C does not support templates like C++. ........ Merged revisions 402438 from http://svn.asterisk.org/svn/asterisk/branches/12 git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@402439 65c4cc65-6c06-0410-ace0-fbb531ad65f3
846 lines
23 KiB
C
846 lines
23 KiB
C
/*
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* Asterisk -- An open source telephony toolkit.
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*
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* Copyright (C) 2013, Digium, Inc.
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*
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* David M. Lee, II <dlee@digium.com>
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*
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* See http://www.asterisk.org for more information about
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* the Asterisk project. Please do not directly contact
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* any of the maintainers of this project for assistance;
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* the project provides a web site, mailing lists and IRC
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* channels for your use.
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*
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* This program is free software, distributed under the terms of
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* the GNU General Public License Version 2. See the LICENSE file
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* at the top of the source tree.
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*/
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/*! \file
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*
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* \brief Stasis Message Bus API.
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*
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* \author David M. Lee, II <dlee@digium.com>
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*/
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/*** MODULEINFO
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<support_level>core</support_level>
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***/
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#include "asterisk.h"
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ASTERISK_FILE_VERSION(__FILE__, "$Revision$");
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#include "asterisk/astobj2.h"
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#include "asterisk/stasis_internal.h"
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#include "asterisk/stasis.h"
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#include "asterisk/taskprocessor.h"
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#include "asterisk/utils.h"
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#include "asterisk/uuid.h"
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#include "asterisk/vector.h"
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/*!
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* \page stasis-impl Stasis Implementation Notes
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*
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* \par Reference counting
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*
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* Stasis introduces a number of objects, which are tightly related to one
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* another. Because we rely on ref-counting for memory management, understanding
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* these relationships is important to understanding this code.
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*
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* \code{.txt}
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*
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* stasis_topic <----> stasis_subscription
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* ^ ^
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* \ /
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* \ /
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* dispatch
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* |
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* |
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* v
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* stasis_message
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* |
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* |
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* v
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* stasis_message_type
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*
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* \endcode
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*
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* The most troubling thing in this chart is the cyclic reference between
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* stasis_topic and stasis_subscription. This is both unfortunate, and
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* necessary. Topics need the subscription in order to dispatch messages;
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* subscriptions need the topics to unsubscribe and check subscription status.
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*
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* The cycle is broken by stasis_unsubscribe(). The unsubscribe will remove the
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* topic's reference to a subscription. When the subcription is destroyed, it
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* will remove its reference to the topic.
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*
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* This means that until a subscription has be explicitly unsubscribed, it will
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* not be destroyed. Neither will a topic be destroyed while it has subscribers.
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* The destructors of both have assertions regarding this to catch ref-counting
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* problems where a subscription or topic has had an extra ao2_cleanup().
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*
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* The \ref dispatch object is a transient object, which is posted to a
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* subscription's taskprocessor to send a message to the subscriber. They have
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* short life cycles, allocated on one thread, destroyed on another.
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*
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* During shutdown, or the deletion of a domain object, there are a flurry of
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* ao2_cleanup()s on subscriptions and topics, as the final in-flight messages
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* are processed. Any one of these cleanups could be the one to actually destroy
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* a given object, so care must be taken to ensure that an object isn't
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* referenced after an ao2_cleanup(). This includes the implicit ao2_unlock()
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* that might happen when a RAII_VAR() goes out of scope.
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*
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* \par Typical life cycles
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*
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* \li stasis_topic - There are several topics which live for the duration of
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* the Asterisk process (ast_channel_topic_all(), etc.) but most of these
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* are actually fed by shorter-lived topics whose lifetime is associated
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* with some domain object (like ast_channel_topic() for a given
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* ast_channel).
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*
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* \li stasis_subscription - Subscriptions have a similar mix of lifetimes as
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* topics, for similar reasons.
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*
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* \li dispatch - Very short lived; just long enough to post a message to a
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* subscriber.
