribe to the maximum mask we ever might be interested in, and suppress + * events we don't care for client-side. */ + + LIST_FOREACH(inotify.by_inode_data, s, d->event_sources) { + + if ((s->inotify.mask & IN_EXCL_UNLINK) == 0) + excl_unlink = false; + + combined |= s->inotify.mask; + } + + return (combined & ~(IN_ONESHOT|IN_DONT_FOLLOW|IN_ONLYDIR|IN_EXCL_UNLINK)) | (excl_unlink ? IN_EXCL_UNLINK : 0); +} + +static int inode_data_realize_watch(sd_event *e, struct inode_data *d) { + uint32_t combined_mask; + int wd, r; + + assert(d); + assert(d->fd >= 0); + + combined_mask = inode_data_determine_mask(d); + + if (d->wd >= 0 && combined_mask == d->combined_mask) + return 0; + + r = hashmap_ensure_allocated(&d->inotify_data->wd, NULL); + if (r < 0) + return r; + + wd = inotify_add_watch_fd(d->inotify_data->fd, d->fd, combined_mask); + if (wd < 0) + return -errno; + + if (d->wd < 0) { + r = hashmap_put(d->inotify_data->wd, INT_TO_PTR(wd), d); + if (r < 0) { + (void) inotify_rm_watch(d->inotify_data->fd, wd); + return r; + } + + d->wd = wd; + + } else if (d->wd != wd) { + + log_debug("Weird, the watch descriptor we already knew for this inode changed?"); + (void) inotify_rm_watch(d->fd, wd); + return -EINVAL; + } + + d->combined_mask = combined_mask; + return 1; +} + +_public_ int sd_event_add_inotify( + sd_event *e, + sd_event_source **ret, + const char *path, + uint32_t mask, + sd_event_inotify_handler_t callback, + void *userdata) { + + struct inotify_data *inotify_data = NULL; + struct inode_data *inode_data = NULL; + _cleanup_close_ int fd = -1; + _cleanup_(source_freep) sd_event_source *s = NULL; + struct stat st; + int r; + + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(path, -EINVAL); + assert_return(callback, -EINVAL); + assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(!event_pid_changed(e), -ECHILD); + + /* Refuse IN_MASK_ADD since we coalesce watches on the same inode, and hence really don't want to merge + * masks. Or in other words, this whole code exists only to manage IN_MASK_ADD type operations for you, hence + * the user can't use them for us. */ + if (mask & IN_MASK_ADD) + return -EINVAL; + + fd = open(path, O_PATH|O_CLOEXEC| + (mask & IN_ONLYDIR ? O_DIRECTORY : 0)| + (mask & IN_DONT_FOLLOW ? O_NOFOLLOW : 0)); + if (fd < 0) + return -errno; + + if (fstat(fd, &st) < 0) + return -errno; + + s = source_new(e, !ret, SOURCE_INOTIFY); + if (!s) + return -ENOMEM; + + s->enabled = mask & IN_ONESHOT ? SD_EVENT_ONESHOT : SD_EVENT_ON; + s->inotify.mask = mask; + s->inotify.callback = callback; + s->userdata = userdata; + + /* Allocate an inotify object for this priority, and an inode object within it */ + r = event_make_inotify_data(e, SD_EVENT_PRIORITY_NORMAL, &inotify_data); + if (r < 0) + return r; + + r = event_make_inode_data(e, inotify_data, st.st_dev, st.st_ino, &inode_data); + if (r < 0) { + event_free_inotify_data(e, inotify_data); + return r; + } + + /* Keep the O_PATH fd around until the first iteration of the loop, so that we can still change the priority of + * the event source, until then, for which we need the original inode. */ + if (inode_data->fd < 0) { + inode_data->fd = TAKE_FD(fd); + LIST_PREPEND(to_close, e->inode_data_to_close, inode_data); + } + + /* Link our event source to the inode data object */ + LIST_PREPEND(inotify.by_inode_data, inode_data->event_sources, s); + s->inotify.inode_data = inode_data; + + /* Actually realize the watch now */ + r = inode_data_realize_watch(e, inode_data); + if (r < 0) + return r; + + (void) sd_event_source_set_description(s, path); + + if (ret) + *ret = s; + TAKE_PTR(s); + + return 0; +} + +static sd_event_source* event_source_free(sd_event_source *s) { + if (!s) + return NULL; + + /* Here's a special hack: when we are called from a + * dispatch handler we won't free the event source + * immediately, but we will detach the fd from the + * epoll. This way it is safe for the caller to unref + * the event source and immediately close the fd, but + * we still retain a valid event source object after + * the callback. */ + + if (s->dispatching) { + if (s->type == SOURCE_IO) + source_io_unregister(s); + + source_disconnect(s); + } else + source_free(s); + + return NULL; +} + +DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(sd_event_source, sd_event_source, event_source_free); + +_public_ int sd_event_source_set_description(sd_event_source *s, const char *description) { + assert_return(s, -EINVAL); + assert_return(!event_pid_changed(s->event), -ECHILD); + + return free_and_strdup(&s->description, description); +} + +_public_ int sd_event_source_get_description(sd_event_source *s, const char **description) { + assert_return(s, -EINVAL); + assert_return(description, -EINVAL); + assert_return(!event_pid_changed(s->event), -ECHILD); + + if (!s->description) + return -ENXIO; + + *description = s->description; + return 0; +} + +_public_ sd_event *sd_event_source_get_event(sd_event_source *s) { + assert_return(s, NULL); + + return s->event; +} + +_public_ int sd_event_source_get_pending(sd_event_source *s) { + assert_return(s, -EINVAL); + assert_return(s->type != SOURCE_EXIT, -EDOM); + assert_return(s->event->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(!event_pid_changed(s->event), -ECHILD); + + return s->pending; +} + +_public_ int sd_event_source_get_io_fd(sd_event_source *s) { + assert_return(s, -EINVAL); + assert_return(s->type == SOURCE_IO, -EDOM); + assert_return(!event_pid_changed(s->event), -ECHILD); + + return s->io.fd; +} + +_public_ int sd_event_source_set_io_fd(sd_event_source *s, int fd) { + int r; + + assert_return(s, -EINVAL); + assert_return(fd >= 0, -EBADF); + assert_return(s->type == SOURCE_IO, -EDOM); + assert_return(!event_pid_changed(s->event), -ECHILD); + + if (s->io.fd == fd) + return 0; + + if (s->enabled == SD_EVENT_OFF) { + s->io.fd = fd; + s->io.registered = false; + } else { + int saved_fd; + + saved_fd = s->io.fd; + assert(s->io.registered); + + s->io.fd = fd; + s->io.registered = false; + + r = source_io_register(s, s->enabled, s->io.events); + if (r < 0) { + s->io.fd = saved_fd; + s->io.registered = true; + return r; + } + + epoll_ctl(s->event->epoll_fd, EPOLL_CTL_DEL, saved_fd, NULL); + } + + return 0; +} + +_public_ int sd_event_source_get_io_fd_own(sd_event_source *s) { + assert_return(s, -EINVAL); + assert_return(s->type == SOURCE_IO, -EDOM); + + return s->io.owned; +} + +_public_ int sd_event_source_set_io_fd_own(sd_event_source *s, int own) { + assert_return(s, -EINVAL); + assert_return(s->type == SOURCE_IO, -EDOM); + + s->io.owned = own; + return 0; +} + +_public_ int sd_event_source_get_io_events(sd_event_source *s, uint32_t* events) { + assert_return(s, -EINVAL); + assert_return(events, -EINVAL); + assert_return(s->type == SOURCE_IO, -EDOM); + assert_return(!event_pid_changed(s->event), -ECHILD); + + *events = s->io.events; + return 0; +} + +_public_ int sd_event_source_set_io_events(sd_event_source *s, uint32_t events) { + int r; + + assert_return(s, -EINVAL); + assert_return(s->type == SOURCE_IO, -EDOM); + assert_return(!(events & ~(EPOLLIN|EPOLLOUT|EPOLLRDHUP|EPOLLPRI|EPOLLERR|EPOLLHUP|EPOLLET)), -EINVAL); + assert_return(s->event->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(!event_pid_changed(s->event), -ECHILD); + + /* edge-triggered updates are never skipped, so we can reset edges */ + if (s->io.events == events && !(events & EPOLLET)) + return 0; + + r = source_set_pending(s, false); + if (r < 0) + return r; + + if (s->enabled != SD_EVENT_OFF) { + r = source_io_register(s, s->enabled, events); + if (r < 0) + return r; + } + + s->io.events = events; + + return 0; +} + +_public_ int sd_event_source_get_io_revents(sd_event_source *s, uint32_t* revents) { + assert_return(s, -EINVAL); + assert_return(revents, -EINVAL); + assert_return(s->type == SOURCE_IO, -EDOM); + assert_return(s->pending, -ENODATA); + assert_return(!event_pid_changed(s->event), -ECHILD); + + *revents = s->io.revents; + return 0; +} + +_public_ int sd_event_source_get_signal(sd_event_source *s) { + assert_return(s, -EINVAL); + assert_return(s->type == SOURCE_SIGNAL, -EDOM); + assert_return(!event_pid_changed(s->event), -ECHILD); + + return s->signal.sig; +} + +_public_ int sd_event_source_get_priority(sd_event_source *s, int64_t *priority) { + assert_return(s, -EINVAL); + assert_return(!event_pid_changed(s->event), -ECHILD); + + *priority = s->priority; + return 0; +} + +_public_ int sd_event_source_set_priority(sd_event_source *s, int64_t priority) { + bool rm_inotify = false, rm_inode = false; + struct inotify_data *new_inotify_data = NULL; + struct inode_data *new_inode_data = NULL; + int r; + + assert_return(s, -EINVAL); + assert_return(s->event->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(!event_pid_changed(s->event), -ECHILD); + + if (s->priority == priority) + return 0; + + if (s->type == SOURCE_INOTIFY) { + struct inode_data *old_inode_data; + + assert(s->inotify.inode_data); + old_inode_data = s->inotify.inode_data; + + /* We need the original fd to change the priority. If we don't have it we can't change the priority, + * anymore. Note that we close any fds when entering the next event loop iteration, i.e. for inotify + * events we allow priority changes only until the first following iteration. */ + if (old_inode_data->fd < 0) + return -EOPNOTSUPP; + + r = event_make_inotify_data(s->event, priority, &new_inotify_data); + if (r < 0) + return r; + rm_inotify = r > 0; + + r = event_make_inode_data(s->event, new_inotify_data, old_inode_data->dev, old_inode_data->ino, &new_inode_data); + if (r < 0) + goto fail; + rm_inode = r > 0; + + if (new_inode_data->fd < 0) { + /* Duplicate the fd for the new inode object if we don't have any yet */ + new_inode_data->fd = fcntl(old_inode_data->fd, F_DUPFD_CLOEXEC, 3); + if (new_inode_data->fd < 0) { + r = -errno; + goto fail; + } + + LIST_PREPEND(to_close, s->event->inode_data_to_close, new_inode_data); + } + + /* Move the event source to the new inode data structure */ + LIST_REMOVE(inotify.by_inode_data, old_inode_data->event_sources, s); + LIST_PREPEND(inotify.by_inode_data, new_inode_data->event_sources, s); + s->inotify.inode_data = new_inode_data; + + /* Now create the new watch */ + r = inode_data_realize_watch(s->event, new_inode_data); + if (r < 0) { + /* Move it back */ + LIST_REMOVE(inotify.by_inode_data, new_inode_data->event_sources, s); + LIST_PREPEND(inotify.by_inode_data, old_inode_data->event_sources, s); + s->inotify.inode_data = old_inode_data; + goto fail; + } + + s->priority = priority; + + event_gc_inode_data(s->event, old_inode_data); + + } else if (s->type == SOURCE_SIGNAL && s->enabled != SD_EVENT_OFF) { + struct signal_data *old, *d; + + /* Move us from the signalfd belonging to the old + * priority to the signalfd of the new priority */ + + assert_se(old = hashmap_get(s->event->signal_data, &s->priority)); + + s->priority = priority; + + r = event_make_signal_data(s->event, s->signal.sig, &d); + if (r < 0) { + s->priority = old->priority; + return r; + } + + event_unmask_signal_data(s->event, old, s->signal.sig); + } else + s->priority = priority; + + if (s->pending) + prioq_reshuffle(s->event->pending, s, &s->pending_index); + + if (s->prepare) + prioq_reshuffle(s->event->prepare, s, &s->prepare_index); + + if (s->type == SOURCE_EXIT) + prioq_reshuffle(s->event->exit, s, &s->exit.prioq_index); + + return 0; + +fail: + if (rm_inode) + event_free_inode_data(s->event, new_inode_data); + + if (rm_inotify) + event_free_inotify_data(s->event, new_inotify_data); + + return r; +} + +_public_ int sd_event_source_get_enabled(sd_event_source *s, int *m) { + assert_return(s, -EINVAL); + assert_return(!event_pid_changed(s->event), -ECHILD); + + if (m) + *m = s->enabled; + return s->enabled != SD_EVENT_OFF; +} + +_public_ int sd_event_source_set_enabled(sd_event_source *s, int m) { + int r; + + assert_return(s, -EINVAL); + assert_return(IN_SET(m, SD_EVENT_OFF, SD_EVENT_ON, SD_EVENT_ONESHOT), -EINVAL); + assert_return(!event_pid_changed(s->event), -ECHILD); + + /* If we are dead anyway, we are fine with turning off + * sources, but everything else needs to fail. */ + if (s->event->state == SD_EVENT_FINISHED) + return m == SD_EVENT_OFF ? 