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

1 files changed, 103 insertions, 23 deletions

diff --git a/main/stasis_message_router.c b/main/stasis_message_router.c
index 4409d2226..26d2f2c0c 100644
--- a/main/stasis_message_router.c
+++ b/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,