confbridge: Fix MOH on simultaneous user entry to a new conference.

When two users entered a new conference simultaneously, one of the callers
hears MOH.  This happened if two unmarked users entered simultaneously and
also if a waitmarked and a marked user entered simultaneously.

* Created a confbridge internal MOH API to eliminate the inlined MOH
handling code.  Note that the conference mixing bridge needs to be locked
when actually starting/stopping MOH because there is a small window
between the conference join unsuspend MOH and actually joining the mixing
bridge.

* Created the concept of suspended MOH so it can be interrupted while
conference join announcements to the user and DTMF features can operate.

* Suspend any MOH until the user is about to actually join the mixing
bridge of the conference.  This way any pre-join file playback does not
need to worry about MOH.

* Made post-join actions only play deferred entry announcement files.
Changing the user/conference state during that time is not protected or
controlled by the state machine.

(closes issue ASTERISK-20606)
Reported by: Eugenia Belova
Tested by: rmudgett

Review: https://reviewboard.asterisk.org/r/2232/
........

Merged revisions 377992 from http://svn.asterisk.org/svn/asterisk/branches/10
........

Merged revisions 377993 from http://svn.asterisk.org/svn/asterisk/branches/11


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@378002 65c4cc65-6c06-0410-ace0-fbb531ad65f3

5 files changed, 172 insertions, 49 deletions

diff --git a/apps/app_confbridge.c b/apps/app_confbridge.c
index b4ec076ed..22e97f193 100644
--- a/apps/app_confbridge.c
+++ b/apps/app_confbridge.c
@@ -909,6 +909,94 @@ static int handle_conf_user_leave(struct conference_bridge_user *cbu)
 	return 0;
 }
 
+void conf_moh_stop(struct conference_bridge_user *user)
+{
+	user->playing_moh = 0;
+	if (!user->suspended_moh) {
+		int in_bridge;
+
+		/*
+		 * Locking the ast_bridge here is the only way to hold off the
+		 * call to ast_bridge_join() in confbridge_exec() from
+		 * interfering with the bridge and MOH operations here.
+		 */
+		ast_bridge_lock(user->conference_bridge->bridge);
+
+		/*
+		 * Temporarily suspend the user from the bridge so we have
+		 * control to stop MOH if needed.
+		 */
+		in_bridge = !ast_bridge_suspend(user->conference_bridge->bridge, user->chan);
+		ast_moh_stop(user->chan);
+		if (in_bridge) {
+			ast_bridge_unsuspend(user->conference_bridge->bridge, user->chan);
+		}
+
+		ast_bridge_unlock(user->conference_bridge->bridge);
+	}
+}
+
+void conf_moh_start(struct conference_bridge_user *user)
+{
+	user->playing_moh = 1;
+	if (!user->suspended_moh) {
+		int in_bridge;
+
+		/*
+		 * Locking the ast_bridge here is the only way to hold off the
+		 * call to ast_bridge_join() in confbridge_exec() from
+		 * interfering with the bridge and MOH operations here.
+		 */
+		ast_bridge_lock(user->conference_bridge->bridge);
+
+		/*
+		 * Temporarily suspend the user from the bridge so we have
+		 * control to start MOH if needed.
+		 */
+		in_bridge = !ast_bridge_suspend(user->conference_bridge->bridge, user->chan);
+		ast_moh_start(user->chan, user->u_profile.moh_class, NULL);
+		if (in_bridge) {
+			ast_bridge_unsuspend(user->conference_bridge->bridge, user->chan);
+		}
+
+		ast_bridge_unlock(user->conference_bridge->bridge);
+	}
+}
+
+/*!
+ * \internal
+ * \brief Unsuspend MOH for the conference user.
+ *
+ * \param user Conference user to unsuspend MOH on.
+ *
+ * \return Nothing
+ */
+static void conf_moh_unsuspend(struct conference_bridge_user *user)
+{
+	ao2_lock(user->conference_bridge);
+	if (--user->suspended_moh == 0 && user->playing_moh) {
+		ast_moh_start(user->chan, user->u_profile.moh_class, NULL);
+	}
+	ao2_unlock(user->conference_bridge);
+}
+
+/*!
+ * \internal
+ * \brief Suspend MOH for the conference user.
+ *
+ * \param user Conference user to suspend MOH on.
+ *
+ * \return Nothing
+ */
+static void conf_moh_suspend(struct conference_bridge_user *user)
+{
+	ao2_lock(user->conference_bridge);
+	if (user->suspended_moh++ == 0 && user->playing_moh) {
+		ast_moh_stop(user->chan);
+	}
+	ao2_unlock(user->conference_bridge);
+}
+
 int conf_handle_first_marked_common(struct conference_bridge_user *cbu)
 {
 	if (!ast_test_flag(&cbu->u_profile, USER_OPT_QUIET) && play_prompt_to_user(cbu, conf_get_sound(CONF_SOUND_PLACE_IN_CONF, cbu->b_profile.sounds))) {
@@ -919,19 +1007,12 @@ int conf_handle_first_marked_common(struct conference_bridge_user *cbu)
 