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*
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* \li stasis_message - Short to intermediate lifetimes, but that is mostly
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* irrelevant. Messages are strictly data and have no behavior associated
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* with them, so it doesn't really matter if/when they are destroyed. By
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* design, a component could hold a ref to a message forever without any
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* ill consequences (aside from consuming more memory).
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*
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* \li stasis_message_type - Long life cycles, typically only destroyed on
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* module unloading or _clean_ process exit.
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*
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* \par Subscriber shutdown sequencing
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*
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* Subscribers are sensitive to shutdown sequencing, specifically in how the
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* reference message types. This is fully detailed on the wiki at
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* https://wiki.asterisk.org/wiki/x/K4BqAQ.
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*
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* In short, the lifetime of the \a data (and \a callback, if in a module) must
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* be held until the stasis_subscription_final_message() has been received.
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* Depending on the structure of the subscriber code, this can be handled by
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* using stasis_subscription_final_message() to free resources on the final
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* message, or using stasis_subscription_join()/stasis_unsubscribe_and_join() to
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* block until the unsubscribe has completed.
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*/
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/*! Initial size of the subscribers list. */
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#define INITIAL_SUBSCRIBERS_MAX 4
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/*! The number of buckets to use for topic pools */
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#define TOPIC_POOL_BUCKETS 57
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STASIS_MESSAGE_TYPE_DEFN(stasis_subscription_change_type);
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/*! \internal */
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struct stasis_topic {
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char *name;
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/*! Variable length array of the subscribers */
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AST_VECTOR(, struct stasis_subscription *) subscribers;
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/*! Topics forwarding into this topic */
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AST_VECTOR(, struct stasis_topic *) upstream_topics;
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};
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/* Forward declarations for the tightly-coupled subscription object */
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static int topic_add_subscription(struct stasis_topic *topic,
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struct stasis_subscription *sub);
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static int topic_remove_subscription(struct stasis_topic *topic, struct stasis_subscription *sub);
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/*! \brief Lock two topics. */
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#define topic_lock_both(topic1, topic2) \
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do { \
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ao2_lock(topic1); \
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while (ao2_trylock(topic2)) { \
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AO2_DEADLOCK_AVOIDANCE(topic1); \
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} \
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} while (0)
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static void topic_dtor(void *obj)
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{
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struct stasis_topic *topic = obj;
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/* Subscribers hold a reference to topics, so they should all be
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* unsubscribed before we get here. */
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ast_assert(AST_VECTOR_SIZE(&topic->subscribers) == 0);
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ast_free(topic->name);
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topic->name = NULL;
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AST_VECTOR_FREE(&topic->subscribers);
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AST_VECTOR_FREE(&topic->upstream_topics);
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}
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struct stasis_topic *stasis_topic_create(const char *name)
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{
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RAII_VAR(struct stasis_topic *, topic, NULL, ao2_cleanup);
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int res = 0;
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topic = ao2_alloc(sizeof(*topic), topic_dtor);
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if (!topic) {
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return NULL;
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}
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topic->name = ast_strdup(name);
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if (!topic->name) {
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return NULL;
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}
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res |= AST_VECTOR_INIT(&topic->subscribers, INITIAL_SUBSCRIBERS_MAX);
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res |= AST_VECTOR_INIT(&topic->upstream_topics, 0);
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if (res != 0) {
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return NULL;
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}
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ao2_ref(topic, +1);
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return topic;
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}
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const char *stasis_topic_name(const struct stasis_topic *topic)
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{
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return topic->name;
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}
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/*! \internal */
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struct stasis_subscription {
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/*! Unique ID for this subscription */
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char uniqueid[AST_UUID_STR_LEN];
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/*! Topic subscribed to. */
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struct stasis_topic *topic;
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/*! Mailbox for processing incoming messages. */
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struct ast_taskprocessor *mailbox;
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/*! Callback function for incoming message processing. */
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stasis_subscription_cb callback;
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/*! Data pointer to be handed to the callback. */
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void *data;
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/*! Lock for completion flags \c final_message_{rxed,processed}. */
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ast_mutex_t join_lock;
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/*! Condition for joining with subscription. */
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ast_cond_t join_cond;
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/*! Flag set when final message for sub has been received.
