Fix TCP concurrent sending problem

socket/tcp-bsd.c

@@ -312,6 +312,8 @@ socket_send_message (NiceSocket *sock,
   if (priv->error)
     return -1;
 
+  g_mutex_lock(&mutex);
+
   message_len = output_message_get_size (message);
 
   /* First try to send the data, don't send it later if it can be sent now
@@ -353,6 +355,8 @@ socket_send_message (NiceSocket *sock,
     }
   }
 
+  g_mutex_unlock(&mutex);
+
   return ret;
 }