rem: eca_jack_process_engine_iteration(nframes, current);
add: if (current->is_running() == true) { eca_jack_process_engine_iteration(nframes, current); } else { eca_jack_process_mute(nframes, current); }
context: static int eca_jack_process(jack_nframes_t nframes, void *arg){  AUDIO_IO_JACK_MANAGER* current = static_cast<AUDIO_IO_JACK_MANAGER*>(arg);  PROFILE_CE_STATEMENT(eca_jack_process_profile_pre());  /* try to get the driver lock; if it fails or connection    * is not fully establish, skip this processing cycle */  int ret = pthread_mutex_trylock(&current->engine_mod_lock_rep);  if (ret == 0) {    // DEBUG_CFLOW_STATEMENT(cerr << "eca_jack_process(): got lock" << endl);        /* 1. transport control processing in "slave" mode */    if (current->mode_rep == AUDIO_IO_JACK_MANAGER::Slave) {      eca_jack_process_timebase_slave(nframes, arg);    }    /* 2. transport control processing in "master" mode */    else if (current->mode_rep == AUDIO_IO_JACK_MANAGER::Master) {      eca_jack_process_timebase_master(nframes, arg);    }    /* 3. transport control processing in "streaming" mode */    else {      /* execute one engine iteration */      eca_jack_process_engine_iteration(nframes, current);    }    pthread_mutex_unlock(&current->engine_mod_lock_rep);  }  else {    // DEBUG_CFLOW_STATEMENT(cerr << "eca_jack_process(): couldn't get lock; muting" << endl);    eca_jack_process_mute(nframes, current);  }    PROFILE_CE_STATEMENT(eca_jack_process_profile_post());    return(0);}