Using multi-threaded programming, you are required to implement a hotel system, which provides a check-out with cash payment use case depicted in Fig. 1 and Fig. 2. Fig. 1 depicts the communication diagram for the check-out with cash payment use case and Fig. 2 depicts the simplified software architecture that consists of the Hotel Client and Hotel Server subsystems. In the software architecture (Fig. 2), the Desk Clerk Interface object and Check-out Manager object are active objects (i.e., threads) and they communicates messages using synchronous message communication, which is implemented by means of a mes sage buffer and response connector class (Fig. 3 and Fig. 4). Fig. 5 depicts the specification of Check-out Manager object. Fig. 6 and Fig. 7 depict the specifications of classes in Fig. 2.

Fig. 3 message buffer and response connector aProducerTask aConsumerTask send (in message, out response) receive (out message)// reply (iin response) connecton> aMessage connector Buffer&Response MessageBuffer&Response - messageBuffer: Buffer - responseBuffer: Buffer + send (in message, out response) + receive (out message) + reply (in response) 21 Fig. 3 message buffer and response connector aProducerTask aConsumerTask send (in message, out response) receive (out message)// reply (iin response) connecton> aMessage connector Buffer&Response MessageBuffer&Response - messageBuffer: Buffer - responseBuffer: Buffer + send (in message, out response) + receive (out message) + reply (in response) 21