chiark / gitweb /
bus: support implicit serialization of strv string arrays within vtables
[elogind.git] / src / libsystemd-bus / bus-objects.c
index 1d32566c3a057b371fa564bf9c4651b7f9796428..92781e9adcc1ef2192c40c4657f9759b03632dd8 100644 (file)
@@ -27,6 +27,7 @@
 #include "bus-signature.h"
 #include "bus-introspect.h"
 #include "bus-objects.h"
+#include "bus-util.h"
 
 static int node_vtable_get_userdata(
                 sd_bus *bus,
@@ -77,6 +78,8 @@ static int vtable_property_get_userdata(
         r = node_vtable_get_userdata(bus, path, p->parent, &u);
         if (r <= 0)
                 return r;
+        if (bus->nodes_modified)
+                return 0;
 
         *userdata = vtable_property_convert_userdata(p->vtable, u);
         return 1;
@@ -98,6 +101,9 @@ static int add_enumerated_to_set(
         LIST_FOREACH(enumerators, c, first) {
                 char **children = NULL, **k;
 
+                if (bus->nodes_modified)
+                        return 0;
+
                 r = c->callback(bus, prefix, &children, c->userdata);
                 if (r < 0)
                         return r;
@@ -142,6 +148,8 @@ static int add_subtree_to_set(
         r = add_enumerated_to_set(bus, prefix, n->enumerators, s);
         if (r < 0)
                 return r;
+        if (bus->nodes_modified)
+                return 0;
 
         LIST_FOREACH(siblings, i, n->child) {
                 char *t;
@@ -157,6 +165,8 @@ static int add_subtree_to_set(
                 r = add_subtree_to_set(bus, prefix, i, s);
                 if (r < 0)
                         return r;
+                if (bus->nodes_modified)
+                        return 0;
         }
 
         return 0;
@@ -205,6 +215,9 @@ static int node_callbacks_run(
         assert(found_object);
 
         LIST_FOREACH(callbacks, c, first) {
+                if (bus->nodes_modified)
+                        return 0;
+
                 if (require_fallback && !c->is_fallback)
                         continue;
 
@@ -213,6 +226,8 @@ static int node_callbacks_run(
                 if (c->last_iteration == bus->iteration_counter)
                         continue;
 
+                c->last_iteration = bus->iteration_counter;
+
                 r = sd_bus_message_rewind(m, true);
                 if (r < 0)
                         return r;
@@ -247,20 +262,27 @@ static int method_callbacks_run(
         r = node_vtable_get_userdata(bus, m->path, c->parent, &u);
         if (r <= 0)
                 return r;
+        if (bus->nodes_modified)
+                return 0;
 
         *found_object = true;
 
+        if (c->last_iteration == bus->iteration_counter)
+                return 0;
+
+        c->last_iteration = bus->iteration_counter;
+
         r = sd_bus_message_rewind(m, true);
         if (r < 0)
                 return r;
 
-        r = sd_bus_message_get_signature(m, true, &signature);
-        if (r < 0)
-                return r;
+        signature = sd_bus_message_get_signature(m, true);
+        if (!signature)
+                return -EINVAL;
 
         if (!streq(strempty(c->vtable->x.method.signature), signature)) {
                 r = sd_bus_reply_method_errorf(bus, m,
-                                               "org.freedesktop.DBus.Error.InvalidArgs",
+                                               SD_BUS_ERROR_INVALID_ARGS,
                                                "Invalid arguments '%s' to call %s:%s, expecting '%s'.",
                                                signature, c->interface, c->member, strempty(c->vtable->x.method.signature));
                 if (r < 0)
@@ -290,8 +312,7 @@ static int invoke_property_get(
                 sd_bus_error *error,
                 void *userdata) {
 
-        int r;
-        void *p;
+        const void *p;
 
         assert(bus);
         assert(v);
@@ -305,15 +326,22 @@ static int invoke_property_get(
 
