并发编程之线程池的底层原理的详细解析

public static ExecutorService newFixedThreadPool(int nThreads) {
        return new ThreadPoolExecutor(nThreads, nThreads,
                                      0L, TimeUnit.MILLISECONDS,
                                      new LinkedBlockingQueue<Runnable>());
    }
​
    public static ExecutorService newSingleThreadExecutor() {
        return new FinalizableDelegatedExecutorService
            (new ThreadPoolExecutor(1, 1,
                                    0L, TimeUnit.MILLISECONDS,
                                    new LinkedBlockingQueue<Runnable>()));
    }
​
​
    public static ExecutorService newCachedThreadPool() {
        return new ThreadPoolExecutor(0, Integer.MAX_VALUE,
                                      60L, TimeUnit.SECONDS,
                                      new SynchronousQueue<Runnable>());
    }
​
    public ThreadPoolExecutor(int corePoolSize,     //线程池中的常驻核心线程数
                              int maximumPoolSize,  //线程池能容纳同时执行的最大线程数，此值必须大于等于1
                              long keepAliveTime,   //多余的空闲线程的存活时间，当前池中线程数量超过corePoolSize时，当空闲时间达到keepAliveTime时，多余线程就会被销毁到只剩下corePoolSize为止
                              TimeUnit unit,        //keepAliveTime的单位
                              BlockingQueue<Runnable> workQueue,    //任务队列，被提交但尚未执行的任务
                              ThreadFactory threadFactory,          //创建线程的工厂，默认即可
                              RejectedExecutionHandler handler      //拒绝策略，当队列满（maximumPoolSize）时，根据该handler决定如何拒绝请求执行的runnable
                             ) { 
        .....
            ....
                ...
    }
​
​