Fix bridge/channel AMI event ordering issues

The stasis_cache_update messages are somewhat cumbersome to handle
with the stasis_message_router. Since all updates have the same
message type, they are normally handled with the same route.

Since caching itself is a first class component of stasis-core, it
makes sense for the router to handle the cache update messages itself.
This patch adds stasis_message_router_add_cache_update() and
stasis_message_router_remove_cache_update() to handle the routing of
stasis_cache_update messages.

This patch also corrects an issue with manager_{bridging,channels}.c,
where events might be reordered. The reordering occurs because the
components use different message routers, which they needed because
they both needed to route cache update messages. They now both use
manager's router, and add cache routes for just the cache updates they
are interested in.

(closes issue ASTERISK-22038)
Review: https://reviewboard.asterisk.org/r/2677/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@395118 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/stasis_message_router.h

@@ -95,6 +95,11 @@ int stasis_message_router_is_done(struct stasis_message_router *router);
 /*!
  * \brief Add a route to a message router.
  *
+ * A particular \a message_type may have at most one route per \a router. If
+ * you route \ref stasis_cache_update messages, the callback will only receive
+ * updates for types not handled by routes added with
+ * stasis_message_router_add_cache_update().
+ *
  * \param router Router to add the route to.
  * \param message_type Type of message to route.
  * \param callback Callback to forard messages of \a message_type to.
@@ -106,9 +111,29 @@ int stasis_message_router_is_done(struct stasis_message_router *router);
  * \since 12
  */
 int stasis_message_router_add(struct stasis_message_router *router,
-			      struct stasis_message_type *message_type,
-			      stasis_subscription_cb callback,
-			      void *data);
+	struct stasis_message_type *message_type,
+	stasis_subscription_cb callback, void *data);
+
+/*!
+ * \brief Add a route for \ref stasis_cache_update messages to a message router.
+ *
+ * A particular \a message_type may have at most one cache route per \a router.
+ * These are distinct from regular routes, so one could have both a regular
+ * route and a cache route for the same \a message_type.
+ *
+ * \param router Router to add the route to.
+ * \param message_type Subtype of cache update to route.
+ * \param callback Callback to forard messages of \a message_type to.
+ * \param data Data pointer to pass to \a callback.
+ *
+ * \retval 0 on success
+ * \retval -1 on failure
+ *
+ * \since 12
+ */
+int stasis_message_router_add_cache_update(struct stasis_message_router *router,
+	struct stasis_message_type *message_type,
+	stasis_subscription_cb callback, void *data);
 
 /*!
  * \brief Remove a route from a message router.
@@ -119,7 +144,19 @@ int stasis_message_router_add(struct stasis_message_router *router,
  * \since 12
  */
 void stasis_message_router_remove(struct stasis_message_router *router,
-			      struct stasis_message_type *message_type);
+	struct stasis_message_type *message_type);
+
+/*!
+ * \brief Remove a cache route from a message router.
+ *
+ * \param router Router to remove the route from.
+ * \param message_type Type of message to route.
+ *
+ * \since 12
+ */
+void stasis_message_router_remove_cache_update(
+	struct stasis_message_router *router,
+	struct stasis_message_type *message_type);
 
 /*!
  * \brief Sets the default route of a router.

main/cdr.c

@@ -1967,9 +1967,7 @@ static void handle_channel_cache_message(void *data, struct stasis_subscription
 	struct cdr_object *it_cdr;
 
 	ast_assert(update != NULL);
-	if (ast_channel_snapshot_type() != update->type) {
-		return;
-	}
+	ast_assert(ast_channel_snapshot_type() == update->type);
 
