[JUC-4]ThreadPoolExecutor源码分析

 相关博文：

https://segmentfault.com/a/1190000008693801

https://www.jianshu.com/p/fa1eac9710c8

//构造器1
public ThreadPoolExecutor(int corePoolSize,
                          int maximumPoolSize,
                          long keepAliveTime,
                          TimeUnit unit,
                          BlockingQueue<Runnable> workQueue) {
    this(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue,
         Executors.defaultThreadFactory(), defaultHandler);
}
//构造器2
public ThreadPoolExecutor(int corePoolSize,
                          int maximumPoolSize,
                          long keepAliveTime,
                          TimeUnit unit,
                          BlockingQueue<Runnable> workQueue,
                          RejectedExecutionHandler handler) {
    this(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue,
         Executors.defaultThreadFactory(), handler);
}
//构造器3
public ThreadPoolExecutor(int corePoolSize, int maximumPoolSize,
 long keepAliveTime, TimeUnit unit, 
 BlockingQueue<Runnable> workQueue, 
 ThreadFactory threadFactory, RejectedExecutionHandler handler);

构造器参数详解如下：
corePoolSize：核心线程的数量；
maximumPoolSize：最大的线程数量；
keepAliveTime：当线程数量大于corePoolSize时，多余的线程的最大存活时间（如果空闲的话）；
unit：keepAliveTime的单位；
workQueue：提交但尚未被执行的任务队列；
threadFactory：线程工厂，用于创建线程；
handler：拒绝策略，当任务提交不能被执行时的补救措施；

线程池大小设置

https://www.cnblogs.com/lengender-12/p/6869554.html

http://ifeve.com/how-to-calculate-threadpool-size/