tomcat源码学习--线程池
写个前言：
通常大家知道tomcat的线程池是可以配置的，去找到conf下面的的server.xml就可以搞定，先配置指定参数
maxThreads="150" minSpareThreads="4"/>
-->

在配置连接器使用它，注释中都给出了例子
connectionTimeout="20000"
redirectPort="8443" />
<!-- A "Connector" using the shared thread pool-->
<!--
<Connector executor="tomcatThreadPool"
port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
-->


但现在不是想说这个，是想看看tomcat源码里的线程池，只看配置文件没啥意义，不好玩
开始->>
首先看tomcat的源码，ThreadPool里面的成员变量

   初始化一切搞定，当线程调用run，那么会去查找相关已经初始化的线程，再取出来，对应去运行
/** Implemented if you want to run a piece of code inside a thread pool. */public interface ThreadPoolRunnable {    // XXX use notes or a hashtable-like    // Important: ThreadData in JDK1.2 is implemented as a Hashtable( Thread -> object ),    // expensive.        /** Called when this object is first loaded in the thread pool.     *  Important: all workers in a pool must be of the same type,     *  otherwise the mechanism becomes more complex.     */    public Object[] getInitData();    /** This method will be executed in one of the pool's threads. The     *  thread will be returned to the pool.     */    public void runIt(Object thData[]);}

   那么tomcat又在何处使用它了，利用eclipse工具，找到调用类PoolTcpEndpoint，里面的线程是LeaderFollowerWorkerThread还实现了ThreadPoolRunnable，感兴趣可以自己去看看

    综上所述，它实现是怎样的，先初始化一定数量的线程，他们都先睡着，线程池 runIt(listener)传入线程，传入后就不notify然后就 shouldRun = true，然后就调用传进来的线程。但是包装的东西好多啊，控制的东西验证的东西也好多，造成了这个类好大。