         /* Automatic handling if no callback is defined. */
 
+        if (streq(v->x.property.signature, "as"))
+                return sd_bus_message_append_strv(m, *(char***) userdata);
+
         assert(signature_is_single(v->x.property.signature, false));
         assert(bus_type_is_basic(v->x.property.signature[0]));
 
         switch (v->x.property.signature[0]) {
 
         case SD_BUS_TYPE_STRING:
-        case SD_BUS_TYPE_OBJECT_PATH:
         case SD_BUS_TYPE_SIGNATURE:
+                p = strempty(*(char**) userdata);
+                break;
+
+        case SD_BUS_TYPE_OBJECT_PATH:
                 p = *(char**) userdata;
+                assert(p);
                 break;
 
         default:
@@ -321,11 +349,7 @@ static int invoke_property_get(
                 break;
         }
 
-        r = sd_bus_message_append_basic(m, v->x.property.signature[0], p);
-        if (r < 0)
-                return r;
-
-        return 1;
+        return sd_bus_message_append_basic(m, v->x.property.signature[0], p);
 }
 
 static int invoke_property_set(
@@ -412,6 +436,8 @@ static int property_get_set_callbacks_run(
         r = vtable_property_get_userdata(bus, m->path, c, &u);
         if (r <= 0)
                 return r;
+        if (bus->nodes_modified)
+                return 0;
 
         *found_object = true;
 
@@ -419,9 +445,14 @@ static int property_get_set_callbacks_run(
         if (r < 0)
                 return r;
 
-        c->last_iteration = bus->iteration_counter;
-
         if (is_get) {
+                /* Note that we do not protect against reexecution
+                 * here (using the last_iteration check, see below),
+                 * should the node tree have changed and we got called
+                 * again. We assume that property Get() calls are
+                 * ultimately without side-effects or if they aren't
+                 * then at least idempotent. */
+
                 r = sd_bus_message_open_container(reply, 'v', c->vtable->x.property.signature);
                 if (r < 0)
                         return r;
@@ -438,14 +469,26 @@ static int property_get_set_callbacks_run(
                         return 1;
                 }
 
+                if (bus->nodes_modified)
+                        return 0;
+
                 r = sd_bus_message_close_container(reply);
                 if (r < 0)
                         return r;
 
         } else {
                 if (c->vtable->type != _SD_BUS_VTABLE_WRITABLE_PROPERTY)
-                        sd_bus_error_setf(&error, "org.freedesktop.DBus.Error.PropertyReadOnly", "Property '%s' is not writable.", c->member);
+                        sd_bus_error_setf(&error, SD_BUS_ERROR_PROPERTY_READ_ONLY, "Property '%s' is not writable.", c->member);
                 else  {
+                        /* Avoid that we call the set routine more
+                         * than once if the processing of this message
+                         * got restarted because the node tree
+                         * changed. */
+                        if (c->last_iteration == bus->iteration_counter)
+                                return 0;
+
+                        c->last_iteration = bus->iteration_counter;
+
                         r = sd_bus_message_enter_container(m, 'v', c->vtable->x.property.signature);
                         if (r < 0)
                                 return r;
@@ -463,6 +506,9 @@ static int property_get_set_callbacks_run(
                         return 1;
                 }
 
+                if (bus->nodes_modified)
+                        return 0;
+
                 r = sd_bus_message_exit_container(m);
                 if (r < 0)
                         return r;
@@ -510,9 +556,10 @@ static int vtable_append_all_properties(
                 r = invoke_property_get(bus, v, path, c->interface, v->x.property.member, reply, error, vtable_property_convert_userdata(v, userdata));
                 if (r < 0)
                         return r;
-
                 if (sd_bus_error_is_set(error))
                         return 0;
+                if (bus->nodes_modified)
+                        return 0;
 
                 r = sd_bus_message_close_container(reply);
                 if (r < 0)
@@ -536,7 +583,7 @@ static int property_get_all_callbacks_run(
 
         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
         struct node_vtable *c;
-        bool found_interface = false;
+        bool found_interface;
         int r;
 
         assert(bus);
@@ -551,6 +598,11 @@ static int property_get_all_callbacks_run(
         if (r < 0)
                 return r;
 
+        found_interface = !iface ||
+                streq(iface, "org.freedesktop.DBus.Properties") ||
+                streq(iface, "org.freedesktop.DBus.Peer") ||
+                streq(iface, "org.freedesktop.DBus.Introspectable");
+
         LIST_FOREACH(vtables, c, first) {
                 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
                 void *u;
@@ -561,6 +613,8 @@ static int property_get_all_callbacks_run(
                 r = node_vtable_get_userdata(bus, m->path, c, &u);
                 if (r < 0)
                         return r;
+                if (bus->nodes_modified)
+                        return 0;
                 if (r == 0)
                         continue;
 
@@ -570,8 +624,6 @@ static int property_get_all_callbacks_run(
                         continue;
                 found_interface = true;
 
-                c->last_iteration = bus->iteration_counter;
-
                 r = vtable_append_all_properties(bus, reply, m->path, c, u, &error);
                 if (r < 0)
                         return r;
@@ -583,12 +635,14 @@ static int property_get_all_callbacks_run(
 
                         return 1;
                 }
+                if (bus->nodes_modified)
+                        return 0;
         }
 
         if (!found_interface) {
                 r = sd_bus_reply_method_errorf(
                                 bus, m,
-                                "org.freedesktop.DBus.Error.UnknownInterface",
+                                SD_BUS_ERROR_UNKNOWN_INTERFACE,
                                 "Unknown interface '%s'.", iface);
                 if (r < 0)
                         return r;
@@ -650,6 +704,8 @@ static bool bus_node_exists(
 
                 if (node_vtable_get_userdata(bus, path, c, NULL) > 0)
                         return true;
+                if (bus->nodes_modified)
+                        return false;
         }
 
         return !require_fallback && (n->enumerators || n->object_manager);
@@ -677,6 +733,8 @@ static int process_introspect(
         r = get_child_nodes(bus, m->path, n, &s);
         if (r < 0)
                 return r;
+        if (bus->nodes_modified)
+                return 0;
 
         r = introspect_begin(&intro);
         if (r < 0)
@@ -695,6 +753,8 @@ static int process_introspect(
                 r = node_vtable_get_userdata(bus, m->path, c, NULL);
                 if (r < 0)
                         return r;
+                if (bus->nodes_modified)
+                        return 0;
                 if (r == 0)
                         continue;
 
@@ -711,7 +771,8 @@ static int process_introspect(
                 r = bus_node_exists(bus, n, m->path, require_fallback);
                 if (r < 0)
                         return r;
-
+                if (bus->nodes_modified)
+                        return 0;
                 if (r == 0)
                         goto finish;
         }
@@ -768,6 +829,8 @@ static int object_manager_serialize_vtable(
         r = vtable_append_all_properties(bus, reply, path, c, userdata, error);
         if (r < 0)
                 return r;
+        if (bus->nodes_modified)
+                return 0;
 
         r = sd_bus_message_close_container(reply);
         if (r < 0)
@@ -812,6 +875,8 @@ static int object_manager_serialize_path(
                 r = node_vtable_get_userdata(bus, path, i, &u);
                 if (r < 0)
                         return r;
+                if (bus->nodes_modified)
+                        return 0;
                 if (r == 0)
                         continue;
 
@@ -836,6 +901,8 @@ static int object_manager_serialize_path(
                         return r;
                 if (sd_bus_error_is_set(error))
                         return 0;
+                if (bus->nodes_modified)
+                        return 0;
         }
 
         if (found_something) {
@@ -871,6 +938,8 @@ static int object_manager_serialize_path_and_fallbacks(
                 return r;
         if (sd_bus_error_is_set(error))
                 return 0;
+        if (bus->nodes_modified)
+                return 0;
 