 int conf_handle_inactive_waitmarked(struct conference_bridge_user *cbu)
 {
-	/* Be sure we are muted so we can't talk to anybody else waiting */
-	cbu->features.mute = 1;
 	/* If we have not been quieted play back that they are waiting for the leader */
 	if (!ast_test_flag(&cbu->u_profile, USER_OPT_QUIET) && play_prompt_to_user(cbu,
 			conf_get_sound(CONF_SOUND_WAIT_FOR_LEADER, cbu->b_profile.sounds))) {
 		/* user hungup while the sound was playing */
 		return -1;
 	}
-	/* Start music on hold if needed */
-	if (ast_test_flag(&cbu->u_profile, USER_OPT_MUSICONHOLD)) {
-		ast_moh_start(cbu->chan, cbu->u_profile.moh_class, NULL);
-		cbu->playing_moh = 1;
-	}
 	return 0;
 }
 
@@ -970,11 +1051,8 @@ void conf_handle_second_active(struct conference_bridge *conference_bridge)
 	/* If we are the second participant we may need to stop music on hold on the first */
 	struct conference_bridge_user *first_participant = AST_LIST_FIRST(&conference_bridge->active_list);
 
-	/* Temporarily suspend the above participant from the bridge so we have control to stop MOH if needed */
-	if (ast_test_flag(&first_participant->u_profile, USER_OPT_MUSICONHOLD) && !ast_bridge_suspend(conference_bridge->bridge, first_participant->chan)) {
-		first_participant->playing_moh = 0;
-		ast_moh_stop(first_participant->chan);
-		ast_bridge_unsuspend(conference_bridge->bridge, first_participant->chan);
+	if (ast_test_flag(&first_participant->u_profile, USER_OPT_MUSICONHOLD)) {
+		conf_moh_stop(first_participant);
 	}
 	if (!ast_test_flag(&first_participant->u_profile, USER_OPT_STARTMUTED)) {
 		first_participant->features.mute = 0;
@@ -1099,6 +1177,13 @@ static struct conference_bridge *join_conference_bridge(const char *name, struct
 
 	ao2_lock(conference_bridge);
 
+	/*
+	 * Suspend any MOH until the user actually joins the bridge of
+	 * the conference.  This way any pre-join file playback does not
+	 * need to worry about MOH.
+	 */
+	conference_bridge_user->suspended_moh = 1;
+
 	if (handle_conf_user_join(conference_bridge_user)) {
 		/* Invalid event, nothing was done, so we don't want to process a leave. */
 		ao2_unlock(conference_bridge);
@@ -1530,21 +1615,18 @@ static int confbridge_exec(struct ast_channel *chan, const char *data)
 	/* Play the Join sound to both the conference and the user entering. */
 	if (!quiet) {
 		const char *join_sound = conf_get_sound(CONF_SOUND_JOIN, conference_bridge_user.b_profile.sounds);
-		if (conference_bridge_user.playing_moh) {
-			ast_moh_stop(chan);
-		}
+
 		ast_stream_and_wait(chan, join_sound, "");
 		ast_autoservice_start(chan);
 		play_sound_file(conference_bridge, join_sound);
 		ast_autoservice_stop(chan);
-		if (conference_bridge_user.playing_moh) {
-			ast_moh_start(chan, conference_bridge_user.u_profile.moh_class, NULL);
-		}
 	}
 
 	/* See if we need to automatically set this user as a video source or not */
 	handle_video_on_join(conference_bridge, conference_bridge_user.chan, ast_test_flag(&conference_bridge_user.u_profile, USER_OPT_MARKEDUSER));
 
