FS-4867 --resolve

src/include/switch_channel.h

@@ -541,6 +541,10 @@ SWITCH_DECLARE(switch_channel_state_t) switch_channel_perform_hangup(switch_chan
   \return number of digits in the queue
 */
 SWITCH_DECLARE(switch_size_t) switch_channel_has_dtmf(_In_ switch_channel_t *channel);
+SWITCH_DECLARE(switch_status_t) switch_channel_dtmf_lock(switch_channel_t *channel); 
+SWITCH_DECLARE(switch_status_t) switch_channel_try_dtmf_lock(switch_channel_t *channel);
+SWITCH_DECLARE(switch_status_t) switch_channel_dtmf_unlock(switch_channel_t *channel); 
+
 
 /*!
   \brief Queue DTMF on a given channel

src/switch_channel.c

@@ -363,6 +363,21 @@ SWITCH_DECLARE(switch_status_t) switch_channel_alloc(switch_channel_t **channel,
 	return SWITCH_STATUS_SUCCESS;
 }
 
+SWITCH_DECLARE(switch_status_t) switch_channel_dtmf_lock(switch_channel_t *channel) 
+{
+	return switch_mutex_lock(channel->dtmf_mutex);
+}
+
+SWITCH_DECLARE(switch_status_t) switch_channel_try_dtmf_lock(switch_channel_t *channel) 
+{
+	return switch_mutex_trylock(channel->dtmf_mutex);
+}
+
+SWITCH_DECLARE(switch_status_t) switch_channel_dtmf_unlock(switch_channel_t *channel) 
+{
+	return switch_mutex_unlock(channel->dtmf_mutex);
+}
+
 SWITCH_DECLARE(switch_size_t) switch_channel_has_dtmf(switch_channel_t *channel)
 {
 	switch_size_t has;

src/switch_core_io.c

@@ -151,7 +151,10 @@ SWITCH_DECLARE(switch_status_t) switch_core_session_read_frame(switch_core_sessi
 	
 	for(i = 0; i < 2; i++) {
 		if (session->dmachine[i] && !switch_channel_test_flag(session->channel, CF_BROADCAST)) {
-			switch_ivr_dmachine_ping(session->dmachine[i], NULL);
+			if (switch_channel_try_dtmf_lock(session->channel) == SWITCH_STATUS_SUCCESS) {
+				switch_ivr_dmachine_ping(session->dmachine[i], NULL);
+				switch_channel_dtmf_unlock(session->channel);
+			}
 		}
 	}