virtual void SetJitCompileRewrite(bool enable) = 0;

  // Sets the device placement policy for the current thread.
  virtual void SetThreadLocalDevicePlacementPolicy(
      ContextDevicePlacementPolicy policy) = 0;
  // Returns the device placement policy for the current thread.
  virtual ContextDevicePlacementPolicy GetDevicePlacementPolicy() const = 0;

  // Configure graph collection in RunMetadata.

 * instances is using {@link CacheBuilder}.
 *
 * <p>Implementations of this interface are expected to be thread-safe, and can be safely accessed
 * by multiple concurrent threads.
 *
 * <p>When evaluated as a {@link Function}, a cache yields the same result as invoking {@link
 * #getUnchecked}.
 *

    /*
     * This will occur before the waiting get() in the
     * listenInPoolThread-spawned thread completes:
     */
    RecordingRunnable earlyListener = new RecordingRunnable();
    listenable.addListener(earlyListener, directExecutor());

    input.allowGetToComplete.countDown();
    // Now give the get() thread time to finish:
    assertTrue(earlyListener.wasRun.await(1, SECONDS));

  }
}

internal inline fun Lockable.assertLockNotHeld() {
  if (assertionsEnabled && Thread.holdsLock(this)) {
    throw AssertionError("Thread ${Thread.currentThread().name} MUST NOT hold lock on $this")
  }
}

internal inline fun Lockable.assertLockHeld() {
  if (assertionsEnabled && !Thread.holdsLock(this)) {
    throw AssertionError("Thread ${Thread.currentThread().name} MUST hold lock on $this")
  }
}

        // Start a thread to set crawler running after a delay
        Thread thread = new Thread(() -> {
            try {
                Thread.sleep(100);
                helper.setCrawlerRunning(true);
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
            }
        });
        thread.start();

  }

  public void testFutureCancellableBeforeFunctionCompletion() throws Exception {
    // Set the result in a separate thread since this test runs the function
    // (which will block) in the same thread.
    new Thread() {
      @Override
      public void run() {
        inputFuture.set(SLOW_FUNC_VALID_INPUT_DATA);
      }
    }.start();
    funcIsWaitingLatch.await();

  }

  public void testFutureCancellableBeforeFunctionCompletion() throws Exception {
    // Set the result in a separate thread since this test runs the function
    // (which will block) in the same thread.
    new Thread() {
      @Override
      public void run() {
        inputFuture.set(SLOW_FUNC_VALID_INPUT_DATA);
      }
    }.start();
    funcIsWaitingLatch.await();

  /**
   * 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>
   *

      assertBitEquals(x, at.get());
      prev = x;
    }
  }

  /** compareAndSet in one thread enables another waiting for value to succeed */
  public void testCompareAndSetInMultipleThreads() throws Exception {
    AtomicDouble at = new AtomicDouble(1.0);
    Thread t =
        newStartedThread(
            new CheckedRunnable() {
              @Override

 * comparator is not consistent with {@code equals}.
 *
 * <p>The {@code standard} methods are not guaranteed to be thread-safe, even when all of the
 * methods that they depend on are thread-safe.
 *
 * @author Mike Bostock
 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible