Refactor Lock Engine

by Wensheng Dou for The Codehaus

Since Java 5, Java has introduced the java.util.concurrent API. But the Castor project has not supported java.util.concurrent API yet. In the Castor JDO module, the LockEngine implements the read/write lock, and use custom lock mechanism. So the LockEngine is very complicated and error-prone. The “Refactor Lock Engine” project I propose here will refactor the Castor to support the java.util.concurrent API, and make LockEngine more readable and maintainable, and repair some concurrency bugs.