vector: Update API to be more flexible.
authorRichard Mudgett <rmudgett@digium.com>
Sat, 2 Nov 2013 04:12:36 +0000 (04:12 +0000)
committerRichard Mudgett <rmudgett@digium.com>
Sat, 2 Nov 2013 04:12:36 +0000 (04:12 +0000)
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/
........

Merged revisions 402429 from http://svn.asterisk.org/svn/asterisk/branches/12

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@402430 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/lock.h
include/asterisk/vector.h
main/stasis.c
main/stasis_message_router.c

index d76a8d1..7741654 100644 (file)
@@ -339,6 +339,28 @@ int ast_find_lock_info(void *lock_addr, char *filename, size_t filename_size, in
  * used during deadlock avoidance, to preserve the original location where
  * a lock was originally acquired.
  */
+#define AO2_DEADLOCK_AVOIDANCE(obj) \
+       do { \
+               char __filename[80], __func[80], __mutex_name[80]; \
+               int __lineno; \
+               int __res = ast_find_lock_info(ao2_object_get_lockaddr(obj), __filename, sizeof(__filename), &__lineno, __func, sizeof(__func), __mutex_name, sizeof(__mutex_name)); \
+               int __res2 = ao2_unlock(obj); \
+               usleep(1); \
+               if (__res < 0) { /* Could happen if the ao2 object does not have a mutex. */ \
+                       if (__res2) { \
+                               ast_log(LOG_WARNING, "Could not unlock ao2 object '%s': %s and no lock info found!  I will NOT try to relock.\n", #obj, strerror(__res2)); \
+                       } else { \
+                               ao2_lock(obj); \
+                       } \
+               } else { \
+                       if (__res2) { \
+                               ast_log(LOG_WARNING, "Could not unlock ao2 object '%s': %s.  {{{Originally locked at %s line %d: (%s) '%s'}}}  I will NOT try to relock.\n", #obj, strerror(__res2), __filename, __lineno, __func, __mutex_name); \
+                       } else { \
+                               __ao2_lock(obj, AO2_LOCK_REQ_MUTEX, __filename, __func, __lineno, __mutex_name); \
+                       } \
+               } \
+       } while (0)
+
 #define CHANNEL_DEADLOCK_AVOIDANCE(chan) \
        do { \
                char __filename[80], __func[80], __mutex_name[80]; \
@@ -493,12 +515,17 @@ static inline void delete_reentrancy_cs(struct ast_lock_track **plt)
 
 #else /* !DEBUG_THREADS */
 
-#define        CHANNEL_DEADLOCK_AVOIDANCE(chan) \
+#define AO2_DEADLOCK_AVOIDANCE(obj) \
+       ao2_unlock(obj); \
+       usleep(1); \
+       ao2_lock(obj);
+
+#define CHANNEL_DEADLOCK_AVOIDANCE(chan) \
        ast_channel_unlock(chan); \
        usleep(1); \
        ast_channel_lock(chan);
 
-#define        DEADLOCK_AVOIDANCE(lock) \
+#define DEADLOCK_AVOIDANCE(lock) \
        do { \
                int __res; \
                if (!(__res = ast_mutex_unlock(lock))) { \
index f5d3e9a..4efc5ce 100644 (file)
  * \since 12
  */
 
-/*! \brief Define a vector structure */
-#define ast_vector(type)                       \
-       struct {                                \
+/*!
+ * \brief Define a vector structure
+ *
+ * \param name Optional vector struct name.
+ * \param type Vector element type.
+ */
+#define ast_vector(name, type)                 \
+       struct name {                           \
                type *elems;                    \
                size_t max;                     \
                size_t current;                 \
  */
 #define ast_vector_init(vec, size) ({                                  \
        size_t __size = (size);                                         \
-       size_t alloc_size = __size * sizeof(*(vec).elems);              \
-       (vec).elems = alloc_size ? ast_malloc(alloc_size) : NULL;       \
-       (vec).current = 0;                                              \
-       if ((vec).elems) {                                              \
-               (vec).max = __size;                                     \
+       size_t alloc_size = __size * sizeof(*((vec)->elems));           \
+       (vec)->elems = alloc_size ? ast_malloc(alloc_size) : NULL;      \
+       (vec)->current = 0;                                             \
+       if ((vec)->elems) {                                             \
+               (vec)->max = __size;                                    \
        } else {                                                        \
-               (vec).max = 0;                                          \
+               (vec)->max = 0;                                         \
        }                                                               \
-       alloc_size == 0 || (vec).elems != NULL ? 0 : -1;                \
+       (alloc_size == 0 || (vec)->elems != NULL) ? 0 : -1;             \
 })
 