0 : -ESTALE; + + if (s->enabled == m) + return 0; + + if (m == SD_EVENT_OFF) { + + /* Unset the pending flag when this event source is disabled */ + if (!IN_SET(s->type, SOURCE_DEFER, SOURCE_EXIT)) { + r = source_set_pending(s, false); + if (r < 0) + return r; + } + + switch (s->type) { + + case SOURCE_IO: + source_io_unregister(s); + s->enabled = m; + break; + + case SOURCE_TIME_REALTIME: + case SOURCE_TIME_BOOTTIME: + case SOURCE_TIME_MONOTONIC: + case SOURCE_TIME_REALTIME_ALARM: + case SOURCE_TIME_BOOTTIME_ALARM: { + struct clock_data *d; + + s->enabled = m; + d = event_get_clock_data(s->event, s->type); + assert(d); + + prioq_reshuffle(d->earliest, s, &s->time.earliest_index); + prioq_reshuffle(d->latest, s, &s->time.latest_index); + d->needs_rearm = true; + break; + } + + case SOURCE_SIGNAL: + s->enabled = m; + + event_gc_signal_data(s->event, &s->priority, s->signal.sig); + break; + + case SOURCE_CHILD: + s->enabled = m; + + assert(s->event->n_enabled_child_sources > 0); + s->event->n_enabled_child_sources--; + + event_gc_signal_data(s->event, &s->priority, SIGCHLD); + break; + + case SOURCE_EXIT: + s->enabled = m; + prioq_reshuffle(s->event->exit, s, &s->exit.prioq_index); + break; + + case SOURCE_DEFER: + case SOURCE_POST: + case SOURCE_INOTIFY: + s->enabled = m; + break; + + default: + assert_not_reached("Wut? I shouldn't exist."); + } + + } else { + + /* Unset the pending flag when this event source is enabled */ + if (s->enabled == SD_EVENT_OFF && !IN_SET(s->type, SOURCE_DEFER, SOURCE_EXIT)) { + r = source_set_pending(s, false); + if (r < 0) + return r; + } + + switch (s->type) { + + case SOURCE_IO: + r = source_io_register(s, m, s->io.events); + if (r < 0) + return r; + + s->enabled = m; + break; + + case SOURCE_TIME_REALTIME: + case SOURCE_TIME_BOOTTIME: + case SOURCE_TIME_MONOTONIC: + case SOURCE_TIME_REALTIME_ALARM: + case SOURCE_TIME_BOOTTIME_ALARM: { + struct clock_data *d; + + s->enabled = m; + d = event_get_clock_data(s->event, s->type); + assert(d); + + prioq_reshuffle(d->earliest, s, &s->time.earliest_index); + prioq_reshuffle(d->latest, s, &s->time.latest_index); + d->needs_rearm = true; + break; + } + + case SOURCE_SIGNAL: + + s->enabled = m; + + r = event_make_signal_data(s->event, s->signal.sig, NULL); + if (r < 0) { + s->enabled = SD_EVENT_OFF; + event_gc_signal_data(s->event, &s->priority, s->signal.sig); + return r; + } + + break; + + case SOURCE_CHILD: + + if (s->enabled == SD_EVENT_OFF) + s->event->n_enabled_child_sources++; + + s->enabled = m; + + r = event_make_signal_data(s->event, SIGCHLD, NULL); + if (r < 0) { + s->enabled = SD_EVENT_OFF; + s->event->n_enabled_child_sources--; + event_gc_signal_data(s->event, &s->priority, SIGCHLD); + return r; + } + + break; + + case SOURCE_EXIT: + s->enabled = m; + prioq_reshuffle(s->event->exit, s, &s->exit.prioq_index); + break; + + case SOURCE_DEFER: + case SOURCE_POST: + case SOURCE_INOTIFY: + s->enabled = m; + break; + + default: + assert_not_reached("Wut? I shouldn't exist."); + } + } + + if (s->pending) + prioq_reshuffle(s->event->pending, s, &s->pending_index); + + if (s->prepare) + prioq_reshuffle(s->event->prepare, s, &s->prepare_index); + + return 0; +} + +_public_ int sd_event_source_get_time(sd_event_source *s, uint64_t *usec) { + assert_return(s, -EINVAL); + assert_return(usec, -EINVAL); + assert_return(EVENT_SOURCE_IS_TIME(s->type), -EDOM); + assert_return(!event_pid_changed(s->event), -ECHILD); + + *usec = s->time.next; + return 0; +} + +_public_ int sd_event_source_set_time(sd_event_source *s, uint64_t usec) { + struct clock_data *d; + int r; + + assert_return(s, -EINVAL); + assert_return(EVENT_SOURCE_IS_TIME(s->type), -EDOM); + assert_return(s->event->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(!event_pid_changed(s->event), -ECHILD); + + r = source_set_pending(s, false); + if (r < 0) + return r; + + s->time.next = usec; + + d = event_get_clock_data(s->event, s->type); + assert(d); + + prioq_reshuffle(d->earliest, s, &s->time.earliest_index); + prioq_reshuffle(d->latest, s, &s->time.latest_index); + d->needs_rearm = true; + + return 0; +} + +_public_ int sd_event_source_get_time_accuracy(sd_event_source *s, uint64_t *usec) { + assert_return(s, -EINVAL); + assert_return(usec, -EINVAL); + assert_return(EVENT_SOURCE_IS_TIME(s->type), -EDOM); + assert_return(!event_pid_changed(s->event), -ECHILD); + + *usec = s->time.accuracy; + return 0; +} + +_public_ int sd_event_source_set_time_accuracy(sd_event_source *s, uint64_t usec) { + struct clock_data *d; + int r; + + assert_return(s, -EINVAL); + assert_return(usec != (uint64_t) -1, -EINVAL); + assert_return(EVENT_SOURCE_IS_TIME(s->type), -EDOM); + assert_return(s->event->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(!event_pid_changed(s->event), -ECHILD); + + r = source_set_pending(s, false); + if (r < 0) + return r; + + if (usec == 0) + usec = DEFAULT_ACCURACY_USEC; + + s->time.accuracy = usec; + + d = event_get_clock_data(s->event, s->type); + assert(d); + + prioq_reshuffle(d->latest, s, &s->time.latest_index); + d->needs_rearm = true; + + return 0; +} + +_public_ int sd_event_source_get_time_clock(sd_event_source *s, clockid_t *clock) { + assert_return(s, -EINVAL); + assert_return(clock, -EINVAL); + assert_return(EVENT_SOURCE_IS_TIME(s->type), -EDOM); + assert_return(!event_pid_changed(s->event), -ECHILD); + + *clock = event_source_type_to_clock(s->type); + return 