PROCEDURE performance_update (wait_time_in IN NUMBER) 
IS
	pipe_status INTEGER;
	production_total NUMBER;
BEGIN
	/* Infinite loop to check production every hour */
	LOOP
		/*
		|| Read a message from the named pipe. Use the parameter value
		|| to determine how long the program is willing to wait.
		*/
		pipe_status := 
			DBMS_PIPE.RECEIVE_MESSAGE ('production', wait_time_in);

		/* Having retrieved the message, unpack and analyze data. */
		IF pipe_status = 0
		THEN
			DBMS_PIPE.UNPACK_MESSAGE (production_total);
			analyze_production (SYSDATE, production_total);
		ELSE
			RAISE_APPLICATION_ERROR 
				(-20000, 'Unable to obtain production data.');
		END IF;

		/* Wait for one hour (3600 seconds) to read the next message. */
		DBMS_LOCK.SLEEP (3600);
		
	END IF;
END;