+	conf_moh_unsuspend(&conference_bridge_user);
+
 	/* Join our conference bridge for real */
 	send_join_event(conference_bridge_user.chan, conference_bridge->name);
 	ast_bridge_join(conference_bridge->bridge,
@@ -1925,25 +2007,14 @@ int conf_handle_dtmf(struct ast_bridge_channel *bridge_channel,
 	struct conf_menu_entry *menu_entry,
 	struct conf_menu *menu)
 {
-	struct conference_bridge *conference_bridge = conference_bridge_user->conference_bridge;
-
 	/* See if music on hold is playing */
-	ao2_lock(conference_bridge);
-	if (conference_bridge_user->playing_moh) {
-		/* MOH is going, let's stop it */
-		ast_moh_stop(bridge_channel->chan);
-	}
-	ao2_unlock(conference_bridge);
+	conf_moh_suspend(conference_bridge_user);
 
 	/* execute the list of actions associated with this menu entry */
-	execute_menu_entry(conference_bridge, conference_bridge_user, bridge_channel, menu_entry, menu);
+	execute_menu_entry(conference_bridge_user->conference_bridge, conference_bridge_user, bridge_channel, menu_entry, menu);
 
 	/* See if music on hold needs to be started back up again */
-	ao2_lock(conference_bridge);
-	if (conference_bridge_user->playing_moh) {
-		ast_moh_start(bridge_channel->chan, conference_bridge_user->u_profile.moh_class, NULL);
-	}
-	ao2_unlock(conference_bridge);
+	conf_moh_unsuspend(conference_bridge_user);
 
 	return 0;
 }
@@ -2835,13 +2906,7 @@ void conf_mute_only_active(struct conference_bridge *conference_bridge)
 	/* Turn on MOH/mute if the single participant is set up for it */
 	if (ast_test_flag(&only_participant->u_profile, USER_OPT_MUSICONHOLD)) {
 		only_participant->features.mute = 1;
-		if (!ast_channel_internal_bridge(only_participant->chan) || !ast_bridge_suspend(conference_bridge->bridge, only_participant->chan)) {
-			ast_moh_start(only_participant->chan, only_participant->u_profile.moh_class, NULL);
-			only_participant->playing_moh = 1;
-			if (ast_channel_internal_bridge(only_participant->chan)) {
-				ast_bridge_unsuspend(conference_bridge->bridge, only_participant->chan);
-			}
-		}
+		conf_moh_start(only_participant);
 	}
 }
 
diff --git a/apps/confbridge/conf_state.c b/apps/confbridge/conf_state.c
index e3684058a..ea5ab10f0 100644
--- a/apps/confbridge/conf_state.c
+++ b/apps/confbridge/conf_state.c
@@ -47,9 +47,28 @@ void conf_invalid_event_fn(struct conference_bridge_user *cbu)
 	ast_log(LOG_ERROR, "Invalid event for confbridge user '%s'\n", cbu->u_profile.name);
 }
 
+/*!
+ * \internal
+ * \brief Mute the user and play MOH if the user requires it.
+ *
+ * \param user Conference user to mute and optionally start MOH on.
+ *
+ * \return Nothing
+ */
+static void conf_mute_moh_inactive_waitmarked(struct conference_bridge_user *user)
+{
+	/* Be sure we are muted so we can't talk to anybody else waiting */
+	user->features.mute = 1;
+	/* Start music on hold if needed */
+	if (ast_test_flag(&user->u_profile, USER_OPT_MUSICONHOLD)) {
+		conf_moh_start(user);
+	}
+}
+
 void conf_default_join_waitmarked(struct conference_bridge_user *cbu)
 {
 	conf_add_user_waiting(cbu->conference_bridge, cbu);
+	conf_mute_moh_inactive_waitmarked(cbu);
 	conf_add_post_join_action(cbu, conf_handle_inactive_waitmarked);
 }
 
