ReentrantReadWriteLock的Strategy模式

曾经使用信号量实现过第一类和第二类读写者问题，《java多线程设计模式》中使用notify()和wait()来实现，

在《Java核心技术》下册中，有ReentrantReadWriteLock类。

因为测试它发现一直是读者优先，然后阅读其源码，发现构造函数：

隐藏行号 复制代码 ？ ReentrantReadWriteLock的构造函数

1. public ReentrantReadWriteLock(boolean fair) {

2.     sync = (fair)? new FairSync() : new NonfairSync();

3.     readerLock = new ReadLock(this);

4.     writerLock = new WriteLock(this);

5. }

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