core: emit changes for NFailedUnits property

By notifying the clients when this property is changed it's possible to
allow "system health monitor" tools to get transitions like
running<->degraded. This is an alternative to send changes on the
SystemState property since the latter is more difficult to derive.

1 files changed, 17 insertions, 0 deletions

diff --git a/src/core/manager.c b/src/core/manager.c
index 79a9d54954..7966b387fc 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -3053,6 +3053,23 @@ const char *manager_get_runtime_prefix(Manager *m) {
                getenv("XDG_RUNTIME_DIR");
 }
 
+void manager_update_failed_units(Manager *m, Unit *u, bool failed) {
+        unsigned size;
+
+        assert(m);
+        assert(u->manager == m);
+
+        size = set_size(m->failed_units);
+
+        if (failed)
+                set_put(m->failed_units, u);
+        else
+                set_remove(m->failed_units, u);
+
+        if (set_size(m->failed_units) != size)
+                bus_manager_send_change_signal(m);
+}
+
 ManagerState manager_state(Manager *m) {
         Unit *u;