code: public void readLock(EntityKey key, int timeout) {
  		ReadWriteLock lock = getLock( key );
  		Lock readLock = lock.readLock();
  		acquireLock( key, timeout, readLock );
  	}
docs: Acquires a read lock on a specific key.
  @param key The key to lock
  @param timeout in milliseconds; -1 means wait indefinitely, 0 means no wait.