Java Review - 线程池资源一直不被释放案例&源码分析

import java.util.concurrent.*;

/**
 * @author 小工匠
 * @version 1.0
 * @description: TODO
 * @date 2021/11/20 23:33
 * @mark: show me the code , change the world
 */
public class PoolShutDownTest {

    public static void main(String[] args) {

        // 异步执行业务1
        ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(5, 10, 10,
                TimeUnit.MINUTES, new LinkedBlockingDeque<>(100));

        threadPoolExecutor.execute(()->{
            try {
                TimeUnit.SECONDS.sleep(3);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println("业务1----模拟业务");
        });

        // 异步执行业务2
         ExecutorService executorService = Executors.newSingleThreadExecutor();
         executorService.execute(()->System.out.println("业务2"));


        // 业务执行完成
        System.out.println("executor over");

    }
}

    /**
     * Initiates an orderly shutdown in which previously submitted
     * tasks are executed, but no new tasks will be accepted.
     * Invocation has no additional effect if already shut down.
     *
     * This method does not wait for previously submitted tasks to
     * complete execution.  Use {@link #awaitTermination awaitTermination}
     * to do that.
     *
     * @throws SecurityException {@inheritDoc}
     */
    public void shutdown() {
        final ReentrantLock mainLock = this.mainLock;
        mainLock.lock();
        try {
            checkShutdownAccess();
            // 设置线程池状态为SHUTDOWN
            advanceRunState(SHUTDOWN);
            // 中断所有的空闲工作线程
            interruptIdleWorkers();
            onShutdown(); // hook for ScheduledThreadPoolExecutor
        } finally {
            mainLock.unlock();
        }
        tryTerminate();
    }

/**
     * Transitions runState to given target, or leaves it alone if
     * already at least the given target.
     *
     * @param targetState the desired state, either SHUTDOWN or STOP
     *        (but not TIDYING or TERMINATED -- use tryTerminate for that)
     */
    private void advanceRunState(int targetState) {
        for (;;) {
            int c = ctl.get();
            if (runStateAtLeast(c, targetState) ||
                ctl.compareAndSet(c, ctlOf(targetState, workerCountOf(c))))
                break;
        }
    }

final void runWorker(Worker w) {
        .......
        try {
            while (task != null || (task = getTask()) != null) {
               .......   
        } finally {
             .......
        }
    }

 private Runnable getTask() {
        boolean timedOut = false; // Did the last poll() time out?

        for (;;) {
            ....
            // Check if queue empty only if necessary.
            // 代码1 
            if (rs >= SHUTDOWN && (rs >= STOP || workQueue.isEmpty())) {
                decrementWorkerCount();
                return null;
            }

            
            try {
               // 代码2
                Runnable r = timed ?
                    workQueue.poll(keepAliveTime, TimeUnit.NANOSECONDS) :
                    workQueue.take();
                if (r != null)
                    return r;
                timedOut = true;
            } catch (InterruptedException retry) {
                timedOut = false;
            }
        }
    }