 	old_snapshot = stasis_message_data(update->old_snapshot);
 	new_snapshot = stasis_message_data(update->new_snapshot);
@@ -4024,7 +4022,7 @@ int ast_cdr_engine_init(void)
 	if (!stasis_router) {
 		return -1;
 	}
-	stasis_message_router_add(stasis_router, stasis_cache_update_type(), handle_channel_cache_message, NULL);
+	stasis_message_router_add_cache_update(stasis_router, ast_channel_snapshot_type(), handle_channel_cache_message, NULL);
 	stasis_message_router_add(stasis_router, ast_channel_dial_type(), handle_dial_message, NULL);
 	stasis_message_router_add(stasis_router, ast_channel_entered_bridge_type(), handle_bridge_enter_message, NULL);
 	stasis_message_router_add(stasis_router, ast_channel_left_bridge_type(), handle_bridge_leave_message, NULL);

main/manager_bridging.c

@@ -196,9 +196,7 @@ static void bridge_snapshot_update(void *data, struct stasis_subscription *sub,
 
 	update = stasis_message_data(message);
 
-	if (ast_bridge_snapshot_type() != update->type) {
-		return;
-	}
+	ast_assert(ast_bridge_snapshot_type() == update->type);
 
 	old_snapshot = stasis_message_data(update->old_snapshot);
 	new_snapshot = stasis_message_data(update->new_snapshot);
@@ -495,35 +493,22 @@ int manager_bridging_init(void)
 		return -1;
 	}
 
-	/* BUGBUG - This should really route off of the manager_router, but
-	 * can't b/c manager_channels is already routing the
-	 * stasis_cache_update_type() messages. Having a separate router can
-	 * cause some message ordering issues with bridge and channel messages.
-	 */
-	bridge_state_router = stasis_message_router_create(bridge_topic);
+	bridge_state_router = ast_manager_get_message_router();
 	if (!bridge_state_router) {
 		return -1;
 	}
 
-	ret |= stasis_message_router_add(bridge_state_router,
-					 stasis_cache_update_type(),
-					 bridge_snapshot_update,
-					 NULL);
+	ret |= stasis_message_router_add_cache_update(bridge_state_router,
+		ast_bridge_snapshot_type(), bridge_snapshot_update, NULL);
 
 	ret |= stasis_message_router_add(bridge_state_router,
-					 ast_bridge_merge_message_type(),
-					 bridge_merge_cb,
-					 NULL);
+		ast_bridge_merge_message_type(), bridge_merge_cb, NULL);
 
 	ret |= stasis_message_router_add(bridge_state_router,
-					 ast_channel_entered_bridge_type(),
-					 channel_enter_cb,
-					 NULL);
+		ast_channel_entered_bridge_type(), channel_enter_cb, NULL);
 
 	ret |= stasis_message_router_add(bridge_state_router,
-					 ast_channel_left_bridge_type(),
-					 channel_leave_cb,
-					 NULL);
+		ast_channel_left_bridge_type(), channel_leave_cb, NULL);
 
 	ret |= ast_manager_register_xml_core("BridgeList", 0, manager_bridges_list);
 	ret |= ast_manager_register_xml_core("BridgeInfo", 0, manager_bridge_info);

main/manager_channels.c

@@ -726,9 +726,7 @@ static void channel_snapshot_update(void *data, struct stasis_subscription *sub,
 
 	update = stasis_message_data(message);
 
-	if (ast_channel_snapshot_type() != update->type) {
-		return;
-	}
+	ast_assert(ast_channel_snapshot_type() == update->type);
 
 	old_snapshot = stasis_message_data(update->old_snapshot);
 	new_snapshot = stasis_message_data(update->new_snapshot);
@@ -1283,85 +1281,57 @@ int manager_channels_init(void)
 
 	ast_register_atexit(manager_channels_shutdown);
 
