if (logger.isDebugEnabled()) {
                        logger.debug("Add thumbnail task: {}", task);
                    }
                    if (!thumbnailTaskQueue.offer(task)) {
                        logger.warn("Failed to add thumbnail task: {}", task);
                    }
                    return true;
                }
                return false;
            }
        }

# o schema   -- The schema name.
# o user     -- The database user name.
# o password -- The database password.
# o propertiesMap -- The properties that depends on the database.
# o variousMap    -- The various settings about JDBC task.
#
# *The line that starts with '#' means comment-out.
#
map:{
    ; driver   = org.h2.Driver
    ; url      = jdbc:h2:file:../src/test/resources/dummydb/dummydb
    ; schema   =  
    ; user     = sa

  public <T extends @Nullable Object> Future<T> submit(Callable<T> task) {
    return delegate().submit(task);
  }

  @Override
  public Future<?> submit(Runnable task) {
    return delegate().submit(task);
  }

  @Override
  public <T extends @Nullable Object> Future<T> submit(
      Runnable task, @ParametricNullness T result) {
    return delegate().submit(task, result);
  }

class SmokeTests(
    model: CIBuildModel,
    stage: Stage,
    testJava: JvmCategory,
    id: String,
    task: String = "smokeTest",
    splitNumber: Int = 1,
) : OsAwareBaseGradleBuildType(os = Os.LINUX, stage = stage, init = {
        id("${model.projectId}_SmokeTest_$id")
        name = "Smoke Tests with 3rd Party Plugins ($task) - ${testJava.version.toCapitalized()} Linux"

/**
 * An abstract {@code ScheduledExecutorService} that allows subclasses to {@linkplain
 * #wrapTask(Callable) wrap} tasks before they are submitted to the underlying executor.
 *
 * <p>Note that task wrapping may occur even if the task is never executed.
 *
 * @author Luke Sandberg
 */
@J2ktIncompatible
@GwtIncompatible
abstract class WrappingScheduledExecutorService extends WrappingExecutorService

It's called "asynchronous" because the computer / program doesn't have to be "synchronized" with the slow task, waiting for the exact moment that the task finishes, while doing nothing, to be able to take the task result and continue the work.

/**
 * An abstract {@code ScheduledExecutorService} that allows subclasses to {@linkplain
 * #wrapTask(Callable) wrap} tasks before they are submitted to the underlying executor.
 *
 * <p>Note that task wrapping may occur even if the task is never executed.
 *
 * @author Luke Sandberg
 */
@J2ktIncompatible
@GwtIncompatible
abstract class WrappingScheduledExecutorService extends WrappingExecutorService

  }

  /**
   * Submits a blocking task for the given {@link Future} to provide {@link ListenableFuture}
   * functionality.
   *
   * <p><b>Warning:</b> If the input future does not already implement {@code ListenableFuture}, the
   * returned future will emulate {@link ListenableFuture#addListener} by submitting a task to the
   * given executor at the first call to {@code addListener}. The task must be started by the

        Thread.sleep(10);
        int count = expiredCount;
        task.stop();
        TimeoutManager.getInstance().start();
        assertNotNull(TimeoutManager.getInstance().thread);
        Thread.sleep(2000);
        assertEquals(count, expiredCount);
        assertEquals(1, TimeoutManager.getInstance().getTimeoutTaskCount());
        task.cancel();
        Thread.sleep(2000);

    unit: TimeUnit,
  ) = apply {
    actions += { Thread.sleep(unit.toMillis(duration)) }
  }

  override fun handle(socket: Socket) {
    val task = serviceSocketTask(socket.asBufferedSocket())
    results.add(task)
    task.run()
  }

  /** Returns a task that processes both request and response from [socket]. */
  private fun serviceSocketTask(socket: BufferedSocket): FutureTask<Void> {
    return FutureTask<Void> {