diff --git a/apps/confbridge/conf_state_multi_marked.c b/apps/confbridge/conf_state_multi_marked.c
index 69850b18d..252926609 100644
--- a/apps/confbridge/conf_state_multi_marked.c
+++ b/apps/confbridge/conf_state_multi_marked.c
@@ -107,12 +107,8 @@ static void leave_marked(struct conference_bridge_user *cbu)
 				cbu_iter->conference_bridge->waitingusers++;
 				/* Handle muting/moh of cbu_iter if necessary */
 				if (ast_test_flag(&cbu_iter->u_profile, USER_OPT_MUSICONHOLD)) {
-				   cbu_iter->features.mute = 1;
-					if (!ast_bridge_suspend(cbu_iter->conference_bridge->bridge, cbu_iter->chan)) {
-						ast_moh_start(cbu_iter->chan, cbu_iter->u_profile.moh_class, NULL);
-						cbu_iter->playing_moh = 1;
-						ast_bridge_unsuspend(cbu_iter->conference_bridge->bridge, cbu_iter->chan);
-					}
+					cbu_iter->features.mute = 1;
+					conf_moh_start(cbu_iter);
 				}
 			}
 		}
@@ -173,10 +169,8 @@ static void transition_to_marked(struct conference_bridge_user *cbu)
 		cbu->conference_bridge->waitingusers--;
 		AST_LIST_INSERT_TAIL(&cbu->conference_bridge->active_list, cbu_iter, list);
 		cbu->conference_bridge->activeusers++;
-		if (cbu_iter->playing_moh && !ast_bridge_suspend(cbu->conference_bridge->bridge, cbu_iter->chan)) {
-			cbu_iter->playing_moh = 0;
-			ast_moh_stop(cbu_iter->chan);
-			ast_bridge_unsuspend(cbu->conference_bridge->bridge, cbu_iter->chan);
+		if (cbu_iter->playing_moh) {
+			conf_moh_stop(cbu_iter);
 		}
 		/* only unmute them if they are not supposed to start muted */
 		if (!ast_test_flag(&cbu_iter->u_profile, USER_OPT_STARTMUTED)) {
diff --git a/apps/confbridge/include/confbridge.h b/apps/confbridge/include/confbridge.h
index 0891f5d4e..059262065 100644
--- a/apps/confbridge/include/confbridge.h
+++ b/apps/confbridge/include/confbridge.h
@@ -236,6 +236,7 @@ struct conference_bridge_user {
 	struct ast_channel *chan;                    /*!< Asterisk channel participating */
 	struct ast_bridge_features features;         /*!< Bridge features structure */
 	struct ast_bridge_tech_optimizations tech_args; /*!< Bridge technology optimizations for talk detection */
+	unsigned int suspended_moh;                  /*!< Count of active suspended MOH actions. */
 	unsigned int kicked:1;                       /*!< User has been kicked from the conference */
 	unsigned int playing_moh:1;                  /*!< MOH is currently being played to the user */
 	AST_LIST_HEAD_NOLOCK(, post_join_action) post_join_list; /*!< List of sounds to play after joining */;
@@ -358,6 +359,24 @@ int play_sound_file(struct conference_bridge *conference_bridge, const char *fil
  */
 void conf_ended(struct conference_bridge *conference_bridge);
 
+/*!
+ * \brief Stop MOH for the conference user.
+ *
+ * \param user Conference user to stop MOH on.
+ *
+ * \return Nothing
+ */
+void conf_moh_stop(struct conference_bridge_user *user);
+
+/*!
+ * \brief Start MOH for the conference user.
+ *
+ * \param user Conference user to start MOH on.
+ *
+ * \return Nothing
+ */
+void conf_moh_start(struct conference_bridge_user *user);
+
 /*! \brief Attempt to mute/play MOH to the only user in the conference if they require it
  * \param conference_bridge A conference bridge containing a single user
  */
diff --git a/include/asterisk/bridging.h b/include/asterisk/bridging.h
index 0f194f418..2c41f4618 100644
--- a/include/asterisk/bridging.h
+++ b/include/asterisk/bridging.h
@@ -271,6 +271,32 @@ struct ast_bridge {
  */
 struct ast_bridge *ast_bridge_new(uint32_t capabilities, int flags);
 
+/*!
+ * \brief Lock the bridge.
+ *
+ * \param bridge Bridge to lock
+ *
+ * \return Nothing
+ */
+#define ast_bridge_lock(bridge)	_ast_bridge_lock(bridge, __FILE__, __PRETTY_FUNCTION__, __LINE__, #bridge)
+static inline void _ast_bridge_lock(struct ast_bridge *bridge, const char *file, const char *function, int line, const char *var)
+{
+	__ao2_lock(bridge, AO2_LOCK_REQ_MUTEX, file, function, line, var);
+}
+
+/*!
+ * \brief Unlock the bridge.
+ *
+ * \param bridge Bridge to unlock
+ *
+ * \return Nothing
+ */
+#define ast_bridge_unlock(bridge)	_ast_bridge_unlock(bridge, __FILE__, __PRETTY_FUNCTION__, __LINE__, #bridge)
+static inline void _ast_bridge_unlock(struct ast_bridge *bridge, const char *file, const char *function, int line, const char *var)
+{
+	__ao2_unlock(bridge, file, function, line, var);
+}
+
 /*! \brief See if it is possible to create a bridge
  *
  * \param capabilities The capabilities that the bridge will use