 /*!
  * \param vec Vector to deallocate.
  */
 #define ast_vector_free(vec) do {              \
-       ast_free((vec).elems);                  \
-       (vec).elems = NULL;                     \
-       (vec).max = 0;                          \
-       (vec).current = 0;                      \
+       ast_free((vec)->elems);                 \
+       (vec)->elems = NULL;                    \
+       (vec)->max = 0;                         \
+       (vec)->current = 0;                     \
 } while (0)
 
 /*!
  * \return 0 on success.
  * \return Non-zero on failure.
  */
-#define ast_vector_append(vec, elem) ({                                        \
-       int res = 0;                                                    \
-                                                                       \
-       if ((vec).current + 1 > (vec).max) {                            \
-               size_t new_max = (vec).max ? 2 * (vec).max : 1;         \
-               typeof((vec).elems) new_elems = ast_realloc(            \
-                       (vec).elems, new_max * sizeof(*new_elems));     \
-               if (new_elems) {                                        \
-                       (vec).elems = new_elems;                                \
-                       (vec).max = new_max;                            \
-               } else {                                                \
-                       res = -1;                                       \
-               }                                                       \
-       }                                                               \
-                                                                       \
-       if (res == 0) {                                                 \
-               (vec).elems[(vec).current++] = (elem);                  \
-       }                                                               \
-       res;                                                            \
+#define ast_vector_append(vec, elem) ({                                                \
+       int res = 0;                                                            \
+       do {                                                                    \
+               if ((vec)->current + 1 > (vec)->max) {                          \
+                       size_t new_max = (vec)->max ? 2 * (vec)->max : 1;       \
+                       typeof((vec)->elems) new_elems = ast_realloc(           \
+                               (vec)->elems, new_max * sizeof(*new_elems));    \
+                       if (new_elems) {                                        \
+                               (vec)->elems = new_elems;                       \
+                               (vec)->max = new_max;                           \
+                       } else {                                                \
+                               res = -1;                                       \
+                               break;                                          \
+                       }                                                       \
+               }                                                               \
+               (vec)->elems[(vec)->current++] = (elem);                        \
+       } while (0);                                                            \
+       res;                                                                    \
 })
 
 /*!
  * \return The element that was removed.
  */
 #define ast_vector_remove_unordered(vec, idx) ({               \
-       typeof((vec).elems[0]) res;                             \
+       typeof((vec)->elems[0]) res;                            \
        size_t __idx = (idx);                                   \
-       ast_assert(__idx < (vec).current);                      \
-       res = (vec).elems[__idx];                               \
-       (vec).elems[__idx] = (vec).elems[--(vec).current];      \
+       ast_assert(__idx < (vec)->current);                     \
+       res = (vec)->elems[__idx];                              \
+       (vec)->elems[__idx] = (vec)->elems[--(vec)->current];   \
        res;                                                    \
 })
 
  * \param vec Vector to remove from.
  * \param value Value to pass into comparator.
  * \param cmp Comparator function/macros (called as \c cmp(elem, value))
+ * \param cleanup How to cleanup a removed element macro/function.
+ *
  * \return 0 if element was removed.
  * \return Non-zero if element was not in the vector.
  */
-#define ast_vector_remove_cmp_unordered(vec, value, cmp) ({            \
+#define ast_vector_remove_cmp_unordered(vec, value, cmp, cleanup) ({   \
        int res = -1;                                                   \
        size_t idx;                                                     \
        typeof(value) __value = (value);                                \
-       for (idx = 0; idx < (vec).current; ++idx) {                     \
-               if (cmp((vec).elems[idx], __value)) {                   \
+       for (idx = 0; idx < (vec)->current; ++idx) {                    \
+               if (cmp((vec)->elems[idx], __value)) {                  \
+                       cleanup((vec)->elems[idx]);                     \
                        ast_vector_remove_unordered((vec), idx);        \
                        res = 0;                                        \
                        break;                                          \
        res;                                                            \
 })
 