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* Be sure join_lock is held before reading/setting. */
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int final_message_rxed;
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/*! Flag set when final message for sub has been processed.
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* Be sure join_lock is held before reading/setting. */
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int final_message_processed;
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};
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static void subscription_dtor(void *obj)
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{
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struct stasis_subscription *sub = obj;
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/* Subscriptions need to be manually unsubscribed before destruction
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* b/c there's a cyclic reference between topics and subscriptions */
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ast_assert(!stasis_subscription_is_subscribed(sub));
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/* If there are any messages in flight to this subscription; that would
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* be bad. */
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ast_assert(stasis_subscription_is_done(sub));
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ao2_cleanup(sub->topic);
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sub->topic = NULL;
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ast_taskprocessor_unreference(sub->mailbox);
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sub->mailbox = NULL;
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ast_mutex_destroy(&sub->join_lock);
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ast_cond_destroy(&sub->join_cond);
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}
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/*!
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* \brief Invoke the subscription's callback.
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* \param sub Subscription to invoke.
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* \param topic Topic message was published to.
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* \param message Message to send.
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*/
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static void subscription_invoke(struct stasis_subscription *sub,
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struct stasis_message *message)
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{
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/* Notify that the final message has been received */
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if (stasis_subscription_final_message(sub, message)) {
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SCOPED_MUTEX(lock, &sub->join_lock);
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sub->final_message_rxed = 1;
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ast_cond_signal(&sub->join_cond);
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}
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/* Since sub is mostly immutable, no need to lock sub */
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sub->callback(sub->data, sub, message);
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/* Notify that the final message has been processed */
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if (stasis_subscription_final_message(sub, message)) {
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SCOPED_MUTEX(lock, &sub->join_lock);
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sub->final_message_processed = 1;
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ast_cond_signal(&sub->join_cond);
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}
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}
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static void send_subscription_subscribe(struct stasis_topic *topic, struct stasis_subscription *sub);
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static void send_subscription_unsubscribe(struct stasis_topic *topic, struct stasis_subscription *sub);
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struct stasis_subscription *internal_stasis_subscribe(
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struct stasis_topic *topic,
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stasis_subscription_cb callback,
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void *data,
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int needs_mailbox)
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{
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RAII_VAR(struct stasis_subscription *, sub, NULL, ao2_cleanup);
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if (!topic) {
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return NULL;
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}
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sub = ao2_alloc(sizeof(*sub), subscription_dtor);
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if (!sub) {
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return NULL;
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}
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ast_uuid_generate_str(sub->uniqueid, sizeof(sub->uniqueid));
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if (needs_mailbox) {
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/* With a small number of subscribers, a thread-per-sub is
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* acceptable. If our usage changes so that we have larger
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* numbers of subscribers, we'll probably want to consider
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* a threadpool. We had that originally, but with so few
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* subscribers it was actually a performance loss instead of
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* a gain.
