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event: refuse operation if the caller tries to reuse an event loop after a fork()

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This commit is contained in:
Lennart Poettering
2013-10-10 21:37:50 +02:00
parent c2ba3ad660
commit eaa3cbef3b
2 changed files with 106 additions and 46 deletions
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src/libsystemd-bus/sd-event.c
+105 -45
View File
@@ -124,11 +124,12 @@ struct sd_event {
unsigned iteration;
usec_t realtime_next, monotonic_next;
usec_t perturb;
bool quit;
bool need_process_child;
bool quit:1;
bool need_process_child:1;
pid_t original_pid;
};
static int pending_prioq_compare(const void *a, const void *b) {
@@ -307,6 +308,7 @@ int sd_event_new(sd_event** ret) {
e->n_ref = REFCNT_INIT;
e->signal_fd = e->realtime_fd = e->monotonic_fd = e->epoll_fd = -1;
e->realtime_next = e->monotonic_next = (usec_t) -1;
e->original_pid = getpid();
assert_se(sigemptyset(&e->sigset) == 0);
@@ -349,6 +351,15 @@ sd_event* sd_event_unref(sd_event *e) {
return NULL;
}
static bool event_pid_changed(sd_event *e) {
assert(e);
/* We don't support people creating am event loop and keeping
* it around over a fork(). Let's complain. */
return e->original_pid != getpid();
}
static int source_io_unregister(sd_event_source *s) {
int r;
@@ -517,6 +528,8 @@ int sd_event_add_io(
return -EINVAL;
if (!ret)
return -EINVAL;
if (event_pid_changed(e))
return -ECHILD;
s = source_new(e, SOURCE_IO);
if (!s)
@@ -607,6 +620,8 @@ static int event_add_time_internal(
return -EINVAL;
if (accuracy == (uint64_t) -1)
return -EINVAL;
if (event_pid_changed(e))
return -ECHILD;
assert(timer_fd);
assert(earliest);
@@ -711,6 +726,8 @@ int sd_event_add_signal(sd_event *e, int sig, sd_signal_handler_t callback, void
return -EINVAL;
if (!ret)
return -EINVAL;
if (event_pid_changed(e))
return -ECHILD;
if (!e->signal_sources) {
e->signal_sources = new0(sd_event_source*, _NSIG);
@@ -756,6 +773,8 @@ int sd_event_add_child(sd_event *e, pid_t pid, int options, sd_child_handler_t c
return -EINVAL;
if (!ret)
return -EINVAL;
if (event_pid_changed(e))
return -ECHILD;
r = hashmap_ensure_allocated(&e->child_sources, trivial_hash_func, trivial_compare_func);
if (r < 0)
@@ -805,6 +824,8 @@ int sd_event_add_defer(sd_event *e, sd_defer_handler_t callback, void *userdata,
return -EINVAL;
if (!ret)
return -EINVAL;
if (event_pid_changed(e))
return -ECHILD;
s = source_new(e, SOURCE_DEFER);
if (!s)
@@ -842,9 +863,19 @@ sd_event_source* sd_event_source_unref(sd_event_source *s) {
return NULL;
}
sd_event *sd_event_get(sd_event_source *s) {
if (!s)
return NULL;
return s->event;
}
int sd_event_source_get_pending(sd_event_source *s) {
if (!s)
return -EINVAL;
if (event_pid_changed(s->event))
return -ECHILD;
return s->pending;
}
@@ -854,6 +885,8 @@ int sd_event_source_get_io_fd(sd_event_source *s) {
return -EINVAL;
if (s->type != SOURCE_IO)
return -EDOM;
if (event_pid_changed(s->event))
return -ECHILD;
return s->io.fd;
}
@@ -865,6 +898,8 @@ int sd_event_source_get_io_events(sd_event_source *s, uint32_t* events) {
return -EDOM;
if (!events)
return -EINVAL;
if (event_pid_changed(s->event))
return -ECHILD;
*events = s->io.events;
return 0;
@@ -879,6 +914,8 @@ int sd_event_source_set_io_events(sd_event_source *s, uint32_t events) {
return -EDOM;
if (events & ~(EPOLLIN|EPOLLOUT|EPOLLRDHUP|EPOLLPRI|EPOLLERR|EPOLLHUP))
return -EINVAL;
if (event_pid_changed(s->event))
return -ECHILD;
if (s->io.events == events)
return 0;
@@ -903,6 +940,8 @@ int sd_event_source_get_io_revents(sd_event_source *s, uint32_t* revents) {
return -EINVAL;
if (!s->pending)
return -ENODATA;
if (event_pid_changed(s->event))
return -ECHILD;
*revents = s->io.revents;
return 0;
@@ -913,6 +952,8 @@ int sd_event_source_get_signal(sd_event_source *s) {
return -EINVAL;
if (s->type != SOURCE_SIGNAL)
return -EDOM;
if (event_pid_changed(s->event))
return -ECHILD;
return s->signal.sig;
}
@@ -920,6 +961,8 @@ int sd_event_source_get_signal(sd_event_source *s) {
int sd_event_source_get_priority(sd_event_source *s, int *priority) {
if (!s)
return -EINVAL;
if (event_pid_changed(s->event))
return -ECHILD;
return s->priority;
}