-	ret |= stasis_message_router_add(message_router,
-					 stasis_cache_update_type(),
-					 channel_snapshot_update,
-					 NULL);
+	ret |= stasis_message_router_add_cache_update(message_router,
+		ast_channel_snapshot_type(), channel_snapshot_update, NULL);
 
 	ret |= stasis_message_router_add(message_router,
-					 ast_channel_user_event_type(),
-					 channel_user_event_cb,
-					 NULL);
+		ast_channel_user_event_type(), channel_user_event_cb, NULL);
 
 	ret |= stasis_message_router_add(message_router,
-					 ast_channel_dtmf_begin_type(),
-					 channel_dtmf_begin_cb,
-					 NULL);
+		ast_channel_dtmf_begin_type(), channel_dtmf_begin_cb, NULL);
 
 	ret |= stasis_message_router_add(message_router,
-					 ast_channel_dtmf_end_type(),
-					 channel_dtmf_end_cb,
-					 NULL);
+		ast_channel_dtmf_end_type(), channel_dtmf_end_cb, NULL);
 
 	ret |= stasis_message_router_add(message_router,
-					 ast_channel_hangup_request_type(),
-					 channel_hangup_request_cb,
-					 NULL);
+		ast_channel_hangup_request_type(), channel_hangup_request_cb,
+		NULL);
 
 	ret |= stasis_message_router_add(message_router,
-					 ast_channel_dial_type(),
-					 channel_dial_cb,
-					 NULL);
+		ast_channel_dial_type(), channel_dial_cb, NULL);
 
 	ret |= stasis_message_router_add(message_router,
-					 ast_channel_hold_type(),
-					 channel_hold_cb,
-					 NULL);
+		ast_channel_hold_type(), channel_hold_cb, NULL);
 
 	ret |= stasis_message_router_add(message_router,
-					 ast_channel_unhold_type(),
-					 channel_unhold_cb,
-					 NULL);
+		ast_channel_unhold_type(), channel_unhold_cb, NULL);
 
 	ret |= stasis_message_router_add(message_router,
-					 ast_channel_fax_type(),
-					 channel_fax_cb,
-					 NULL);
+		ast_channel_fax_type(), channel_fax_cb, NULL);
 
 	ret |= stasis_message_router_add(message_router,
-					 ast_channel_chanspy_start_type(),
-					 channel_chanspy_start_cb,
-					 NULL);
+		ast_channel_chanspy_start_type(), channel_chanspy_start_cb,
+		NULL);
 
 	ret |= stasis_message_router_add(message_router,
-					 ast_channel_chanspy_stop_type(),
-					 channel_chanspy_stop_cb,
-					 NULL);
+		ast_channel_chanspy_stop_type(), channel_chanspy_stop_cb, NULL);
 
 	ret |= stasis_message_router_add(message_router,
-					 ast_channel_hangup_handler_type(),
-					 channel_hangup_handler_cb,
-					 NULL);
+		ast_channel_hangup_handler_type(), channel_hangup_handler_cb,
+		NULL);
 
 	ret |= stasis_message_router_add(message_router,
-					 ast_channel_moh_start_type(),
-					 channel_moh_start_cb,
-					 NULL);
+		ast_channel_moh_start_type(), channel_moh_start_cb, NULL);
 
 	ret |= stasis_message_router_add(message_router,
-					 ast_channel_moh_stop_type(),
-					 channel_moh_stop_cb,
-					 NULL);
+		ast_channel_moh_stop_type(), channel_moh_stop_cb, NULL);
 
 	ret |= stasis_message_router_add(message_router,
-					 ast_channel_monitor_start_type(),
-					 channel_monitor_start_cb,
-					 NULL);
+		ast_channel_monitor_start_type(), channel_monitor_start_cb,
+		NULL);
 
 	ret |= stasis_message_router_add(message_router,
-					 ast_channel_monitor_stop_type(),
-					 channel_monitor_stop_cb,
-					 NULL);
+		ast_channel_monitor_stop_type(), channel_monitor_stop_cb, NULL);
 
 	/* If somehow we failed to add any routes, just shut down the whole
 	 * thing and fail it.

main/stasis_message_router.c

@@ -34,6 +34,9 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include "asterisk/astobj2.h"
 #include "asterisk/stasis_message_router.h"
 
