In this assignment, you will implement a variation of the program to control the two trains that uses monitors rather than semaphores.
In this assignment you must use Java.
Your assignment is to adapt the program that controls the trains from the Lab 1 to use monitors instead of semaphores.
All the requirements from the first assignment are also demanded here except that now we use monitors instead of semaphores.
You should use monitors that have explicit locks and condition variables. That is, you must use the
java.util.concurrent.lockspackage from Java 5, not
synchronizedmethods, to implement your monitor.
You should not use the
tryLock()method of the
Lockinterface. If you need such functionality, you have to implement it yourself in your monitor.
Waiting in your monitors should be realised using condition variables. Locks should be held locked only for short moments.
Use the same project for the previous.
Lab2.java, renaming the class, and change
Main.java to use
Lab2 instead of
You do not need to change the map file.
To give you some hints, you should think that each track is represented by a monitor. The monitor will have, at least , the following interface:
public void enter() public void leave()
enter() is called by a train when entering a single track and
when a train leaves a single or double track.
In your submission, you should clearly explain the following items:
- What is the purpose of each method in the monitor?
- How many conditional variables, if any, are needed in your solution? Justify your answer.