Handle DTMF and hold wrapup when a channel leaves the bridging system.

DTMF start/end and hold/unhold events have state because a DTMF begin
event and hold event must be ended by something.

The following cases need to be handled when a channel is moved around in
the system.

* When a channel leaves a bridge it may owe a DTMF end event to the
bridge.

* When a channel leaves a bridge it may owe an UNHOLD event to the bridge.
(This case is explicitly ignored because things like transfers need
explicit control over this.)

* When a channel leaves the bridging system it may need to simulate a DTMF
end event to the channel.

* When a channel leaves the bridging system it may need to simulate an
UNHOLD event to the channel.

The patch also fixes the following:
* Fixes playing a file and restarting MOH using the latest MOH class used.

(closes issue ASTERISK-22043)
Reported by: Matt Jordan

Review: https://reviewboard.asterisk.org/r/2791/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@397577 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/bridge_channel.h

@@ -155,6 +155,13 @@ struct ast_bridge_channel {
 	 * \note Needs to be atomically settable.
 	 */
 	enum bridge_channel_thread_state activity;
+	/*! Owed events to the bridge. */
+	struct {
+		/*! Time started sending the current digit. (Invalid if owed.dtmf_digit is zero.) */
+		struct timeval dtmf_tv;
+		/*! Digit currently sending into the bridge. (zero if not sending) */
+		char dtmf_digit;
+	} owed;
 };
 
 /*!

include/asterisk/bridge_channel_internal.h

@@ -82,6 +82,20 @@ enum bridge_channel_action_type {
  */
 struct ast_bridge_channel *bridge_channel_internal_alloc(struct ast_bridge *bridge);
 
+/*!
+ * \internal
+ * \brief Clear owed events by the channel to the original bridge.
+ * \since 12.0.0
+ *
+ * \param orig_bridge Original bridge the channel was in before leaving.
+ * \param bridge_channel Channel that owes events to the original bridge.
+ *
+ * \note On entry, the orig_bridge is already locked.
+ *
+ * \return Nothing
+ */
+void bridge_channel_settle_owed_events(struct ast_bridge *orig_bridge, struct ast_bridge_channel *bridge_channel);
+
 /*!
  * \internal
  * \brief Push the bridge channel into its specified bridge.

include/asterisk/channel.h

@@ -3792,6 +3792,7 @@ void ast_channel_name_set(struct ast_channel *chan, const char *name);
 DECLARE_STRINGFIELD_SETTERS_FOR(name);
 DECLARE_STRINGFIELD_SETTERS_FOR(language);
 DECLARE_STRINGFIELD_SETTERS_FOR(musicclass);
+DECLARE_STRINGFIELD_SETTERS_FOR(latest_musicclass);
 DECLARE_STRINGFIELD_SETTERS_FOR(accountcode);
 DECLARE_STRINGFIELD_SETTERS_FOR(peeraccount);
 DECLARE_STRINGFIELD_SETTERS_FOR(userfield);
@@ -3805,6 +3806,7 @@ DECLARE_STRINGFIELD_SETTERS_FOR(dialcontext);
 const char *ast_channel_name(const struct ast_channel *chan);
 const char *ast_channel_language(const struct ast_channel *chan);
 const char *ast_channel_musicclass(const struct ast_channel *chan);
+const char *ast_channel_latest_musicclass(const struct ast_channel *chan);
 const char *ast_channel_accountcode(const struct ast_channel *chan);
 const char *ast_channel_peeraccount(const struct ast_channel *chan);
 const char *ast_channel_userfield(const struct ast_channel *chan);
@@ -3857,6 +3859,8 @@ int ast_channel_timingfd(const struct ast_channel *chan);
 void ast_channel_timingfd_set(struct ast_channel *chan, int value);
 int ast_channel_visible_indication(const struct ast_channel *chan);
 void ast_channel_visible_indication_set(struct ast_channel *chan, int value);
+int ast_channel_hold_state(const struct ast_channel *chan);
+void ast_channel_hold_state_set(struct ast_channel *chan, int value);
 int ast_channel_vstreamid(const struct ast_channel *chan);
 void ast_channel_vstreamid_set(struct ast_channel *chan, int value);
 unsigned short ast_channel_transfercapability(const struct ast_channel *chan);