When a child event is disabled (in order to be freed) and there is no
SIGCHLD signal event, sd_event_source_set_enabled will disable SIGCHLD
even if there are other child events.
Also remove some unneeded signalfd updates.
https://bugs.freedesktop.org/show_bug.cgi?id=84659
Based-on-a-patch-by: Hristo Venev mustrum...@gmail.com
---
I think this patch is correct, but since this is easy to get wrong,
I'm sending it to the list first.
src/libsystemd/sd-event/sd-event.c | 86 --
1 file changed, 63 insertions(+), 23 deletions(-)
diff --git a/src/libsystemd/sd-event/sd-event.c
b/src/libsystemd/sd-event/sd-event.c
index 4c67ee87e1..c5f062b3e0 100644
--- a/src/libsystemd/sd-event/sd-event.c
+++ b/src/libsystemd/sd-event/sd-event.c
@@ -590,6 +590,14 @@ 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 void source_disconnect(sd_event_source *s) {
sd_event *event;
@@ -626,11 +634,13 @@ 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);
+}
}
break;
@@ -640,10 +650,12 @@ 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);
+}
+}
hashmap_remove(s-event-child_sources,
INT_TO_PTR(s-child.pid));
}
@@ -963,6 +975,7 @@ _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);
@@ -987,6 +1000,8 @@ _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;
@@ -997,9 +1012,10 @@ _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);
@@ -1023,6 +1039,7 @@ _public_ int sd_event_add_child(
sd_event_source *s;
int r;
+bool previous;
assert_return(e, -EINVAL);
assert_return(pid 1, -EINVAL);
@@ -1039,6 +1056,8 @@ _public_ int sd_event_add_child(
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;
@@ -1057,9 +1076,9 @@ _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);
@@ -1437,23 +1456,32 @@ _public_ int
sd_event_source_set_enabled(sd_event_source *s, int m) {
}
case
