res/res_stasis: Fix crash on module unload while performing operation

When the res_stasis module is unloaded, it will dispose of the apps_registry
container. This is a problem if an ARI operation is in flight that attempts
to use the registry, as the shutdown occurs in a separate thread. This patch
adds some sanity checks to the various routines that access the registry which
cause the operations to fail if the apps_registry does not exist.

Crash caught by the Asterisk Test Suite.

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/12@426995 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/res/res_stasis.c b/res/res_stasis.c
index 36d0132ae06e277ac732c2f6b359e51e40cf64a2..b848fafad36fabc97a5a99fdcf562ae06a61bd79 100644 (file)
--- a/res/res_stasis.c
+++ b/res/res_stasis.c
@@ -1204,6 +1204,10 @@ int stasis_app_exec(struct ast_channel *chan, const char *app_name, int argc,
         */
        remove_stasis_end_published(chan);
 
+       if (!apps_registry) {
+               return -1;
+       }
+
        app = ao2_find(apps_registry, app_name, OBJ_SEARCH_KEY);
        if (!app) {
                ast_log(LOG_ERROR,
@@ -1364,6 +1368,10 @@ int stasis_app_send(const char *app_name, struct ast_json *message)
 {
        RAII_VAR(struct stasis_app *, app, NULL, ao2_cleanup);
 
+       if (!apps_registry) {
+               return -1;
+       }
+
        app = ao2_find(apps_registry, app_name, OBJ_SEARCH_KEY);
        if (!app) {
                /* XXX We can do a better job handling late binding, queueing up
@@ -1381,6 +1389,10 @@ static struct stasis_app *find_app_by_name(const char *app_name)
 {
        struct stasis_app *res = NULL;
 
+       if (!apps_registry) {
+               return NULL;
+       }
+
        if (!ast_strlen_zero(app_name)) {
                res = ao2_find(apps_registry, app_name, OBJ_SEARCH_KEY);
        }
@@ -1405,6 +1417,10 @@ struct ao2_container *stasis_app_get_all(void)
 {
        RAII_VAR(struct ao2_container *, apps, NULL, ao2_cleanup);
 
+       if (!apps_registry) {
+               return NULL;
+       }
+
        apps = ast_str_container_alloc(1);
        if (!apps) {
                return NULL;
@@ -1419,8 +1435,11 @@ int stasis_app_register(const char *app_name, stasis_app_cb handler, void *data)
 {
        RAII_VAR(struct stasis_app *, app, NULL, ao2_cleanup);
 
-       SCOPED_LOCK(apps_lock, apps_registry, ao2_lock, ao2_unlock);
+       if (!apps_registry) {
+               return -1;
+       }
 
+       ao2_lock(apps_registry);
        app = ao2_find(apps_registry, app_name, OBJ_SEARCH_KEY | OBJ_NOLOCK);
        if (app) {
                app_update(app, handler, data);
@@ -1429,6 +1448,7 @@ int stasis_app_register(const char *app_name, stasis_app_cb handler, void *data)
                if (app) {
                        ao2_link_flags(apps_registry, app, OBJ_NOLOCK);
                } else {
+                       ao2_unlock(apps_registry);
                        return -1;
                }
        }
@@ -1437,6 +1457,7 @@ int stasis_app_register(const char *app_name, stasis_app_cb handler, void *data)
         * prevent memory leaks, and we're lazy.
         */
        cleanup();
+       ao2_unlock(apps_registry);
        return 0;
 }
 
@@ -1448,6 +1469,10 @@ void stasis_app_unregister(const char *app_name)
                return;
        }
 
+       if (!apps_registry) {
+               return;
+       }
+
        app = ao2_find(apps_registry, app_name, OBJ_SEARCH_KEY);
        if (!app) {
                ast_log(LOG_ERROR,
@@ -1837,6 +1862,7 @@ static int unload_module(void)
 
        messaging_cleanup();
 
+       cleanup();
        ao2_cleanup(apps_registry);
        apps_registry = NULL;