pthread_mutex_lock(<t_channel_mutex);
free(channels);
urcu_ref_put(&index_urcu_ref, release_trace_channel);
pthread_mutex_unlock(<t_channel_mutex);
pthread_mutex_lock(<t_channel_mutex);
free(channels);
urcu_ref_put(&index_urcu_ref, release_trace_channel);
pthread_mutex_unlock(<t_channel_mutex);