- for (list<InternalSend*>::iterator i = _sends.begin(); i != _sends.end(); ++i) {
- if ((*i)->active ()) {
- bufs.merge_from ((*i)->get_buffers(), nframes);
+ if (lm.locked ()) {
+ for (list<InternalSend*>::iterator i = _sends.begin(); i != _sends.end(); ++i) {
+ if ((*i)->active () && (!(*i)->source_route() || (*i)->source_route()->active())) {
+ bufs.merge_from ((*i)->get_buffers(), nframes);
+ }