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*/
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sub->mailbox = ast_taskprocessor_get(sub->uniqueid,
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TPS_REF_DEFAULT);
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if (!sub->mailbox) {
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return NULL;
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}
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ast_taskprocessor_set_local(sub->mailbox, sub);
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/* Taskprocessor has a reference */
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ao2_ref(sub, +1);
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}
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ao2_ref(topic, +1);
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sub->topic = topic;
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sub->callback = callback;
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sub->data = data;
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ast_mutex_init(&sub->join_lock);
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ast_cond_init(&sub->join_cond, NULL);
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if (topic_add_subscription(topic, sub) != 0) {
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return NULL;
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}
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send_subscription_subscribe(topic, sub);
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ao2_ref(sub, +1);
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return sub;
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}
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struct stasis_subscription *stasis_subscribe(
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struct stasis_topic *topic,
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stasis_subscription_cb callback,
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void *data)
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{
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return internal_stasis_subscribe(topic, callback, data, 1);
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}
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static int sub_cleanup(void *data)
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{
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struct stasis_subscription *sub = data;
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ao2_cleanup(sub);
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return 0;
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}
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struct stasis_subscription *stasis_unsubscribe(struct stasis_subscription *sub)
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{
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/* The subscription may be the last ref to this topic. Hold
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* the topic ref open until after the unlock. */
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RAII_VAR(struct stasis_topic *, topic,
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ao2_bump(sub ? sub->topic : NULL), ao2_cleanup);
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if (!sub) {
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return NULL;
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}
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/* We have to remove the subscription first, to ensure the unsubscribe
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* is the final message */
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if (topic_remove_subscription(sub->topic, sub) != 0) {
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ast_log(LOG_ERROR,
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"Internal error: subscription has invalid topic\n");
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return NULL;
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}
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/* Now let everyone know about the unsubscribe */
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send_subscription_unsubscribe(topic, sub);
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/* When all that's done, remove the ref the mailbox has on the sub */
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if (sub->mailbox) {
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ast_taskprocessor_push(sub->mailbox, sub_cleanup, sub);
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}
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/* Unsubscribing unrefs the subscription */
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ao2_cleanup(sub);
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return NULL;
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}
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void stasis_subscription_join(struct stasis_subscription *subscription)
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{
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if (subscription) {
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SCOPED_MUTEX(lock, &subscription->join_lock);
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/* Wait until the processed flag has been set */
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while (!subscription->final_message_processed) {
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ast_cond_wait(&subscription->join_cond,
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&subscription->join_lock);
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}
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}
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}
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int stasis_subscription_is_done(struct stasis_subscription *subscription)
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{
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if (subscription) {
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SCOPED_MUTEX(lock, &subscription->join_lock);
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return subscription->final_message_rxed;
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}
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/* Null subscription is about as done as you can get */
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return 1;
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}
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struct stasis_subscription *stasis_unsubscribe_and_join(
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struct stasis_subscription *subscription)
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{
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if (!subscription) {
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return NULL;
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}
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/* Bump refcount to hold it past the unsubscribe */
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ao2_ref(subscription, +1);
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stasis_unsubscribe(subscription);
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stasis_subscription_join(subscription);
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/* Now decrement the refcount back */
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ao2_cleanup(subscription);
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return NULL;
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}
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int stasis_subscription_is_subscribed(const struct stasis_subscription *sub)
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{
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if (sub) {
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size_t i;
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struct stasis_topic *topic = sub->topic;
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SCOPED_AO2LOCK(lock_topic, topic);
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for (i = 0; i < AST_VECTOR_SIZE(&topic->subscribers); ++i) {
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if (AST_VECTOR_GET(&topic->subscribers, i) == sub) {
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return 1;
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}
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}
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}
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return 0;
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}
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const char *stasis_subscription_uniqueid(const struct stasis_subscription *sub)
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{
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return sub->uniqueid;
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}
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int stasis_subscription_final_message(struct stasis_subscription *sub, struct stasis_message *msg)
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{
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struct stasis_subscription_change *change;
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if (stasis_message_type(msg) != stasis_subscription_change_type()) {
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return 0;
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}
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change = stasis_message_data(msg);
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if (strcmp("Unsubscribe", change->description)) {
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return 0;
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}
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if (strcmp(stasis_subscription_uniqueid(sub), change->uniqueid)) {
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return 0;
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}
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return 1;
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}
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/*!
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* \brief Add a subscriber to a topic.
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* \param topic Topic
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* \param sub Subscriber
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* \return 0 on success
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* \return Non-zero on error
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*/
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static int topic_add_subscription(struct stasis_topic *topic, struct stasis_subscription *sub)
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{
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size_t idx;
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SCOPED_AO2LOCK(lock, topic);
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/* The reference from the topic to the subscription is shared with
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* the owner of the subscription, which will explicitly unsubscribe
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* to release it.