         /* Second, add fallback vtables registered for any of the prefixes */
         prefix = alloca(strlen(path) + 1);
@@ -878,9 +947,10 @@ static int object_manager_serialize_path_and_fallbacks(
                 r = object_manager_serialize_path(bus, reply, prefix, path, true, error);
                 if (r < 0)
                         return r;
-
                 if (sd_bus_error_is_set(error))
                         return 0;
+                if (bus->nodes_modified)
+                        return 0;
         }
 
         return 0;
@@ -909,6 +979,8 @@ static int process_get_managed_objects(
         r = get_child_nodes(bus, m->path, n, &s);
         if (r < 0)
                 return r;
+        if (bus->nodes_modified)
+                return 0;
 
         r = sd_bus_message_new_method_return(bus, m, &reply);
         if (r < 0)
@@ -960,6 +1032,9 @@ static int process_get_managed_objects(
 
                                 return 1;
                         }
+
+                        if (bus->nodes_modified)
+                                return 0;
                 }
         }
 
@@ -998,6 +1073,8 @@ static int object_find_and_run(
         r = node_callbacks_run(bus, m, n->callbacks, require_fallback, found_object);
         if (r != 0)
                 return r;
+        if (bus->nodes_modified)
+                return 0;
 
         if (!m->interface || !m->member)
                 return 0;
@@ -1012,6 +1089,8 @@ static int object_find_and_run(
                 r = method_callbacks_run(bus, m, v, require_fallback, found_object);
                 if (r != 0)
                         return r;
+                if (bus->nodes_modified)
+                        return 0;
         }
 
         /* Then, look for a known property */
@@ -1071,11 +1150,13 @@ static int object_find_and_run(
                         return r;
         }
 
+        if (bus->nodes_modified)
+                return 0;
+
         if (!*found_object) {
                 r = bus_node_exists(bus, n, m->path, require_fallback);
                 if (r < 0)
                         return r;
-
                 if (r > 0)
                         *found_object = true;
         }
@@ -1091,7 +1172,7 @@ int bus_process_object(sd_bus *bus, sd_bus_message *m) {
         assert(bus);
         assert(m);
 
-        if (m->header->type != SD_BUS_MESSAGE_TYPE_METHOD_CALL)
+        if (m->header->type != SD_BUS_MESSAGE_METHOD_CALL)
                 return 0;
 
         if (!m->path)
@@ -1130,12 +1211,12 @@ int bus_process_object(sd_bus *bus, sd_bus_message *m) {
             sd_bus_message_is_method_call(m, "org.freedesktop.DBus.Properties", "Set"))
                 r = sd_bus_reply_method_errorf(
                                 bus, m,
-                                "org.freedesktop.DBus.Error.UnknownProperty",
+                                SD_BUS_ERROR_UNKNOWN_PROPERTY,
                                 "Unknown property or interface.");
         else
                 r = sd_bus_reply_method_errorf(
                                 bus, m,
-                                "org.freedesktop.DBus.Error.UnknownMethod",
+                                SD_BUS_ERROR_UNKNOWN_METHOD,
                                 "Unknown method '%s' or interface '%s'.", m->member, m->interface);
 
         if (r < 0)
@@ -1196,7 +1277,7 @@ static struct node *bus_node_allocate(sd_bus *bus, const char *path) {
         }
 
         if (parent)
-                LIST_PREPEND(struct node, siblings, parent->child, n);
+                LIST_PREPEND(siblings, parent->child, n);
 
         return n;
 }
@@ -1217,7 +1298,7 @@ static void bus_node_gc(sd_bus *b, struct node *n) {
         assert(hashmap_remove(b->nodes, n->path) == n);
 
         if (n->parent)
-                LIST_REMOVE(struct node, siblings, n->parent->child, n);
+                LIST_REMOVE(siblings, n->parent->child, n);
 
         free(n->path);
         bus_node_gc(b, n->parent);
@@ -1255,7 +1336,9 @@ static int bus_add_object(
         c->userdata = userdata;
         c->is_fallback = fallback;
 
-        LIST_PREPEND(struct node_callback, callbacks, n->callbacks, c);
+        LIST_PREPEND(callbacks, n->callbacks, c);
+        bus->nodes_modified = true;
+
         return 0;
 
 fail:
@@ -1289,10 +1372,11 @@ static int bus_remove_object(
         if (!c)
                 return 0;
 
