#Peterson Lock Using Binary Tree

This is a project attempting to implement a Peterson Lock for concurrency using a Binary Tree.

##Peterson Lock Peterson Locks are objects used for 2 threaded systems to ensure one thread always waits while the other is writing to a shared object/variable. We call this thread the 'victim.' Peterson Locks, however, are only good for 2 threaded systems, not n-threaded system.

As a basis to this project, you'll find a Peterson.java class that is the standard implementation of a Peterson lock. This will be used to create the Tree implementation.

##Peterson Tree Lock

The Peterson Tree Lock uses a "tree-type" heuristic for solving the problem of n-threads, by making providing levels of locks that the threads must pass through. The lock is only obtained by a thread by making it to level {0,1} (i.e., the root of the tree) and obtaining the that level's lock.

You'll find the Peterson Tree Lock in the PetersonTree.java class file. This implementation has been tested so far on 8 cores and works fast (statistics to come).

##Filter Lock

A Filter Lock is another implementation of a lock for an n-threaded system. It uses a similar locking system, except instead of using the Peterson Lock as a backbone, it employs a multi-dimensional system for keeping track of "victims" and must waste time on a for-loop to check the progress of other threads.

This implementation is much slower, and can be used for comparison. A Filter Lock implementation is found in the Filter.java class file.