+/*! Number of hash buckets for the route table. Keep it prime! */
+#define ROUTE_TABLE_BUCKETS 7
+
 /*! \internal */
 struct stasis_message_route {
 	/*! Message type handle by this route. */
@@ -75,6 +78,8 @@ struct stasis_message_router {
 	struct stasis_subscription *subscription;
 	/*! Subscribed routes */
 	struct ao2_container *routes;
+	/*! Subscribed routes for \ref stasi_cache_update messages */
+	struct ao2_container *cache_routes;
 	/*! Route of last resort */
 	struct stasis_message_route *default_route;
 };
@@ -90,13 +95,46 @@ static void router_dtor(void *obj)
 	ao2_cleanup(router->routes);
 	router->routes = NULL;
 
+	ao2_cleanup(router->cache_routes);
+	router->cache_routes = NULL;
+
 	ao2_cleanup(router->default_route);
 	router->default_route = NULL;
 }
 
-static struct stasis_message_route *find_route(struct stasis_message_router *router, struct stasis_message_type *message_type)
+static struct stasis_message_route *find_route(
+	struct stasis_message_router *router,
+	struct stasis_message *message)
 {
-	return ao2_find(router->routes, message_type, OBJ_KEY);
+	RAII_VAR(struct stasis_message_route *, route, NULL, ao2_cleanup);
+	struct stasis_message_type *type = stasis_message_type(message);
+	SCOPED_AO2LOCK(lock, router);
+
+	if (type == stasis_cache_update_type()) {
+		/* Find a cache route */
+		struct stasis_cache_update *update =
+			stasis_message_data(message);
+		route = ao2_find(router->cache_routes, update->type, OBJ_KEY);
+	}
+
+	if (route == NULL) {
+		/* Find a regular route */
+		route = ao2_find(router->routes, type, OBJ_KEY);
+	}
+
+	if (route == NULL) {
+		/* Maybe the default route, then? */
+		if ((route = router->default_route)) {
+			ao2_ref(route, +1);
+		}
+	}
+
+	if (route == NULL) {
+		return NULL;
+	}
+
+	ao2_ref(route, +1);
+	return route;
 }
 
 static void router_dispatch(void *data,
@@ -105,29 +143,18 @@ static void router_dispatch(void *data,
 			    struct stasis_message *message)
 {
 	struct stasis_message_router *router = data;
-	RAII_VAR(struct stasis_message_router *, router_needs_cleanup, NULL, ao2_cleanup);
 	RAII_VAR(struct stasis_message_route *, route, NULL, ao2_cleanup);
-	struct stasis_message_type *type = stasis_message_type(message);
 
-	{
-		SCOPED_AO2LOCK(lock, router);
-
-		if (!(route = find_route(router, type))) {
-			if ((route = router->default_route)) {
-				ao2_ref(route, +1);
-			}
-		}
-	}
+	route = find_route(router, message);
 
 	if (route) {
 		route->callback(route->data, sub, topic, message);
 	}
 
+
 	if (stasis_subscription_final_message(sub, message)) {
-		router_needs_cleanup = router;
-		return;
+		ao2_cleanup(router);
 	}
-
 }
 
 struct stasis_message_router *stasis_message_router_create(
@@ -140,7 +167,15 @@ struct stasis_message_router *stasis_message_router_create(
 		return NULL;
 	}
 
-	if (!(router->routes = ao2_container_alloc(7, route_hash, route_cmp))) {
+	router->routes = ao2_container_alloc(ROUTE_TABLE_BUCKETS, route_hash,
+		route_cmp);
+	if (!router->routes) {
+		return NULL;
+	}
+
+	router->cache_routes = ao2_container_alloc(ROUTE_TABLE_BUCKETS,
+		route_hash, route_cmp);
+	if (!router->cache_routes) {
 		return NULL;
 	}
 
@@ -211,7 +246,10 @@ static int add_route(struct stasis_message_router *router,
 	RAII_VAR(struct stasis_message_route *, existing_route, NULL, ao2_cleanup);
 	SCOPED_AO2LOCK(lock, router);
 
