Unlocking lock owned by another thread java

Question

I have a LockManager that manages the locks of several threads. Sometimes the threads are bad boys, and I have to kill them and ask the LockManager to release all their lock

Answer 1

Why don't you simply wrap the code of your thread around the following:

ReentrantLock lock = ... obtain your lock somehow ...
lock.lock();
try {
  ... the "bad boy" code here ...
} finally {
  lock.unlock();
}

Then, when your thread finishes (either by normally finishing, or by throwing an exception from your "kill"), it will release the lock.

This is actually the way Oracle recommends using ReentrantLock: http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/locks/ReentrantLock.html