-        LIST_REMOVE(struct node_callback, callbacks, n->callbacks, c);
+        LIST_REMOVE(callbacks, n->callbacks, c);
         free(c);
 
         bus_node_gc(bus, n);
+        bus->nodes_modified = true;
 
         return 1;
 }
@@ -1501,7 +1585,7 @@ static int add_object_vtable_internal(
 
                         if (!member_name_is_valid(v->x.property.member) ||
                             !signature_is_single(v->x.property.signature, false) ||
-                            !(v->x.property.get || bus_type_is_basic(v->x.property.signature[0])) ||
+                            !(v->x.property.get || bus_type_is_basic(v->x.property.signature[0]) || streq(v->x.property.signature, "as")) ||
                             v->flags & SD_BUS_VTABLE_METHOD_NO_REPLY ||
                             (v->flags & SD_BUS_VTABLE_PROPERTY_INVALIDATE_ONLY && !(v->flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE))) {
                                 r = -EINVAL;
@@ -1533,7 +1617,7 @@ static int add_object_vtable_internal(
                 case _SD_BUS_VTABLE_SIGNAL:
 
                         if (!member_name_is_valid(v->x.signal.member) ||
-                            !signature_is_single(strempty(v->x.signal.signature), false)) {
+                            !signature_is_valid(strempty(v->x.signal.signature), false)) {
                                 r = -EINVAL;
                                 goto fail;
                         }
@@ -1546,7 +1630,9 @@ static int add_object_vtable_internal(
                 }
         }
 
-        LIST_PREPEND(struct node_vtable, vtables, n->vtables, c);
+        LIST_PREPEND(vtables, n->vtables, c);
+        bus->nodes_modified = true;
+
         return 0;
 
 fail:
@@ -1582,11 +1668,13 @@ static int remove_object_vtable_internal(
         if (!c)
                 return 0;
 
-        LIST_REMOVE(struct node_vtable, vtables, n->vtables, c);
+        LIST_REMOVE(vtables, n->vtables, c);
 
         free_node_vtable(bus, c);
         bus_node_gc(bus, n);
 
+        bus->nodes_modified = true;
+
         return 1;
 }
 
@@ -1656,7 +1744,10 @@ int sd_bus_add_node_enumerator(
         c->callback = callback;
         c->userdata = userdata;
 
-        LIST_PREPEND(struct node_enumerator, enumerators, n->enumerators, c);
+        LIST_PREPEND(enumerators, n->enumerators, c);
+
+        bus->nodes_modified = true;
+
         return 0;
 
 fail:
@@ -1690,11 +1781,13 @@ int sd_bus_remove_node_enumerator(
         if (!c)
                 return 0;
 
-        LIST_REMOVE(struct node_enumerator, enumerators, n->enumerators, c);
+        LIST_REMOVE(enumerators, n->enumerators, c);
         free(c);
 
         bus_node_gc(bus, n);
 
+        bus->nodes_modified = true;
+
         return 1;
 }
 
@@ -1738,6 +1831,8 @@ static int emit_properties_changed_on_interface(
         r = node_vtable_get_userdata(bus, path, c, &u);
         if (r <= 0)
                 return r;
+        if (bus->nodes_modified)
+                return 0;
 
         r = sd_bus_message_new_signal(bus, path, "org.freedesktop.DBus.Properties", "PropertiesChanged", &m);
         if (r < 0)
@@ -1788,9 +1883,8 @@ static int emit_properties_changed_on_interface(
                 r = invoke_property_get(bus, v->vtable, m->path, interface, *property, m, &error, vtable_property_convert_userdata(v->vtable, u));
                 if (r < 0)
                         return r;
-
-                if (sd_bus_error_is_set(&error))
-                        return bus_error_to_errno(&error);
+                if (bus->nodes_modified)
+                        return 0;
 
                 r = sd_bus_message_close_container(m);
                 if (r < 0)
@@ -1843,6 +1937,7 @@ int sd_bus_emit_properties_changed_strv(
                 const char *interface,
                 char **names) {
 
+        BUS_DONT_DESTROY(bus);
         char *prefix;
         int r;
 