-/*! \brief Default comparator for ast_vector_remove_elem_unordered() */
-#define AST_VECTOR_DEFAULT_CMP(a, b) ((a) == (b))
+/*!
+ * \brief Default comparator for ast_vector_remove_elem_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 AST_VECTOR_ELEM_DEFAULT_CMP(elem, value) ((elem) == (value))
+
+/*!
+ * \brief Vector element cleanup that does nothing.
+ *
+ * \param elem Element to cleanup
+ *
+ * \return Nothing
+ */
+#define AST_VECTOR_ELEM_CLEANUP_NOOP(elem)
 
 /*!
  * \brief Remove an element from a vector.
  *
  * \param vec Vector to remove from.
  * \param elem Element to remove
+ * \param cleanup How to cleanup a removed element macro/function.
+ *
  * \return 0 if element was removed.
  * \return Non-zero if element was not in the vector.
  */
-#define ast_vector_remove_elem_unordered(vec, elem) ({ \
-       ast_vector_remove_cmp_unordered((vec), (elem),  \
-               AST_VECTOR_DEFAULT_CMP);                \
+#define ast_vector_remove_elem_unordered(vec, elem, cleanup) ({        \
+       ast_vector_remove_cmp_unordered((vec), (elem),          \
+               AST_VECTOR_ELEM_DEFAULT_CMP, cleanup);          \
 })
 
 /*!
  * \param vec Vector to query.
  * \return Number of elements in the vector.
  */
-#define ast_vector_size(vec) (vec).current
+#define ast_vector_size(vec) (vec)->current
+
+/*!
+ * \brief Get an address of element in a vector.
+ *
+ * \param vec Vector to query.
+ * \param idx Index of the element to get address of.
+ */
+#define ast_vector_get_addr(vec, idx) ({       \
+       size_t __idx = (idx);                   \
+       ast_assert(__idx < (vec)->current);     \
+       &(vec)->elems[__idx];                   \
+})
 
 /*!
  * \brief Get an element from a vector.
  */
 #define ast_vector_get(vec, idx) ({            \
        size_t __idx = (idx);                   \
-       ast_assert(__idx < (vec).current);      \
-       (vec).elems[__idx];                     \
+       ast_assert(__idx < (vec)->current);     \
+       (vec)->elems[__idx];                    \
 })
 
 #endif /* _ASTERISK_VECTOR_H */
index eabdfdc..db95986 100644 (file)
@@ -140,10 +140,10 @@ STASIS_MESSAGE_TYPE_DEFN(stasis_subscription_change_type);
 struct stasis_topic {
        char *name;
        /*! Variable length array of the subscribers */
-       ast_vector(struct stasis_subscription *) subscribers;
+       ast_vector(, struct stasis_subscription *) subscribers;
 
        /*! Topics forwarding into this topic */
-       ast_vector(struct stasis_topic *) upstream_topics;
+       ast_vector(, struct stasis_topic *) upstream_topics;
 };
 
 /* Forward declarations for the tightly-coupled subscription object */
@@ -152,18 +152,28 @@ static int topic_add_subscription(struct stasis_topic *topic,
 
 static int topic_remove_subscription(struct stasis_topic *topic, struct stasis_subscription *sub);
 
+/*! \brief Lock two topics. */
+#define topic_lock_both(topic1, topic2) \
+       do { \
+               ao2_lock(topic1); \
+               while (ao2_trylock(topic2)) { \
+                       AO2_DEADLOCK_AVOIDANCE(topic1); \
+               } \
+       } while (0)
+
 static void topic_dtor(void *obj)
 {
        struct stasis_topic *topic = obj;
 
        /* Subscribers hold a reference to topics, so they should all be
         * unsubscribed before we get here. */
-       ast_assert(ast_vector_size(topic->subscribers) == 0);
+       ast_assert(ast_vector_size(&topic->subscribers) == 0);
+
        ast_free(topic->name);
        topic->name = NULL;
 
-       ast_vector_free(topic->subscribers);
-       ast_vector_free(topic->upstream_topics);
+       ast_vector_free(&topic->subscribers);
+       ast_vector_free(&topic->upstream_topics);
 }
 
 struct stasis_topic *stasis_topic_create(const char *name)
@@ -182,8 +192,8 @@ struct stasis_topic *stasis_topic_create(const char *name)
                return NULL;
        }
 
