Here you can find the source of getGradingReadLock()
public static Lock getGradingReadLock()
//package com.java2s; //License from project: Open Source License import java.util.concurrent.locks.Lock; import java.util.concurrent.locks.ReadWriteLock; import java.util.concurrent.locks.ReentrantReadWriteLock; public class Main { private static final ReadWriteLock READ_WRITE_LOCK = new ReentrantReadWriteLock(); public static Lock getGradingReadLock() { return READ_WRITE_LOCK.readLock(); }/* w w w . j av a 2 s .com*/ }