0; +} + +_public_ int sd_event_source_get_child_pid(sd_event_source *s, pid_t *pid) { + assert_return(s, -EINVAL); + assert_return(pid, -EINVAL); + assert_return(s->type == SOURCE_CHILD, -EDOM); + assert_return(!event_pid_changed(s->event), -ECHILD); + + *pid = s->child.pid; + return 0; +} + +_public_ int sd_event_source_get_inotify_mask(sd_event_source *s, uint32_t *mask) { + assert_return(s, -EINVAL); + assert_return(mask, -EINVAL); + assert_return(s->type == SOURCE_INOTIFY, -EDOM); + assert_return(!event_pid_changed(s->event), -ECHILD); + + *mask = s->inotify.mask; + return 0; +} + +_public_ int sd_event_source_set_prepare(sd_event_source *s, sd_event_handler_t callback) { + int r; + + assert_return(s, -EINVAL); + assert_return(s->type != SOURCE_EXIT, -EDOM); + assert_return(s->event->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(!event_pid_changed(s->event), -ECHILD); + + if (s->prepare == callback) + return 0; + + if (callback && s->prepare) { + s->prepare = callback; + return 0; + } + + r = prioq_ensure_allocated(&s->event->prepare, prepare_prioq_compare); + if (r < 0) + return r; + + s->prepare = callback; + + if (callback) { + r = prioq_put(s->event->prepare, s, &s->prepare_index); + if (r < 0) + return r; + } else + prioq_remove(s->event->prepare, s, &s->prepare_index); + + return 0; +} + +_public_ void* sd_event_source_get_userdata(sd_event_source *s) { + assert_return(s, NULL); + + return s->userdata; +} + +_public_ void *sd_event_source_set_userdata(sd_event_source *s, void *userdata) { + void *ret; + + assert_return(s, NULL); + + ret = s->userdata; + s->userdata = userdata; + + return ret; +} + +static usec_t sleep_between(sd_event *e, usec_t a, usec_t b) { + usec_t c; + assert(e); + assert(a <= b); + + if (a <= 0) + return 0; + if (a >= USEC_INFINITY) + return USEC_INFINITY; + + if (b <= a + 1) + return a; + + initialize_perturb(e); + + /* + Find a good time to wake up again between times a and b. We + have two goals here: + + a) We want to wake up as seldom as possible, hence prefer + later times over earlier times. + + b) But if we have to wake up, then let's make sure to + dispatch as much as possible on the entire system. + + We implement this by waking up everywhere at the same time + within any given minute if we can, synchronised via the + perturbation value determined from the boot ID. If we can't, + then we try to find the same spot in every 10s, then 1s and + then 250ms step. Otherwise, we pick the last possible time + to wake up. + */ + + c = (b / USEC_PER_MINUTE) * USEC_PER_MINUTE + e->perturb; + if (c >= b) { + if (_unlikely_(c < USEC_PER_MINUTE)) + return b; + + c -= USEC_PER_MINUTE; + } + + if (c >= a) + return c; + + c = (b / (USEC_PER_SEC*10)) * (USEC_PER_SEC*10) + (e->perturb % (USEC_PER_SEC*10)); + if (c >= b) { + if (_unlikely_(c < USEC_PER_SEC*10)) + return b; + + c -= USEC_PER_SEC*10; + } + + if (c >= a) + return c; + + c = (b / USEC_PER_SEC) * USEC_PER_SEC + (e->perturb % USEC_PER_SEC); + if (c >= b) { + if (_unlikely_(c < USEC_PER_SEC)) + return b; + + c -= USEC_PER_SEC; + } + + if (c >= a) + return c; + + c = (b / (USEC_PER_MSEC*250)) * (USEC_PER_MSEC*250) + (e->perturb % (USEC_PER_MSEC*250)); + if (c >= b) { + if (_unlikely_(c < USEC_PER_MSEC*250)) + return b; + + c -= USEC_PER_MSEC*250; + } + + if (c >= a) + return c; + + return b; +} + +static int event_arm_timer( + sd_event *e, + struct clock_data *d) { + + struct itimerspec its = {}; + sd_event_source *a, *b; + usec_t t; + int r; + + assert(e); + assert(d); + + if (!d->needs_rearm) + return 0; + else + d->needs_rearm = false; + + a = prioq_peek(d->earliest); + if (!a || a->enabled == SD_EVENT_OFF || a->time.next == USEC_INFINITY) { + + if (d->fd < 0) + return 0; + + if (d->next == USEC_INFINITY) + return 0; + + /* disarm */ + r = timerfd_settime(d->fd, TFD_TIMER_ABSTIME, &its, NULL); + if (r < 0) + return r; + + d->next = USEC_INFINITY; + return 0; + } + + b = prioq_peek(d->latest); + assert_se(b && b->enabled != SD_EVENT_OFF); + + t = sleep_between(e, a->time.next, time_event_source_latest(b)); + if (d->next == t) + return 0; + + assert_se(d->fd >= 0); + + if (t == 0) { + /* We don' want to disarm here, just mean some time looooong ago. */ + its.it_value.tv_sec = 0; + its.it_value.tv_nsec = 1; + } else + timespec_store(&its.it_value, t); + + r = timerfd_settime(d->fd, TFD_TIMER_ABSTIME, &its, NULL); + if (r < 0) + return -errno; + + d->next = t; + return 0; +} + +static int process_io(sd_event *e, sd_event_source *s, uint32_t revents) { + assert(e); + assert(s); + assert(s->type == SOURCE_IO); + + /* If the event source was already pending, we just OR in the + * new revents, otherwise we reset the value. The ORing is + * necessary to handle EPOLLONESHOT events properly where + * readability might happen independently of writability, and + * we need to keep track of both */ + + if (s->pending) + s->io.revents |= revents; + else + s->io.revents = revents; + + return source_set_pending(s, true); +} + +static int flush_timer(sd_event *e, int fd, uint32_t events, usec_t *next) { + uint64_t x; + ssize_t ss; + + assert(e); + assert(fd >= 0); + + assert_return(events == EPOLLIN, -EIO); + + ss = read(fd, &x, sizeof(x)); + if (ss < 0) { + if (IN_SET(errno, EAGAIN, EINTR)) + return 0; + + return -errno; + } + + if (_unlikely_(ss != sizeof(x))) + return -EIO; + + if (next) + *next = USEC_INFINITY; + + return 0; +} + +static int process_timer( + sd_event *e, + usec_t n, + struct clock_data *d) { + + sd_event_source *s; + int r; + + assert(e); + assert(d); + + for (;;) { + s = prioq_peek(d->earliest); + if (!s || + s->time.next > n || + s->enabled == SD_EVENT_OFF || + s->pending) + break; + + r = source_set_pending(s, true); + if (r < 0) + return r; + + prioq_reshuffle(d->earliest, s, &s->time.earliest_index); + prioq_reshuffle(d->latest, s, &s->time.latest_index); + d->needs_rearm = true; + } + + return 0; +} + +static int process_child(sd_event *e) { + sd_event_source *s; + Iterator i; + int r; + + assert(e); + + e->need_process_child = false; + + /* + So, this is ugly. We iteratively invoke waitid() with P_PID + + WNOHANG for each PID we wait for, instead of using + P_ALL. This is because we only want to get child + information of very specific child processes, and not all + of them. We might not have processed the SIGCHLD even of a + previous invocation and we don't want to maintain a + unbounded *per-child* event queue, hence we really don't + want anything flushed out of the kernel's queue that we + don't care about. Since this is O(n) this means that if you + have a lot of processes you probably want to handle SIGCHLD + yourself. + + We do not reap the children here (by using WNOWAIT), this + is only done after the event source is dispatched so that + the callback still sees the process as a zombie. + */ + + HASHMAP_FOREACH(s, e->child_sources, i) { + assert(s->type == SOURCE_CHILD); + + if (s->pending) + continue; + + if (s->enabled == SD_EVENT_OFF) + continue; + + zero(s->child.siginfo); + r = waitid(P_PID, s->child.pid, &s->child.siginfo, + WNOHANG | (s->child.options & WEXITED ? WNOWAIT : 0) | s->child.options); + if (r < 0) + return -errno; + + if (s->child.siginfo.si_pid != 0) { + bool zombie = IN_SET(s->child.siginfo.si_code, CLD_EXITED, CLD_KILLED, CLD_DUMPED); + + if (!zombie && (s->child.options & WEXITED)) { + /* If the child isn't dead then let's + * immediately remove the state change + * from the queue, since there's no + * benefit in leaving it queued */ + + assert(s->child.options & (WSTOPPED|WCONTINUED)); + waitid(P_PID, s->child.pid, &s->child.siginfo, WNOHANG|(s->child.options & (WSTOPPED|WCONTINUED))); + } + + r = source_set_pending(s, true); + if (r < 0) + return r; + } + } + + return 0; +} + +static int process_signal(sd_event *e, struct signal_data *d, uint32_t events) { + bool read_one = false; + int r; + + assert(e); + assert(d); + assert_return(events == EPOLLIN, -EIO); + + /* If there's a signal queued on this priority and SIGCHLD is + on this priority too, then make sure to recheck the + children we watch. This is because we only ever dequeue + the first signal per priority, and if we dequeue one, and + SIGCHLD might be enqueued later we wouldn't know, but we + might have higher priority children we care about hence we + need to check that explicitly. */ + + if (sigismember(&d->sigset, SIGCHLD)) + e->need_process_child = true; + + /* If there's already an event source pending for this + * priority we don't read another */ + if (d->current) + return 0; + + for (;;) { + struct signalfd_siginfo si; + ssize_t n; + sd_event_source *s = NULL; + + n = read(d->fd, &si, sizeof(si)); + if (n < 0) { + if (IN_SET(errno, EAGAIN, EINTR)) + return read_one; + + return -errno; + } + + if (_unlikely_(n != sizeof(si))) + return -EIO; + + assert(SIGNAL_VALID(si.ssi_signo)); + + read_one = true; + + if (e->signal_sources) + s = e->signal_sources[si.ssi_signo]; + if (!s) + continue; + if (s->pending) + continue; + + s->signal.siginfo = si; + d->current = s; + + r = source_set_pending(s, true); + if (r < 0) + return r; + + return 1; + } +} + +static int event_inotify_data_read(sd_event *e, struct inotify_data *d, uint32_t revents) { + ssize_t n; + + assert(e); + assert(d); + + assert_return(revents == EPOLLIN, -EIO); + + /* If there's already an event source pending for this priority, don't read another */ + if (d->n_pending > 0) + return 0; + + /* Is the read buffer non-empty? If so, let's not read more */ + if (d->buffer_filled > 0) + return 0; + + n = read(d->fd, &d->buffer, sizeof(d->buffer)); + if (n < 0) { + if (IN_SET(errno, EAGAIN, EINTR)) + return 0; + + return -errno; + } + + assert(n > 0); + d->buffer_filled = (size_t) n; + LIST_PREPEND(buffered, e->inotify_data_buffered, d); + + return 1; +} + +static void event_inotify_data_drop(sd_event *e, struct inotify_data *d, size_t sz) { + assert(e); + assert(d); + assert(sz <= d->buffer_filled); + + if (sz == 0) + return; + + /* Move the rest to the buffer to the front, in order to get things properly aligned again */ + memmove(d->buffer.raw, d->buffer.raw + sz, d->buffer_filled - sz); + d->buffer_filled -= sz; + + if (d->buffer_filled == 0) + LIST_REMOVE(buffered, e->inotify_data_buffered, d); +} + +static int event_inotify_data_process(sd_event *e, struct inotify_data *d) { + int r; + + assert(e); + assert(d); + + /* If there's already an event source pending for this priority, don't read another */ + if (d->n_pending > 0) + return 0; + + while (d->buffer_filled > 0) { + size_t sz; + + /* Let's validate that the event structures are complete */ + if (d->buffer_filled < offsetof(struct inotify_event, name)) + return -EIO; + + sz = offsetof(struct inotify_event, name) + d->buffer.ev.len; + if (d->buffer_filled < sz) + return -EIO; + + if (d->buffer.ev.mask & IN_Q_OVERFLOW) { + struct inode_data *inode_data; + Iterator i; + + /* The queue overran, let's pass this event to all event sources connected to this inotify + * object */ + + HASHMAP_FOREACH(inode_data, d->inodes, i) { + sd_event_source *s; + + LIST_FOREACH(inotify.by_inode_data, s, inode_data->event_sources) { + + if (s->enabled == SD_EVENT_OFF) + continue; + + r = source_set_pending(s, true); + if (r < 0) + return r; + } + } + } else { + struct inode_data *inode_data; + sd_event_source *s; + + /* Find the inode object for this watch descriptor. If IN_IGNORED is set we also remove it from + * our watch descriptor table. */ + if (d->buffer.ev.mask & IN_IGNORED) { + + inode_data = hashmap_remove(d->wd, INT_TO_PTR(d->buffer.ev.wd)); + if (!inode_data) { + event_inotify_data_drop(e, d, sz); + continue; + } + + /* The watch descriptor was removed by the kernel, let's drop it here too */ + inode_data->wd = -1; + } else { + inode_data = hashmap_get(d->wd, INT_TO_PTR(d->buffer.ev.wd)); + if (!inode_data) { + event_inotify_data_drop(e, d, sz); + continue; + } + } + + /* Trigger all event sources that are interested in these events. Also trigger all event + * sources if IN_IGNORED or IN_UNMOUNT is set. */ + LIST_FOREACH(inotify.by_inode_data, s, inode_data->event_sources) { + + if (s->enabled == SD_EVENT_OFF) + continue; + + if ((d->buffer.ev.mask & (IN_IGNORED|IN_UNMOUNT)) == 0 && + (s->inotify.mask & d->buffer.ev.mask & IN_ALL_EVENTS) == 0) + continue; + + r = source_set_pending(s, true); + if (r < 0) + return r; + } + } + + /* Something pending now? If so, let's finish, otherwise let's read more. */ + if (d->n_pending > 0) + return 1; + } + + return 0; +} + +static int process_inotify(sd_event *e) { + struct inotify_data *d; + int r, done = 0; + + assert(e); + + LIST_FOREACH(buffered, d, e->inotify_data_buffered) { + r = event_inotify_data_process(e, d); + if (r < 0) + return r; + if (r > 0) + done ++; + } + + return done; +} + +static int source_dispatch(sd_event_source *s) { + EventSourceType saved_type; + int r = 0; + + assert(s); + assert(s->pending || s->type == SOURCE_EXIT); + + /* Save the event source type, here, so that we still know it after the event callback which might invalidate + * the event. */ + saved_type = s->type; + + if (!IN_SET(s->type, SOURCE_DEFER, SOURCE_EXIT)) { + r = source_set_pending(s, false); + if (r < 0) + return r; + } + + if (s->type != SOURCE_POST) { + sd_event_source *z; + Iterator i; + + /* If we execute a non-post source, let's mark all + * post sources as pending */ + + SET_FOREACH(z, s->event->post_sources, i) { + if (z->enabled == SD_EVENT_OFF) + continue; + + r = source_set_pending(z, true); + if (r < 0) + return r; + } + } + + if (s->enabled == SD_EVENT_ONESHOT) { + r = sd_event_source_set_enabled(s, SD_EVENT_OFF); + if (r < 0) + return r; + } + + s->dispatching = true; + + switch (s->type) { + + case SOURCE_IO: + r = s->io.callback(s, s->io.fd, s->io.revents, s->userdata); + break; + + case SOURCE_TIME_REALTIME: + case SOURCE_TIME_BOOTTIME: + case SOURCE_TIME_MONOTONIC: + case SOURCE_TIME_REALTIME_ALARM: + case SOURCE_TIME_BOOTTIME_ALARM: + r = s->time.callback(s, s->time.next, s->userdata); + break; + + case SOURCE_SIGNAL: + r = s->signal.callback(s, &s->signal.siginfo, s->userdata); + break; + + case SOURCE_CHILD: { + bool zombie; + + zombie = IN_SET(s->child.siginfo.si_code, CLD_EXITED, CLD_KILLED, CLD_DUMPED); + + r = s->child.callback(s, &s->child.siginfo, s->userdata); + + /* Now, reap the PID for good. */ + if (zombie) + (void) waitid(P_PID, s->child.pid, &s->child.siginfo, WNOHANG|WEXITED); + + break; + } + + case SOURCE_DEFER: + r = s->defer.callback(s, s->userdata); + break; + + case SOURCE_POST: + r = s->post.callback(s, s->userdata); + break; + + case SOURCE_EXIT: + r = s->exit.callback(s, s->userdata); + break; + + case SOURCE_INOTIFY: { + struct sd_event *e = s->event; + struct inotify_data *d; + size_t sz; + + assert(s->inotify.inode_data); + assert_se(d = s->inotify.inode_data->inotify_data); + + assert(d->buffer_filled >= offsetof(struct inotify_event, name)); + sz = offsetof(struct inotify_event, name) + d->buffer.ev.len; + assert(d->buffer_filled >= sz); + + r = s->inotify.callback(s, &d->buffer.ev, s->userdata); + + /* When no event is pending anymore on this inotify object, then let's drop the event from the + * buffer. */ + if (d->n_pending == 0) + event_inotify_data_drop(e, d, sz); + + break; + } + + case SOURCE_WATCHDOG: + case _SOURCE_EVENT_SOURCE_TYPE_MAX: + case _SOURCE_EVENT_SOURCE_TYPE_INVALID: + assert_not_reached("Wut? I shouldn't exist."); + } + + s->dispatching = false; + + if (r < 0) + log_debug_errno(r, "Event source %s (type %s) returned error, disabling: %m", + strna(s->description), event_source_type_to_string(saved_type)); + + if (s->n_ref == 0) + source_free(s); + else if (r < 0) + sd_event_source_set_enabled(s, SD_EVENT_OFF); + + return 1; +} + +static int event_prepare(sd_event *e) { + int r; + + assert(e); + + for (;;) { + sd_event_source *s; + + s = prioq_peek(e->prepare); + if (!s || s->prepare_iteration == e->iteration || s->enabled == SD_EVENT_OFF) + break; + + s->prepare_iteration = e->iteration; + r = prioq_reshuffle(e->prepare, s, &s->prepare_index); + if (r < 0) + return r; + + assert(s->prepare); + + s->dispatching = true; + r = s->prepare(s, s->userdata); + s->dispatching = false; + + if (r < 0) + log_debug_errno(r, "Prepare callback of event source %s (type %s) returned error, disabling: %m", + strna(s->description), event_source_type_to_string(s->type)); + + if (s->n_ref == 0) + source_free(s); + else if (r < 0) + sd_event_source_set_enabled(s, SD_EVENT_OFF); + } + + return 0; +} + +static int dispatch_exit(sd_event *e) { + sd_event_source *p; + _cleanup_(sd_event_unrefp) sd_event *ref = NULL; + int r; + + assert(e); + + p = prioq_peek(e->exit); + if (!p || p->enabled == SD_EVENT_OFF) { + e->state = SD_EVENT_FINISHED; + return 0; + } + + ref = sd_event_ref(e); + e->iteration++; + e->state = SD_EVENT_EXITING; + r = source_dispatch(p); + e->state = SD_EVENT_INITIAL; + return r; +} + +static sd_event_source* event_next_pending(sd_event *e) { + sd_event_source *p; + + assert(e); + + p = prioq_peek(e->pending); + if (!p) + return NULL; + + if (p->enabled == SD_EVENT_OFF) + return NULL; + + return p; +} + +static int arm_watchdog(sd_event *e) { + struct itimerspec its = {}; + usec_t t; + int r; + + assert(e); + assert(e->watchdog_fd >= 0); + + t = sleep_between(e, + e->watchdog_last + (e->watchdog_period / 2), + e->watchdog_last + (e->watchdog_period * 3 / 4)); + + timespec_store(&its.it_value, t); + + /* Make sure we never set the watchdog to 0, which tells the + * kernel to disable it. */ + if (its.it_value.tv_sec == 0 && its.it_value.tv_nsec == 0) + its.it_value.tv_nsec = 1; + + r = timerfd_settime(e->watchdog_fd, TFD_TIMER_ABSTIME, &its, NULL); + if (r < 0) + return -errno; + + return 0; +} + +static int process_watchdog(sd_event *e) { + assert(e); + + if (!e->watchdog) + return 0; + + /* Don't notify watchdog too often */ + if (e->watchdog_last + e->watchdog_period / 4 > e->timestamp.monotonic) + return 0; + + sd_notify(false, "WATCHDOG=1"); + e->watchdog_last = e->timestamp.monotonic; + + return arm_watchdog(e); +} + +static void event_close_inode_data_fds(sd_event *e) { + struct inode_data *d; + + assert(e); + + /* Close the fds pointing to the inodes to watch now. We need to close them as they might otherwise pin + * filesystems. But we can't close them right-away as we need them as long as the user still wants to make + * adjustments to the even source, such as changing the priority (which requires us to remove and readd a watch + * for the inode). Hence, let's close them when entering the first iteration after they were added, as a + * compromise. */ + + while ((d = e->inode_data_to_close)) { + assert(d->fd >= 0); + d->fd = safe_close(d->fd); + + LIST_REMOVE(to_close, e->inode_data_to_close, d); + } +} + +_public_ int sd_event_prepare(sd_event *e) { + int r; + + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(!event_pid_changed(e), -ECHILD); + assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(e->state == SD_EVENT_INITIAL, -EBUSY); + + if (e->exit_requested) + goto pending; + + e->iteration++; + + e->state = SD_EVENT_PREPARING; + r = event_prepare(e); + e->state = SD_EVENT_INITIAL; + if (r < 0) + return r; + + r = event_arm_timer(e, &e->realtime); + if (r < 0) + return r; + + r = event_arm_timer(e, &e->boottime); + if (r < 0) + return r; + + r = event_arm_timer(e, &e->monotonic); + if (r < 0) + return r; + + r = event_arm_timer(e, &e->realtime_alarm); + if (r < 0) + return r; + + r = event_arm_timer(e, &e->boottime_alarm); + if (r < 0) + return r; + + event_close_inode_data_fds(e); + + if (event_next_pending(e) || e->need_process_child) + goto pending; + + e->state = SD_EVENT_ARMED; + + return 0; + +pending: + e->state = SD_EVENT_ARMED; + r = sd_event_wait(e, 0); + if (r == 0) + e->state = SD_EVENT_ARMED; + + return r; +} + +_public_ int sd_event_wait(sd_event *e, uint64_t timeout) { + struct epoll_event *ev_queue; + unsigned ev_queue_max; + int r, m, i; + + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(!event_pid_changed(e), -ECHILD); + assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(e->state == SD_EVENT_ARMED, -EBUSY); + + if (e->exit_requested) { + e->state = SD_EVENT_PENDING; + return 1; + } + + ev_queue_max = MAX(e->n_sources, 1u); + ev_queue = newa(struct epoll_event, ev_queue_max); + + /* If we still have inotify data buffered, then query the other fds, but don't wait on it */ + if (e->inotify_data_buffered) + timeout = 0; + + m = epoll_wait(e->epoll_fd, ev_queue, ev_queue_max, + timeout == (uint64_t) -1 ? -1 : (int) ((timeout + USEC_PER_MSEC - 1) / USEC_PER_MSEC)); + if (m < 0) { + if (errno == EINTR) { + e->state = SD_EVENT_PENDING; + return 1; + } + + r = -errno; + goto finish; + } + + triple_timestamp_get(&e->timestamp); + + for (i = 0; i < m; i++) { + + if (ev_queue[i].data.ptr == INT_TO_PTR(SOURCE_WATCHDOG)) + r = flush_timer(e, e->watchdog_fd, ev_queue[i].events, NULL); + else { + WakeupType *t = ev_queue[i].data.ptr; + + switch (*t) { + + case WAKEUP_EVENT_SOURCE: + r = process_io(e, ev_queue[i].data.ptr, ev_queue[i].events); + break; + + case WAKEUP_CLOCK_DATA: { + struct clock_data *d = ev_queue[i].data.ptr; + r = flush_timer(e, d->fd, ev_queue[i].events, &d->next); + break; + } + + case WAKEUP_SIGNAL_DATA: + r = process_signal(e, ev_queue[i].data.ptr, ev_queue[i].events); + break; + + case WAKEUP_INOTIFY_DATA: + r = event_inotify_data_read(e, ev_queue[i].data.ptr, ev_queue[i].events); + break; + + default: + assert_not_reached("Invalid wake-up pointer"); + } + } + if (r < 0) + goto finish; + } + + r = process_watchdog(e); + if (r < 0) + goto finish; + + r = process_timer(e, e->timestamp.realtime, &e->realtime); + if (r < 0) + goto finish; + + r = process_timer(e, e->timestamp.boottime, &e->boottime); + if (r < 0) + goto finish; + + r = process_timer(e, e->timestamp.monotonic, &e->monotonic); + if (r < 0) + goto finish; + + r = process_timer(e, e->timestamp.realtime, &e->realtime_alarm); + if (r < 0) + goto finish; + + r = process_timer(e, e->timestamp.boottime, &e->boottime_alarm); + if (r < 0) + goto finish; + + if (e->need_process_child) { + r = process_child(e); + if (r < 0) + goto finish; + } + + r = process_inotify(e); + if (r < 0) + goto finish; + + if (event_next_pending(e)) { + e->state = SD_EVENT_PENDING; + + return 1; + } + + r = 0; + +finish: + e->state = SD_EVENT_INITIAL; + + return r; +} + +_public_ int sd_event_dispatch(sd_event *e) { + sd_event_source *p; + int r; + + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(!event_pid_changed(e), -ECHILD); + assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(e->state == SD_EVENT_PENDING, -EBUSY); + + if (e->exit_requested) + return dispatch_exit(e); + + p = event_next_pending(e); + if (p) { + _cleanup_(sd_event_unrefp) sd_event *ref = NULL; + + ref = sd_event_ref(e); + e->state = SD_EVENT_RUNNING; + r = source_dispatch(p); + e->state = SD_EVENT_INITIAL; + return r; + } + + e->state = SD_EVENT_INITIAL; + + return 1; +} + +static void event_log_delays(sd_event *e) { + char b[ELEMENTSOF(e->delays) * DECIMAL_STR_MAX(unsigned) + 1]; + unsigned i; + int o; + + for (i = o = 0; i < ELEMENTSOF(e->delays); i++) { + o += snprintf(&b[o], sizeof(b) - o, "%u ", e->delays[i]); + e->delays[i] = 0; + } + log_debug("Event loop iterations: %.