@@ -1855,16 +1950,25 @@ int sd_bus_emit_properties_changed_strv(
         if (strv_isempty(names))
                 return 0;
 
-        r = emit_properties_changed_on_interface(bus, path, path, interface, false, names);
-        if (r != 0)
-                return r;
+        do {
+                bus->nodes_modified = false;
 
-        prefix = alloca(strlen(path) + 1);
-        OBJECT_PATH_FOREACH_PREFIX(prefix, path) {
-                r = emit_properties_changed_on_interface(bus, prefix, path, interface, true, names);
+                r = emit_properties_changed_on_interface(bus, path, path, interface, false, names);
                 if (r != 0)
                         return r;
-        }
+                if (bus->nodes_modified)
+                        continue;
+
+                prefix = alloca(strlen(path) + 1);
+                OBJECT_PATH_FOREACH_PREFIX(prefix, path) {
+                        r = emit_properties_changed_on_interface(bus, prefix, path, interface, true, names);
+                        if (r != 0)
+                                return r;
+                        if (bus->nodes_modified)
+                                break;
+                }
+
+        } while (bus->nodes_modified);
 
         return -ENOENT;
 }
@@ -1875,8 +1979,7 @@ int sd_bus_emit_properties_changed(
                 const char *interface,
                 const char *name, ...)  {
 
-        _cleanup_strv_free_ char **names = NULL;
-        va_list ap;
+        char **names;
 
         assert_return(bus, -EINVAL);
         assert_return(object_path_is_valid(path), -EINVAL);
@@ -1887,12 +1990,7 @@ int sd_bus_emit_properties_changed(
         if (!name)
                 return 0;
 
-        va_start(ap, name);
-        names = strv_new_ap(name, ap);
-        va_end(ap);
-
-        if (!names)
-                return -ENOMEM;
+        names = strv_from_stdarg_alloca(name);
 
         return sd_bus_emit_properties_changed_strv(bus, path, interface, names);
 }
@@ -1935,6 +2033,8 @@ static int interfaces_added_append_one_prefix(
         r = node_vtable_get_userdata(bus, path, c, &u);
         if (r <= 0)
                 return r;
+        if (bus->nodes_modified)
+                return 0;
 
         r = sd_bus_message_append_basic(m, 's', interface);
         if (r < 0)
@@ -1947,9 +2047,8 @@ static int interfaces_added_append_one_prefix(
         r = vtable_append_all_properties(bus, m,path, c, u, &error);
         if (r < 0)
                 return r;
-
-        if (sd_bus_error_is_set(&error))
-                return bus_error_to_errno(&error);
+        if (bus->nodes_modified)
+                return 0;
 
         r = sd_bus_message_close_container(m);
         if (r < 0)
@@ -1975,18 +2074,24 @@ static int interfaces_added_append_one(
         r = interfaces_added_append_one_prefix(bus, m, path, path, interface, false);
         if (r != 0)
                 return r;
+        if (bus->nodes_modified)
+                return 0;
 
         prefix = alloca(strlen(path) + 1);
         OBJECT_PATH_FOREACH_PREFIX(prefix, path) {
                 r = interfaces_added_append_one_prefix(bus, m, prefix, path, interface, true);
                 if (r != 0)
                         return r;
+                if (bus->nodes_modified)
+                        return 0;
         }
 
         return -ENOENT;
 }
 
 int sd_bus_emit_interfaces_added_strv(sd_bus *bus, const char *path, char **interfaces) {
+        BUS_DONT_DESTROY(bus);
+
         _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
         char **i;
         int r;
@@ -1999,56 +2104,64 @@ int sd_bus_emit_interfaces_added_strv(sd_bus *bus, const char *path, char **inte
         if (strv_isempty(interfaces))
                 return 0;
 
-        r = sd_bus_message_new_signal(bus, path, "org.freedesktop.DBus.ObjectManager", "InterfacesAdded", &m);
-        if (r < 0)
-                return r;
-
-        r = sd_bus_message_append_basic(m, 'o', path);
-        if (r < 0)
-                return r;
+        do {
+                bus->nodes_modified = false;
 
