vector: Update API to be more flexible.

Made the vector macro API be more like linked lists.
1) Added a name parameter to ast_vector() to name the vector struct.
2) Made the API take a pointer to the vector struct instead of the struct
itself.
3) Added an element cleanup macro/function parameter when removing an
element from the vector for ast_vector_remove_cmp_unordered() and
ast_vector_remove_elem_unordered().
4) Added ast_vector_get_addr() in case the vector element is not a simple
pointer.

* Converted an inline vector usage in stasis_message_router to use the
vector API.  It needed the API improvements so it could be converted.

* Fixed topic reference leak in router_dtor() when the
stasis_message_router is destroyed.

* Fixed deadlock potential in stasis_forward_all() and
stasis_forward_cancel().  Locking two topics at the same time requires
deadlock avoidance.

* Made internal_stasis_subscribe() tolerant of a NULL topic.

* Made stasis_message_router_add(),
stasis_message_router_add_cache_update(), stasis_message_router_remove(),
and stasis_message_router_remove_cache_update() tolerant of a NULL
message_type.

* Promoted a LOG_DEBUG message to LOG_ERROR as intended in
dispatch_message().

Review: https://reviewboard.asterisk.org/r/2903/


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/12@402429 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/stasis_message_router.c

@@ -33,6 +33,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 
 #include "asterisk/astobj2.h"
 #include "asterisk/stasis_message_router.h"
+#include "asterisk/vector.h"
 
 /*! \internal */
 struct stasis_message_route {
@@ -44,19 +45,13 @@ struct stasis_message_route {
 	void *data;
 };
 
-struct route_table {
-	/*! Current number of entries in the route table */
-	size_t current_size;
-	/*! Allocated number of entires in the route table */
-	size_t max_size;
-	/*! The route table itself */
-	struct stasis_message_route routes[];
-};
+ast_vector(route_table, struct stasis_message_route);
 
-static struct stasis_message_route *table_find_route(struct route_table *table,
+static struct stasis_message_route *route_table_find(struct route_table *table,
 	struct stasis_message_type *message_type)
 {
 	size_t idx;
+	struct stasis_message_route *route;
 
 	/* While a linear search for routes may seem very inefficient, most
 	 * route tables have six routes or less. For such small data, it's
@@ -64,59 +59,74 @@ static struct stasis_message_route *table_find_route(struct route_table *table,
 	 * tables, then we can look into containers with more efficient
 	 * lookups.
 	 */
-	for (idx = 0; idx < table->current_size; ++idx) {
-		if (table->routes[idx].message_type == message_type) {
-			return &table->routes[idx];
+	for (idx = 0; idx < ast_vector_size(table); ++idx) {
+		route = ast_vector_get_addr(table, idx);
+		if (route->message_type == message_type) {
+			return route;
 		}
 	}
 
 	return NULL;
 }
 
-static int table_add_route(struct route_table **table_ptr,
+/*!
+ * \brief route_table comparator for ast_vector_remove_cmp_unordered()
+ *
+ * \param elem Element to compare against
+ * \param value Value to compare with the vector element.
+ *
+ * \return 0 if element does not match.
+ * \return Non-zero if element matches.
+ */
+#define ROUTE_TABLE_ELEM_CMP(elem, value) ((elem).message_type == (value))
+
+/*!
+ * \brief route_table vector element cleanup.
+ *
+ * \param elem Element to cleanup
+ *
+ * \return Nothing
+ */
+#define ROUTE_TABLE_ELEM_CLEANUP(elem)  ao2_cleanup((elem).message_type)
+
+static int route_table_remove(struct route_table *table,
+	struct stasis_message_type *message_type)
+{
+	return ast_vector_remove_cmp_unordered(table, message_type, ROUTE_TABLE_ELEM_CMP,
+		ROUTE_TABLE_ELEM_CLEANUP);
+}
+
+static int route_table_add(struct route_table *table,
 	struct stasis_message_type *message_type,
 	stasis_subscription_cb callback, void *data)
 {
-	struct route_table *table = *table_ptr;
-	struct stasis_message_route *route;
+	struct stasis_message_route route;
+	int res;
 
-	ast_assert(table_find_route(table, message_type) == NULL);
+	ast_assert(callback != NULL);
+	ast_assert(route_table_find(table, message_type) == NULL);
 
-	if (table->current_size + 1 > table->max_size) {
-		size_t new_max_size = table->max_size ? table->max_size * 2 : 1;
-		struct route_table *new_table = ast_realloc(table,
-			sizeof(*new_table) +
-			sizeof(new_table->routes[0]) * new_max_size);
-		if (!new_table) {
-			return -1;
-		}
-		*table_ptr = table = new_table;
-		table->max_size = new_max_size;
+	route.message_type = ao2_bump(message_type);
+	route.callback = callback;
+	route.data = data;
+
+	res = ast_vector_append(table, route);
+	if (res) {
+		ROUTE_TABLE_ELEM_CLEANUP(route);
 	}
-
-	route = &table->routes[table->current_size++];
-
-	route->message_type = ao2_bump(message_type);
-	route->callback = callback;
-	route->data = data;
-
-	return 0;
+	return res;
 }
 
-static int table_remove_route(struct route_table *table,
-	struct stasis_message_type *message_type)
+static void route_table_dtor(struct route_table *table)
 {
 	size_t idx;
+	struct stasis_message_route *route;
 
