Rework stasis cache clear events

Stasis cache clear message payloads now consist of a stasis_message
representative of the message to be cleared from the cache. This allows
multiple parallel caches to coexist and be cleared properly by the same
cache clear message even when keyed on different fields.

This change fixes a bug where multiple cache clears could be posted for
channels. The cache clear is now produced in the destructor instead of
ast_hangup.

Additionally, dummy channels are no longer capable of producing channel
snapshots.

Review: https://reviewboard.asterisk.org/r/2596


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@390830 65c4cc65-6c06-0410-ace0-fbb531ad65f3

5 files changed, 94 insertions, 48 deletions

diff --git a/main/bridging.c b/main/bridging.c
index d5d17ae9e..6a21c0b64 100644
--- a/main/bridging.c
+++ b/main/bridging.c
@@ -1283,17 +1283,32 @@ static void bridge_handle_actions(struct ast_bridge *bridge)
 	}
 }
 
+static struct stasis_message *create_bridge_snapshot_message(struct ast_bridge *bridge)
+{
+	RAII_VAR(struct ast_bridge_snapshot *, snapshot, NULL, ao2_cleanup);
+	snapshot = ast_bridge_snapshot_create(bridge);
+	if (!snapshot) {
+		return NULL;
+	}
+
+	return stasis_message_create(ast_bridge_snapshot_type(), snapshot);
+}
+
 static void destroy_bridge(void *obj)
 {
 	struct ast_bridge *bridge = obj;
-	RAII_VAR(struct stasis_message *, msg, NULL, ao2_cleanup);
+	RAII_VAR(struct stasis_message *, clear_msg, NULL, ao2_cleanup);
 
 	ast_debug(1, "Bridge %s: actually destroying %s bridge, nobody wants it anymore\n",
 		bridge->uniqueid, bridge->v_table->name);
 
-	msg = stasis_cache_clear_create(ast_bridge_snapshot_type(), bridge->uniqueid);
-	if (msg) {
-		stasis_publish(ast_bridge_topic(bridge), msg);
+	clear_msg = create_bridge_snapshot_message(bridge);
+	if (clear_msg) {
+		RAII_VAR(struct stasis_message *, msg, NULL, ao2_cleanup);
+		msg = stasis_cache_clear_create(clear_msg);
+		if (msg) {
+			stasis_publish(ast_bridge_topic(bridge), msg);
+		}
 	}
 
 	/* Do any pending actions in the context of destruction. */
diff --git a/main/channel.c b/main/channel.c
index 4adff953c..f3aabd04a 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -817,11 +817,28 @@ int ast_str2cause(const char *name)
 	return -1;
 }
 
+static struct stasis_message *create_channel_snapshot_message(struct ast_channel *channel)
+{
+	RAII_VAR(struct ast_channel_snapshot *, snapshot, NULL, ao2_cleanup);
+	snapshot = ast_channel_snapshot_create(channel);
+	if (!snapshot) {
+		return NULL;
+	}
+
+	return stasis_message_create(ast_channel_snapshot_type(), snapshot);
+}
+
 static void publish_cache_clear(struct ast_channel *chan)
 {
 	RAII_VAR(struct stasis_message *, message, NULL, ao2_cleanup);
+	RAII_VAR(struct stasis_message *, clear_msg, NULL, ao2_cleanup);
 
-	message = stasis_cache_clear_create(ast_channel_snapshot_type(), ast_channel_uniqueid(chan));
+	clear_msg = create_channel_snapshot_message(chan);
+	if (!clear_msg) {
+		return;
+	}
+
+	message = stasis_cache_clear_create(clear_msg);
 	stasis_publish(ast_channel_topic(chan), message);
 }
 
@@ -1161,6 +1178,7 @@ __ast_channel_alloc_ap(int needqueue, int state, const char *cid_num, const char
 	}
 
 	ast_channel_internal_finalize(tmp);
+	ast_publish_channel_state(tmp);
 	return tmp;
 }
 
@@ -2369,6 +2387,8 @@ static void ast_channel_destructor(void *obj)
 	char device_name[AST_CHANNEL_NAME];
 	struct ast_callid *callid;
 