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*
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* If we bumped the refcount here, the owner would have to unsubscribe
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* and cleanup, which is a bit awkward. */
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AST_VECTOR_APPEND(&topic->subscribers, sub);
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for (idx = 0; idx < AST_VECTOR_SIZE(&topic->upstream_topics); ++idx) {
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topic_add_subscription(
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AST_VECTOR_GET(&topic->upstream_topics, idx), sub);
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}
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return 0;
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}
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static int topic_remove_subscription(struct stasis_topic *topic, struct stasis_subscription *sub)
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{
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size_t idx;
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SCOPED_AO2LOCK(lock_topic, topic);
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for (idx = 0; idx < AST_VECTOR_SIZE(&topic->upstream_topics); ++idx) {
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topic_remove_subscription(
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AST_VECTOR_GET(&topic->upstream_topics, idx), sub);
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}
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return AST_VECTOR_REMOVE_ELEM_UNORDERED(&topic->subscribers, sub,
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AST_VECTOR_ELEM_CLEANUP_NOOP);
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}
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/*!
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* \brief Dispatch a message to a subscriber
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* \param data \ref dispatch object
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* \return 0
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*/
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static int dispatch_exec(struct ast_taskprocessor_local *local)
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{
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struct stasis_subscription *sub = local->local_data;
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struct stasis_message *message = local->data;
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subscription_invoke(sub, message);
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ao2_cleanup(message);
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return 0;
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}
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static void dispatch_message(struct stasis_subscription *sub,
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|
struct stasis_message *message)
|
|
{
|
|
if (sub->mailbox) {
|
|
ao2_bump(message);
|
|
if (ast_taskprocessor_push_local(sub->mailbox, dispatch_exec, message) != 0) {
|
|
/* Push failed; ugh. */
|
|
ast_log(LOG_ERROR, "Dropping dispatch\n");
|
|
ao2_cleanup(message);
|
|
}
|
|
} else {
|
|
/* Dispatch directly */
|
|
subscription_invoke(sub, message);
|
|
}
|
|
}
|
|
|
|
void stasis_publish(struct stasis_topic *topic, struct stasis_message *message)
|
|
{
|
|
size_t i;
|
|
|
|
ast_assert(topic != NULL);
|
|
ast_assert(message != NULL);
|
|
|
|
/*
|
|
* 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);
|
|
}
|
|
|
|
/*!
|
|