-	if ((existing_route = find_route(router, route->message_type))) {
+	existing_route = ao2_find(router->routes, route->message_type, OBJ_KEY);
+
+	if (existing_route) {
+		ast_log(LOG_ERROR, "Cannot add route; route exists\n");
 		return -1;
 	}
 
@@ -219,10 +257,27 @@ static int add_route(struct stasis_message_router *router,
 	return 0;
 }
 
+static int add_cache_route(struct stasis_message_router *router,
+		     struct stasis_message_route *route)
+{
+	RAII_VAR(struct stasis_message_route *, existing_route, NULL, ao2_cleanup);
+	SCOPED_AO2LOCK(lock, router);
+
+	existing_route = ao2_find(router->cache_routes, route->message_type,
+		OBJ_KEY);
+
+	if (existing_route) {
+		ast_log(LOG_ERROR, "Cannot add route; route exists\n");
+		return -1;
+	}
+
+	ao2_link(router->cache_routes, route);
+	return 0;
+}
+
 int stasis_message_router_add(struct stasis_message_router *router,
-			      struct stasis_message_type *message_type,
-			      stasis_subscription_cb callback,
-			      void *data)
+	struct stasis_message_type *message_type,
+	stasis_subscription_cb callback, void *data)
 {
 	RAII_VAR(struct stasis_message_route *, route, NULL, ao2_cleanup);
 
@@ -234,12 +289,37 @@ int stasis_message_router_add(struct stasis_message_router *router,
 	return add_route(router, route);
 }
 
+int stasis_message_router_add_cache_update(struct stasis_message_router *router,
+	struct stasis_message_type *message_type,
+	stasis_subscription_cb callback, void *data)
+{
+	RAII_VAR(struct stasis_message_route *, route, NULL, ao2_cleanup);
+
+	route = route_create(message_type, callback, data);
+	if (!route) {
+		return -1;
+	}
+
+	return add_cache_route(router, route);
+}
+
 void stasis_message_router_remove(struct stasis_message_router *router,
-			      struct stasis_message_type *message_type)
+	struct stasis_message_type *message_type)
+{
+	SCOPED_AO2LOCK(lock, router);
+
+	ao2_find(router->routes, message_type,
+		OBJ_UNLINK | OBJ_NODATA | OBJ_KEY);
+}
+
+void stasis_message_router_remove_cache_update(
+	struct stasis_message_router *router,
+	struct stasis_message_type *message_type)
 {
 	SCOPED_AO2LOCK(lock, router);
 
-	ao2_find(router->routes, message_type, OBJ_UNLINK | OBJ_NODATA | OBJ_KEY);
+	ao2_find(router->cache_routes, message_type,
+		OBJ_UNLINK | OBJ_NODATA | OBJ_KEY);
 }
 
 int stasis_message_router_set_default(struct stasis_message_router *router,

tests/test_stasis.c

@@ -230,7 +230,7 @@ static int consumer_wait_for_completion(struct consumer *consumer)
 {
 	struct timeval start = ast_tvnow();
 	struct timespec end = {
-		.tv_sec = start.tv_sec + 30,
+		.tv_sec = start.tv_sec + 3,
 		.tv_nsec = start.tv_usec * 1000
 	};
 
