// unpark even though the thread has already removed itself from the list. But even if we did
      // use a CAS, that race would still exist (it would just be ever so slightly smaller).
      Thread w = thread;
      if (w != null) {
        thread = null;
        LockSupport.unpark(w);
      }
    }
  }

  /*

                }
              });
      thread.start();
      // we want to wait until each thread is WAITING - one thread waiting inside CacheLoader.load
      // (in startSignal.await()), and the others waiting for that thread's result.
      while (thread.isAlive() && thread.getState() != Thread.State.WAITING) {
        Thread.yield();
      }
    }
    gettersStartedSignal.countDown();

     * simple approach would be for each caller CAS it from null to a Set populated with its
     * exception. But there's another race: If the first thread fails with an exception and a second
     * thread immediately fails with the same exception:
     *
     * Thread1: calls setException(), which returns true, context switch before it can CAS
     * seenExceptionsField to its exception
     *

   * calling thread. Tasks are run to completion before a {@code Future} is returned to the caller
   * (unless the executor has been shutdown).
   *
   * <p>The returned executor is backed by the executor returned by {@link
   * MoreExecutors#newDirectExecutorService} and subject to the same constraints.
   *
   * <p>Although all tasks are immediately executed in the thread that submitted the task, this

     * Stops background processing and waits for threads to complete.
     */
    @PreDestroy
    public void destroy() {
        generating = false;
        thumbnailQueueThread.interrupt();
        try {
            thumbnailQueueThread.join(10000);
        } catch (final InterruptedException e) {
            logger.warn("Thumbnail thread timed out.", e);
        }
        generatorList.forEach(g -> {

                    throw new IllegalArgumentException("Invalid threads core multiplier value: '" + threadConfiguration
                            + "'. Value must be positive.");
                }

                int procs = Runtime.getRuntime().availableProcessors();
                int threads = (int) (coreMultiplier * procs);
                return threads == 0 ? 1 : threads;
            } else {

      // unpark even though the thread has already removed itself from the list. But even if we did
      // use a CAS, that race would still exist (it would just be ever so slightly smaller).
      Thread w = thread;
      if (w != null) {
        thread = null;
        LockSupport.unpark(w);
      }
    }
  }

  /*

 *   <li>Dynamic replanning when necessary (e.g., for forked executions)</li>
 *   <li>Project setup, execution, and teardown phases management</li>
 * </ol>
 *
 * <h2>Thread Management:</h2>
 * <p>The number of threads used is determined by:</p>
 * <pre>
 * min(degreeOfConcurrency, numberOfProjects)
 * </pre>
 * where degreeOfConcurrency is set via the -T command-line option.
 *

        method.setAccessible(true);
        final boolean result = (boolean) method.invoke(crawlerThread, urlQueue);

        assertFalse(result);
    }

    /**
     * Test isContinue method when thread check count is below max.
     */
    public void test_isContinue_belowMaxThreadCheckCount() throws Exception {
        // Use reflection to access protected method

crawler.system.monitor.interval=60
# Whether to ignore idle threads in hot thread monitoring.
crawler.hotthread.ignore_idle_threads=true
# Interval for hot thread monitoring (e.g., 500ms).
crawler.hotthread.interval=500ms
# Number of snapshots for hot thread monitoring.
crawler.hotthread.snapshots=10
# Number of threads for hot thread monitoring.
crawler.hotthread.threads=3
# Timeout for hot thread monitoring (e.g., 30s).
crawler.hotthread.timeout=30s