-	for (idx = 0; idx < table->current_size; ++idx) {
-		if (table->routes[idx].message_type == message_type) {
-			ao2_cleanup(message_type);
-			table->routes[idx] =
-				table->routes[--table->current_size];
-			return 0;
-		}
+	for (idx = 0; idx < ast_vector_size(table); ++idx) {
+		route = ast_vector_get_addr(table, idx);
+		ROUTE_TABLE_ELEM_CLEANUP(*route);
 	}
-	return -1;
+	ast_vector_free(table);
 }
 
 /*! \internal */
@@ -124,9 +134,9 @@ struct stasis_message_router {
 	/*! Subscription to the upstream topic */
 	struct stasis_subscription *subscription;
 	/*! Subscribed routes */
-	struct route_table *routes;
+	struct route_table routes;
 	/*! Subscribed routes for \ref stasis_cache_update messages */
-	struct route_table *cache_routes;
+	struct route_table cache_routes;
 	/*! Route of last resort */
 	struct stasis_message_route default_route;
 };
@@ -137,13 +147,11 @@ static void router_dtor(void *obj)
 
 	ast_assert(!stasis_subscription_is_subscribed(router->subscription));
 	ast_assert(stasis_subscription_is_done(router->subscription));
+
 	router->subscription = NULL;
 
-	ast_free(router->routes);
-	router->routes = NULL;
-
-	ast_free(router->cache_routes);
-	router->cache_routes = NULL;
+	route_table_dtor(&router->routes);
+	route_table_dtor(&router->cache_routes);
 }
 
 static int find_route(
@@ -161,12 +169,12 @@ static int find_route(
 		/* Find a cache route */
 		struct stasis_cache_update *update =
 			stasis_message_data(message);
-		route = table_find_route(router->cache_routes, update->type);
+		route = route_table_find(&router->cache_routes, update->type);
 	}
 
 	if (route == NULL) {
 		/* Find a regular route */
-		route = table_find_route(router->routes, type);
+		route = route_table_find(&router->routes, type);
 	}
 
 	if (route == NULL && router->default_route.callback) {
@@ -201,6 +209,7 @@ static void router_dispatch(void *data,
 struct stasis_message_router *stasis_message_router_create(
 	struct stasis_topic *topic)
 {
+	int res;
 	RAII_VAR(struct stasis_message_router *, router, NULL, ao2_cleanup);
 
 	router = ao2_alloc(sizeof(*router), router_dtor);
@@ -208,13 +217,10 @@ struct stasis_message_router *stasis_message_router_create(
 		return NULL;
 	}
 
-	router->routes = ast_calloc(1, sizeof(*router->routes));
-	if (!router->routes) {
-		return NULL;
-	}
-
-	router->cache_routes = ast_calloc(1, sizeof(*router->cache_routes));
-	if (!router->cache_routes) {
+	res = 0;
+	res |= ast_vector_init(&router->routes, 0);
+	res |= ast_vector_init(&router->cache_routes, 0);
+	if (res) {
 		return NULL;
 	}
 
@@ -259,40 +265,78 @@ int stasis_message_router_add(struct stasis_message_router *router,
 	struct stasis_message_type *message_type,
 	stasis_subscription_cb callback, void *data)
 {
-	SCOPED_AO2LOCK(lock, router);
-	return table_add_route(&router->routes, message_type, callback, data);
+	int res;
+
+	ast_assert(router != NULL);
+
+	if (!message_type) {
+		/* Cannot route to NULL type. */
+		return -1;
+	}
+	ao2_lock(router);
+	res = route_table_add(&router->routes, message_type, callback, data);
+	ao2_unlock(router);
+	return res;
 }
 
 int stasis_message_router_add_cache_update(struct stasis_message_router *router,
 	struct stasis_message_type *message_type,
 	stasis_subscription_cb callback, void *data)
 {
-	SCOPED_AO2LOCK(lock, router);
-	return table_add_route(&router->cache_routes, message_type, callback, data);
+	int res;
+
+	ast_assert(router != NULL);
+
+	if (!message_type) {
+		/* Cannot cache a route to NULL type. */
+		return -1;
+	}
+	ao2_lock(router);
+	res = route_table_add(&router->cache_routes, message_type, callback, data);
+	ao2_unlock(router);
+	return res;
 }
 
 void stasis_message_router_remove(struct stasis_message_router *router,
 	struct stasis_message_type *message_type)
 {
-	SCOPED_AO2LOCK(lock, router);
-	table_remove_route(router->routes, message_type);
+	ast_assert(router != NULL);
+
+	if (!message_type) {
+		/* Cannot remove a NULL type. */
+		return;
+	}
+	ao2_lock(router);
+	route_table_remove(&router->routes, message_type);
+	ao2_unlock(router);
 }
 
 void stasis_message_router_remove_cache_update(
 	struct stasis_message_router *router,
 	struct stasis_message_type *message_type)
 {
-	SCOPED_AO2LOCK(lock, router);
-	table_remove_route(router->cache_routes, message_type);
+	ast_assert(router != NULL);
+
+	if (!message_type) {
+		/* Cannot remove a NULL type. */
+		return;
+	}
+	ao2_lock(router);
+	route_table_remove(&router->cache_routes, message_type);
+	ao2_unlock(router);
 }
 
 int stasis_message_router_set_default(struct stasis_message_router *router,
-				      stasis_subscription_cb callback,
-				      void *data)
+	stasis_subscription_cb callback,
+	void *data)
 {
-	SCOPED_AO2LOCK(lock, router);
+	ast_assert(router != NULL);
+	ast_assert(callback != NULL);
+
+	ao2_lock(router);
 	router->default_route.callback = callback;
 	router->default_route.data = data;
+	ao2_unlock(router);
 	/* While this implementation can never fail, it used to be able to */
 	return 0;
 }