@@ -867,7 +867,7 @@ AST_TEST_DEFINE(cache_dump)
 AST_TEST_DEFINE(route_conflicts)
 {
 	RAII_VAR(struct stasis_topic *, topic, NULL, ao2_cleanup);
-	RAII_VAR(struct stasis_message_router *, uut, NULL, stasis_message_router_unsubscribe);
+	RAII_VAR(struct stasis_message_router *, uut, NULL, stasis_message_router_unsubscribe_and_join);
 	RAII_VAR(struct stasis_message_type *, test_message_type, NULL, ao2_cleanup);
 	RAII_VAR(struct consumer *, consumer1, NULL, ao2_cleanup);
 	RAII_VAR(struct consumer *, consumer2, NULL, ao2_cleanup);
@@ -913,7 +913,7 @@ AST_TEST_DEFINE(route_conflicts)
 AST_TEST_DEFINE(router)
 {
 	RAII_VAR(struct stasis_topic *, topic, NULL, ao2_cleanup);
-	RAII_VAR(struct stasis_message_router *, uut, NULL, stasis_message_router_unsubscribe);
+	RAII_VAR(struct stasis_message_router *, uut, NULL, stasis_message_router_unsubscribe_and_join);
 	RAII_VAR(char *, test_data, NULL, ao2_cleanup);
 	RAII_VAR(struct stasis_message_type *, test_message_type1, NULL, ao2_cleanup);
 	RAII_VAR(struct stasis_message_type *, test_message_type2, NULL, ao2_cleanup);
@@ -1006,6 +1006,126 @@ AST_TEST_DEFINE(router)
 	return AST_TEST_PASS;
 }
 
