Java ReentrantReadWriteLocks - how to safely acquire write lock?

Question

I am using in my code at the moment a ReentrantReadWriteLock to synchronize access over a tree-like structure. This structure is large, and read by many threads at once wit

Answer 1

Java 8 now has a java.util.concurrent.locks.StampedLock with a tryConvertToWriteLock(long) API

More info at http://www.javaspecialists.eu/archive/Issue215.html