+	publish_cache_clear(chan);
+
 	if (ast_channel_internal_is_finalized(chan)) {
 		ast_cel_report_event(chan, AST_CEL_CHANNEL_END, NULL, NULL, NULL);
 		ast_cel_check_retire_linkedid(chan);
@@ -2884,7 +2904,6 @@ int ast_hangup(struct ast_channel *chan)
 	ast_cc_offer(chan);
 
 	ast_publish_channel_state(chan);
-	publish_cache_clear(chan);
 
 	if (ast_channel_cdr(chan) && !ast_test_flag(ast_channel_cdr(chan), AST_CDR_FLAG_BRIDGED) &&
 		!ast_test_flag(ast_channel_cdr(chan), AST_CDR_FLAG_POST_DISABLED) &&
diff --git a/main/endpoints.c b/main/endpoints.c
index c2d0577f9..a5d50cfde 100644
--- a/main/endpoints.c
+++ b/main/endpoints.c
@@ -145,18 +145,25 @@ static void endpoint_channel_snapshot(void *data,
 	}
 }
 
+/*! \brief Handler for channel snapshot cache clears */
 static void endpoint_cache_clear(void *data,
 	struct stasis_subscription *sub, struct stasis_topic *topic,
 	struct stasis_message *message)
 {
 	struct ast_endpoint *endpoint = data;
-	struct stasis_cache_clear *clear = stasis_message_data(message);
+	struct stasis_message *clear_msg = stasis_message_data(message);
+	struct ast_channel_snapshot *clear_snapshot;
+
+	if (stasis_message_type(clear_msg) != ast_channel_snapshot_type()) {
+		return;
+	}
+
+	clear_snapshot = stasis_message_data(clear_msg);
 
 	ast_assert(endpoint != NULL);
-	ast_assert(clear != NULL);
 
 	ao2_lock(endpoint);
-	ao2_find(endpoint->channel_ids, clear->id, OBJ_POINTER | OBJ_NODATA | OBJ_UNLINK);
+	ast_str_container_remove(endpoint->channel_ids, clear_snapshot->uniqueid);
 	ao2_unlock(endpoint);
 	endpoint_publish_snapshot(endpoint);
 }
@@ -247,17 +254,32 @@ const char *ast_endpoint_get_tech(const struct ast_endpoint *endpoint)
 	return endpoint->tech;
 }
 
+static struct stasis_message *create_endpoint_snapshot_message(struct ast_endpoint *endpoint)
+{
+	RAII_VAR(struct ast_endpoint_snapshot *, snapshot, NULL, ao2_cleanup);
+	snapshot = ast_endpoint_snapshot_create(endpoint);
+	if (!snapshot) {
+		return NULL;
+	}
+
+	return stasis_message_create(ast_endpoint_snapshot_type(), snapshot);
+}
+
 void ast_endpoint_shutdown(struct ast_endpoint *endpoint)
 {
-	RAII_VAR(struct stasis_message *, message, NULL, ao2_cleanup);
+	RAII_VAR(struct stasis_message *, clear_msg, NULL, ao2_cleanup);
 
 	if (endpoint == NULL) {
 		return;
 	}
 
-	message = stasis_cache_clear_create(ast_endpoint_snapshot_type(), endpoint->id);
-	if (message) {
-		stasis_publish(endpoint->topic, message);
+	clear_msg = create_endpoint_snapshot_message(endpoint);
+	if (clear_msg) {
+		RAII_VAR(struct stasis_message *, message, NULL, ao2_cleanup);
+		message = stasis_cache_clear_create(clear_msg);
+		if (message) {
+			stasis_publish(endpoint->topic, message);
+		}
 	}
 
 	/* Bump refcount to hold on to the router */
diff --git a/main/stasis_cache.c b/main/stasis_cache.c
index ac34959db..546ad4998 100644
--- a/main/stasis_cache.c
+++ b/main/stasis_cache.c
@@ -262,30 +262,11 @@ struct ao2_container *stasis_cache_dump(struct stasis_caching_topic *caching_top
 STASIS_MESSAGE_TYPE_DEFN(stasis_cache_clear_type);
 STASIS_MESSAGE_TYPE_DEFN(stasis_cache_update_type);
 