-       res |= ast_vector_init(topic->subscribers, INITIAL_SUBSCRIBERS_MAX);
-       res |= ast_vector_init(topic->upstream_topics, 0);
+       res |= ast_vector_init(&topic->subscribers, INITIAL_SUBSCRIBERS_MAX);
+       res |= ast_vector_init(&topic->upstream_topics, 0);
 
        if (res != 0) {
                return NULL;
@@ -280,6 +290,10 @@ struct stasis_subscription *internal_stasis_subscribe(
 {
        RAII_VAR(struct stasis_subscription *, sub, NULL, ao2_cleanup);
 
+       if (!topic) {
+               return NULL;
+       }
+
        sub = ao2_alloc(sizeof(*sub), subscription_dtor);
        if (!sub) {
                return NULL;
@@ -414,8 +428,8 @@ int stasis_subscription_is_subscribed(const struct stasis_subscription *sub)
                struct stasis_topic *topic = sub->topic;
                SCOPED_AO2LOCK(lock_topic, topic);
 
-               for (i = 0; i < ast_vector_size(topic->subscribers); ++i) {
-                       if (ast_vector_get(topic->subscribers, i) == sub) {
+               for (i = 0; i < ast_vector_size(&topic->subscribers); ++i) {
+                       if (ast_vector_get(&topic->subscribers, i) == sub) {
                                return 1;
                        }
                }
@@ -466,11 +480,11 @@ static int topic_add_subscription(struct stasis_topic *topic, struct stasis_subs
         *
         * If we bumped the refcount here, the owner would have to unsubscribe
         * and cleanup, which is a bit awkward. */
-       ast_vector_append(topic->subscribers, sub);
+       ast_vector_append(&topic->subscribers, sub);
 
-       for (idx = 0; idx < ast_vector_size(topic->upstream_topics); ++idx) {
+       for (idx = 0; idx < ast_vector_size(&topic->upstream_topics); ++idx) {
                topic_add_subscription(
-                       ast_vector_get(topic->upstream_topics, idx), sub);
+                       ast_vector_get(&topic->upstream_topics, idx), sub);
        }
 
        return 0;
@@ -481,12 +495,13 @@ static int topic_remove_subscription(struct stasis_topic *topic, struct stasis_s
        size_t idx;
        SCOPED_AO2LOCK(lock_topic, topic);
 
-       for (idx = 0; idx < ast_vector_size(topic->upstream_topics); ++idx) {
+       for (idx = 0; idx < ast_vector_size(&topic->upstream_topics); ++idx) {
                topic_remove_subscription(
-                       ast_vector_get(topic->upstream_topics, idx), sub);
+                       ast_vector_get(&topic->upstream_topics, idx), sub);
        }
 
-       return ast_vector_remove_elem_unordered(topic->subscribers, sub);
+       return ast_vector_remove_elem_unordered(&topic->subscribers, sub,
+               AST_VECTOR_ELEM_CLEANUP_NOOP);
 }
 
 /*!
@@ -512,7 +527,7 @@ static void dispatch_message(struct stasis_subscription *sub,
                ao2_bump(message);
                if (ast_taskprocessor_push_local(sub->mailbox, dispatch_exec, message) != 0) {
                        /* Push failed; ugh. */
-                       ast_log(LOG_DEBUG, "Dropping dispatch\n");
+                       ast_log(LOG_ERROR, "Dropping dispatch\n");
                        ao2_cleanup(message);
                }
        } else {
@@ -521,26 +536,28 @@ static void dispatch_message(struct stasis_subscription *sub,
        }
 }
 
-void stasis_publish(struct stasis_topic *_topic, struct stasis_message *message)
+void stasis_publish(struct stasis_topic *topic, struct stasis_message *message)
 {
        size_t i;
-       /* The topic may be unref'ed by the subscription invocation.
-        * Make sure we hold onto a reference while dispatching. */
-       RAII_VAR(struct stasis_topic *, topic, ao2_bump(_topic),
-               ao2_cleanup);
-       SCOPED_AO2LOCK(lock, topic);
 
        ast_assert(topic != NULL);
        ast_assert(message != NULL);
 
-       for (i = 0; i < ast_vector_size(topic->subscribers); ++i) {
-               struct stasis_subscription *sub =
-                       ast_vector_get(topic->subscribers, i);
+       /*
+        * The topic may be unref'ed by the subscription invocation.
+        * Make sure we hold onto a reference while dispatching.
+        */
+       ao2_ref(topic, +1);
+       ao2_lock(topic);
+       for (i = 0; i < ast_vector_size(&topic->subscribers); ++i) {
+               struct stasis_subscription *sub = ast_vector_get(&topic->subscribers, i);
 
                ast_assert(sub != NULL);
 
                dispatch_message(sub, message);
        }
+       ao2_unlock(topic);
+       ao2_ref(topic, -1);
 }
 
