@Override
          public void run() {
            list.execute();
          }
        };
    Thread thread1 = new Thread(execute);
    Thread thread2 = new Thread(execute);
    thread1.start();
    thread2.start();
    assertEquals(0, runCalled.get());
    okayToRun.countDown();
    thread1.join();
    thread2.join();
    assertEquals(1, runCalled.get());
  }

              @Override
              public Integer call() {
                return Thread.currentThread().getStackTrace().length;
              }
            },
            directExecutor());
    settableFuture.set(null);
    assertThat(getDone(stackDepthCheck))
        .isLessThan(Thread.currentThread().getStackTrace().length + 100);
  }

 * This class provides access to the underlying process and manages
 * the input stream thread for capturing process output.
 */
public class JobProcess {
    /**
     * The underlying system process.
     */
    protected Process process;

    /**
     * The thread that handles reading from the process input stream.
     */
    protected InputStreamThread inputStreamThread;

    /**

        final ClassLoader context = Thread.currentThread().getContextClassLoader();
        try {
            final ClassLoader cl = new URLClassLoader(new URL[0], getClass().getClassLoader());
            Thread.currentThread().setContextClassLoader(cl);
            assertThat(ClassLoaderUtil.getClassLoader(TestCase.class), is(sameInstance(cl)));
        } finally {
            Thread.currentThread().setContextClassLoader(context);

import jakarta.annotation.Resource;

/**
 * The {@code CrawlerThread} class represents a thread that executes the crawling process.
 * It is responsible for fetching URLs from the queue, accessing the content,
 * processing the response, and extracting child URLs.
 *
 * <p>
 * This class implements the {@link Runnable} interface, allowing it to be executed in a separate thread.

     */
    public void setTimeout(final long timeout) {
        this.timeout = timeout;
    }

    /**
     * Sets whether the extraction thread should be a daemon thread.
     * @param isDaemonThread true to make it a daemon thread, false otherwise.
     */
    public void setDaemonThread(final boolean isDaemonThread) {
        this.isDaemonThread = isDaemonThread;
    }

    @Test
    public void testThreadSafety() throws InterruptedException {
        // Test concurrent updates from multiple threads
        Thread[] threads = new Thread[10];

        for (int i = 0; i < threads.length; i++) {
            final int index = i;
            threads[i] = new Thread(() -> {
                for (int j = 0; j < 100; j++) {
                    String name = "file" + index + "_" + j + ".txt";

  /**
   * Returns an exception handler that exits the system. This is particularly useful for the main
   * thread, which may start up other, non-daemon threads, but fail to fully initialize the
   * application successfully.
   *
   * <p>Example usage:
   *
   * <pre>
   * public static void main(String[] args) {
   *   Thread.currentThread().setUncaughtExceptionHandler(UncaughtExceptionHandlers.systemExit());
   *   ...
   * </pre>
   *

  protected AbstractExecutionThreadService() {}

  /**
   * Start the service. This method is invoked on the execution thread.
   *
   * <p>By default this method does nothing.
   */
  protected void startUp() throws Exception {}

  /**
   * Run the service. This method is invoked on the execution thread. Implementations must respond
   * to stop requests. You could poll for lifecycle changes in a work loop:
   *
   * <pre>

        // start
        AccessTimeoutTarget accessTimeoutTarget = null;
        TimeoutTask accessTimeoutTask = null;
        if (accessTimeout != null) {
            accessTimeoutTarget = new AccessTimeoutTarget(Thread.currentThread());
            accessTimeoutTask = TimeoutManager.getInstance().addTimeoutTarget(accessTimeoutTarget, accessTimeout, false);
        }

        try {