* \brief Forwarding information
|
|
*
|
|
* Any message posted to \a from_topic is forwarded to \a to_topic.
|
|
*
|
|
* In cases where both the \a from_topic and \a to_topic need to be locked,
|
|
* always lock the \a to_topic first, then the \a from_topic. Lest you deadlock.
|
|
*/
|
|
struct stasis_forward {
|
|
/*! Originating topic */
|
|
struct stasis_topic *from_topic;
|
|
/*! Destination topic */
|
|
struct stasis_topic *to_topic;
|
|
};
|
|
|
|
static void forward_dtor(void *obj)
|
|
{
|
|
struct stasis_forward *forward = obj;
|
|
|
|
ao2_cleanup(forward->from_topic);
|
|
forward->from_topic = NULL;
|
|
ao2_cleanup(forward->to_topic);
|
|
forward->to_topic = NULL;
|
|
}
|
|
|
|
struct stasis_forward *stasis_forward_cancel(struct stasis_forward *forward)
|
|
{
|
|
int idx;
|
|
struct stasis_topic *from;
|
|
struct stasis_topic *to;
|
|
|
|
if (!forward) {
|
|
return NULL;
|
|
}
|
|
|
|
from = forward->from_topic;
|
|
to = forward->to_topic;
|
|
|
|
topic_lock_both(to, from);
|
|
AST_VECTOR_REMOVE_ELEM_UNORDERED(&to->upstream_topics, from,
|
|
AST_VECTOR_ELEM_CLEANUP_NOOP);
|
|
|
|
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);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
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) {
|
|
return NULL;
|
|
}
|
|
|
|
forward = ao2_alloc(sizeof(*forward), forward_dtor);
|
|
if (!forward) {
|
|
return NULL;
|
|
}
|
|
|
|
forward->from_topic = ao2_bump(from_topic);
|
|
forward->to_topic = ao2_bump(to_topic);
|
|
|
|
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;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
static void subscription_change_dtor(void *obj)
|
|
{
|
|
struct stasis_subscription_change *change = obj;
|
|
ast_string_field_free_memory(change);
|
|
ao2_cleanup(change->topic);
|
|
}
|
|
|
|
static struct stasis_subscription_change *subscription_change_alloc(struct stasis_topic *topic, const char *uniqueid, const char *description)
|
|
{
|
|
RAII_VAR(struct stasis_subscription_change *, change, NULL, ao2_cleanup);
|
|
|
|
change = ao2_alloc(sizeof(struct stasis_subscription_change), subscription_change_dtor);
|
|
if (ast_string_field_init(change, 128)) {
|
|
return NULL;
|
|
}
|
|
|
|
ast_string_field_set(change, uniqueid, uniqueid);
|
|
ast_string_field_set(change, description, description);
|
|
ao2_ref(topic, +1);
|
|
change->topic = topic;
|
|
|
|
ao2_ref(change, +1);
|
|
return change;
|
|
}
|
|
|
|
static void send_subscription_subscribe(struct stasis_topic *topic, struct stasis_subscription *sub)
|
|
{
|
|
RAII_VAR(struct stasis_subscription_change *, change, NULL, ao2_cleanup);
|
|
RAII_VAR(struct stasis_message *, msg, NULL, ao2_cleanup);
|
|
|
|
/* This assumes that we have already unsubscribed */
|
|
ast_assert(stasis_subscription_is_subscribed(sub));
|
|
|
|
change = subscription_change_alloc(topic, sub->uniqueid, "Subscribe");
|
|
|
|
if (!change) {
|
|
return;
|
|
}
|
|
|
|
msg = stasis_message_create(stasis_subscription_change_type(), change);
|
|
|
|
if (!msg) {
|
|
return;
|
|
}
|
|
|
|
stasis_publish(topic, msg);
|
|
}
|
|
|
|
static void send_subscription_unsubscribe(struct stasis_topic *topic,
|
|
struct stasis_subscription *sub)
|
|
{
|
|
RAII_VAR(struct stasis_subscription_change *, change, NULL, ao2_cleanup);
|
|
RAII_VAR(struct stasis_message *, msg, NULL, ao2_cleanup);
|
|
|
|
/* This assumes that we have already unsubscribed */
|
|
ast_assert(!stasis_subscription_is_subscribed(sub));
|
|
|
|
change = subscription_change_alloc(topic, sub->uniqueid, "Unsubscribe");
|
|
|
|
if (!change) {
|
|
return;
|
|
}
|
|
|
|
msg = stasis_message_create(stasis_subscription_change_type(), change);
|
|
|
|
if (!msg) {
|
|
return;
|
