res_stasis.c: Fix locking issues with the app_bridge_moh container.
authorRichard Mudgett <rmudgett@digium.com>
Fri, 8 Nov 2013 20:37:08 +0000 (20:37 +0000)
committerRichard Mudgett <rmudgett@digium.com>
Fri, 8 Nov 2013 20:37:08 +0000 (20:37 +0000)
* Fix unlinking from the app_bridges_moh container in remove_bridge_moh()
without a lock under normal circumstances.

* Made check ast_bridge_set_after_callback() return value in
bridge_moh_create() to handle failure.

* Fixed SCOPED_AO2LOCK() locking over too much scope in
stasis_app_bridge_moh_channel() and stasis_app_bridge_moh_stop().

* Fixed unusual usage of ao2_unlink_flag() in control_unlink().

* Fixed orphaned bridge from off nominal path in
stasis_app_bridge_create().

* Fixed strange construct in stasis_app_unsubscribe().  From a bad merge?

* Made load_module() cleanup on failure.

Review: https://reviewboard.asterisk.org/r/2962/
........

Merged revisions 402593 from http://svn.asterisk.org/svn/asterisk/branches/12

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@402595 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_stasis.c

index e883ff6..8fe4ab4 100644 (file)
@@ -403,11 +403,7 @@ static int bridges_moh_sort_fn(const void *obj_left, const void *obj_right, cons
 /*! Removes the bridge to music on hold channel link */
 static void remove_bridge_moh(char *bridge_id)
 {
-       RAII_VAR(struct stasis_app_bridge_moh_wrapper *, moh_wrapper, ao2_find(app_bridges_moh, bridge_id, OBJ_SEARCH_KEY), ao2_cleanup);
-
-       if (moh_wrapper) {
-               ao2_unlink_flags(app_bridges_moh, moh_wrapper, OBJ_NOLOCK);
-       }
+       ao2_find(app_bridges_moh, bridge_id, OBJ_SEARCH_KEY | OBJ_UNLINK | OBJ_NODATA);
        ast_free(bridge_id);
 }
 
@@ -448,7 +444,8 @@ static void *moh_channel_thread(void *data)
 {
        struct ast_channel *moh_channel = data;
 
-       while (!ast_safe_sleep(moh_channel, 1000));
+       while (!ast_safe_sleep(moh_channel, 1000)) {
+       }
 
        ast_moh_stop(moh_channel);
        ast_hangup(moh_channel);
@@ -477,14 +474,16 @@ static struct ast_channel *bridge_moh_create(struct ast_bridge *bridge)
        }
 
        chan = prepare_bridge_moh_channel();
-
        if (!chan) {
                return NULL;
        }
 
        /* The after bridge callback assumes responsibility of the bridge_id. */
-       ast_bridge_set_after_callback(chan, moh_after_bridge_cb, moh_after_bridge_cb_failed, bridge_id);
-
+       if (ast_bridge_set_after_callback(chan,
+               moh_after_bridge_cb, moh_after_bridge_cb_failed, bridge_id)) {
+               ast_hangup(chan);
+               return NULL;
+       }
        bridge_id = NULL;
 
        if (ast_unreal_channel_push_to_bridge(chan, bridge,
@@ -493,7 +492,8 @@ static struct ast_channel *bridge_moh_create(struct ast_bridge *bridge)
                return NULL;
        }
 
-       new_wrapper = ao2_alloc_options(sizeof(*new_wrapper), stasis_app_bridge_moh_wrapper_destructor, AO2_ALLOC_OPT_LOCK_NOLOCK);
+       new_wrapper = ao2_alloc_options(sizeof(*new_wrapper),
+               stasis_app_bridge_moh_wrapper_destructor, AO2_ALLOC_OPT_LOCK_NOLOCK);
        if (!new_wrapper) {
                ast_hangup(chan);
                return NULL;
@@ -503,11 +503,10 @@ static struct ast_channel *bridge_moh_create(struct ast_bridge *bridge)
                ast_hangup(chan);
                return NULL;
        }
-
        ast_string_field_set(new_wrapper, bridge_id, bridge->uniqueid);
        ast_string_field_set(new_wrapper, channel_id, ast_channel_uniqueid(chan));
 
-       if (!ao2_link(app_bridges_moh, new_wrapper)) {
+       if (!ao2_link_flags(app_bridges_moh, new_wrapper, OBJ_NOLOCK)) {
                ast_hangup(chan);
                return NULL;
        }
@@ -526,13 +525,13 @@ struct ast_channel *stasis_app_bridge_moh_channel(struct ast_bridge *bridge)
 {
        RAII_VAR(struct stasis_app_bridge_moh_wrapper *, moh_wrapper, NULL, ao2_cleanup);
 
-       SCOPED_AO2LOCK(lock, app_bridges_moh);
-
-       moh_wrapper = ao2_find(app_bridges_moh, bridge->uniqueid, OBJ_SEARCH_KEY | OBJ_NOLOCK);
+       {
+               SCOPED_AO2LOCK(lock, app_bridges_moh);
 
-       if (!moh_wrapper) {
-               struct ast_channel *bridge_moh_channel = bridge_moh_create(bridge);
-               return bridge_moh_channel;
+               moh_wrapper = ao2_find(app_bridges_moh, bridge->uniqueid, OBJ_SEARCH_KEY | OBJ_NOLOCK);
+               if (!moh_wrapper) {
+                       return bridge_moh_create(bridge);
+               }
        }
 
        return ast_channel_get_by_name(moh_wrapper->channel_id);
@@ -543,10 +542,7 @@ int stasis_app_bridge_moh_stop(struct ast_bridge *bridge)
        RAII_VAR(struct stasis_app_bridge_moh_wrapper *, moh_wrapper, NULL, ao2_cleanup);
        struct ast_channel *chan;
 
