X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Flibsystemd%2Fsd-event%2Fsd-event.c;h=fb436adc13a971a6bbfebb99caa8cb11f3cb8583;hp=32777e386b3f6b0d68f401d5a53b91eb7edb725e;hb=f4b2933ee7890e5d414ab266d8586f19027a2bd9;hpb=6d148a842ebb04a9a9bc2853e167a9d8eddf8cd8 diff --git a/src/libsystemd/sd-event/sd-event.c b/src/libsystemd/sd-event/sd-event.c index 32777e386..fb436adc1 100644 --- a/src/libsystemd/sd-event/sd-event.c +++ b/src/libsystemd/sd-event/sd-event.c @@ -66,6 +66,8 @@ struct sd_event_source { void *userdata; sd_event_handler_t prepare; + char *description; + EventSourceType type:5; int enabled:3; bool pending:1; @@ -588,6 +590,44 @@ static struct clock_data* event_get_clock_data(sd_event *e, EventSourceType t) { } } +static bool need_signal(sd_event *e, int signal) { + return (e->signal_sources && e->signal_sources[signal] && + e->signal_sources[signal]->enabled != SD_EVENT_OFF) + || + (signal == SIGCHLD && + e->n_enabled_child_sources > 0); +} + +static int event_update_signal_fd(sd_event *e) { + struct epoll_event ev = {}; + bool add_to_epoll; + int r; + + assert(e); + + add_to_epoll = e->signal_fd < 0; + + r = signalfd(e->signal_fd, &e->sigset, SFD_NONBLOCK|SFD_CLOEXEC); + if (r < 0) + return -errno; + + e->signal_fd = r; + + if (!add_to_epoll) + return 0; + + ev.events = EPOLLIN; + ev.data.ptr = INT_TO_PTR(SOURCE_SIGNAL); + + r = epoll_ctl(e->epoll_fd, EPOLL_CTL_ADD, e->signal_fd, &ev); + if (r < 0) { + e->signal_fd = safe_close(e->signal_fd); + return -errno; + } + + return 0; +} + static void source_disconnect(sd_event_source *s) { sd_event *event; @@ -624,11 +664,17 @@ static void source_disconnect(sd_event_source *s) { case SOURCE_SIGNAL: if (s->signal.sig > 0) { - if (s->signal.sig != SIGCHLD || s->event->n_enabled_child_sources == 0) - assert_se(sigdelset(&s->event->sigset, s->signal.sig) == 0); - if (s->event->signal_sources) s->event->signal_sources[s->signal.sig] = NULL; + + /* If the signal was on and now it is off... */ + if (s->enabled != SD_EVENT_OFF && !need_signal(s->event, s->signal.sig)) { + assert_se(sigdelset(&s->event->sigset, s->signal.sig) == 0); + + (void) event_update_signal_fd(s->event); + /* If disabling failed, we might get a spurious event, + * but otherwise nothing bad should happen. */ + } } break; @@ -638,10 +684,16 @@ static void source_disconnect(sd_event_source *s) { if (s->enabled != SD_EVENT_OFF) { assert(s->event->n_enabled_child_sources > 0); s->event->n_enabled_child_sources--; - } - if (!s->event->signal_sources || !s->event->signal_sources[SIGCHLD]) - assert_se(sigdelset(&s->event->sigset, SIGCHLD) == 0); + /* We know the signal was on, if it is off now... */ + if (!need_signal(s->event, SIGCHLD)) { + assert_se(sigdelset(&s->event->sigset, SIGCHLD) == 0); + + (void) event_update_signal_fd(s->event); + /* If disabling failed, we might get a spurious event, + * but otherwise nothing bad should happen. */ + } + } hashmap_remove(s->event->child_sources, INT_TO_PTR(s->child.pid)); } @@ -685,6 +737,7 @@ static void source_free(sd_event_source *s) { assert(s); source_disconnect(s); + free(s->description); free(s); } @@ -914,36 +967,6 @@ fail: return r; } -static int event_update_signal_fd(sd_event *e) { - struct epoll_event ev = {}; - bool add_to_epoll; - int r; - - assert(e); - - add_to_epoll = e->signal_fd < 0; - - r = signalfd(e->signal_fd, &e->sigset, SFD_NONBLOCK|SFD_CLOEXEC); - if (r < 0) - return -errno; - - e->signal_fd = r; - - if (!add_to_epoll) - return 0; - - ev.events = EPOLLIN; - ev.data.ptr = INT_TO_PTR(SOURCE_SIGNAL); - - r = epoll_ctl(e->epoll_fd, EPOLL_CTL_ADD, e->signal_fd, &ev); - if (r < 0) { - e->signal_fd = safe_close(e->signal_fd); - return -errno; - } - - return 0; -} - static int signal_exit_callback(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) { assert(s); @@ -960,6 +983,7 @@ _public_ int sd_event_add_signal( sd_event_source *s; sigset_t ss; int r; + bool previous; assert_return(e, -EINVAL); assert_return(sig > 0, -EINVAL); @@ -984,6 +1008,8 @@ _public_ int sd_event_add_signal( } else if (e->signal_sources[sig]) return -EBUSY; + previous = need_signal(e, sig); + s = source_new(e, !ret, SOURCE_SIGNAL); if (!s) return -ENOMEM; @@ -994,9 +1020,10 @@ _public_ int sd_event_add_signal( s->enabled = SD_EVENT_ON; e->signal_sources[sig] = s; - assert_se(sigaddset(&e->sigset, sig) == 0); - if (sig != SIGCHLD || e->n_enabled_child_sources == 0) { + if (!previous) { + assert_se(sigaddset(&e->sigset, sig) == 0); + r = event_update_signal_fd(e); if (r < 0) { source_free(s); @@ -1004,6 +1031,9 @@ _public_ int sd_event_add_signal( } } + /* 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; @@ -1020,6 +1050,7 @@ _public_ int sd_event_add_child( sd_event_source *s; int r; + bool previous; assert_return(e, -EINVAL); assert_return(pid > 1, -EINVAL); @@ -1029,13 +1060,15 @@ _public_ int sd_event_add_child( assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); assert_return(!event_pid_changed(e), -ECHILD); - r = hashmap_ensure_allocated(&e->child_sources, trivial_hash_func, trivial_compare_func); + r = hashmap_ensure_allocated(&e->child_sources, NULL); if (r < 0) return r; if (hashmap_contains(e->child_sources, INT_TO_PTR(pid))) return -EBUSY; + previous = need_signal(e, SIGCHLD); + s = source_new(e, !ret, SOURCE_CHILD); if (!s) return -ENOMEM; @@ -1054,9 +1087,9 @@ _public_ int sd_event_add_child( e->n_enabled_child_sources ++; - assert_se(sigaddset(&e->sigset, SIGCHLD) == 0); + if (!previous) { + assert_se(sigaddset(&e->sigset, SIGCHLD) == 0); - if (!e->signal_sources || !e->signal_sources[SIGCHLD]) { r = event_update_signal_fd(e); if (r < 0) { source_free(s); @@ -1120,7 +1153,7 @@ _public_ int sd_event_add_post( assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); assert_return(!event_pid_changed(e), -ECHILD); - r = set_ensure_allocated(&e->post_sources, trivial_hash_func, trivial_compare_func); + r = set_ensure_allocated(&e->post_sources, NULL); if (r < 0) return r; @@ -1223,6 +1256,23 @@ _public_ sd_event_source* sd_event_source_unref(sd_event_source *s) { return NULL; } +_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(s->description, -ENXIO); + assert_return(!event_pid_changed(s->event), -ECHILD); + + *description = s->description; + return 0; +} + _public_ sd_event *sd_event_source_get_event(sd_event_source *s) { assert_return(s, NULL); @@ -1419,23 +1469,32 @@ _public_ int sd_event_source_set_enabled(sd_event_source *s, int m) { } case SOURCE_SIGNAL: + assert(need_signal(s->event, s->signal.sig)); + s->enabled = m; - if (s->signal.sig != SIGCHLD || s->event->n_enabled_child_sources == 0) { + + if (!need_signal(s->event, s->signal.sig)) { assert_se(sigdelset(&s->event->sigset, s->signal.sig) == 0); - event_update_signal_fd(s->event); + + (void) event_update_signal_fd(s->event); + /* If disabling failed, we might get a spurious event, + * but otherwise nothing bad should happen. */ } break; case SOURCE_CHILD: + assert(need_signal(s->event, SIGCHLD)); + s->enabled = m; assert(s->event->n_enabled_child_sources > 0); s->event->n_enabled_child_sources--; - if (!s->event->signal_sources || !s->event->signal_sources[SIGCHLD]) { + if (!need_signal(s->event, SIGCHLD)) { assert_se(sigdelset(&s->event->sigset, SIGCHLD) == 0); - event_update_signal_fd(s->event); + + (void) event_update_signal_fd(s->event); } break; @@ -1483,22 +1542,34 @@ _public_ int sd_event_source_set_enabled(sd_event_source *s, int m) { } case SOURCE_SIGNAL: - s->enabled = m; - - if (s->signal.sig != SIGCHLD || s->event->n_enabled_child_sources == 0) { + /* Check status before enabling. */ + if (!need_signal(s->event, s->signal.sig)) { assert_se(sigaddset(&s->event->sigset, s->signal.sig) == 0); - event_update_signal_fd(s->event); + + r = event_update_signal_fd(s->event); + if (r < 0) { + s->enabled = SD_EVENT_OFF; + return r; + } } + + s->enabled = m; break; case SOURCE_CHILD: + /* Check status before enabling. */ if (s->enabled == SD_EVENT_OFF) { - s->event->n_enabled_child_sources++; - - if (!s->event->signal_sources || !s->event->signal_sources[SIGCHLD]) { - assert_se(sigaddset(&s->event->sigset, SIGCHLD) == 0); - event_update_signal_fd(s->event); + if (!need_signal(s->event, SIGCHLD)) { + assert_se(sigaddset(&s->event->sigset, s->signal.sig) == 0); + + r = event_update_signal_fd(s->event); + if (r < 0) { + s->enabled = SD_EVENT_OFF; + return r; + } } + + s->event->n_enabled_child_sources++; } s->enabled = m; @@ -1955,20 +2026,22 @@ static int process_signal(sd_event *e, uint32_t events) { for (;;) { struct signalfd_siginfo si; - ssize_t ss; + ssize_t n; sd_event_source *s = NULL; - ss = read(e->signal_fd, &si, sizeof(si)); - if (ss < 0) { + n = read(e->signal_fd, &si, sizeof(si)); + if (n < 0) { if (errno == EAGAIN || errno == EINTR) return read_one; return -errno; } - if (_unlikely_(ss != sizeof(si))) + if (_unlikely_(n != sizeof(si))) return -EIO; + assert(si.ssi_signo < _NSIG); + read_one = true; if (si.ssi_signo == SIGCHLD) { @@ -2083,8 +2156,12 @@ static int source_dispatch(sd_event_source *s) { s->dispatching = false; - if (r < 0) - log_debug("Event source %p returned error, disabling: %s", s, strerror(-r)); + if (r < 0) { + if (s->description) + log_debug("Event source '%s' returned error, disabling: %s", s->description, strerror(-r)); + else + log_debug("Event source %p returned error, disabling: %s", s, strerror(-r)); + } if (s->n_ref == 0) source_free(s); @@ -2117,8 +2194,12 @@ static int event_prepare(sd_event *e) { r = s->prepare(s, s->userdata); s->dispatching = false; - if (r < 0) - log_debug("Prepare callback of event source %p returned error, disabling: %s", s, strerror(-r)); + if (r < 0) { + if (s->description) + log_debug("Prepare callback of event source '%s' returned error, disabling: %s", s->description, strerror(-r)); + else + log_debug("Prepare callback of event source %p returned error, disabling: %s", s, strerror(-r)); + } if (s->n_ref == 0) source_free(s);