-static void cache_clear_dtor(void *obj)
+struct stasis_message *stasis_cache_clear_create(struct stasis_message *id_message)
 {
-	struct stasis_cache_clear *ev = obj;
-	ao2_cleanup(ev->type);
-	ev->type = NULL;
-}
-
-struct stasis_message *stasis_cache_clear_create(struct stasis_message_type *type, const char *id)
-{
-	RAII_VAR(struct stasis_cache_clear *, ev, NULL, ao2_cleanup);
 	RAII_VAR(struct stasis_message *, msg, NULL, ao2_cleanup);
 
-	ev = ao2_alloc(sizeof(*ev) + strlen(id) + 1, cache_clear_dtor);
-	if (!ev) {
-		return NULL;
-	}
-
-	/* strcpy safe */
-	strcpy(ev->id, id);
-	ao2_ref(type, +1);
-	ev->type = type;
-
-	msg = stasis_message_create(stasis_cache_clear_type(), ev);
-
+	msg = stasis_message_create(stasis_cache_clear_type(), id_message);
 	if (!msg) {
 		return NULL;
 	}
@@ -363,21 +344,25 @@ static void caching_topic_exec(void *data, struct stasis_subscription *sub, stru
 	if (stasis_cache_clear_type() == stasis_message_type(message)) {
 		RAII_VAR(struct stasis_message *, old_snapshot, NULL, ao2_cleanup);
 		RAII_VAR(struct stasis_message *, update, NULL, ao2_cleanup);
-		struct stasis_cache_clear *clear = stasis_message_data(message);
-		ast_assert(clear->type != NULL);
-		ast_assert(clear->id != NULL);
-		old_snapshot = cache_put(caching_topic, clear->type, clear->id, NULL);
-		if (old_snapshot) {
-			update = update_create(topic, old_snapshot, NULL);
-			stasis_publish(caching_topic->topic, update);
-		} else {
-			/* While this could be a problem, it's very likely to
-			 * happen with message forwarding */
-			ast_debug(1,
-				"Attempting to remove an item from the cache that isn't there: %s %s\n",
-				stasis_message_type_name(clear->type), clear->id);
+		struct stasis_message *clear_msg = stasis_message_data(message);
+		const char *clear_id = caching_topic->id_fn(clear_msg);
+		struct stasis_message_type *clear_type = stasis_message_type(clear_msg);
+
+		ast_assert(clear_type != NULL);
+
+		if (clear_id) {
+			old_snapshot = cache_put(caching_topic, clear_type, clear_id, NULL);
+			if (old_snapshot) {
+				update = update_create(topic, old_snapshot, NULL);
+				stasis_publish(caching_topic->topic, update);
+				return;
+			}
+
+			ast_log(LOG_ERROR,
+				"Attempting to remove an item from the %s cache that isn't there: %s %s\n",
+				stasis_topic_name(caching_topic->topic), stasis_message_type_name(clear_type), clear_id);
+			return;
 		}
-		return;
 	}
 
 	id = caching_topic->id_fn(message);
diff --git a/main/stasis_channels.c b/main/stasis_channels.c
index 52b6ef4ce..65e9f917d 100644
--- a/main/stasis_channels.c
+++ b/main/stasis_channels.c
@@ -131,6 +131,11 @@ struct ast_channel_snapshot *ast_channel_snapshot_create(struct ast_channel *cha
 {
 	RAII_VAR(struct ast_channel_snapshot *, snapshot, NULL, ao2_cleanup);
 
+	/* no snapshots for dummy channels */
+	if (!ast_channel_tech(chan)) {
+		return NULL;
+	}
+
 	snapshot = ao2_alloc(sizeof(*snapshot), channel_snapshot_dtor);
 	if (!snapshot || ast_string_field_init(snapshot, 1024)) {
 		return NULL;