-       SCOPED_AO2LOCK(lock, app_bridges_moh);
-
-       moh_wrapper = ao2_find(app_bridges_moh, bridge->uniqueid, OBJ_SEARCH_KEY | OBJ_NOLOCK);
-
+       moh_wrapper = ao2_find(app_bridges_moh, bridge->uniqueid, OBJ_SEARCH_KEY | OBJ_UNLINK);
        if (!moh_wrapper) {
                return -1;
        }
@@ -560,8 +556,6 @@ int stasis_app_bridge_moh_stop(struct ast_bridge *bridge)
        ast_softhangup(chan, AST_CAUSE_NORMAL_CLEARING);
        ao2_cleanup(chan);
 
-       ao2_unlink_flags(app_bridges_moh, moh_wrapper, OBJ_NOLOCK);
-
        return 0;
 }
 
@@ -582,15 +576,15 @@ static void control_unlink(struct stasis_app_control *control)
                return;
        }
 
-       ao2_unlink_flags(app_controls, control,
-               OBJ_SEARCH_OBJECT | OBJ_UNLINK | OBJ_NODATA);
+       ao2_unlink(app_controls, control);
        ao2_cleanup(control);
 }
 
 struct ast_bridge *stasis_app_bridge_create(const char *type)
 {
        struct ast_bridge *bridge;
-       int capabilities, flags = AST_BRIDGE_FLAG_MERGE_INHIBIT_FROM | AST_BRIDGE_FLAG_MERGE_INHIBIT_TO
+       int capabilities;
+       int flags = AST_BRIDGE_FLAG_MERGE_INHIBIT_FROM | AST_BRIDGE_FLAG_MERGE_INHIBIT_TO
                | AST_BRIDGE_FLAG_SWAP_INHIBIT_FROM | AST_BRIDGE_FLAG_SWAP_INHIBIT_TO
                | AST_BRIDGE_FLAG_TRANSFER_PROHIBITED;
 
@@ -607,7 +601,10 @@ struct ast_bridge *stasis_app_bridge_create(const char *type)
 
        bridge = ast_bridge_base_new(capabilities, flags);
        if (bridge) {
-               ao2_link(app_bridges, bridge);
+               if (!ao2_link(app_bridges, bridge)) {
+                       ast_bridge_destroy(bridge, 0);
+                       bridge = NULL;
+               }
        }
        return bridge;
 }
@@ -1072,12 +1069,12 @@ enum stasis_app_subscribe_res stasis_app_unsubscribe(const char *app_name,
        int i;
 
        if (app_name) {
-               ast_log(LOG_WARNING, "Could not find app '%s'\n",
-                       app_name ? : "(null)");
                app = ao2_find(apps_registry, app_name, OBJ_SEARCH_KEY);
        }
 
        if (!app) {
+               ast_log(LOG_WARNING, "Could not find app '%s'\n",
+                       app_name ? : "(null)");
                return STASIS_ASR_APP_NOT_FOUND;
        }
 
@@ -1139,34 +1136,6 @@ void stasis_app_unref(void)
        ast_module_unref(ast_module_info->self);
 }
 
-static int load_module(void)
-{
-       apps_registry = ao2_container_alloc(APPS_NUM_BUCKETS, app_hash,
-               app_compare);
-       if (apps_registry == NULL) {
-               return AST_MODULE_LOAD_FAILURE;
-       }
-
-       app_controls = ao2_container_alloc(CONTROLS_NUM_BUCKETS, control_hash,
-               control_compare);
-       if (app_controls == NULL) {
-               return AST_MODULE_LOAD_FAILURE;
-       }
-
-        app_bridges = ao2_container_alloc(BRIDGES_NUM_BUCKETS, bridges_hash,
-               bridges_compare);
-
-       app_bridges_moh = ao2_container_alloc_hash(
-               AO2_ALLOC_OPT_LOCK_MUTEX, AO2_CONTAINER_ALLOC_OPT_DUPS_REJECT,
-               37, bridges_moh_hash_fn, bridges_moh_sort_fn, NULL);
-
-       if (!app_bridges_moh) {
-               return AST_MODULE_LOAD_FAILURE;
-       }
-
-       return AST_MODULE_LOAD_SUCCESS;
-}
-
 static int unload_module(void)
 {
        ao2_cleanup(apps_registry);
@@ -1184,6 +1153,22 @@ static int unload_module(void)
        return 0;
 }
 
+static int load_module(void)
+{
+       apps_registry = ao2_container_alloc(APPS_NUM_BUCKETS, app_hash, app_compare);
+       app_controls = ao2_container_alloc(CONTROLS_NUM_BUCKETS, control_hash, control_compare);
+       app_bridges = ao2_container_alloc(BRIDGES_NUM_BUCKETS, bridges_hash, bridges_compare);
+       app_bridges_moh = ao2_container_alloc_hash(
+               AO2_ALLOC_OPT_LOCK_MUTEX, AO2_CONTAINER_ALLOC_OPT_DUPS_REJECT,
+               37, bridges_moh_hash_fn, bridges_moh_sort_fn, NULL);
+       if (!apps_registry || !app_controls || !app_bridges || !app_bridges_moh) {
+               unload_module();
+               return AST_MODULE_LOAD_FAILURE;
+       }
+
+       return AST_MODULE_LOAD_SUCCESS;
+}
+
 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_GLOBAL_SYMBOLS, "Stasis application support",
        .load = load_module,
        .unload = unload_module,