void ctl_message_queue_receive_uc(CTL_MESSAGE_QUEUE_t *q, void **message);
ctl_message_queue_receive_uc pops the oldest message in the message queue pointed to by q into the memory pointed to by message. ctl_message_queue_receive_uc will unconditionally block if no messages are available.
ctl_message_queue_receive_uc must not be called from an interrupt service routine.