The Sleeping Teaching Assistant

A university computer science department has a teaching assistant (TA) who helps undergraduate students with their programming assignments during regular office hours. The TAs office is rather small and has room for only one desk with a chair and computer. There are three chairs in the hallway outside the office where students can sit and wait if the TA is currently helping another student. When there are no students who need help during office hours, the TA sits at the desk and takes a nap. If a student arrives during office hours and finds the TA sleeping, the student must awaken the TA to ask for help. If a student arrives and finds the TA currently helping another student, the student sits on one of the chairs in the hallway and waits. If no chairs are available, the student will come back at a later time.

Using threads and semaphores, implement a solution in JAVA that coordinates the activities of the TA and the students.

1. Create n students, each will run as a separate thread.

2. Student threads will alternate between programming for a period of time and seeking help from the TA.

3. If the TA is available, students will obtain help

4. If the TA is not available, students will sit in a chair in the hallway (waitList)

5. If no chairs are available, students will resume programming and seek help at a later time

6. If the TA is sleeping, the student will notify TA with a semaphore

7. Use a semaphore to indicate a student in help mode

8. When a TA finishes helping a student, the TA must check to see if there are students waiting for help in the hallway.

9. The TA must help the students waiting in the hallway in the order that they started waiting.

10. If no students are waiting, then the TA can resume napping.

The best option for simulating students programming as well as the TA providing help to a student is to have appropriate threads sleep for a random period of time.

Make sure your output includes when the semaphores acquire permits and release permits, displays current mode (programming or getting help), and TA is sleeping or helping which student.