-        r = sd_bus_message_open_container(m, 'a', "{sa{sv}}");
-        if (r < 0)
-                return r;
+                if (m)
+                        m = sd_bus_message_unref(m);
 
-        STRV_FOREACH(i, interfaces) {
-                assert_return(interface_name_is_valid(*i), -EINVAL);
+                r = sd_bus_message_new_signal(bus, path, "org.freedesktop.DBus.ObjectManager", "InterfacesAdded", &m);
+                if (r < 0)
+                        return r;
 
-                r = sd_bus_message_open_container(m, 'e', "sa{sv}");
+                r = sd_bus_message_append_basic(m, 'o', path);
                 if (r < 0)
                         return r;
 
-                r = interfaces_added_append_one(bus, m, path, *i);
+                r = sd_bus_message_open_container(m, 'a', "{sa{sv}}");
                 if (r < 0)
                         return r;
 
+                STRV_FOREACH(i, interfaces) {
+                        assert_return(interface_name_is_valid(*i), -EINVAL);
+
+                        r = sd_bus_message_open_container(m, 'e', "sa{sv}");
+                        if (r < 0)
+                                return r;
+
+                        r = interfaces_added_append_one(bus, m, path, *i);
+                        if (r < 0)
+                                return r;
+
+                        if (bus->nodes_modified)
+                                break;
+
+                        r = sd_bus_message_close_container(m);
+                        if (r < 0)
+                                return r;
+                }
+
+                if (bus->nodes_modified)
+                        continue;
+
                 r = sd_bus_message_close_container(m);
                 if (r < 0)
                         return r;
-        }
 
-        r = sd_bus_message_close_container(m);
-        if (r < 0)
-                return r;
+        } while (bus->nodes_modified);
 
         return sd_bus_send(bus, m, NULL);
 }
 
 int sd_bus_emit_interfaces_added(sd_bus *bus, const char *path, const char *interface, ...) {
-        _cleanup_strv_free_ char **interfaces = NULL;
-        va_list ap;
+        char **interfaces;
 
         assert_return(bus, -EINVAL);
         assert_return(object_path_is_valid(path), -EINVAL);
         assert_return(BUS_IS_OPEN(bus->state), -ENOTCONN);
         assert_return(!bus_pid_changed(bus), -ECHILD);
 
-        va_start(ap, interface);
-        interfaces = strv_new_ap(interface, ap);
-        va_end(ap);
-
-        if (!interfaces)
-                return -ENOMEM;
+        interfaces = strv_from_stdarg_alloca(interface);
 
         return sd_bus_emit_interfaces_added_strv(bus, path, interfaces);
 }
@@ -2081,20 +2194,14 @@ int sd_bus_emit_interfaces_removed_strv(sd_bus *bus, const char *path, char **in
 }
 
 int sd_bus_emit_interfaces_removed(sd_bus *bus, const char *path, const char *interface, ...) {
-        _cleanup_strv_free_ char **interfaces = NULL;
-        va_list ap;
+        char **interfaces;
 
         assert_return(bus, -EINVAL);
         assert_return(object_path_is_valid(path), -EINVAL);
         assert_return(BUS_IS_OPEN(bus->state), -ENOTCONN);
         assert_return(!bus_pid_changed(bus), -ECHILD);
 
-        va_start(ap, interface);
-        interfaces = strv_new_ap(interface, ap);
-        va_end(ap);
-
-        if (!interfaces)
-                return -ENOMEM;
+        interfaces = strv_from_stdarg_alloca(interface);
 
         return sd_bus_emit_interfaces_removed_strv(bus, path, interfaces);
 }
@@ -2111,6 +2218,7 @@ int sd_bus_add_object_manager(sd_bus *bus, const char *path) {
                 return -ENOMEM;
 
         n->object_manager = true;
+        bus->nodes_modified = true;
         return 0;
 }
 
@@ -2129,6 +2237,7 @@ int sd_bus_remove_object_manager(sd_bus *bus, const char *path) {
                 return 0;
 
         n->object_manager = false;
+        bus->nodes_modified = true;
         bus_node_gc(bus, n);
 
         return 1;