*s", o, b); +} + +_public_ int sd_event_run(sd_event *e, uint64_t timeout) { + int r; + + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(!event_pid_changed(e), -ECHILD); + assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(e->state == SD_EVENT_INITIAL, -EBUSY); + + if (e->profile_delays && e->last_run) { + usec_t this_run; + unsigned l; + + this_run = now(CLOCK_MONOTONIC); + + l = u64log2(this_run - e->last_run); + assert(l < sizeof(e->delays)); + e->delays[l]++; + + if (this_run - e->last_log >= 5*USEC_PER_SEC) { + event_log_delays(e); + e->last_log = this_run; + } + } + + r = sd_event_prepare(e); + if (r == 0) + /* There was nothing? Then wait... */ + r = sd_event_wait(e, timeout); + + if (e->profile_delays) + e->last_run = now(CLOCK_MONOTONIC); + + if (r > 0) { + /* There's something now, then let's dispatch it */ + r = sd_event_dispatch(e); + if (r < 0) + return r; + + return 1; + } + + return r; +} + +_public_ int sd_event_loop(sd_event *e) { + _cleanup_(sd_event_unrefp) sd_event *ref = NULL; + int r; + + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(!event_pid_changed(e), -ECHILD); + assert_return(e->state == SD_EVENT_INITIAL, -EBUSY); + + ref = sd_event_ref(e); + + while (e->state != SD_EVENT_FINISHED) { + r = sd_event_run(e, (uint64_t) -1); + if (r < 0) + return r; + } + + return e->exit_code; +} + +_public_ int sd_event_get_fd(sd_event *e) { + + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(!event_pid_changed(e), -ECHILD); + + return e->epoll_fd; +} + +_public_ int sd_event_get_state(sd_event *e) { + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(!event_pid_changed(e), -ECHILD); + + return e->state; +} + +_public_ int sd_event_get_exit_code(sd_event *e, int *code) { + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(code, -EINVAL); + assert_return(!event_pid_changed(e), -ECHILD); + + if (!e->exit_requested) + return -ENODATA; + + *code = e->exit_code; + return 0; +} + +_public_ int sd_event_exit(sd_event *e, int code) { + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); + assert_return(!event_pid_changed(e), -ECHILD); + + e->exit_requested = true; + e->exit_code = code; + + return 0; +} + +_public_ int sd_event_now(sd_event *e, clockid_t clock, uint64_t *usec) { + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(usec, -EINVAL); + assert_return(!event_pid_changed(e), -ECHILD); + + if (!TRIPLE_TIMESTAMP_HAS_CLOCK(clock)) + return -EOPNOTSUPP; + + /* Generate a clean error in case CLOCK_BOOTTIME is not available. Note that don't use clock_supported() here, + * for a reason: there are systems where CLOCK_BOOTTIME is supported, but CLOCK_BOOTTIME_ALARM is not, but for + * the purpose of getting the time this doesn't matter. */ + if (IN_SET(clock, CLOCK_BOOTTIME, CLOCK_BOOTTIME_ALARM) && !clock_boottime_supported()) + return -EOPNOTSUPP; + + if (!triple_timestamp_is_set(&e->timestamp)) { + /* Implicitly fall back to now() if we never ran + * before and thus have no cached time. */ + *usec = now(clock); + return 1; + } + + *usec = triple_timestamp_by_clock(&e->timestamp, clock); + return 0; +} + +_public_ int sd_event_default(sd_event **ret) { + sd_event *e = NULL; + int r; + + if (!ret) + return !!default_event; + + if (default_event) { + *ret = sd_event_ref(default_event); + return 0; + } + + r = sd_event_new(&e); + if (r < 0) + return r; + + e->default_event_ptr = &default_event; + e->tid = gettid(); + default_event = e; + + *ret = e; + return 1; +} + +_public_ int sd_event_get_tid(sd_event *e, pid_t *tid) { + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(tid, -EINVAL); + assert_return(!event_pid_changed(e), -ECHILD); + + if (e->tid != 0) { + *tid = e->tid; + return 0; + } + + return -ENXIO; +} + +_public_ int sd_event_set_watchdog(sd_event *e, int b) { + int r; + + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(!event_pid_changed(e), -ECHILD); + + if (e->watchdog == !!b) + return e->watchdog; + + if (b) { + struct epoll_event ev; + + r = sd_watchdog_enabled(false, &e->watchdog_period); + if (r <= 0) + return r; + + /* Issue first ping immediately */ + sd_notify(false, "WATCHDOG=1"); + e->watchdog_last = now(CLOCK_MONOTONIC); + + e->watchdog_fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC); + if (e->watchdog_fd < 0) + return -errno; + + r = arm_watchdog(e); + if (r < 0) + goto fail; + + ev = (struct epoll_event) { + .events = EPOLLIN, + .data.ptr = INT_TO_PTR(SOURCE_WATCHDOG), + }; + + r = epoll_ctl(e->epoll_fd, EPOLL_CTL_ADD, e->watchdog_fd, &ev); + if (r < 0) { + r = -errno; + goto fail; + } + + } else { + if (e->watchdog_fd >= 0) { + epoll_ctl(e->epoll_fd, EPOLL_CTL_DEL, e->watchdog_fd, NULL); + e->watchdog_fd = safe_close(e->watchdog_fd); + } + } + + e->watchdog = !!b; + return e->watchdog; + +fail: + e->watchdog_fd = safe_close(e->watchdog_fd); + return r; +} + +_public_ int sd_event_get_watchdog(sd_event *e) { + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(!event_pid_changed(e), -ECHILD); + + return e->watchdog; +} + +_public_ int sd_event_get_iteration(sd_event *e, uint64_t *ret) { + assert_return(e, -EINVAL); + assert_return(e = event_resolve(e), -ENOPKG); + assert_return(!event_pid_changed(e), -ECHILD); + + *ret = e->iteration; + return 0; +} + +_public_ int sd_event_source_set_destroy_callback(sd_event_source *s, sd_event_destroy_t callback) { + assert_return(s, -EINVAL); + + s->destroy_callback = callback; + return 0; +} + +_public_ int sd_event_source_get_destroy_callback(sd_event_source *s, sd_event_destroy_t *ret) { + assert_return(s, -EINVAL); + + if (ret) + *ret = s->destroy_callback; + + return !!s->destroy_callback; +} + +_public_ int sd_event_source_get_floating(sd_event_source *s) { + assert_return(s, -EINVAL); + + return s->floating; +} + +_public_ int sd_event_source_set_floating(sd_event_source *s, int b) { + assert_return(s, -EINVAL); + + if (s->floating == !!b) + return 0; + + if (!s->event) /* Already disconnected */ + return -ESTALE; + + s->floating = b; + + if (b) { + sd_event_source_ref(s); + sd_event_unref(s->event); + } else { + sd_event_ref(s->event); + sd_event_source_unref(s); + } + + return 1; +} |