@@ -927,6 +970,8 @@ int sd_event_source_get_priority(sd_event_source *s, int *priority) {
int sd_event_source_set_priority(sd_event_source *s, int priority) {
if (!s)
return -EINVAL;
if (event_pid_changed(s->event))
return -ECHILD;
if (s->priority == priority)
return 0;
@@ -947,6 +992,8 @@ int sd_event_source_get_mute(sd_event_source *s, sd_event_mute_t *m) {
return -EINVAL;
if (!m)
return -EINVAL;
if (event_pid_changed(s->event))
return -ECHILD;
*m = s->mute;
return 0;
@@ -959,6 +1006,8 @@ int sd_event_source_set_mute(sd_event_source *s, sd_event_mute_t m) {
return -EINVAL;
if (m != SD_EVENT_MUTED && m != SD_EVENT_UNMUTED && !SD_EVENT_ONESHOT)
return -EINVAL;
if (event_pid_changed(s->event))
return -ECHILD;
if (s->mute == m)
return 0;
@@ -1081,6 +1130,8 @@ int sd_event_source_get_time(sd_event_source *s, uint64_t *usec) {
return -EINVAL;
if (s->type != SOURCE_REALTIME && s->type != SOURCE_MONOTONIC)
return -EDOM;
if (event_pid_changed(s->event))
return -ECHILD;
*usec = s->time.next;
return 0;
@@ -1093,6 +1144,8 @@ int sd_event_source_set_time(sd_event_source *s, uint64_t usec) {
return -EINVAL;
if (s->type != SOURCE_REALTIME && s->type != SOURCE_MONOTONIC)
return -EDOM;
if (event_pid_changed(s->event))
return -ECHILD;
if (s->time.next == usec)
return 0;
@@ -1110,11 +1163,52 @@ int sd_event_source_set_time(sd_event_source *s, uint64_t usec) {
return 0;
}
int sd_event_source_set_time_accuracy(sd_event_source *s, uint64_t usec) {
if (!s)
return -EINVAL;
if (s->type != SOURCE_MONOTONIC && s->type != SOURCE_REALTIME)
return -EDOM;
if (event_pid_changed(s->event))
return -ECHILD;
if (usec == 0)
usec = DEFAULT_ACCURACY_USEC;
if (s->time.accuracy == usec)
return 0;
s->time.accuracy = usec;
if (s->type == SOURCE_REALTIME)
prioq_reshuffle(s->event->realtime_latest, s, &s->time.latest_index);
else
prioq_reshuffle(s->event->monotonic_latest, s, &s->time.latest_index);
return 0;
}
int sd_event_source_get_time_accuracy(sd_event_source *s, uint64_t *usec) {
if (!s)
return -EINVAL;
if (!usec)
return -EINVAL;
if (s->type != SOURCE_MONOTONIC && s->type != SOURCE_REALTIME)
return -EDOM;
if (event_pid_changed(s->event))
return -ECHILD;
*usec = s->time.accuracy;
return 0;
}
int sd_event_source_set_prepare(sd_event_source *s, sd_prepare_handler_t callback) {
int r;
if (!s)
return -EINVAL;
if (event_pid_changed(s->event))
return -ECHILD;
if (s->prepare == callback)
return 0;
@@ -1500,6 +1594,8 @@ int sd_event_run(sd_event *e, uint64_t timeout) {
return -EINVAL;
if (e->quit)
return -ESTALE;
if (event_pid_changed(e))
return -ECHILD;
e->iteration++;
@@ -1568,6 +1664,8 @@ int sd_event_loop(sd_event *e) {
if (!e)
return -EINVAL;
if (event_pid_changed(e))
return -ECHILD;
while (!e->quit) {
r = sd_event_run(e, (uint64_t) -1);
@@ -1581,6 +1679,8 @@ int sd_event_loop(sd_event *e) {
int sd_event_quit(sd_event *e) {
if (!e)
return EINVAL;
if (event_pid_changed(e))
return -ECHILD;
return e->quit;
}
@@ -1588,49 +1688,9 @@ int sd_event_quit(sd_event *e) {
int sd_event_request_quit(sd_event *e) {
if (!e)
return -EINVAL;
if (event_pid_changed(e))
return -ECHILD;
e->quit = true;
return 0;
}
sd_event *sd_event_get(sd_event_source *s) {
if (!s)
return NULL;
return s->event;
}
int sd_event_source_set_time_accuracy(sd_event_source *s, uint64_t usec) {
if (!s)
return -EINVAL;
if (s->type != SOURCE_MONOTONIC && s->type != SOURCE_REALTIME)
return -EDOM;
if (usec == 0)
usec = DEFAULT_ACCURACY_USEC;
if (s->time.accuracy == usec)
return 0;
s->time.accuracy = usec;
if (s->type == SOURCE_REALTIME)
prioq_reshuffle(s->event->realtime_latest, s, &s->time.latest_index);
else
prioq_reshuffle(s->event->monotonic_latest, s, &s->time.latest_index);
return 0;
}
int sd_event_source_get_time_accuracy(sd_event_source *s, uint64_t *usec) {
if (!s)
return -EINVAL;
if (!usec)
return -EINVAL;
if (s->type != SOURCE_MONOTONIC && s->type != SOURCE_REALTIME)
return -EDOM;
*usec = s->time.accuracy;
return 0;
}
src/systemd/sd-event.h
+1 -1
View File
@@ -33,11 +33,11 @@
- Supports event source priorisation
- Scales better with a large number of time events, since it doesn't require one timerfd each
- Automatically tries to coalesce timer events system-wide
- Handles signals and child PIDs
TODO:
- Detect forks and return ECHILD
- quit hooks
*/