+static const char *cache_simple(struct stasis_message *message) {
+	const char *type_name =
+		stasis_message_type_name(stasis_message_type(message));
+	if (!ast_begins_with(type_name, "Cache")) {
+		return NULL;
+	}
+
+	return "cached";
+}
+
+AST_TEST_DEFINE(router_cache_updates)
+{
+	RAII_VAR(struct stasis_topic *, topic, NULL, ao2_cleanup);
+	RAII_VAR(struct stasis_caching_topic *, caching_topic, NULL, stasis_caching_unsubscribe);
+	RAII_VAR(struct stasis_message_type *, test_message_type1, NULL, ao2_cleanup);
+	RAII_VAR(struct stasis_message_type *, test_message_type2, NULL, ao2_cleanup);
+	RAII_VAR(struct stasis_message_type *, test_message_type3, NULL, ao2_cleanup);
+	RAII_VAR(struct stasis_message_router *, uut, NULL, stasis_message_router_unsubscribe_and_join);
+	RAII_VAR(char *, test_data, NULL, ao2_cleanup);
+	RAII_VAR(struct stasis_message *, test_message1, NULL, ao2_cleanup);
+	RAII_VAR(struct stasis_message *, test_message2, NULL, ao2_cleanup);
+	RAII_VAR(struct stasis_message *, test_message3, NULL, ao2_cleanup);
+	RAII_VAR(struct consumer *, consumer1, NULL, ao2_cleanup);
+	RAII_VAR(struct consumer *, consumer2, NULL, ao2_cleanup);
+	RAII_VAR(struct consumer *, consumer3, NULL, ao2_cleanup);
+	RAII_VAR(struct stasis_message *, message1, NULL, ao2_cleanup);
+	RAII_VAR(struct stasis_message *, message2, NULL, ao2_cleanup);
+	struct stasis_cache_update *update;
+	int actual_len, ret;
+	struct stasis_message *actual;
+
+	switch (cmd) {
+	case TEST_INIT:
+		info->name = __func__;
+		info->category = test_category;
+		info->summary = "Test special handling cache_update messages";
+		info->description = "Test special handling cache_update messages";
+		return AST_TEST_NOT_RUN;
+	case TEST_EXECUTE:
+		break;
+	}
+
+	topic = stasis_topic_create("TestTopic");
+	ast_test_validate(test, NULL != topic);
+
+	caching_topic = stasis_caching_topic_create(topic, cache_simple);
+	ast_test_validate(test, NULL != caching_topic);
+
+	consumer1 = consumer_create(1);
+	ast_test_validate(test, NULL != consumer1);
+	consumer2 = consumer_create(1);
+	ast_test_validate(test, NULL != consumer2);
+	consumer3 = consumer_create(1);
+	ast_test_validate(test, NULL != consumer3);
+
+	test_message_type1 = stasis_message_type_create("Cache1", NULL);
+	ast_test_validate(test, NULL != test_message_type1);
+	test_message_type2 = stasis_message_type_create("Cache2", NULL);
+	ast_test_validate(test, NULL != test_message_type2);
+	test_message_type3 = stasis_message_type_create("NonCache", NULL);
+	ast_test_validate(test, NULL != test_message_type3);
+
+	uut = stasis_message_router_create(
+		stasis_caching_get_topic(caching_topic));
+	ast_test_validate(test, NULL != uut);
+
+	ret = stasis_message_router_add_cache_update(
+		uut, test_message_type1, consumer_exec, consumer1);
+	ast_test_validate(test, 0 == ret);
+	ao2_ref(consumer1, +1);
+	ret = stasis_message_router_add(
+		uut, stasis_cache_update_type(), consumer_exec, consumer2);
+	ast_test_validate(test, 0 == ret);
+	ao2_ref(consumer2, +1);
+	ret = stasis_message_router_set_default(uut, consumer_exec, consumer3);
+	ast_test_validate(test, 0 == ret);
+	ao2_ref(consumer3, +1);
+
+	test_data = ao2_alloc(1, NULL);
+	ast_test_validate(test, NULL != test_data);
+	test_message1 = stasis_message_create(test_message_type1, test_data);
+	ast_test_validate(test, NULL != test_message1);
+	test_message2 = stasis_message_create(test_message_type2, test_data);
+	ast_test_validate(test, NULL != test_message2);
+	test_message3 = stasis_message_create(test_message_type3, test_data);
+	ast_test_validate(test, NULL != test_message3);
+
+	stasis_publish(topic, test_message1);
+	stasis_publish(topic, test_message2);
+	stasis_publish(topic, test_message3);
+
+	actual_len = consumer_wait_for(consumer1, 1);
+	ast_test_validate(test, 1 == actual_len);
+	actual_len = consumer_wait_for(consumer2, 1);
+	ast_test_validate(test, 1 == actual_len);
+	actual_len = consumer_wait_for(consumer3, 1);
+	ast_test_validate(test, 1 == actual_len);
+
+	actual = consumer1->messages_rxed[0];
+	ast_test_validate(test, stasis_cache_update_type() == stasis_message_type(actual));
+	update = stasis_message_data(actual);
+	ast_test_validate(test, test_message_type1 == update->type);
+	ast_test_validate(test, test_message1 == update->new_snapshot);
+
+	actual = consumer2->messages_rxed[0];
+	ast_test_validate(test, stasis_cache_update_type() == stasis_message_type(actual));
+	update = stasis_message_data(actual);
+	ast_test_validate(test, test_message_type2 == update->type);
+	ast_test_validate(test, test_message2 == update->new_snapshot);
+
+	actual = consumer3->messages_rxed[0];
+	ast_test_validate(test, test_message3 == actual);
+
+	/* consumer1 and consumer2 do not get the final message. */
+	ao2_cleanup(consumer1);
+	ao2_cleanup(consumer2);
+
+	return AST_TEST_PASS;
+}
+
 AST_TEST_DEFINE(no_to_json)
 {
 	RAII_VAR(struct stasis_message_type *, type, NULL, ao2_cleanup);
@@ -1160,6 +1280,7 @@ static int unload_module(void)
 	AST_TEST_UNREGISTER(cache_dump);
 	AST_TEST_UNREGISTER(route_conflicts);
 	AST_TEST_UNREGISTER(router);
+	AST_TEST_UNREGISTER(router_cache_updates);
 	AST_TEST_UNREGISTER(interleaving);
 	AST_TEST_UNREGISTER(no_to_json);
 	AST_TEST_UNREGISTER(to_json);
@@ -1181,6 +1302,7 @@ static int load_module(void)
 	AST_TEST_REGISTER(cache_dump);
 	AST_TEST_REGISTER(route_conflicts);
 	AST_TEST_REGISTER(router);
+	AST_TEST_REGISTER(router_cache_updates);
 	AST_TEST_REGISTER(interleaving);
 	AST_TEST_REGISTER(no_to_json);
 	AST_TEST_REGISTER(to_json);