 /*!
@@ -570,23 +587,26 @@ static void forward_dtor(void *obj)
 
 struct stasis_forward *stasis_forward_cancel(struct stasis_forward *forward)
 {
-       if (forward) {
-               int idx;
+       int idx;
+       struct stasis_topic *from;
+       struct stasis_topic *to;
 
-               struct stasis_topic *from = forward->from_topic;
-               struct stasis_topic *to = forward->to_topic;
+       if (!forward) {
+               return NULL;
+       }
 
-               SCOPED_AO2LOCK(to_lock, to);
+       from = forward->from_topic;
+       to = forward->to_topic;
 
-               ast_vector_remove_elem_unordered(to->upstream_topics, from);
+       topic_lock_both(to, from);
+       ast_vector_remove_elem_unordered(&to->upstream_topics, from,
+               AST_VECTOR_ELEM_CLEANUP_NOOP);
 
-               ao2_lock(from);
-               for (idx = 0; idx < ast_vector_size(to->subscribers); ++idx) {
-                       topic_remove_subscription(
-                               from, ast_vector_get(to->subscribers, idx));
-               }
-               ao2_unlock(from);
+       for (idx = 0; idx < ast_vector_size(&to->subscribers); ++idx) {
+               topic_remove_subscription(from, ast_vector_get(&to->subscribers, idx));
        }
+       ao2_unlock(from);
+       ao2_unlock(to);
 
        ao2_cleanup(forward);
 
@@ -596,6 +616,8 @@ struct stasis_forward *stasis_forward_cancel(struct stasis_forward *forward)
 struct stasis_forward *stasis_forward_all(struct stasis_topic *from_topic,
        struct stasis_topic *to_topic)
 {
+       int res;
+       size_t idx;
        RAII_VAR(struct stasis_forward *, forward, NULL, ao2_cleanup);
 
        if (!from_topic || !to_topic) {
@@ -610,23 +632,19 @@ struct stasis_forward *stasis_forward_all(struct stasis_topic *from_topic,
        forward->from_topic = ao2_bump(from_topic);
        forward->to_topic = ao2_bump(to_topic);
 
-       {
-               SCOPED_AO2LOCK(lock, to_topic);
-               int res;
-
-               res = ast_vector_append(to_topic->upstream_topics, from_topic);
-               if (res != 0) {
-                       return NULL;
-               }
+       topic_lock_both(to_topic, from_topic);
+       res = ast_vector_append(&to_topic->upstream_topics, from_topic);
+       if (res != 0) {
+               ao2_unlock(from_topic);
+               ao2_unlock(to_topic);
+               return NULL;
+       }
 
-               {
-                       SCOPED_AO2LOCK(lock, from_topic);
-                       size_t idx;
-                       for (idx = 0; idx < ast_vector_size(to_topic->subscribers); ++idx) {
-                               topic_add_subscription(from_topic, ast_vector_get(to_topic->subscribers, idx));
-                       }
-               }
+       for (idx = 0; idx < ast_vector_size(&to_topic->subscribers); ++idx) {
+               topic_add_subscription(from_topic, ast_vector_get(&to_topic->subscribers, idx));
        }
+       ao2_unlock(from_topic);
+       ao2_unlock(to_topic);
 
        return ao2_bump(forward);
 }
index 8c82dec..7ed9bcb 100644 (file)
@@ -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;
-
-       ast_assert(table_find_route(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;
-       }
+       struct stasis_message_route route;
+       int res;
 
-       route = &table->routes[table->current_size++];
+       ast_assert(callback != NULL);
+       ast_assert(route_table_find(table, message_type) == NULL);
 
-       route->message_type = ao2_bump(message_type);
-       route->callback = callback;
-       route->data = data;
+       route.message_type = ao2_bump(message_type);
+       route.callback = callback;
+       route.data = data;
 
-       return 0;
+       res = ast_vector_append(table, route);
+       if (res) {
+               ROUTE_TABLE_ELEM_CLEANUP(route);
+       }
+       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;
+       router->subscription = 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;
 }