|
}
|
|
|
|
stasis_publish(topic, msg);
|
|
|
|
/* Now we have to dispatch to the subscription itself */
|
|
dispatch_message(sub, msg);
|
|
}
|
|
|
|
struct topic_pool_entry {
|
|
struct stasis_forward *forward;
|
|
struct stasis_topic *topic;
|
|
};
|
|
|
|
static void topic_pool_entry_dtor(void *obj)
|
|
{
|
|
struct topic_pool_entry *entry = obj;
|
|
entry->forward = stasis_forward_cancel(entry->forward);
|
|
ao2_cleanup(entry->topic);
|
|
entry->topic = NULL;
|
|
}
|
|
|
|
static struct topic_pool_entry *topic_pool_entry_alloc(void)
|
|
{
|
|
return ao2_alloc(sizeof(struct topic_pool_entry), topic_pool_entry_dtor);
|
|
}
|
|
|
|
struct stasis_topic_pool {
|
|
struct ao2_container *pool_container;
|
|
struct stasis_topic *pool_topic;
|
|
};
|
|
|
|
static void topic_pool_dtor(void *obj)
|
|
{
|
|
struct stasis_topic_pool *pool = obj;
|
|
ao2_cleanup(pool->pool_container);
|
|
pool->pool_container = NULL;
|
|
ao2_cleanup(pool->pool_topic);
|
|
pool->pool_topic = NULL;
|
|
}
|
|
|
|
static int topic_pool_entry_hash(const void *obj, const int flags)
|
|
{
|
|
const char *topic_name = (flags & OBJ_KEY) ? obj : stasis_topic_name(((struct topic_pool_entry*) obj)->topic);
|
|
return ast_str_case_hash(topic_name);
|
|
}
|
|
|
|
static int topic_pool_entry_cmp(void *obj, void *arg, int flags)
|
|
{
|
|
struct topic_pool_entry *opt1 = obj, *opt2 = arg;
|
|
const char *topic_name = (flags & OBJ_KEY) ? arg : stasis_topic_name(opt2->topic);
|
|
return strcasecmp(stasis_topic_name(opt1->topic), topic_name) ? 0 : CMP_MATCH | CMP_STOP;
|
|
}
|
|
|
|
struct stasis_topic_pool *stasis_topic_pool_create(struct stasis_topic *pooled_topic)
|
|
{
|
|
RAII_VAR(struct stasis_topic_pool *, pool, ao2_alloc(sizeof(*pool), topic_pool_dtor), ao2_cleanup);
|
|
if (!pool) {
|
|
return NULL;
|
|
}
|
|
pool->pool_container = ao2_container_alloc(TOPIC_POOL_BUCKETS, topic_pool_entry_hash, topic_pool_entry_cmp);
|
|
ao2_ref(pooled_topic, +1);
|
|
pool->pool_topic = pooled_topic;
|
|
|
|
ao2_ref(pool, +1);
|
|
return pool;
|
|
}
|
|
|
|
struct stasis_topic *stasis_topic_pool_get_topic(struct stasis_topic_pool *pool, const char *topic_name)
|
|
{
|
|
RAII_VAR(struct topic_pool_entry *, topic_pool_entry, NULL, ao2_cleanup);
|
|
SCOPED_AO2LOCK(topic_container_lock, pool->pool_container);
|
|
topic_pool_entry = ao2_find(pool->pool_container, topic_name, OBJ_KEY | OBJ_NOLOCK);
|
|
|
|
if (topic_pool_entry) {
|
|
return topic_pool_entry->topic;
|
|
}
|
|
|
|
topic_pool_entry = topic_pool_entry_alloc();
|
|
|
|
if (!topic_pool_entry) {
|
|
return NULL;
|
|
}
|
|
|
|
topic_pool_entry->topic = stasis_topic_create(topic_name);
|
|
if (!topic_pool_entry->topic) {
|
|
return NULL;
|
|
}
|
|
|
|
topic_pool_entry->forward = stasis_forward_all(topic_pool_entry->topic, pool->pool_topic);
|
|
if (!topic_pool_entry->forward) {
|
|
return NULL;
|
|
}
|
|
|
|
ao2_link_flags(pool->pool_container, topic_pool_entry, OBJ_NOLOCK);
|
|
|
|
return topic_pool_entry->topic;
|
|
}
|
|
|
|
void stasis_log_bad_type_access(const char *name)
|
|
{
|
|
ast_log(LOG_ERROR, "Use of %s() before init/after destruction\n", name);
|
|
}
|
|
|
|
/*! \brief Cleanup function for graceful shutdowns */
|
|
static void stasis_cleanup(void)
|
|
{
|
|
STASIS_MESSAGE_TYPE_CLEANUP(stasis_subscription_change_type);
|
|
}
|
|
|
|
int stasis_init(void)
|
|
{
|
|
int cache_init;
|
|
|
|
/* Be sure the types are cleaned up after the message bus */
|
|
ast_register_cleanup(stasis_cleanup);
|
|
|
|
cache_init = stasis_cache_init();
|
|
if (cache_init != 0) {
|
|
return -1;
|
|
}
|
|
|
|
if (STASIS_MESSAGE_TYPE_INIT(stasis_subscription_change_type) != 0) {
|
|
return -1;
|
|
}
|
|
|
|
return 0;
|
|
}
|